bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthese und Kristallstruktur von [Rb(18-Krone-6)]2[Zn(Se4)(Se6)] / Synthesis and Crystal Structure of [Rb(18-Crown-6)]2[Zn(Se4)(Se6)]
Authors: Fenske Dieter , Magull Sylvia , Dehnicke Kurt
Published: March 2015

[Rb(18-crown-6)]2[Zn(Se4)(Se6)] has been prepared by the reaction of a lithium polyselenide solution in DMF with zinc acetate in the presence of rubidium iodide and 18-crown-6. It forms dark red crystals, which were characterized by FIR spectroscopy as well as by an X-ray structure determination. Space group C2/c, Z = 4, 3012 observed unique reflections, R = 0.073. Lattice dimensions at —50 °C: a = 1963.1(14), b = 1125.9(9), c = 2060.3(16) pm, β = 90.05(3)°. The compound has a complex ionic structure, in which the zinc atom of the anion [Zn(Se4)(Se6)]2- is coordinated tetrahedrally by four selenium atoms of a Se4
2- and a Se6
2- unit in five and seven membered rings, respectively. The complex cations [Rb(18-crown-6)]+ have Rb · · · Se contacts of 360.7 and 372.0 pm with selenium atoms of the ZnSe4-ring.
Darstellung und Reaktionen von N-substituierten N,1,3-Triphenyl-2-methylpropan-1,3-diketiminderivaten-Kristallstruktur von (Me3Si)2N –CPh=CMe – CPh=NPh · GaCl3 / Syntheses and Reactions of N-Substituted N,1,3-Triphenyl-2-methylpropane-1,3-diketimino Derivatives – Crystal Structure of (Me3Si)2N–CPh=CMe–CPh=NPh · GaCl3
Authors: Roesky Herbert W. , Meller-Rehbein Birgit , Noltemeyer Mathias
Published: March 2015

Starting from PhN=CPh—CMe=CPh—NH2 (1) the silylated products PhN=CPh—CMe=CPh—NHSiMe3 (2), PhN=CPh—CMe=CPh—N(SiMe3)2 (3), [PhN=CPh—CMe=CPh—NSiMe3]-Li+ (4) and the heterocyclic compound

(9) have been obtained. 4 and ZrCl4 react to form PhN=CPh—CMe=CPh—NSiMe3—ZrCl3 (6), while 3 reacts with GaCl3 to yield the adduct (Me3Si)2N—CPh=CMe—CPh=NPh·GaCl3 (5). Compound 2 reacts with ZrCl4 and NbCl5 to give [PhN=CPh—CMe=CPh—NH—]2ZrCl2 (7) and PhN=CPh—CMe=CPh—NH—NbCl4 (8), respectively. The crystal structure of 5 is reported.
A New Route to Imidazo(1,5-a)pyridines and -quinolines
Authors: Kolar Patrik , Tišler Miha
Published: March 2015

A new synthetic approach for imidazo(1,5-a)pyridines and imidazo(1,5-a)quinolines from the corresponding alkyl(pyridyl-2′)- or (quinolyl-2′)glycinates is described.
Notizen: Potential Error Sources in Combined Electrochemistry/Neutron Detection Experiments
Authors: Rieker A. , Speiser B. , Mangold K.-M. , Hanack M.
Published: March 2015

Recently, experimental evidence for the occurrence of electrochemically induced (“cold”) nuclear fusion of deuterium nuclei has been proposed by several groups [1-3]. In particular, increased neutron counts and excess heat production of the electrolytic cell have been reported. Although much debated, the results have neither been proven nor refuted unequivocally [4].
Die Kristallstruktur von [Na(12-Krone-4)2
+]2Se8
2- · (Se6, Se7) / The Crystal Structure of [Na(12-Crown-4)2
+]2Se8
2- · (Se6, Se7)
Authors: Staffel Rüdiger , Müller Ulrich , Ahle Andreas , Dehnicke Kurt
Published: March 2015

The title compound was prepared from sodium polyselenide and 12-crown-4 in DMF solution in the presence of cerium(III)chloride in the form of black needles. The crystal structure determination by X-ray diffraction shows a partially disordered structure, in which the anionic units Se8
2- · Se7 and Se8
2- · Se6 are present in the ratio 0.72/0.28. These units are associated to layers parallel to (100); the layers alternate with pseudohexagonal layers of [Na(12-crown-4)2]+ ions. Space group P1̅, Z = 2, 3903 observed unique reflections, R = 0.114, wR= 0.084. Lattice dimensions at -65°C: a = 1247.9(3), b = 1367.8(8), c = 1660(1) pm, α = 94.65(5), β = 98.94(3), γ = 91.10(3)°.
The Crystal and Molecular Structure and Properties of Diaqua[N-salicylidene – (S) – (+) – glutamato]copper(II) Monohydrate
Authors: Krätsmár-Šmogrovič J. , Pavelčík F. , Soldánová J. , Sivy J. , Seressová V. , Žemlička M.
Published: March 2015

The crystal and molecular structure of the title complex was determinated by single crystal X-ray diffraction (R = 0.066 for 1059 observed reflections). The approximately square-pyramidal coordination of Cu(II) results from donor atoms O(12), O(1), N(1), O(5) of one H2O molecule as well as the tridentate Schiff base dianion ligand and from the weakly bonded O(1) donor atom of one other H2O molecule in the apical site.

The magnetic behaviour of the complex studied obeys the Curie—Weiss law in the temperature range 94—309 K with a small value of the Weiss constant, θ = 1.4 Κ. A similar cryomagnetic behaviour is also characteristic for the anhydrous compound, [N-salicylidene—(S)—(+)-glutamato]copper(II), obtained by thermal dehydration of the title complex.
Übergangsmetallkomplexe mit Schwefelliganden, LXV. Diastereospezifische Alkylierung von [Mo(NO)2(′S2′)2]2- zu chiralen [Mo(NO)2(′RS4')]-Komplexen mit chirotopen und prostereogenen Mo-Zentren / Transition Metal Complexes with Sulfur Ligands, LXV. Diastereospecific Alkylation of [Mo(NO)2(′S2')2]2- to Chiral [Mo(NO)2(′RS4')] Complexes with Chirotopic and Prostereogenic Mo-Centers
Authors: Sellmann Dieter , Grasser Franz , Knoch Falk , Moll Matthias
Published: March 2015

In order to investigate how chirotopicity and stereogenicity of metal centers influence the enantioselectivity of metal centered reactions the stereogenic properties of metal centers in chiral complexes have to be varied without changing their electronic character. Diastereospecific alkylation of [Mo(NO)2(′S2′ )2]2- by racemic 1,2-dibromopropane and 1,2-dibromobutane yields the title complexes [Mo(NO)2(′MeS4′ )] and [Mo(NO)2(′EtS4′)] that differ from the parent compound [Mo(NO)2('S4′)] with respect to the stereogenicity of the metal center and allow future investigations of the question raised above.
Intermediates in the Palladium-Catalyzed Reaction of 1,3-Dienes, Part 6 [1]
Authors: Benn R. , Betz P. , Goddard R. , Jolly P. W. , Kokel N. , Krüger C. , Topalović I.
Published: March 2015

The structure of the (1,3-butadiene)M(R2PC2H4PR2) compounds (M = Ni, Pd, Pt; R = Pri, Bu′, Cy) in the solid-state have been investigated by 13C and 31P CP/MAS NMR spectroscopy. The bonding mode adopted by the diene is dependent upon the nature of the metal: the palladium compounds contain an η2-diene molecule, the nickel compound where R is cyclohexyl contains an η4-diene molecule whereas the Pr2
iPC2H4PPr2
i-stabilized platinum compound con- tains a platinacyclopentene ring. The crystal structures of (η2-1,3-C4H6)Pd(Cy2PC2H4PCy2) and (η4-1,3-C4H6)Ni(Cy2PC2H4PCy2) have been confirmed by X-ray diffraction.
Über die Reaktionen der Halogene Cl2, Br2 und I2 mit CH3OSO+MF6-(M = As, Sb) / On the Reaction of the Halogenes Cl2, Br2 and I2 with CH3OSO+MF6- (M = As, Sb)
Authors: Minkwitz Rolf , Gerhard Volker
Published: March 2015

Chlorine reacts with CH3OSO+MF6- (M = As, Sb) at 298 K to form AsCl4
+AsF6
- and SbCl4
+Sb2Cl2F9
-, respectively. The analogous reactions with bromine at 233 K result in the formation of (CH3)2Br+AsF6
- and Sb2F11
-. With iodine, the new methyliodonium salts (CH3I2)n
n+(MF6
-)n (M = As, Sb) with yet unknown constitution are obtained.
Platinum(II) and Palladium(II) Complexes of Selectively Acylated 1,2,4-Butanetriamines
Authors: Altman Janina , Schuhmann Elfriede , Karaghiosoff Konstantin , Eichin-Karaghiosoff Edith , Beck Wolfgang
Published: March 2015

New N1,N2-di-Boc-N4-acyl-1,2,4-butanetriamines 5 (acyl = acetyl, trifluoroacetyl, benzoyl, carboxycyclohexyl, caproyl, carboxycyclobutyl) have been prepared by ring cleavage acylation of Nw-acylated histamines with di-tert-butyl dicarbonate, and reduction with Raney nickel. Free vicinal diamines 6 were generated by acidic removal of Boc-protecting groups and transformed into dichloroplatinum(II) 7 and dichloropalladium(II) complexes 8. By basic treatment of the N1,N2-di-Boc-N4-trifluoroacetyl-1,2,4-butanetriamine 5b the protecting group was removed from the terminal amine to give N1,N2-di-Boc-1,2,4-butanetriamine 9 which forms cis-dichloroplatinum(II) and palladium(II) complexes 10, 11. The compounds have been characterized by IR, NMR (1H, 13C) spectroscopy and elemental analysis, and the structures of the trifluoroacetyl compounds confirmed by 1H 13C and 1H 1H 2D NMR spectroscopy.
Darstellung, Schwingungsspektren und Normalkoordinatenanalyse der Chloro-Bromo-Technetate(IV), [TcCl„Br6_n]2-, n = 0-6 / Preparation, Vibrational Spectra and Normal Coordinate Analysis of Chloro-Bromo-Technetates(IV), [TcCln Br6-n]2-, n = 0-6
Authors: Preetz W. , Wendt A.
Published: March 2015

The mixed chloro-bromo-technetates(IV), [TcClnBr6-n
2-, n = 1-5, have been separated for the first time by ion exchange chromatography on diethylaminoethyl-cellulose. Due to the stronger trans-effect of Br as compared to Cl, the ligand exchange reactions of [TcBr6
2- with HCl and of [TcCl6]2- with HBr proceed stereospecifically, to form either cis/fac- or trans/merspecies for n = 2, 3, 4, respectively. To avoid photoisomerization the compounds have to be handled in the absence of light. The IR and Raman spectra of the ten chloro-bromo-techne-tates(IV), including the pure geometrical isomers, have been recorded at low temperature (80 K) and completely assigned to structures of point groups Oh, D4h, C4v, C3v, and C2v, supported by normal coordinate analysis based on a general valence force field. Due to the different trans-influences Cl < Br in asymmetric Cl′—Tc— Br′ axes, the Tc— Br′ bonds are strengthened and the Tc—Cl′ bonds are weakened, as indicated by valence force constants, for Tc—Br′ on average 6% higher and for Tc—Cl′ 10% lower, as compared with the values calculated for symmetric Br—Tc—Br and CI—Tc—Cl axes, respectively.
Zur Hydrolyse von Trisalkoxyvanadylverbindungen / On the Hydrolysis of Trisalkoxyvanadyl Compounds
Authors: Langbein Hubert , Polte Annette , Lang Reinhard , Großmann Gisbert
Published: March 2015

Trisalkoxyvanadyl compounds and products of their hydrolysis were characterized by 51V NMR spectroscopy. There are characteristic connections between interactions of VO(OR)3 compounds in solution and the hydrolysis behaviour. On hydrolysis, a fast condensation process leads to intermediate decavanadate species. In a following slow reaction depending on the composition of the solution different equilibrium species are formed.
Kubanartige Molybdän-Halogen-Schwefel-Clusterdithiophosphinate / Cubane Type Molybdenum-Halogen-Sulfur Clusterdithiophosphinates
Authors: Borgs Georg , Keck Helmut , Kuchen Wilhelm , Mootz Dietrich , Wiskemann René , Wunderlich Hartmut
Published: March 2015

Diamagnetic clusters [Mo3X-μ-(S2)3-μ3(S)(R2PS2)3] 2-4 (2: X = Cl; 3: X = Br; 4: X = I; 2-4: a: R = Et; b: R = Pr; c: R = Bu) are conveniently obtained by reaction of [Mo3S7(R2PS2)3]+(R2PS2)- 1 either with alkyl halides RX or with tetraalkylammonium halides R4NX. Between halogen X and one of the S atoms of each disulfido bridge there exist bonds which seem to be mainly of covalent character. Thus X is incorporated into the cluster core leading to a cubane type structure. [Mo3ClS7(Et2PS2)3] forms orthorhombic crystals with space group Pnma, Z = 4, a = 1931.9(7), b = 1551.2(6), c = 1286.5(4) pm. Isostructural substructures of 3b, 4a and 4b (space group P21) were also studied. All these cluster molecules reveal similar core geometries with distances S—Cl 239.4(4), S—Br 305(1) and S—I 322.5(3) pm much less than the sum of the van der Waals radii. The results of structural and spectroscopic investigations are discussed.
Bicyclo[2.2.2]octane-2-spirocyclohexanes, Part 1. Production and Structure of Spirodiisophora-3′,6-dione
Authors: Kurzer Frederick , Hawkes Jane E. , Cobb Jonathan
Published: March 2015

The bicyclo[2.2.2]octane-2-spirocycylohexane structure o f dimers arising from 3-methylcyclohex-2-enones by sodamide-catalyzed self-condensation is established by a study of the 3′,6-dione and 3′-hydroxy-6-ketone by the 13C NMR two-dimensional spectral (INADEQUATE) technique. The 3′,6-dione, the ultimate source of all other compounds of this series, is obtained by an improved procedure. Only one of its keto-groups reacts with ketonic reagents, resulting exclusively in 3′-monosubstituted derivatives
Notizen: Darstellung und Charakterisierung einiger (Cyanmethyl)alkylphenylphosphane R(C6H5)PCH2CN / Preparation and Characterization of Some (Cyanomethyl)alkylphenyl Phosphines R(C6H5)PCH2CN
Authors: Wolfsberger Werner
Published: March 2015

Some (cyanomethyl)alkylphenyl phosphines R(C6H5)PCH2CN (R = CH3, C2H5, C3H7, C4H9, i-C4H9, C5H11,) were prepared by the reaction of the corresponding (trimethylsilyl)alkylphenyl phosphines with chloroacetonitrile and characterized by elemental analyses and spectroscopic data (IR; 1H, 31P and 13C NMR).
Übergangsmetallkomplexe mit Schwefelliganden, LXXV / Transition Metal Complexes with Sulfur Ligands, LXXV
Authors: Sellmann Dieter , Fünfgelder Stefan , Knoch Falk
Published: March 2015

[Ni(′NHS′4)]2 (′NHS′4
2- = 2,2′-bis(2-mercaptophenylthio)diethylamine(2-)) was synthesized from Ni(ac)2 and Na2—′NHS′4 and characterized by X-ray structure analysis. In the solid state [Ni(′NHS′4)]2 contains two pseudooctahedral [Ni(′NHS′4)] fragments bridged via thiolate donors, in DMF solution at 110 °C it dissociates into mononuclear entities. The product of the template reaction between [Ni(′S′2)2]2- (′S′2
2- = 1,2-benzenedithiolate) and (BrC2H4)2NH was shown to contain an as yet unidentified by-product in addition to [Ni(′NHS′4)]2. Pure [Ni(′NHS′4)]2 does not react with pyridine, but the template product forms [Ni(Py)2(′S′2)] which has a square planar coordination geometry with the pyridine rings perpendicular to the NiS2N, plane.

Investigation of the template formation of [Ni(′NHS′4)]2 provided evidence that the reaction of [Ni(′S′2)2]2- with (BrC2H4)2NH involves radicals, suggesting a radical chain reaction mechanism.
Disorder of a Trigonally Planar Coordinated Water Molecule in Cobalt Sulfate Heptahydrate, CoSO4 · 7 D2O (Bieberite)+
Authors: Kellersohn Thomas , Delaplane Robert G. , Olovsson Ivar
Published: March 2015

Cobalt sulfate heptahydrate (d-14), CoSO4·7D2O, Mr = 294.99, monoclinic, P21/c, a = 1404.8(1), b = 649.41(6), c= 1092.5(2) pm, β = 105.232(8), V = 961.66·106 pm3, Z = 4, Dx = 2.073 Mg· m-3, λ(MoKa) = 71.073 pm, [(sin θ)/λ]max = 0.7035· 10-2 pm-1, μ = 20.26 cm-1, F(000) = 580, T = 298 K, R(F) = 0.0264 for 2339 observed unique reflections. CoSO4·7 D2O is shown to be isotypic to FeSO4· 7 H2O (Melanterite). The deuterated compound is stable at ambient conditions in contrast to the normal hydrate. Its structure is built up by [Co(D2O)6]2+ octahedra, SO4
2- tetrahedra, and “lattice” water molecules. One water molecule, which is almost exactly trigonally planar coordinated in its average position, exhibits a distinct oxygen disorder. The “lattice” water molecule accepts two strong hydrogen bonds and donates a linear and a bifurcated one. The hydrogen-bond lengths (O···O distances) are in the range 271-302 pm.
Die Bildung von [Co(C5H5)2]NO3 und [Co(C5H5)2]2[Co(NCO)4] aus Cobaltocen, Ozon und Acetonitril sowie deren Kristallstrukturen / Formation of [Co(C5H5)2]NO3 and [Co(C5H5)2]2[Co(NCO)4] from Cobaltocene, Ozone and Acetonitrile and their Crystal Structures
Authors: Ruhlandt-Senge Karin , Sens Irina , Müller Ulrich
Published: March 2015

The title compounds were obtained by the reaction of cobaltocene with ozone in acetonitrile at -40°C. Their crystal structures were determined by X-ray diffraction. [Co(C5H5)2]NO3: orthorhombic, space group Pnma, a = 1566.4(3), b = 831.6(2), c = 765.7(1) pm, Z = 4, R = 0.055 for 587 observed unique reflexions. [Co(C5H5)2]2[Co(NCO)4]: monoclinic, P 2,/c, a = 1792.6(8), b = 2079.2(9), c = 1311(1) pm, β = 99.18(6)°, Ζ = 8, R = 0.067 for 2994 reflexions. Both compounds contain sandwich-type cobalticenium ions. The cyanato group of the [Co(NCO)4]2- ions are bonded to Co via their N atoms with CoNC angles ranging between 160 and 173°.
Synthese und Reaktionen von 1,2,4,5-Tetramethylimidazol; die Kristallstruktur von Pentamethylimidazolium-iodid / Synthesis and Reactions of 1,2,4,5-Tetramethylimidazole; the Crystal Structure of Pentamethylimidazolium Iodide
Authors: Kuhn Norbert , Henkel Gerald , Kreutzberg Jörg
Published: March 2015

1,2,4,5-Tetramethylimidazole (3) is obtained by metalation of 2,4,5-trimethylimidazole (2) with sodium in liquid ammonia and subsequent addition of methyl iodide. 3 reacts with Lewis acids to form the compounds Me4C3N2 · BH3 (8) and Me4C3N2 · E+ (4, 5, 7, 10; E = Me, H, SiMe3, C(O)Me). The X-ray structure reveals the ionic nature of pentamethylimidazolium iodide (4) in the solid state.
Notizen: Über den Einbau vierwertiger Kationen in das Calcium-Fluorapatit-Gitter / Incorporation of Tetravalent Cations in the Calcium Fluoroapatite Lattice
Authors: Manca S. G. , Urquiza N. , Baran E. J.
Published: March 2015

In order to determine the effect of tetravalent cations on the inorganic phase of hard tissues, a model study has been undertaken, investigating a series of fluoroapatites in which part of the Ca(II) ions were substituted by Th(IV), Zr(IV) or Hf(IV). Diffractometric and vibrational spectroscopic studies show that low concentrations of the incorporated metals neither affect the crystallographic characteristics nor the strength of the P—O bonds of these apatitic materials.
Reaktionen von Titanocentrihalogeniden mit Tris(trimethylstannyl)amin / Reactions of Titanocentrihalides with Tris(trimethylstannyl)amine
Authors: Bai Yuniu , Roesky Herbert W. , Schmidt Hans-Georg , Noltemeyer Mathias
Published: March 2015

A new route for the preparation of (Me3Ge)3N (2 a) using Me3GeCl and (Me3Sn)3N is described. Cp′TiCl3 (Cp′ = Me5C5 (la) and Me3SiC5H4 (lb)) reacts with (Me3Sn)3N to yield (Cp′TiClNSnMe3)2 (3a) and (3b). (Me5C5TiFNSnMe3)2 (3c) is formed when Me5C5TiF3 is treated with (Me3Sn)3N. The X-ray structures of 3a and (Me3SiC5H4TiClNtBu)2 (5) are reported. 3a and 5 consist in the solid state of four-membered Ti2N2 rings with the substituents in different positions.
Azaborolyl-Komplexe, 27 / Azaborolyl Complexes, 27
Authors: Schmid Günter , Meyer-Zaika Wolfgang
Published: March 2015

Alkenyl substituted 1H-1,2-azaborolyl (Ab) complexes are promising candidates for stereoselective reactions, due to the chirality of the AbM moiety and the intramolecular coordination of the alkenyl group to the metal atom. The synthesis of [1-tert-butyl-2-methy1-3-(4-penten- l -y1)-η5-1H-1,2-azaborolyl]-bis(triphenylphosphine)rhodium (3) is achieved by the reaction of AbLi (2) [from AbH (1)] with (Ph3P)3RhCl. In benzene solution one PPh3 ligand of 3 is substituted by the C=C group of the pentenyl substituent. Simultaneously the η5-coordination of the Ab ring changes to an allylic η3-coordination forming 4. Steric reasons seem to be responsible for this intramolecular rearrangement. The shorter 2-propen-1-yl substituent is unable to act in the same way and therefore only forms the stable complex [1-tert-butyl-2-methyl-3-(2-propen- l -yl)-η5-1H-1,2-azaborolyl]-bis(triphenylphosphine)rhodium (7). Mass spectrometry, 1H, 11B and 31P NMR data were used to characterize the novel complexes.
Synthesis and Structure of Tetrakis(diphenylphosphanylmethyl)methane and its Tetranuclear AuCl Complex
Authors: Schmidbaur Hubert , Stützer Albert , Bissinger Peter
Published: March 2015

Tetrakis(diphenylphosphanylmethyl)methane C(CH2–PPh2)4 was prepared (following modified literature methods), its structure determined by X-ray diffraction methods, and its spectroscopic data complemented. The tetranuclear gold(I) complex C[CH2–PPh2·AuCl]4 was obtained by treatment of the tetrafunctional ligand with four equivalents of (Me2S)AuCl, and its structure was also determined. The changes in structure and conformation as compared to that of the free ligand provide evidence for attractive intramolecular Au ··· Au interactions for one pair of gold(I) centers. Owing to steric congestion of the molecule, the remainder pair are independent structural units not engaged in metal–metal interactions.
Übergangsmetallkomplexe mit Schwefelliganden, LXXXV. / Transition-Metal Complexes with Sulfur Ligands, LXXXV.
Authors: Sellmann D. , Schillinger H. , Knoch F.
Published: March 2015

Ni(II) salts and the tetradentate thioether-thiolate ligand ′S4-C2′2- (= 1,2-bis(2-mercaptophenylthio)ethane(2-)) yield [Ni(′S4-C2′)]x (1), that also forms when Na2[Ni(′S2′ )2] (′S2
2-′ = o-benzenedithiolate(2-)) is alkylated by 1,2-dibromoethane. In boiling pyridine 1 adds two solvent molecules and gives pseudooctahedral [Ni(pyr)2(′S4-C2′ )] (2) which was characterized by X-ray structure determination. Reaction of 1 with PMe3 yields [Ni(PMe3)(′S4-C2′)] (4). X-ray structure determination of 4 showed that the Ni center is surrounded by one P and four S atoms in a distorted tetragonal pyramid in which the P atom, one thioether S atom and both of the thiolate S atoms form the base while the second thioether S atom occupies the apical position. Reaction of 1 with n-BuLi leads to removal of the C2H4 bridge of the ′S4-C2′2- ligand and formation of Li2[Ni(′S2′)2].

When [Ni(acac)2]3 is reacted with ′buS4-C2′2 (= 1,2-bis(3,5-ditertiarybutyl-2-mercaptophenylthio)ethane(2-)) which is analogous to ′S4-C2′2-, the trinuclear [Ni(′buS4-C2′)]3 (3) forms. 3 · THF was characterized by X-ray structure determination. It contains one tetrahedrally distorted and two planar [NiS4] cores that are connected via the C2H4 groups of the ligands such that a macrocycle forms. PMe3 cleaves 3 to give mononuclear [Ni(PMe3)(′buS4-C2′)] (5). Due to its lability, it was characterized only by spectroscopic methods.
Selektive Ligandensubstitutionsreaktionen an Carbin-Wolframkomplexen des Typs [W(CPh)Br(CO)2L2] (L = Stickstoff-Donorligand) / Selective Ligand Substitution Reactions on Carbyne Tungsten Complexes of the Type [W(CPh)Br(CO)2L2] (L = Nitrogen Donor Ligand)
Authors: Steil Peter , Mayr Andreas
Published: March 2015

The reaction of [W(CPh)Br(CO)2(py)2] (1) with one equivalent of triisopropylphosphine gives [W(CPh)Br(CO)2(py)(P-i-Pr3)] (3). The reaction of 1 with two equivalents of triisopropylphosphine under irradiation with visible light affords trans-[W(CPh)Br(CO)2(P-i-Pr3)2] (4). Substitution of the pyridine ligand in 3 by other ligands L (t-butylisocyanide, trimethylphosphine and trimethylphosphite) gives the complexes [W(CPh)Br(CO)2(L)(P-i-Pr3)]. Reaction of 4 with t-butylisocyanide gives trans-[W(CPh)Br(CO)(CNCMe3)(P-i-Pr3)2]. Irradiation of [W(CPh)Br(CO)2(tmeda)] in the presence of excess trimethylphosphine gives [W(CPh)Br(CO)(PMe3)3]. The reaction of 1 with maleic anhydride gives [W(CPh)Br(CO)(C4H203)(py)2].
Studies on 1-Trimethylsilyl-2,4,6-triethylborazine and Related Species
Authors: Niedenzu Kurt , Serwatowska Joanne , Serwatowski Janusz
Published: March 2015

The unsymmetrically substituted borazine (C6H5)3B3N3H2[Si(CH3)3] has been obtained from the reaction of C6H5BCl2 with HN[Si(CH3)3]2, and an improved synthesis of (C2H5)3B3N3H2[Si(CH3)3] has been developed. The reaction of the latter with an excess of BC13 proceeds with the ultimate formation of Cl3B3N3H2[Si(CH3)3], whereas the reaction with one molar equivalent of BBr3 leads to the formation of Br(C2H5)2B3N3H2[Si(CH3)3], but which is contaminated by substantial amounts of Br(C2H5)2B3N3H3 besides a diborazinyl and additional products. C6H5BBr2 reacts with N[Si(CH3)3]3 to give the aminoborane [(CH3)3Si]2NBBr(C6H5), but C6H5BCl2 does not undergo a reaction under analogous conditions.
Zur Chemie der 4,6-Dioxo-1,3,5,2 λ3-triazaphosphinane. / On the Chemistry of 4,6-Dioxo-1,3,5,2 λ3-triazaphosphinanes.
Authors: Müller Christian , Meyer Thomas G. , Farkens Michael , Sonnenburg Ralf , Schmutzler Reinhard
Published: March 2015

In the reaction of phenylisocyanate, 1, with 1,3-dimethylurea, 2, and 1,3-diphenylurea, 4, 1,3-dimethyl-5-phenyl biuret, 3, and 1,3,5-triphenylbiuret, 5, respectively, were obtained. The reaction of 3, 5 and of 1,3,5-trimethylbiuret 6 with a range of P(III) chloro compounds has furnished the new 4,6-dioxo-1,3,5,2 λ3-triazaphosphinanes, 7-16. The characterization of 7-16 rests, especially, on their 1H, 13C and 31P NMR, and mass spectra.
Neue Synthesen von Magnesiumhydrid / New Syntheses of Magnesium Hydride
Authors: Koerner Götz , Klein Klaus-Dieter , Knott Wilfried
Published: March 2015

A very easy and safe way for the production of Ni-doped magnesium hydride is reported. Another process, which is not requiring transition metals (e. g. nickel) has also been found as a means to ameliorate the kinetics of hydrogen uptake. MgH2 itself exerts a catalytic effect on the formation of magnesium hydride from the elements, i. e. by autocatalysis.
Molekülstrukturen von (o-Brombenzyl)diphenylphosphan und 1,3-Bis(diphenylphosphinomethyl)benzol / Molecular Structures of (o-Bromobenzyl)diphenylphosphine and 1,3-Bis(diphenylphosphinomethyl)benzene
Authors: Müller Gerhard , Lachmann Joachim , Riede Jürgen
Published: March 2015

(o-Bromobenzyl)diphenylphosphine, 1, and 1,3-Bis(diphenylphosphinomethyl)benzene, 2, have conformations in the solid state with the phosphino groups being displaced noticeably from the plane of the central aromatic rings. The molecular structures allow conclusions about the chelating complexation capability of the ligands (o-diphenylphosphinomethyl)phenyl(-1) and 2,6-bis(diphenylphosphinomethyl)phenyl(-1) derived from 1 and 2 by metallation.
Synthesis, Spectroscopic and X-Ray Structural Characterization of [Cd(linpen)]2+, a Model for Metal Complexes of the Chelating Polymer Polyethyleneimine (linpen = Linear Pentaethylenehexamine)
Authors: Strasdeit Henry
Published: March 2015

The isolation of 3,6,9,12-tetraazatetradecane-1,14-diamine (linear isomer of pentaethylenehexamine, linpen) from a technical polyamine mixture is described. In methanol, linpen acts as a hexadentate ligand towards cadmium(II). The solid compounds [Cd(linpen)](BPh4)2 (1), [Cd(linpen)](BPh4)2•2 DMSO (2) and [Cd(linpen)](BF4)2 (3) have been isolated and characterized by elemental analysis, spectroscopy and X-ray powder diffraction. The 113Cd NMR resonance of 1 is at 351 ppm (0.30 M in DMSO-d6, standard: 0.10 M Cd(ClO4)2 in D2O).

2 and 3 have been structurally characterized by single-crystal X-ray diffraction. 2: C 2/c; a = 19.337(1)Å, b = 17.937(1)Å, c = 18.584(1)Å, β = 111.54(1)°; Z = 4, R = 0.034, Rw = 0.033.3: P21/n; a = 8.607(1)Å, b = 14.851(2)Å, c = 15.703(2)Å, ß = 91.21(2)°; Z = 4,R = 0.083, Rw = 0.072. Both compounds contain discrete [Cd(linpen)]2+ complexes. The hexamine wraps around the metal ion in a helical manner. This results in a strong distortion of the coordination polyhedron. The mean Cd-N bond lengths are 2.38Å and 2.37Å for 2 and 3, respectively.

Models for MN6 centers in metal-polyethyleneimine (PEI) complexes are derived from the structure of [Cd(linpen)]2+. For example, loops at the MN6 site in molecules of linear PEI are proposed.
Synthesis and Structural Elucidation of the Acetylation Reaction’s Product(s) of the 2(1H)-Quinoxalinones Derived from L-Ascorbic Acid. X-Ray Molecular Structure of 3-(N-acetyl-2-naphthylhydrazono)-2,3-dihydro-2-acetoxyfuro[2,3-b]quinoxaline [1]
Authors: Amer Adel , Ho Douglas M.
Published: March 2015

Acetylation reaction’s product(s) of 3-[L-threo-2,3,4-trihydroxy-1-(2-naphthylhydrazono)-butyl]quinoxalin-2(1H)-one (2b) were found to be dependent on the reaction condition. While the tri-O-acetyl (3b) was isolated in high yield from 2b under the action of acetic anhydride/pyridine mixture, compounds 4b and 5b as well as trace of 3b were obtained when 2b was heated in acetic anhydride. On the other hand, 3-[1-(2-naphthylhydrazono)-glyoxal-1-yl]quinoxalin-2(1H)-one (7) underwent ring closure and afforded the condensed tricyclic compound 8 under the action of acetic anhydride/pyridine mixture.
Polymeric [N-Lithio-benzimidazole(DMSO)2]∞ The Crystal Structure and ab initio Calculations
Authors: Lambert Christoph , Schleyer Paul von Ragué , Newton M. Gary , Otto Peter , Schreiner Peter
Published: March 2015

That lithiated aromatic amines with more than one nitrogen atom can favor polymeric aggregates in the solid state is demonstrated by the single crystal X-ray diffraction structure of [N-lithio-benzimidazole(DMSO)2]∞ 4; ab initio calculations on model compounds and simple electrostatic models indicate that the preference of the polymeric structure over dimeric alternatives is due to resonance stabilization and to Coulomb attraction between alternating benzimidazole anions and lithium cations.
Notizen: Einfache Synthese funktioneller Mono- und Di(t-butyl)borverbindungen / Facile Synthesis of Functional Mono- and Di(t-butyl)boron Compounds
Authors: Müller Gerhard , Lachmann Joachim
Published: March 2015

The functional mono- and di(t-butyl)boron compounds tBuB(OMe)2 and tBu2Bu2BOMe are easily prepared in good yield by a one-pot synthesis from excess B(OMe)3 and t-butyllithium in ether at -60 °C.
Darstellung und Kristallstrukturen von Chloro- und Bromophenylantimonaten(III) [Ph2SbX2] - und [Ph2Sb2X7]3- (X=Cl, Br) / Preparation and Crystal Structures of Chloro- and Bromophenylantimonates(III) [Ph2SbX2]- and [Ph2Sb2X7]3- (X=Cl, Br)
Authors: Sheldrick W. S. , Martin C.
Published: March 2015

The halophenylantimonates(III) [Ph4P][Ph2SbCl2] (1), [Ph4P][Ph2SbBr2] (2), [Me3NH]3[Ph2Sb2Cl7] (3) and [Me3NH]3[Ph2Sb2Br7] (4) have been prepared and their structures established by single crystal X-ray diffraction. The anions [Ph2SbCl2]- and [Ph2SbBr2]- display w-trigonal bipyramidal geometries with axial halogen atoms. Sb-Cl [2.618(4), 2.601(4)Å] and Sb-Br distances [2.779(3), 2.794(2)A] are very similar to one another in the individual anions of 1 and 2. The anions [Ph2Sb2Cl7]3- and [Ph2Sb2Br7]3- both contain two square pyramidal coordination polyhedra which are vertex-linked to one another via Sb-X-Sb (X=Cl, Br) angles of respectively 152.9(1) and 152.3(1)°; the latter anion displays crystallographic C2-symmetry. trans-Sited Sb-Cl or Sb-Br bond distances in 3 and 4 are structurally correlated to one another.
Electrochemical Cocrystallization Experiments with Gd2Cl3
Authors: Mikheev N. B. , Kamenskaya A. N. , Rumer I. A. , Novitschenko V. L. , Simon A. , Mattausch Hj.
Published: March 2015

Gd2Cl3 is electrocrystallized from molten GdCl3 at 900 K with a current efficiency of 70% referring to the reaction 2GdCl3+3e⁻=Gd2Cl3+3Cl-. The reaction is used to determine cocrystallization coefficients for trivalent rare earths and actinoids (Y, Nd, Cm, Pu), divalent lanthanoids (Eu, Yb), and Sr. The oxidation potential for the above reaction is determined as 2.65 ≤ E° ≤ 2.68 V.
Quinoline Alkaloids. Synthesis of Khaplofoline, Ribalinine, and Flindersine
Authors: Subramanian M. , Mohan P. S. , Shanmugam P. , Rajendra Prasad K. J.
Published: March 2015

Reaction of 4-hydroxy-3-prenylquinolin-2(1 H)one (5 a) with iodine and silver acetate gave a iodopyranoquinoline (6 a), which was then converted into the alkaloids khaplofoline (1) and ribalinine (2). Reaction of 5a with iodine and mercuric oxide afforded a mixture of 6a and its angular isomer 7 a; the coversion of latter into flindersine (10) is described.
Conversion of Lapachol to Rhinacanthin-A and other Cyclized Products
Authors: Singh P. , Pardasani R. T. , Suri A. , Pokharna C. P.
Published: March 2015

A facile synthesis of rhinacanthin-A is achieved by the side chain cyclization of lapachol with meta-chloroperbenzoic acid along with stenocarpoquinone-A, stenocarpoquinone-B and its isomer.
Chemical Shift Nonequivalence of Enantiomers of Amino Acid Derivatives in 1H NMR and 19F NMR Spectroscopy Induced by L-Chirasil- Val.
Authors: Koppenhoefer Bernhard , Hummel Michael
Published: March 2015

Enantiomers of N-trifluoroacetyl-amino acid methyl esters in CC14 solution, after addition of the chiral polysiloxane (L)-Chirasil-Val, display a chemical shift nonequivalence ΔΔδ in both 1H NMR and 19F NMR spectroscopy. The effects found for the leucine and valine derivatives can be correlated with the thermodynamic parameters of interaction in the undiluted system, as determined by gas chromatography. In CDC13 solution, no peak splitting was observed. The method is potentially useful for the determination of the enantiomeric purity of substrates of low volatility.
Stable Oxapenem-3-carboxylic Acids – A New Class of β-Lactam Antibiotics. Influence of 2- and 6-Alkyl Substituents
Authors: Pfaendler Hans Rudolf , Hendel Wolfram , Nagel Ulrich
Published: March 2015

Novel antibacterially active oxapenem-carboxylic acids were prepared. Their increased stability depends on the 2-tert-butyl substituent and arises from its electron releasing inductive effect. The geometry and reactivity of oxapenems are discussed on the basis of two X-ray structure determinations and compared to those of related antibiotics.
Notizen: Synthesis and NM R Study of (η6-1,4-diphenyl-1,3-butadiene)tricarbonylchromium(0)
Authors: Kayran Ceyhan , Özkar Saim
Published: March 2015

(η6-1,4-Diphenyl-1,3-butadiene)tricarbonylchromium(0) has been synthesized in high yield by using an improved procedure, from tris(acetonitrile)chromium(0) and 1,4-diphenyl-1,3-butadiene. The IR and NMR spectroscopic data show that the organic ligand is bonded to the Cr(CO)3 moiety through only one of the two phenyl rings.
Synthese und Kristallstruktur von [Na(15-Krone-5)]2S6 / Synthesis and Crystal Structure of [Na(15-crown-5)]2S6
Authors: Bacher Alfred-Dirk , Müller Ulrich
Published: March 2015

[Na(15-crown-5)]2S6 was obtained from Na2S4 und 15-crown-5 in acetonitrile. Its crystal structure was determined by X-ray diffraction with 2968 observed reflexions, R = 0.119. Crystal data: a = 861.4(9), b = 1006(1), c = 2097(1) pm, α = 89.7(1), β = 100.20(8), γ = 114.6(1)°, Ζ = 2, space group Ρ 1̄. The chain-like S6
2- ion has transoid conformations, each of its terminal atoms is in contact with one Na+ ion which in turn is coordinated with one crown ether molecule.
[ η6-C6Me6Fe- η5-C5H5]2Fe2Cl6 · 2 CH2Cl2: Bildung und Kristallstruktur / [η6-C6Me6Fe-η5-C5H5]2Fe2Cl6· 2CH2Cl2: Formation and Crystal Structure
Authors: Ruhlandt-Senge Karin , Müller Ulrich
Published: March 2015

When hexymethylbenzene-cyclopentadienyl-iron reacts with ozone in dichloromethane, the title compound is one of the products. Its crystal structure was determined by X-ray diffraction (R = 0.145 for 1412 unique reflexions). Crystal data: a = 1815.1(8), b = 1314.8(5), c = 1823.0(8) pm, space group Pbca, Z = 8. The sandwich-like [η6-C6Me6Fe-η5-C5H5]+ ions exhibit large thermal motions, and the CH2C12 molecules are disordered in two orientations. The novel [Fe2Cl6]2- ion has the structure of two tetrahedra sharing an edge. Its IR spectrum is reported.
Trioktaedrische Halogenoarsenate(III) [As3X12]3− (X = Br, I) mit Ecken- und Flächenverknüpfung. Strukturkorrelation für Iodoarsenate(III) / Trioctahedral Haloarsenates(III) [As3X12]3− (X = Br, I) with Vertex and Face Sharing. Structural Correlation for Iodoarsenates(III)
Authors: Sheldrick W. S. , Kiefer J.
Published: March 2015

The haloarsenates(III) [Et3NH]3[As3Br12] (1) and [Me3NH]3[As3I12] (2) have been prepared and their structures established by X-ray analysis. Both trioctahedral anions display a novel structure in which a central AsX6 octahedron shares two faces with a common vertex with two terminal AsX6 octahedra. The bridging As–X-bonds in the latter building units are markedly longer than the opposite terminal As–X-bonds in both anions. For example, the former As–I-bonds in [As3I12]3− lie in the range 3.154(1)-3.400(1)A, the latter As – I-bonds between 2.581(1) and 2.656(1)A. The distortion of the central AsX6 octahedron is less marked for both anions, e.g. the As–I distances in [As3I12]3− lie in this central polyhedron between 2.706(1) and 3.048(1) A. Using the results for (2) and for other characterised anions, a structural correlation is presented for 28 trans-sited As–I bond distances in iodoarsenates(III).
Synthesis and Structure of Eight-Membered Titanium Containing Siloxane Rings
Authors: Liu Feng-quan , Schmidt Hans-Georg , Noltemeyer Mathias , Freire-Erdbrügger Cristina , Sheldrick George M. , Roesky Herbert W.
Published: March 2015

The preparation by different methods of the eight-membered ring compounds (R1XTiOSiR2
2O)2 is reported: (2: R1=C5Η5, X=Cl, R2=tBu; 3: R1=N(SiMe3)2, X=C1, R2=tBu; 4: R1=C5Me5, X=Cl, R2=Ph; 6: R1=X=NEt2, R2=tBu). The six-membered ring Ph2SiO[OTiC5Me5(Cl)]2 5 is formed together with 4 by the reaction of C5Me5TiCl3 and Ph2Si(OLi)2. Compounds 2 and 4 have been characterized by X-ray structural analysis.
Darstellung, Charakterisierung und Normalkoordinatenanalyse von gemischtvalentem Dodekabromotriplatinat(IV,II,IV) [Pt3Br12]2- und Kristallstruktur von (Ph3P=N=PPh3)2[Pt3Br12] · 2 CH2C12 / Preparation, Characterization and Normal Coordinate Analysis of the Mixed Valence Dodecabromotriplatinat(IV,II,IV) [Pt3Br12]2- and Crystal Structure of (Ph3P=N=PPh3)2[Pt3Br12] · 2CH2Cl2
Authors: Hillebrecht H. , Thiele G. , Hollmann P. , Preetz W.
Published: March 2015

Heating a mixture (2:1) of the tetrabutylammonium salts (TBA)2[PtBr6] and (TBA)2[PtBr4] with trifluoroacetic acid leads to the mixed valence dodecabromotriplatinate(IV,II,IV) (TBA)2[Pt3Br12]. The X-ray structure determination of (Ph3P=N=PPh3)2[Pt3Br12] · 2 CH2Cl2 (triclinic, PĪ, Z = 1) shows trinuclear groups with nearly D2h symmetry for the anions, formed of two PtBr6 octahedra and one planar PtBr4 group sharing edges. Using the structural data a normal coordinate analysis based on a general valence force field for [Pt3Br12]2- has been performed, which gives good agreement of the calculated frequencies with the bands observed in the IR and Raman spectra.
Übergangsmetallkomplexe mit Schwefelliganden, XCl+ Fell-Komplexe des fünfzähnigen Thioether-Thiolat-Aminliganden ′buNHS4′-H2: Synthese, Charakterisierung, Reaktivität und Stereochemie (′buNHS4′-H2 = 2,2′-Bis(2-mercapto-3,5-di-tertiärbutyl-phenylthio)diethylamin) / Transition Metal Complexes with Sulfur Ligands, XCI+ Fell Complexes of the Pentadentate Thioether-Thiolate-Amine Ligand ′buNHS4′-H2: Synthesis, Characterization, Reactivity and Stereochemistry (′buNHS4′-H2 = 2,2′-Bis(2-mercapto-3,5-di-tertiarybutyl-phenylthio)diethylamine)
Authors: Sellmann Dieter , Soglowek Wolfgang , Moll Matthias
Published: March 2015

In search of model compounds for the active centers of nitrogenases, [Fe(L)(′buNHS4')] complexes of the pentadentate thioether-thiolate-amine ligand ′buNHS4'2- (′buNHS4'-H2 = 2,2′-bis(2-mercapto-3,5-di-tertiarybutyl-phenylthio)diethylamine) were obtained.

Alkylation of′buS2'-H2 with (BrC2H4)2NH yielded the new ligand ′buNHS4'-H2 as a mixture of positional isomers. Isolation of single isomers was achieved by reacting the mixture with FecL2•4H2O and CO in order to give the corresponding [Fe(CO)] complexes which were separated and hydrolyzed to yield the free ligands.

Reaction of'buNHS4'-H2 with FeCl2•4H2O led to the high-spin complex [Fe(′buNHS4')] which is extremely air-sensitive in solution. It rapidly reacts with L = CO, NO, PMe3, and N2H4, and is the most suitable starting material for syntheses of [Fe(L)(′buNHS4')] complexes which were characterized for L = CO, NO+, NO, PMe3 and N2H4. All complexes are considerably better soluble in organic solvents than the corresponding parent compounds [Fe(L)(′NHS4')], (′NHS4'-H2 = 2,2′-bis(2-mercaptophenylthio)diethylamine), but have similar properties in most other respects. In the oxidation of [Fe(N2H4)(′buNHS4')] at low temperatures, there is evidence for the formation of the diazene complex [μ-N2H2{Fe(′buNHS4')}2].
Darstellung und Charakterisierung von Dekachlorodiiridat(IV), [Ir2Cl10]2-, und Normalkoordinatenanalyse an Dioktaederkomplexen des Typs [M2X10]2-, M = Re, Os, Ir, Pt; X = Cl, Br / Preparation and Characterization of Decachlorodiiridate(IV), [Ir2Cl10]2-, and Normal Coordinate Analysis of Bioctahedral Complexes [M2X10]2-, M = Re, Os, Ir, Pt; X = Cl, Br
Authors: Hollmann P. , Preetz W.
Published: March 2015

On heating the tetraethylammonium salt of [IrCl6]2- with trifluoroacetic acid the edge sharing bioctahedral anion [Ir2Cl10]2- is formed, the IR and Raman spectra of which are assigned according to point group D2h. Normal coordinate analyses, based on a general valence force field, for [M2X10]2-, M = Re, Os, Ir, Pt; X = Cl, Br have been performed, resulting in a good agreement of the calculated frequencies with the bands observed in the IR and Raman spectra. Due to the stronger bonding of the terminal as compared to the bridging ligands, the valence force constants fd(MXt) are significantly higher than fd(MXb).
Darstellung,11B-NMR- und Schwingungsspektren der closo-Hexaborate [B6(SCN)6]2- und [B6(SeCN)6]2- / Preparation, 11 B-NMR and Vibrational Spectra of the closo-Hexaborates [B6(SCN)6]2- and [B6(SeCN)6]2-
Authors: Preetz W. , Hake M. G.
Published: March 2015

On treatment of [N(C4H9)4][B6H7] with (SCN)2 or (SeCN)2 in dichloromethane in the presence of solid KOH the hexaborates [N(C4H9)4]2[B6(SCN)6] and [N(C4H9)4]2[B6(SeCN)6] are formed. The octahedral structure for the B6 cage is proven by 11B NMR spectroscopy. The chemical shifts in relation to BF3 · OEt2 of —9,7 (SCN) and —10,2 ppm (SeCN) show the influence of — I and +M effects of the substituents. The S(Se) coordination is deduced from vibrations within the substituents: νCN is observed at frequencies higher than 2100 cm-1 in the IR and Raman spectra, vcs at 662 and νcse at 556 cm-1 (intense IR bands).
Metall-π-Komplexe von Benzolderivaten, XLa
Selen in der Peripherie des Bis(benzol)chroms: Darstellung, Strukturdynamik und Redoxverhalten eines neuen Hetera-[3]-chromocyclophans / Metal-π Complexes of Benzene Derivatives, XLa
Selenium in the Periphery of Bis(benzene)chromium: Synthesis, Structural Dynamics, and Redox Behavior of a New Hetera-[3]-chromocyclophane
Authors: Elschenbroich Christoph , Burdorf Heike , Burdorf Helmut , Mahrwald Dagmar , Metz Bernhard
Published: March 2015

Lithiation of bis(benzene)chromium and subsequent reaction with Ph2Se2 or Se and CH3I, respectively, afforded the complexes (PhSe-η6-C6H5)2Cr (6) and (MeSe-η6-C6H5)2Cr (8), the latter being convertible into interannularly bridged (MeSe-η6-C6H5)2Cr[M(CO)4] (9-11, M = Cr, Mo, W). According to 1H NMR spectroscopy, 9 undergoes both bridge inversion and reversal, the former displaying spectral coalescence at 283 K (ΔGc
≠ = 55.9 kJ mol-1) whereas the latter is still rapid at 200 K. Substitution of H for –SeMe and addition of a Cr(CO)4 unit effect anodic shifts of the redox potential E1/2(+/0) of 95 mV/SeMe and 230 mV/Cr(CO)4. Despite electron donation from the bis(arene)metal backbone 8 is a fairly weak ligand, cleavage of the interannular bridge occuring with the half life τ1/2 = 41.4 min (9→8) and τ1/2 = 5.8 s (9+•→8+) as inferred from cyclic voltammetry in DME at 293 K.
Structural Investigations on Mono- and Di-Acrolein Substituted Ni(II) Porphyrins and a Ni(II) Benzochlorin. Model Compounds for Photosensitizers in Photodynamic Therapy
Authors: Senge Mathias O. , Vicente Maria da Graça H. , Parkin Sean R. , Hope Håkon , Smith Kevin M.
Published: March 2015

The structures of four Ni complexes and a free base related to tetrapentanoporphyrin (TC7P) and octaethylporphyrin (OEP) have been determined by X-ray crystallograpic methods. The Ni(II) complexes exhibit considerable S4-ruffling induced by coordination hole contraction due to the low spin Ni(II). The degree of conformational distortion is enhanced by one or two additional acrolein substituents at the meso positions. The steric strain imposed by interaction of the meso substituent with the neighboring β-pyrrole substituents leads to a significant displacement from the mean plane of the molecule of the meso carbon(s) involved. Increasing non-planarity of the macrocycles is correlated with shifts to longer wavelenghts in the absorption spectra. Ring closures of the acrolein group to afford benzochlorin type pigments results in further bathochromic shifts and a very non-planar molecular conformation. Long wavelength absorbing pigments such as benzochlorins are useful photosensitizers for photodynamic therapy and thus one criterion for a good photosensitizer might be its conformational distortion. Crystal data – 3. C40H46N4 · CH2Cl2, Mr = 667.7, triclinic, P1̄, a = 7.776(5)Å, b = 8.556(4)Â, c = 14.509(8)Å, α = 73.96(1)°, β = 82.04(2)°, γ = 82.58(2)°, V = 914.5(9)Å3, Ζ = 1, Dx = 1.212 Mg/m3, (ΜοΚα) λ = 0.71069Å, μ = 0.209 mm-1, F(000) = 356, 130 Κ, R = 0.082 for 2217 reflections with I > 1.5σ(Ι). Ni4. C44H40N4NiO · CH2Cl2, Mr = 770.4, triclinic, P1̄, a = 11.283(3)Å, b = 11.800(4)Å, c = 15.871(7)Å, α = 79.28(3)°, β = 88.95(2)°, γ = 62.41(1)°, V = 1838.8(11)Å3, Ζ = 2, Dx = 1.391 Mg/m3, (ΜοΚα), μ = 0.715 mm-1, F(000) = 804, 130 Κ, R = 0.072 for 5309 reflections with I > 2.0σ(Ι). Ni5. C46H28N4NiO2 • CH2CH2, Mr = 812.4, triclinic, P1̄, a = 8.959(4)Å, b = 14.420(7)A, c = 15.471(5)Å, α = 102.73(4)°, β = 101.83(4)°, γ = 92.01(5)°, V = 1901.3(14)Å3, Z = 2, Dx = 1.419 Mg/m3, (ΜοΚα), μ = 0.679 mm-1, F(000) = 836, 130 Κ, R = 0.059 for 4197 reflections with I > 1.75σ(Ι). Ni7. C43H45N4NiO2·CH2Cl2, Mr = 793.5, triclinic, P1̄, a = 8.948(3)Å, b = 13.855(3)Å, c = 15.451(3)Å, α = 82.43(2)°, β = 78.79(2)°, γ = 81.24(2)°, V = 1846.7(8)Å3, Z = 2, Dx = 1.427 Mg/m3, (CuKa) λ = 1.54178 Å, μ = 2.448 mm-1, F(000) = 834, 126 K, R = 0.09 for 4039 reflections with I > 2.0σ(Ι). Ni8. C42H48N4NiO, Mr = 683.6, monoclinic, Ρ21/n, a = 15.168(6)Å, b = 14.796(3)Å, c = 15.983(4)Å, β= 97.17(3)°, V = 3552(2)Å3, Z = 4, Dxx = 1.278 Mg/m3, (ΜοΚα), μ = 0.584 mm-1, F(000) = 1456, 130 Κ, R = 0.042 for 5904 reflections with I > 2.5 σ(I).
Synthese, Struktur und Metallierung von 1,3,5-Tris(dimethylamino)benzol / Synthesis, Structure, and Metalation of 1,3,5-Tris(dimethylamino)benzene
Authors: Kuhn Norbert , Schultena Michael , Boese Roland , Bläser Dieter , Brett Waldemar A. , Stellberg Peter
Published: March 2015

The synthesis of 1,3,5-tris(dimethylamino)benzene (5, Ar–H) is reported. The X-ray structure of 5 reveals two independent molecules in the unit cell both containing planar arene rings; the puckering of the amino substituents is demonstrated to be a consequence of steric interactions. 5 is metalated by n-butyl-lithium to give the isolable aryl-lithium compound Ar–Li (6) from which the phosphane Ar–PCl2 (7) and silane Ar–SiCl3 (8) are obtained.
Studies on the Alkylation of 5′-CMP under Alkaline Conditions
Authors: Khan Khurshid Alam , Qudrat-e-Khuda M. , Ahmad Viqar Uddin
Published: March 2015

The reaction of 5′-CMP with methyl, ethyl, n-propyl and isopropyl iodides gave predominantly ribose alkylated products. Various alkylated derivatives have been characterized using UV spectroscopy, paper electrophoresis, 1H NMR and FAB (negative) mass spectroscopic techniques. Under strongly alkaline conditions the 2′-O-alkylated derivatives are synthesized in maximal yields. Isopropylation reaction gave only a small yield of the 3′-O-isopropyl derivative, this could be explained on the basis of steric hindrance offered to the bulky isopropyl group at the 2′-OH position by the heterocyclic base of the nucleotide.
Preparation and Spectroscopic Characterization of Cyclopenta[1,2-a : 3,4,5-b′c′]dicoronene
Authors: Zander M. , Friedrichsen W.
Published: March 2015

The non-alternant hydrocarbon cyclopenta[1,2-a : 3,4,5-b′c′]dicoronene (3) has been prepared by aluminium chloride catalyzed dimerization of coronene (1). The UV/VIS absorption spectrum, fluorescence spectrum and fluorescence quantum yield of 3 is reported and compared with that of the alternant isomer benzo[1,2,3-bc:4,5,6-b′c′]dicoronene (2). Relationships observed in the UV/VIS absorption spectra of alternant and non-alternant polycyclic aromatic hydrocarbons and preliminary theoretical investigations (PMO calculations) on two model systems (C, E) are also reported.
Strukturvarianten des MgCu2-Typs: Die Verbindungen Mg2Ni3P und Mg2Ni3As / Variants of the MgCu2 Type: The Compounds Mg2Ni3P and Mg2Ni3As
Authors: Keimes Viktor , Mewis Albrecht
Published: March 2015

The compounds Mg2Ni3P and Mg2Ni3As were prepared by heating the elements. Their structures have been determined from single-crystal X-ray data. The structure of the phosphide is a rhombohedral ternary variant of the cubic Laves structure type MgCu2 (R 3̄ m; hexagonal lattice constants: a = 4.971(0) Å, c = 10.961(2) Å). The ordered substitution of one quarter of the metal atoms by phosphorus and the resulting shorter distances are responsible for the rhombohedral symmetry.

The arsenide crystallizes in the MgCu2 type structure (Fd 3 m; a = 6.891(1)A, composition Mg2Ni3As) with a statistic distribution of the Ni and As atoms; the relevant homogeneity range extends from Mg2Ni2.9As1.1 to Mg2Ni3.5As0.5.