bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaktivität des Silaethens Ph2Si=C(SiMe3)2
Authors: Wiberg Nils , Link Matthias 
Published: July 2007

Reactivity of the Silaethene Ph2Si=C(SiMe3)2Frühere Mitteilungen: Lit.

Herrn Prof. Dr. Herbert Schumann zum 60. Geburtstag gewidmet.
Silaethene Ph2Si=C(SiMe3)2 (3), generated as a reaction intermediate by the thermal elimination of LiX from Ph2SiX‐CLi(SiMe3)2 (X = Br, F) or by the thermal cyclore‐version of the [4 + 2] cycloadduct of 3 and Ph2C=NSiMe3, forms adducts 3 donor, the stability of which increases in the order of donor = Et2O < Br− < THF < NEtMe2 < F−, and combines with the reactants a‐b (e.g. R – Li; R = H, Me, nBu, Ph) with insertion into the a‐b bond, with a=b‐c‐H [e.g. O=CtBu‐CH2‐H; CH2=CR‐CH2‐H, R = Me, CMe=CH2, CH2SiPh2CH(SiMe3)2] according to an ene reaction, with a=b (e.g. CH2=CHOMe; Ph2C=NSiMe3) or a=b=c (e.g. tBu2RSiN3, R = Me, tBu) or a=b‐c=d [e.g. CH2=CR‐CR=CH2, R/R = H/H, Me/Me, Me/CH2SiPh2CH‐(SiMe3)2; Ph2C=Y, Y = O, NSiMe3] with [2 + 2] or [3 + 2] or [4 + 2] cycloaddition. The following order of relative reactivity of trapping reagents for Ph2Si=C(SiMe3)2 was found: Ph2CO > tBu2MeSiN3 > butadiene > 2,3‐dimethylbutadiene > Ph2CNSiMe3 > tBu3SiN3 > anthracene. Summing up, it may be said that going from Me2Si=C(SiMe3)2 to Ph2Si=C‐(SiMe3)2 there is only a gradual but not principal change of silaethene reactivity. This change is due to increasing polarity and overcrowding of the double bond, that is increasing Lewis acidity and steric hindrance of the unsaturated rilicon atom. Certainly, the former silaethene stabilizes thermally by dimerization, the latter by isomerization.
Thermische Stabilisierung des Silaethens Ph2Si=C(SiMe3)2
Authors: Wiberg Nils , Link Matthias 
Published: July 2007

Thermal Stabilization of the Silaethene Ph2Si=C(SiMe3)2Frühere Mitteilungen: Lit.

Herrn Prof. Dr. Manfred Regitz zum 60. Geburtstag gewidmet.
Silaethene Ph2Si=C(SiMe3)2 (3) (generated from Ph2SiBr‐C‐Li(SiMe3)2 = 3 · LiBr in Et2O at ‐78·C) reversibly isomerizes fast by methyl migration, then a bit slower by phenyl migration, and finally fast by methyl migration into thermodynamically more stable Me2Si=C(SiMePh2)(SiMe3) (3a), then into medium stable PhMeSi=C(SiMe2Ph)(SiMe3) (3b), and finally into most stable Me2Si=C(SiMe2Ph)2 (3c) (cf. Schemes 1 and 2; Figure 1). Simultaneously with isomerization 3a · 3c [2 + 2] cycloadditions (dimerizations) of 3a and 3c occur (formation of 3a · 3a, 3a · 3c, 3c · 3c; cf. Scheme 2). Over and above that, silaethenes 3a and 3c irreversibly isomerize into disilaindanes 4a, 4b, and 4c (cf. Scheme 6). Certainly, the latter reactions are even slow at 100·C. Thermolysis of 3a · 3a, 3a · 3c, 3c · 3c at 340·C, on the other hand, leads by way of [2 + 2] cycloreversion and the intermediate formation of an equilibrium mixture of 3, 3a, 3b, 3c almost quantitatively to 4. In addition to the thermolysis products mentioned above, products of 3 and its isomers 3a, 3b, 3c with the solvents (for example Et2O; cf. Scheme 7), with the silaethene sources (for example 3 · LiBr; cf. Scheme 8), or with products formed from sources besides silaethene 3 (for example Ph2,C=N‐SiMe3;cf. Scheme 4) are observed.
[4 + 1] Cycloadditions of the Rhodium Di(methoxycarbonyl) Carbenoid to 2‐Siloxy‐1,3‐dienes
Authors: Schnaubelt Jürgen , Marks Elke , Reißig Hans‐Ulrich 
Published: July 2007

AbstractThe rhodium(II) acetate catalyzed reaction of dimethyl diazomalonate with 2‐siloxy‐1,3‐dienes 1a–1d and 1h furnished cyclopentene derivatives 4a–4d and 4h in moderate yields. The mechanism of this unusual [4 + 1] cycloaddition is discussed.
The Coordination of N,N‐Diethyl‐N′‐p‐tolylthiourea to Polynuclear Rhenium Carbonyl Complexes
Authors: Adams Richard D. , Huang Mingsheng , Yamamoto John H. , Zhang Lijuan 
Published: July 2007

AbstractThe reactions of Re2(CO)9(NCMe) and Re3(CO)10‐(CH3CN)2(μ‐H)3 with S=C(NEt2)N(H)(p‐tolyl) have yielded the new compounds Re2(CO)9[S=C(NEt2)N(H)(p‐tolyl)] (1) and Re3(CO)10(μ‐SC(NEt2)N(H)(p‐tolyl)](μ‐H)3 (2) in 89% and 98% yields, respectively. Compounds 1 and 2 were characterized by single‐crystal X‐ray diffraction analyses. Compound 1 contains an S‐coordinated S = C(NEt2)N(H)(p‐tolyl) ligand terminally coordinated in an equatorial coordination site on one of the rhenium atoms. Compound 2 contains the first example of an S‐coordinated bridging thiourea grouping. When solutions of 1 were heated to 97°C, it was transformed to the new compound {Re(CO)3[μ‐SC(N‐p‐tolyl)(NEt2)]}2 (3) plus Re2(CO)10. Compound 3 is a centro‐symmetrical dimer of the unit Re(CO)3[SC(N‐p‐tolyl)(NEt2)] in which the sulfur atom bridges the two rhenium atoms. The tolyl‐substituted nitrogen atoms are coordinated to the rhenium atoms to form two Re–S–C–N rings.
Reactions of the Alkylindium(I) Compound In4[C(SiMe3)3]4 with Sulfur and Tellurium: Syntheses of In4S4[C(SiMe3)3]4 and In4Te4[C(SiMe3)3]4 with Indium Chalcogen Heterocubane Structures
Authors: Uhl Werner , Graupner Rene , Pohlmann Michael , Pohl Siegfried , Saak Wolfgang 
Published: July 2007

AbstractTetrahedro‐Tetrakis[tris(trimethylsilyl)methyl]tetraindane(4) (1) with a tetrahedral In4 molecular center reacts with an excess of elemental sulfur or tellurium in boiling n‐hexane to give in an almost quantitative yield the appropriate In4S4 (2) or In4Te4 derivatives (3). Crystal structure determinations revealed distorted In4X4 (X = S, Te) heterocubane molecular centers for both compounds.
2,5‐Dihydro‐1,2,5‐azoniasilaboratole Derivatives – Useful Starting Materials in Heterocyclic Synthesis
Authors: Wrackmeyer Bernd , Süß Jürgen , Milius Wolfgang 
Published: July 2007

Abstract1‐Alkynyl(diethylamino)dimethylsilanes [CC̊: R = Me (1a), nBu (1b), SiMe3 (1c)] react with triethylborane stereoselectively by 1,1‐ethyloboration to give the alkenes with the boryl and silyl group in cis‐positions at the C=C bond. Owing to the strongly intramolecular coordinative N‐B bond, these products are 2,5‐dihydro‐1,2,5‐azoniasilaboratoles (2a‐c). Protic reagents such as azoles (indole, pyrazole, imidazole, triazole, indazole, benzotriazole) react with 2 to give diethylamine and the respective N‐azolyl derivatives 3–8 which contain tetracoordinate boron in the case of 4–8. Compound 7, derived from indazole, was characterized by an X‐ray analysis. With ethanol, the corresponding 2,5‐dihydro‐1,2,5‐oxoniasilaboratoles 9 are obtained. Treatment of 2 with water affords 1,2,5‐oxasilaborolanes 11, presumably via an intermediate 10 with the structure of a 2,5‐dihydro‐1,2,5‐oxoniasilaboratole. All products were characterized by their 1H‐, 11B‐, 13C‐, 15N‐, and 29Si‐NMR data.
On the Effect of 1,2‐Disubstitution with Me3M (M = Si, Ge, Sn) Groups upon the Electronic Structure of 3,3‐Dimethylcyclopropene
Authors: Eckert‐Maksic Mirjana , Elbel Susanne , Stohlmeier Michael , Untiedt Sven , de Meijere Armin 
Published: July 2007

AbstractHe(I) PE spectra of a series of 3,3‐dimethylcyclopropenes bearing Me3Si (1), Me3Ge (2), and Me3Sn (3) groups in the 1‐ and 2‐positions, as well as the He(II) PE spectra of 1 and 3 were recorded. The changes in the lowest energy ionizations along the series are interpreted in terms of inductive and hy‐perconjugative interactions. The new compounds were prepared by reaction of lithiated 3,3‐dimethylcyclopropene with the corresponding trimethylmetal chlorides.
Preparation, Properties, and Reactions of Metal‐Containing Heterocycles, XCII. Steric and Solvent Effects of the Different Reaction Patterns of Activated Alkynes with Diphosphamanganacyclopropanes
Authors: Lindner Ekkehard , Fisahn Paul , Fawzi Riad , Steimann Manfred 
Published: July 2007

AbstractThe product pattern of the reaction of the alkynes ZCCZ (4–11) [Z = CO2R: R = Me (4), Et (5), nPr (6), iPr (7), nBu (8), nPent (9), neo‐Pent (10), cyc‐Hex (11)] with the diphospha‐manganacyclopropanes (1–3) depends on the polarity of the employed solvent. Whereas in n‐hexane the diphosphamanganabicyclo[3.3.0]octadienones 12a‐q, the diphosphamanganacyclopentenes 13a‐h, and the triphosphamanganabicyclo[3.2.0]heptenones 14a‐h are formed, in THF only the five‐membered heterocycles 13 occur. Compound 14d is easily oxidized to the corresponding oxide 15d. According to X‐ray structural analyses, both 14d and 15d crystallize in the space group P&1macr;. The Lewis basic properties of the phosphorus atom P2 in the heterocycle 1 were corroborated by reaction of 1 with THFCr(CO)5 leading to the adduct (16). Quantitative 31P{1H}‐NMR investigations in CDCl3 enable the determination of the product ratio 13/12 as a function of the steric encumbrance of the ester substituents. An increase of the steric hindrance leads to the preferential formation of the mo‐nocyclic compounds 13. If the steric demand at the phosphorus atom P2 is released, only the bicyclic compounds 12i‐q are formed.
Chelate‐Controlled Additions of Titanium and Lithium Enolates to Chiral β‐Formyl Esters – Diastereofacial and Simple Diastereoselectivity
Authors: Angert Hubert , Schumacher Ralf , Reißig Hans‐Ulrich 
Published: July 2007

AbstractThe aldol‐type additions of metal enolates 2‐Met derived from pinacolone to the chiral β‐formyl carboxylate 1a were optimized. The highest trans:cis ratio (86:14) of the products 3 was obtained when the trichlorotitanium enolate 2‐TiCl3 was combined with 1a precomplexed with one equivalent of TiCl4. The lithium enolate 2‐Li is rather unselective. The simple diastereoselectivity of prochiral enolates 4‐Met was first examined with achiral β‐formyl carboxylates 1b and 1c. Appropriate reagents made products with high anti or with high syn selectivity available when the unbranched aldehyde 1b was the electrophile. In contrast, the sterically more hindered aldehyde 1c provided syn products with all enolates 4‐Met employed. Finally, chiral aldehyde 1a was combined with prochiral enolates 4‐Met. Conditions could be found which furnished either the trans/anti or the trans/syn product 7 with good selectivity. The results are discussed and compared with reactions of related metal enolates with aldehydes capable of chelate formation.
Silanediols Derived from Silanetriols. X‐ray Crystal Structures of (2,4,6‐Me3C6H2)N(SiMe3)Si(OSiMe3)(OH)2 and (2,4,6‐Me3C6H2)N(SiMe3)Si(OSiMe2R)(OH)2 [R = CH2 (2‐NH2‐3,5‐Me2C6H2)]
Authors: Murugavel Ramaswamy , Voigt Andreas , Chandrasekhar Vadapalli , Roesky Herbert W. , Schmidt Hans‐Georg , Noltemeyer Mathias 
Published: July 2007

AbstractThe silanediols RN(SiMe3)Si(OSiMe3)(OH)2 (R = 2,4,6‐Me3C6H2 4, 2,6‐Me2C6H3 5, and 2,6‐iPr2C6H3 6) were prepared by the reactions of the respective silanetriols RN(SiMe3)‐Si(OH)3 1 – 3 with SiMe3Cl in THF/hexane. Silanetriol 1 in CH2Cl2/hexane solution converts over a period of 4 weeks into the silanediol (2,4,6‐Me3C6H2)N(SiMe3)Si(OSiMe2 R)‐(OH)2 [R = CH2(2‐NH2‐3,5‐Me2C6H2)] (7). Compounds 4 – 7 were characterized by means of mass, IR and NMR (1H and 29Si) spectroscopy. Additionally, the molecular structures of 4 and 7 were determined by single‐crystal X‐ray diffraction studies. Compound 4 forms O  H…O hydrogen‐bonded tetramers in the solid state. A nine‐membered ring formed by an intermolecular OH…N hydrogen bond is found in the solid‐state structure of 7.
Addition von CS2 und anderen Heteroallenen an die 16‐Elektronen‐Osmium(0)‐Komplexe trans‐[OsCl(NO)(PiPr2R)2]
Authors: Flügel Ruth , Gevert Olaf , Werner Helmut 
Published: July 2007

Addition of CS2 and Other Heteroallenes to the 16‐Electron Osmium(0) Complexes trans‐[OsCl(NO)(PiPr2R)2]The coordinatively unsaturated 16‐electron compounds trans‐[OsCl(NO)(PiPr2R)2] (1: R = iPr; 2: R = Ph) react with CS2 and COS to form the 1:1 adducts [OsCl(NO){κ2(C,S)‐SCS}(PiPr2R)2)] (3, 4) and [OsCl(NO){κ2(C,S)‐SCO}‐(PiPr2R)2] (6, 7), respectively. While compounds 3, 4 are inert toward PMe3, the Os(COS) complexes 6, 7 react with tri‐methylphosphane by abstraction of sulfur to give (OsCl(NO)‐(CO)(PiPr2R)2] (8, 9). From 1 or 2 and phenylisothiocyanate the corresponding 1:1 adducts (OsCl(NO){κ2(C,S)‐SCNPh}(PiPr2R)2] (10, 11) are obtained. Protonation and methylation reactions of 10 (R = iPr) with HBF4 or CF3SO3Me lead, by addition of the electrophile to the CN nitrogen atom, to the formation of [OsCl(NO){κ2(C,S)‐SCNHPh}‐(PiPr3)2]BF4 (12) and [OsCl(NO){κ2(C,S)‐SCN(Me)Ph}‐(PiPr3)2]CF3SO3 (13). Treatment of 1 with diphenylketene yields [OsCl(NO){κ2(C,O)‐OCCPh2}(PiPr3)2] (14). The X‐ray structure analyses of 10 and 14 confirm the coordination of phenylisothiocyanate via S and C and of diphenylketene via O and C, respectively.
Zinc complexes of the N,N,S ligand (mercaptophenyl)(picolyl)amine
Authors: Brand Udo , Vahrenkamp Heinrich 
Published: July 2007

AbstractThe zinc complex chemistry of the tridentate thiol ligand N‐ (2‐mercaptophenyl)(2‐picolyl)amine (MPPAH) differs considerably from that of the aliphatic analogue N‐(2‐mercaptoethyl)(2‐picolyl)amine reported previously. This is due to the lower basicity and hence bridging tendency of its aromatic thiolate function. With zinc salts of oxo anions the 1:1 complexes (MPPA)ZnX (1a–c: X = ONO2, OAc, OBz) are formed which according to spectroscopic data are monomeric while the halide (MPPA)ZnBr (2) seems to be polymeric. In the absence of coordinating anions the monomeric 2:1 complex (MPPA)2Zn (3) results which according to a crystal structure determination contains tetrahedral zinc coordinated by one MPPA ligand in a tridentate fashion while the other is only monodentate and sulfur‐bound. A similar N2S2 coordination can be deduced for the 1:1:1 complex (MPPA)Zn(STrt) (4) resulting from ZnEt2, MPPAH and triphenylmethanethiol.
Disiloxanes, Disilazanes and Related Compounds Derived from 1,8‐Disilynaphthalene
Authors: Schröck Robert , Dreihäupl Karl‐Heinz , Sladek Alexander , Angermaier Klaus , Schmidbaur Hubert 
Published: July 2007

AbstractThe synthesis, spectroscopic data and molecular structures of heterocycles derived from 1,8‐disilylnaphthalene are reported. The key intermediate for the preparation of the title compounds is 1,8‐bis[(trifluoromethylsulfonyl)silyl]naphthalene (3), which is prepared from 1,8‐bis[(4‐methoxyphenyl)silyl]naphthalene (2) by treatment with two equivalents of triflic acid in toluene at –20°C. The resulting silyl triflate is stable only below this temperature and was not isolated. Its reactions with water, ammonia, amines, and sulfane give the corresponding disiloxane, disilazanes and disilthiane. The molecular structure of Si,Si′‐(Naphthalene‐1,8‐diyl)‐N‐phenyldisilazane (8) was determined by X‐ray diffraction. Treatment of 2 with substoichiometric amounts of triflic acid and subsequent reaction of the resulting monosilyl triflate with tert‐butylamine gives a related chiral N‐tert‐butyl‐Si‐(4‐methoxyphenyl)disilazane 10. Its molecular structure was proven by X‐ray diffraction. A cyclic phosphonium bis(silyl)methylide (11) was synthesized by a transylidation process using 3 and CH2=P(NMe2)3. The structure of 11 was also determined by X‐ray diffraction.
Supermolecules Containing a Tetrahedral Core: A New Class of Liquid‐Crystalline Siloxanes
Authors: Mehl Georg H. , Goodby John W. 
Published: July 2007

AbstractIt is shown that supermolecules with a tetrahedral symmetry and appropriate side‐chains exhibit liquid‐crystalline phase behaviour. The use of an optimised hydrosylation reaction allows for the synthesis of materials that have four mesogenic groups attached to a siloxane core, where the conformation and the configuration are unambiguous. The materials show low glass transition temperatures and, depending on the spacer length, complex liquid‐crystalline morphologies.
A Synthetic and Theoretical Study of the Aggregation of Amidoaluminium Hydrides: Solid‐State Structure of the Trimethylamine Adduct [(Me3Si)2NA1(Cl)(H) · NMe3]
Authors: Gardiner Michael G. , Koutsantonis George A. , Lawrence Stacey M. , Lee Fu‐Chin , Raston Colin L. 
Published: July 2007

AbstractThe amidoaluminium hydride complexes [(Me3Si)2NA1(X)(H) · NMe3], X = H (1), Cl (2), were prepared by the metallation of bis(trimethylsilyl)amine by Al(X)(H)2 · NMe3 (X = H and Cl). The molecular structure of 2 as a monomeric Lewis base adduct with four‐coordinate aluminium centres and terminal amido groups was confirmed by X‐ray crystal structure determination. We also find that bis(trimethylsilyl)amine forms a thermally stable adduct of alane, (Me3Si)2N(H) · AlH3 (3). Ab initio molecular orbital calculations on the possible products arising from these reactions yielding 1 and 2 revealed that the amido‐bridged species, {(μ‐H2N)Al(X)H}2 (X = H and Cl), are favoured over nitrogen donor Lewis base adduct formation, H2NAl(X)(H) · NH3 (X = H and Cl), and then chloro‐bridged, {H2NAl(μ‐X)(H)}2, (X = Cl only), and hydrido‐bridged species, {H2NAl(X)(μ‐H)}2 (X = H and Cl).
Synthesis, Characterization and Dynamic Behavior of (π‐Allyl)palladium Complexes with Polydentate Nitrogen Ligands, Evidence of a Dissociative Mechanism
Authors: Elguero José , Fruchier Alain , De La Hoz Antonio , Jalón Félix A. , Manzano Blanca R. , Otero Antonio , Gómez‐De La Torre Felipe 
Published: July 2007

AbstractNew examples of the fluxional behavior of (η3‐allyl)palla‐dium complexes are described. Variable‐temperature experiments and line‐shape analysis of two (η3‐allyl)palladium complexes containing 2‐(1H‐pyrazol‐1‐yl)azine ligands were performed in order to determine the activation free energies, enthalpies and entropies of the process. A dissociative mechanism pointing to a selective Pd‐N cleavage is proposed on the basis of these results and NOE experiments above and below the coalescence temperature.
Novel Ferrocene‐Based Mono‐ and Bifunctional Tri‐1‐pyrazolylborate Ligands
Authors: Jäkle Frieder , Polborn Kurt , Wagner Matthias 
Published: July 2007

AbstractThe reaction of (dibromoboryl)ferrocene (1a) with pyrazole/NEt3 gave the ferrocenyltri‐1‐pyrazolylborate ligand 2. Its thallium(I) derivative 2‐Tl provides the first example of a polymeric structure with bridging tri‐1‐pyrazolylborate units in the solid state. The trinuclear iron complex 2‐Fe, which is related to 1,1′‐terferrocene, was obtained by reaction of 2 with FeCl2. The bis(polydentate) ligand 1,1′‐ferrocenediyl‐bis(tri‐1‐pyrazolylborate) (3‐Li) was prepared from 1,1′‐bis‐[bis(dimethylamino)boryl]ferrocene (1c) and a mixture of lithium pyrazolide/pyrazole in refluxing toluene/THF. 3‐Li reacts with TlNO3 to give the thallium(I) complex 3‐Tl.
Ir‐Komplexe mit P4‐Bicyclotetraphosphan und P8‐Cunean als Liganden – CO‐Insertion in eine Ir–P‐Bindung
Authors: Scheer Manfred , Becker Uta , Matern Eberhard 
Published: July 2007

Ir Complexes with P4Bicyclotetraphosphane and P8Cunean as Ligands – CO Insertion into an Ir–P BondThe reaction of [Cp*Ir(CO)2] with white phosphorus under photochemical or thermal conditions produces the bicyclotetraphosphane complexes1and2and the cunean‐type complex3. The products were characterized by NMR, IR, and mass spectroscopy as well as by X‐ray structure analyses. Complex1reacts with CO with insertion into a Ir–P bond to form2and finally [Cp*Ir(CO)2].
Hexacoordinated Group‐14 Elements with Phosphorus Donor Ligands: Syntheses and Structures of Me2E[C(PMe2)2(SiMe3)]2 (E = Si, Ge, Sn)
Authors: Karsch Hans H. , Deubelly Brigitte , Keller Ursula , Bienlein Fritz , Richter Roland , Bissinger Peter , Heckel Maximilian , Müller Gerhard 
Published: July 2007

AbstractThe dimethyl group‐14 element dihalides Me2EX2 (E = Si, Ge, Sn; X = Cl or Br) react with two equivalents of Li[C(P‐Me2)2(SiMe3)] to give the cis‐hexacoordinated complexes Me2E[C(PMe2)2 (SiMe3)]2 (E = Si: 2a, E = Ge: 2b, E = Sn: 2c), which were characterized spectroscopically and by means of X‐ray structure determinations. Whereas 2a and 2b are isotypic and crystallize in the space group P21/c, 2c crystallizes in the space group C2/c with crystallographic C2(2) molecular symmetry. In all cases the diphosphanylmethanide ligands bind in an unisobidentate fashion. For compound 2c, this still can be attributed to the trans influence of the methyl group, but in 2a and 2b clearly borderline cases between hexa‐ and tetracoordination are found. Compound 2b (E = Ge) is much more on the side of tetracoordination than 2a, thus underlining the importance of small polarity differences for the actual coordination number achieved in compounds with relatively unpolar bonds.
Ionic Ozonides of Lithium and Sodium: Circumventive Synthesis by Cation Exchange in Liquid Ammonia and Complexation by Cryptands
Authors: Korber Nikolaus , Jansen Martin 
Published: July 2007

AbstractConcentrated solutions of the ozonides LiO3 and NaO3 in anhydrous liquid ammonia were obtained for the first time by using an ion exchange reaction that starts from CsO3. No solid LiO3 or NaO3 can be precipitated. Upon removal of the solvent, the ozonide anion oxidises ammonia, resulting in the precipitation of LiOH and NaOH, respectively. This behaviour is in sharp contrast to that of solutions of KO3, RbO3 and CsO3. Proof of the existence of LiO3 and NaO3 in the solutions is provided by complexation of the cations with cryptands, which leads to solid (Li[2.1.1])O3 and (Na[2.2.2])O3. Crystal structure analysis shows that these are ionic solids containing the V‐shaped O3− anion.
Self‐Assembly of a Triple‐Stranded meso‐Helicate from Two Iron(II) Ions and Three [CH2]3‐Bridged Bis(2,2′‐bipyridine) Ligands
Authors: Albrecht Markus , Riether Cyrill 
Published: July 2007

Abstract1,3‐Bis(5′‐methyl‐2,2′‐bipyrid‐5‐yl)propane (3) can be synthesized by a two‐step procedure starting from 3‐picoline (1). In a spontaneous self‐assembly process 3 forms the binuclear triple‐stranded meso‐helicate [(3)3Fe2][PF6]4 on addition of iron(II) salts. The (Λ,Δ) structure can be shown by symmetry considerations based on NMR spectroscopy and is due to the conformational restrictions of the [CH2]3 spacer.
Syntheses of Hetero‐sila‐closo‐boranes
Authors: Wesemann Lars , Ramjoie Yves , Ganter Beate , Maisch Hartmut 
Published: July 2007

AbstractAddition of 3 equivalents of KH · BEt3 to [Me3NH][Me‐SiB10H12] followed by addition of one equivalent of SnCl2 or SbI3 affords the stanna‐sila‐closo‐borate(1–) 3 and stiba‐sila‐closo‐borane 4, respectively. [MePh3P] · 3 crystallizes in the orthorhombic space group P212121.
Intramolekular stabilisierte Übergangsmetallamide: 2‐(Dimethylaminomethyl)pyrrolyl‐Komplexe des Titan(III), Vanadium(III), Chrom(III), Cobalt(II) und Nickel(II)
Authors: Drevs Helmuth , Schmeißer Annett , Hartung Helmut , Baumeister Ute 
Published: July 2007

Intramolecularly Stabilized Metal Amides: 2‐(Dimethylaminomethyl)pyrrolyl Complexes of Titanium(III), Vanadium(III), Chromium(III), Cobalt(II) and Nickel(II)By the metallation of 2‐(dimethylaminomethyl)pyrrol (HL) with butyllithium the lithium pyrrolide LiL (1) was obtained. The reactions of 1 with TiBr3 · 3 THF, VBr3 · 3 THF, CrBr3 · 3 THF, CoBr2 · 2 THF, and NiBr2 · 1.67 THF result in the formation of the 2‐(dimethylaminomethyl)pyrrolyl complexes of type ML3 (2–4), and ML2 (5, 6), respectively. The structures of these new compounds are discussed on the basis of magnetic and visible absorption measurements. An X‐ray crystal structure determination of 4 reveals a strongly distorted octahedral environment of the chromium atom with facial arrangement of the ligands.
Zirconium Species as Tools in Phosphorus Chemistry, 1 [Cp2ZrHCI]n, a Versatile Reagent
Authors: Majoral Jean‐Pierre , Zablocka Maria , Igau Alain , Cénac Nathalie 
Published: July 2007

Abstract[Cp2ZrHCl]n was found to be a useful reagent for a number of either ring formation or ring opening reactions involving unsaturated phosphorus compounds. Furthermore, treatment of a variety of phosphorus derivatives with [Cp2ZrHCl]n allowed the preparation of several linear or cyclic mono‐, di‐, trior polyphosphanes as well as optically active diphosphanes.