bluuebunny/crossref_metadata_2025 huggingface dataset:
Alken‐, Alkin‐, Isonitril‐ und Carbonyl‐Komplexe von Kupfer(I) und Silber(1) mit dreizähnigen Sauerstoff‐Chelatliganden
Authors: Lenders Bernd , Kläui Wolfgang
Published: July 2007

Alkene, Alkyne, Isonitrile, and Carbonyl Complexes of Copper(I) and Silver(I) with Tris‐Chelating Oxygen Ligands

The preparation of η2‐alkynecopper(I) complexes of the composition [LRCu(η2‐alkyne)], alkyne = tolan, dimethyl acetylenedicarboxylate, is described. LR are anionic tris‐chelating oxygen ligands of the type [(C5H5)Co{P(O)R2}3]−, R  OMe, OEt, O‐i‐Pr. The isonitrile complexes [LRM(CNt‐Bu)], M  Cu, Ag, have been prepared from [LOMeCu(CO)] and [{AgLOEt}2], respectively, The silver carbonyl complex [LOEt}Ag(CO)] [v(CO)  2147 cm−1] forms in hexane and methanol solutions of [{AgLOEt}2] under 1 atm of CO gas. The olefin complexes [LRCu(ba)], ba = benzytlideneacetone, have been prepared from [Cu(CH3CN)4]PF6, NaLOMe, and ba and from the carbonyl complex [LOEtCu(CO)] and ba. The coordination of the carbon‐carbon double bond of ba at the LRCu fragment does not lead to a 1,4‐addition of methyllithium to the α,β‐unsaturated ketone.
Synthese, Reaktivität und Ligandeigenschaften von 1,4‐Dihydro‐1,4‐diboranaphthalin‐ und 2,3‐Benzo‐1,4‐dihydro‐1,4‐diborafulven‐Derivaten
Authors: Febenbecker Achim , Schulz Hartmut , Pritzkow Hans , Siebert Walter
Published: July 2007

Synthesis, Reactivity, and Ligand Properties of 1,4‐Dihydro‐1,4‐diboranaphthalene and 2,3‐Benzo‐1,4‐dihydro‐1,4‐diborafulvene Derivatives

The chlorine derivative 1a of 1,4‐dihydro‐1,4‐diboranaphthalene and 2a of 2,3‐benzo‐1,4‐dihydro‐1,4‐diborafulvene are obtained by treating 1,2‐bis(trimethylstannyl)benzene (3)with (EtCBCl2)2 (4) and 1,2‐bis(dichloroboryl)benzene (5) with 1,1‐bis(trimethylstannyl)‐2‐methyl‐1‐propene (6), respectively. The dimethyl derivatives 1b and 2b react with the Fe(CO)3 complex fragment to yield the iron complexes 7b and 8b, in which the iron is bound to the heterocycle of 1b and 2b, respectively. The X‐ray structure analyses of 7b, 8b, and 2b are described.
Darstellung eines viergliedrigen Indium‐Phosphor‐Rings mit am Phosphor gebundenem Wasserstoff. — Kristallstruktur von [(Me3SiCH2)2InPHtBu]2
Authors: Dembowski Udo , Noltemeyer Mathias , Rockensüß Wilfried , Stuke Michael , Roesky Herbert W.
Published: July 2007

Preparation of a Four‐Membered Indium‐Phosphorus Ring with a Hydrogen Atom Bound to Phosphorus. — Crystal Structure of [(Me3SiCH2)2 InPHtBu]2

Reaction of tBuPH2 (1) with (Me3SiCH2)3In (2) in the presence of Ag+ ions leads to [(Me3SiCH2)2InPHtBu]2 (3). According to an X‐ray structure analysis, 3 forms a four‐membered planar P2In2 ring with alternating P — In bonds and crystallizes in the monoclinic space group C2/c.
Cyclophanes, XXXV. DNMR, molecular mechanics, and crystal structures of 2,11‐dithia[3.3]orthometacyclophane and 2,11‐dithia[3.3]orthoparacyclophane
Authors: Bodwell Graham J. , Ernst Ludger , Hopf Henning , Jones Peter G. , McNally John P. , Schomburg Dietmar
Published: July 2007

The syntheses of 2,11‐dithia[3,3]orthometacyclophane (5) and 2,11‐dithia[3,3]orthoparacyclophane (6) by dithiol‐dibromide coupling are described. Whereas the yield of 5 is not significantly affected by the substrate pairing, that of 6 is. Both compounds exhibit a temperature‐dependent 1H‐NMR spectrum. An energy barrier of 11.0 ± 0.2 kcal/mol (45.7 ± 0.8 kJ/mol) has been calculated for 5, but that of 6 was too low to be determined. Slightly contrasting results were obtained from two different molecular mechanics programs for the relative energies of the six limiting conformations of 5. Crystal structure determinations of 5 and 6 have been carried out, and the conformational behavior of 5 and 6 in solution and in the solid state is discussed.
Macrocyclic pyridinophanetetraene
Authors: Thilgen Carlo , Vögtle Fritz
Published: July 2007

The new pyridinophanetetraene 4 has been prepared in a two‐step synthesis by a modified Kharash coupling reaction of 2,6‐bis[3‐lithio‐(E)‐styryl]pyridine with copper(II) chloride. Starting from isomerically pure 2,6‐bis[3‐bromo‐(E)‐styryl]pyridine (3), the cyclization reaction takes place without rearrangement of the stilbazole double bonds. The electronic spectrum of 4 shows characteristic differences when compared to that of its open‐chain analogue 2,6‐bis[(E)‐styryl]pyridine (7).
1,4‐Dioxino[2,3‐b]pyridine und 1,4‐Oxathiino[2,3‐b]pyridine
Authors: Neunhoeffer Hans , Sponheimer Otto
Published: July 2007

1,4‐Dioxino[2,3‐b]pyridines and 1,4‐Oxathiino[2,3‐b]pyridines

1,4‐Dioxino[2,3‐b]pyridine and 1,4‐Oxathiino[2,3‐b]pyridine Reaction of 3‐hydroxy‐2‐pyridones 1 or 3‐hydroxy‐2‐pyridinthiones 2 with sodium hydride and 1,2‐dibromoethane in hexamethylphosphorous triamide gives 1,4‐dioxino[2,3‐b]pyridines 3 and 1,4‐oxathiino[2,3‐b]pyridines 5 which can be hydrogenated to amino‐1,4‐dioxino[2,3‐b]pyridines 7.
Addition von Alkenen an 5‐(Trifluormethyl)‐1,3,2,4,6‐dithiatriazin
Authors: Maggiulli Roberto , Mews Rüdiger , Noltemeyer Mathias , Offermann Werner , Paape Rainer , Stohrer Wolf‐Dieter
Published: July 2007

Addition of Alkenes to 5‐(Trifluoromethyl)‐1,3,2,4,6‐dithiatriazines

Dechlorination of 1,3‐dichloro‐5‐(trifluoromethyl)‐1,3,2,4,6‐dithiatriazine (1) with Ph3Sb gives (CF3CN3S2)n (2) in quantitative yield. By 1,3‐addition of alkenes (dicyclopentadiene, cyclopentene, cis‐ and trans‐2‐butene, propene, and ethene) to 2 the corresponding penta‐ (4a), tri‐(5a), and bicyclic ring systems 6a, 6b, 7, 8a, 8b, and 9 are prepared in 65–85% yields. The molecular structures of 6a and 7 were determined by single‐crystal X‐ray analysis; the other structures were derived from NMR data. The NMR analyses are in accordance with MNDO calculations. For 4a and 5a only the thermodynamically favoured anti‐isomers are found, as expected from these calculations; for 6 and 8 they show satisfactory agreement for anti/syn‐proportions as determined by NMR spectroscopy. The product distribution corresponds to a symmetry‐allowed alkene addition to a singlet dithiatriazine.
Synthese und Eigenschaften von 1,2,4,3‐Thiadiazaboretidinen. Kristallstruktur des 2,4‐Di‐tert‐butyl‐3‐phenyl‐1,2,4,3‐thiadiazaboretidins
Authors: Habben Carl D. , Heine Andreas , Sheldrick George M. , Stalke Dietmar , Bühl Michael , Schleyer Paul Von R.
Published: July 2007

Synthesis and Properties of 1,2,4,3‐Thiadiazaboretidines. Crystal Structure of 2,4‐Di‐tert‐butyl‐3‐phenyl‐1,2,4,3‐thiadiazaboretidine

Reaction of sulfur diimides with alkyl(aryl)bis(methylthio)boranes leads to reductive 1,3‐cycloaddition of the NSN sequence with formation of the 1,2,4,3‐thiadiazaboretidines 2a‐g. NMR (1H, 11B, 13C, 15N, 29Si), mass spectra and the results of the X‐ray analysis of 21 are reported and discussed. The 11B chemical shifts have been calculated for 3‐phenyl‐1,2,4,3‐thiadiazaboretidine and some related model compounds by the IGLO method and correlate acceptably with the experimental values.
Molecular Structure of Hg[C(COF)SF2O]2
Authors: Bittner Jürgen , Seppelt Konrad
Published: July 2007

Hg[C(COF) = SF2 = O]2 is prepared by the reaction of FCO  CH = SF2 = O with HgF2. This compound represents the third known example of an alkylidenesulfur difluoride oxide. Its molecular structure is the same as that of the most abundant of the three isomers of FCO‐CH = SF2 = O. This is assumed to be the result of weak intramolecular Hg… O contacts. With the exception of the fluorine atoms bound to sulfur, all atoms lie approximately in one plane.
Heterocyclen als Liganden, X 2,2′,5,5′‐Tetra‐tert‐butyl‐1,1′‐diazaferrocen — Stabilisierung der Diheterometallocen‐Struktur durch sterische Abschirmung
Authors: Kuhn Norbert , Jendral Kai , Boese Roland , Bläser Dieter
Published: July 2007

Heterocycles as Ligands, X1). — 2,2′,5,5′‐Tetra‐tert‐butyl‐1,1′‐diazaferrocene – Stabilization of the Diheterometallocene Structure by Steric Shielding

Stable 2,2′,5,5′‐tetra‐tert‐butyl‐1,1′‐diazaferrocene (3) is obtained by the reaction of the corresponding lithiopyrrole with FeCl2. The X‐ray analysis reveals a distorted sandwich structure influenced by repulsive interactions presumably both between the nitrogen atoms and the bulky tert‐butyl substituents.
Is the Fe+‐Induced C — H/C — C Bond Activation of α,ω‐Alkanedinitriles Affected by Bifunctional Interactions?
Authors: Prüsse Tilmann , Czekay Gregor , Schwarz Helmut
Published: July 2007

The metastable‐ion mass spectra of Fe+ complexes of alkanedinitriles NC(CH2)nCN (n = 1 – 10) exhibit six types of reactions: (1) Loss of the intact ligand to regenerate bare Fe+ as the exclusive (n = 1) or major reaction (n = 2) for the lower homologues; (2) generation of nitriles H(CH2)mCN with m = 0 – 6; (3) formation of unsaturated nitriles CH2 = CH(CH2)mCN with m = 0 – 4; (4) production of C2H4; (5) dehydrogenation, and (6) expulsion of the radicals C2H5 and CH2CN+. The branching ratios of these competing processes are governed by the chain length (CH2)n separating the two CN groups. Mechanistic insight is provided by the study of isotopomers. A comparison of the present data with the previously described behaviour of RCN/Fe+ complexes (R = alkyl) leaves no doubt that for the α,ω‐alkanedinitriles it is the Fe+‐mediated interaction of the two functional groups which controls the gas‐phase chemistry of these organometallic systems. For example, results are presented demonstrating inter alia that losses of H2 and C2H4 proceed by completely different pathways when dinitriles serve as precursors, and either reaction is affected by neighbouring group participation. In distinct contrast, for RCN/Fe+ complexes (R = alkyl) the existing data point to common intermediates.
Nucleophile Substitution von Nitrit in Nitrobenzolen, Nitrobiphenylen und Nitronaphthalinen
Authors: Effenberger Franz , Koch Markus , Streicher Willi
Published: July 2007

Nucleophilic Substitution of Nitrite in Nitrobenzenes, Nitrobiphenyls, and Nitronaphthalenes

Aromatic compounds, accessible only by multistep procedures, can be synthesized easily by nucleophilic substitution of nitrite in nitrobenzenes, nitrobiphenyls, and nitronaphthalenes. Thus, meta‐substituted phenols 3, 4, and 7 are obtained from 1,3‐dinitrobenzene (1) and meta‐substituted nitrobenzenes 6, as well as 3,5‐disubstituted phenols 10 and 5‐substituted resorcinol derivatives 11 from 3,5‐disubstituted nitrobenzenes 9. The unsymmetrically substituted nitrobiphenyls 13, 15, 17, 19, 21, 23, 24, and 26 are also available by nitrite exchange from the corresponding easily accessible dinitrobiphenyls 16, 18, 20, 22, and 25. A nitrite exchange with nucleophiles is easily possible in the 1,5‐disubstituted naphthalenes 29, 34, while in the case of the 1,8‐disubstituted naphthalenes 31, 36 only the chloro derivative 36 undergoes this exchange under much stronger conditions in low yield.
Zur Reaktion von Dialkylphosphiten mit α‐Enonen, I Synthese und Allyl‐Umlagerung von (1‐Hydroxy‐2‐alkenyl)‐ und (1‐Hydroxy‐2‐cycloalkenyl)phosphonsäure‐dimethylestern
Authors: Öhler Elisabeth , Zbiral Erich
Published: July 2007

Reaction of Dialkyl Phosphites with α‐Enones, I. – Synthesis and Allylic Rearrangement of Dimethyl (1‐Hydroxy‐2‐alkenyl)‐ and (1‐Hydroxy‐2‐cycloalkenyl)phosphonates

Various β,γ‐unsaturated α‐hydroxyphosphonates 3 are prepared in good yields by NaOCH3‐catalyzed regioselective 1,2‐addition of dimethyl phosphite to acyclic and cyclic α‐enones at −35°C. On acid‐catalyzed acetylation, the allylic α‐hydroxyphosphonates 3 (R1, R2 + H) rearrange under thermodynamic control; yielding the new 3‐acetyloxy‐1‐(cyclo)alkenyl derivatives 8, from which the transposed allylic alcohols 11 are readily obtained. Using shorter reaction times, acetylation of compounds 3 affords mixtures of 1‐ and 3‐acetylated products, 10 and 8, respectively.
Dioxirane Epoxidation of α,β‐Unsaturated Ketones
Authors: Adam Waldemar , Hadjiarapoglou Lazaros , Smerz Alex
Published: July 2007

The synthesis of epoxides 3a – r is achieved in excellent yields by reaction of the α,β‐unsaturated ketones 1a–c, 4,4′‐disubstituted (E)‐chalcones 1d–o, and 2′‐hydroxy‐4‐substituted (E)‐chalcones 1p – r with isolated dimethyldioxirane (2a) (as acetone solution) and/or in situ generated ethyl(methyl)dioxirane (2b). This method constitutes a useful alternative to the Weitz‐Scheffer epoxidation (alkaline H2O2) of such electronpoor substrates.
Dreikernige Niob‐Oxid‐Cluster1). – Synthese von (η5‐C5Me5)3Nb3(μ2‐O)3(μ3‐O)‐(μ2‐Cl)Cl3 und [(η5‐C5Me5)3Nb3(OH)2(μ2‐OH)(μ3‐OH)(μ2‐O)2(μ3‐O)Cl]Cl
Authors: Leichtweis Iring , Roesky Herbert W. , Noltemeyer Mathias , Schmidt Hans‐George
Published: July 2007

Trinuclear Niobium Oxide Clusters1). – Synthesis of (η5‐C5Me5)3Nb3(μ2‐O)3(μ3‐O)(μ2‐Cl)Cl3 and [(η5‐C5Me5)3Nb3(OH)2(μ2‐OH)(μ3‐OH)(μ2‐O)2(μ 3‐O)Cl]Cl

Hydrolysis of η5‐C5Me5NbCl4 with excess of water leads to a mixture of products. Pyrolysis of this crude mixture gives (η5‐C5Me5)3Nb3(μ2‐O)3(μ3‐O)(μ‐Cl)Cl3 (1) in good yield. On treatment of 1 with water [(η5‐C5Me5)3Nb3(OH)2(μ2‐OH)(μ3‐OH)(μ2‐O)2(μ3‐O)Cl]Cl (2) is obtained. The products 1 and 2 were characterized analytically and by X‐ray structure determination.
Phosphane‐Borane Chemistry. – Borane Adducts of Two Polyfunctional Phosphanes
Authors: Schmidbaur Hubert , Wimmer Thomas , Lachmann Joachim , Müller Gerhard
Published: July 2007

The tris(borane) adduct MeC(CH2PMe2BH3)3 (2) of 1,1,1‐tris‐[(dimethylphosphino)methyl]ethane has been prepared from the tripodal phosphane and Me2S–BH3 as the borane source. The crystal structure of 2·1/2 toluene has been determined by single‐crystal X‐ray diffraction methods. The molecules display crystallographic C3 symmetry and an overall staggered conformation. In an analogous way the bis(borane) adduct CH2(PH2BH3)2 (3) of 1,3‐diphosphapropane has been synthesized, which decomposes above 50°C to give insoluble products, whose elemental analysis indicated that termal P–C bond cleavage is more frequent than P–B bond cleavage.
Umsetzungen von Ga2Br4 · 2 Dioxan mit (Trimethylsilyl)methyllithium und Neopentyllithium – Synthese und Kristallstruktur von Lithiumtetraalkylgallanaten(III) mit Li–C–Ga‐Brücke
Authors: Uhl Werner , Klinkhammer Karl‐Wilhelm , Layh Marcus , Massa Werner
Published: July 2007

Reactions of Ga2Br4 · 2 Dioxane with (Trimethylsilyl)methyllithium and Neopentyllithium — Synthesis and Molecular Structure of Lithium Tetraalkylgallanates(III) with Li–C–Ga Bridges

Ga2Br4 · 2 dioxane reacts with (trimethylsilyl)methyllithium or neopentyllithium to yield in n‐pentane/diethyl ether solution besides elemental gallium exclusively the disproportionation product trialkylgallane. In pure n‐pentane the dioxane adducts of the corresponding lithium tetraalkylgallantes (R = CH2SiMe3 2; R = CH2CMe3 4) are formed. 2 and 4 are also synthesized by the reaction of GaBr3 with alkyl lithium in the molar ratio 1:4. The crystal structure of 2 shows a dioxane‐bridged dimer and Li–C–Ga bridges with lithium probably bound by the C–H s̀‐bonds of the central carbon atoms.
Kristallines Tl2B9H9C2Me2: Synthese und Festkörperstruktur; ein Beitrag zum Problem “attraktive Tl(I)–Tl(I)‐Wechselwirkungen”
Authors: Jutzi Peter , Wegener Dirk , Hursthouse Mike B.
Published: July 2007

Crystalline Tl2B2H9C2Me2: Synthesis and Solid State Structure; a Contribution to the Problem of Tl(I)–Tl(i) Interactions

Crystalline Tl2B9H9C2Me2 (1) is obtained in the reaction of the carborane B9H11C2Me2 with two equivalents of thallium(I) ethanolate. An X‐ray diffraction study of 1 shows – contrary to the expectation – the presence of isolated thallium ions and thalladicarbollide counteranions. The latter represent ion pairs composed of Tl(I)+ and B9H9C2Me212− units forming slipped icosahedrons. All possible Tl–Tl distances in 1 are too long for even weak attractive interactions, with one exception: A set of symmetry‐equivalent cations possesses a Tl–Tl distances of 3.67 A, which is in a range postulated by calculations for weak bonding.
Selektivitäten bei Photoadditionen an multifunktionelle Coffein‐Derivate
Authors: Kaupp Gerd , Ringer Ernst
Published: July 2007

Selectivities in Photoadditions with Multifunctional Caffeine Derivatives

Electronically excited stilbene (21*), 4,4′‐dichlorostilbene (1*), and 4,4′‐dimethoxystilbene (18*) are trapped by caffeine derivatives 2, 13, or 22 with variable results. While 1* and 2 react predominantly at the imino double bond (substitutive and fragmentating additions), 1* or 18* and 13 produce mostly propellanes by [2 + 2] photocycloaddition, which hydrolyze or may be hydrolyzed. 21* and the relatively electron‐poor compound 22 produce mostly propellanes, which always show a preponderance of the syn‐10, anti‐11 stereoisomers. These selectivities as well as the competition with reactions at the imino double bonds are rationalized on the basis of diradical mechanisms with the aid of semiempirical AM1 calculations. Earlier results on closely related transformations are also discussed.
Durch Verklammerung gespannte Perylene — Das Coronen‐Isomer Dicyclopenta[1,2,3‐cd:1′,2′,3′‐Im]perylen und Dimethanoperylen
Authors: Jaworek Wilfried , Vögtle Fritz
Published: July 2007

Strained Perylenes By Clamping — The Coronene Isomer Dicyclopenta[1,2,3,‐cd: 1′,2′,3′‐Im]perylene and Dimethanoperylene

Perylene (3) is clamped by C2 and C1 bridges with formation of the heptacyclic title compound dicyclopenta[1,2,3‐cd: 1′,2′,3′‐Im]perylene (10) (characterized) and 1H,6H‐dicyclobuta[1,2,3‐cd: 1′,2′,3′‐Im]perylene (4) (detected by mass spectrometry and 1H‐NMR absorptions). The influence of strain on UV and fluorescence spectra and on cyclic voltammetry is discussed
Photoelectron Spectra of geminal Vinyl‐ and Ethynyl‐Disubstituted Cyclopropane Derivatives
Authors: Eckert‐Maksić M. , Gleiter R. , Zefirov N. S. , Kozushkov S. I. , Kuznetsova T. S.
Published: July 2007

The He(I) photoelectron (PE) spectra of 1,1‐divinylcyclopropane (1), (Z,E)‐ and (Z,Z)‐1,1‐di‐1‐propenylcyclopropane (2 and 3), 1,1‐diethynylcyclopropane (4), 1‐ethynyl‐1‐propynylcyclopropane (5), 1‐ethynyl‐1‐vinylcyclopropane (6), and (Z)‐1‐(1‐propenyl)‐1‐(propynyl)cyclopropane (7) have been recorded. The interpretation of the first bands of the PE spectra is based on the comparison with related compounds and on the results of MO calculations. For the calculations on 1 – 7 the MNDO method, and in case of 1, 4, and 6 an ab‐initio procedure with a 3–21 G basis has been applied. The investigations show that 1, 2, 6, and 7 prefer the bisected conformation while in 3 the propenyl groups are strongly twisted. Our studies reveal also that the three‐membered ring shows relais properties and interacts strongly with both π systems.
Dispiro‐1,2,4‐trioxolane durch Ozonolyse von Cycloalkylidencycloalkanen auf Polyethylen
Authors: Griesbaum Karl , Krieger‐Beck Petra , Beck Johannes
Published: July 2007

Dispiro‐1,2,4‐trioxolanes by Ozonolysis of Cycloalkylidenecycloalkanes on Polyethylene

Ozonolyses of symmetrical (1b – d) and of unsymmetrical cycloalkylidenecycloalkanes (8a, b) afforded the dispiro‐1,2,4‐trioxolanes 4b – d and 9a, b, respectively. Their thermal decompositions gave mixtures of the cyclic ketones (3) and lactones (6). Photolyses afforded in addition to 3 and 6 the cyclic anhydrides 13, which are isomeric with the corresponding dispiro‐1,2,4‐trioxolanes.
Concave Reagents, 71) Concave Benzoic Acids
Authors: Lüning Ulrich , Wangnick Carsten , Peters Karl , Schnering Hans Georg Von
Published: July 2007

Based on m‐terphenyl units, concave benzoic acids 11a and 12a were prepared via the 2,6‐diarylbenzoic acid 7a. Bromination of 7a with NBS gave 9, and cyclization of 9 with dithiols 10 led to the bimacrocyclic concave acids 11a and 12a. Their relative acidities were determined by photometric titrations in ethanol, and the three‐dimensional structure of 11a was determined by X‐ray analysis.
Schwefel(IV)‐Verbindungen als Liganden, XIII. Schwefeldioxid als Brückenligand in unsymmetrischen Zweikernkomplexen
Authors: Schenk Wolfdieter A. , Hilpert Georg H. J.
Published: July 2007

Sulfur(IV) Compounds as Ligands, XIII. – Sulfur Dioxide as a Bridging Ligand in Unsymmetrical Dinuclear Complexes

A series of known or newly synthesized dinuclear complexes with the following combinations of elements: Mo/Ir, Mo/Pd, W/Pd, Mn/Pd, Fe/Rh, Rh/Pt, Ir/Pd, and Ir/Pt has been treated with sulfur dioxide. Only electron‐rich systems are capable of taking up SO2 into a bridging position. [Mo(CO)3(η2‐dppe) (η1‐dppm)] (2) reacts with [PdCl2(C8H12)] to form [MoPdCl2(CO)3(dppe)(μ‐dppm)] (3), which is unstable and does not take up SO2. However, the complexes [FeRhCl(CO)4(μ‐SO2)(μ‐dppee)] (5), [MoIr(μ‐Cl)(CO)3(μ‐SO2)(μ‐dppm)2] (8), and [MnPdBr(CO)2(μ‐SO2)(μ‐dppm)2] (14) have been obtained. Reactions of fac;‐[M(CO)3(η2‐dppm)(η1‐dppm)] (MMo: 6a, W: 6b) or the corresponding mer‐isomers 10a, b with [PdCl2;‐(C8H12)] give the dinuclear complexes [MPdCl(μ‐Cl)(CO)2(μ‐CO)(μ‐dppm)2] (11a, b). From [Ir(CO)(dppm)2]Cl and [Pd(dba)2] in the presence of CO [IrPdCl(CO)2(μ‐dppm)2] (16) is obtained, whereas in dichloromethane under an inert gas the oxidation product [IrPdC]3(CO)(μ‐dppm)2] (17) is formed. 11a, b, 16, and 17 apparently are too electron‐poor to form stable adducts with SO2. However, from 17 and (Me3Si)2S the sulfur‐bridged complex [IrPdCl(μ‐S)(CO)(μ‐dppm)2] (18) is obtained. The alkynyl complexes [MPtCl(CCPh)2(μ‐dppm)2] (M  Rh: 19, Ir: 21) readily add SO2, reversibly in the case of 19. From [IrPtCl‐(C  CPh)2(μ‐SO2)](μ‐dppm)2] (22) the salt [IrPt(C  CPh)2(SO2) (μ‐dppm)2]PF6 (23) is formed by Cl abstraction. 23 is one of the rare examples of terminal coordination of SO2 in a dinuclear complex.
Medizinisch interessante Metallchelate, III. 99mTc‐Komplexe mit vierzähnigen Dibrenzkatechin‐Liganden
Authors: Ekkehardt Hahn F. , Rupprecht Stefan
Published: July 2007

Metal Chelates of Medical Interest, III. – 99mTc Complexes with Tetradentate Dicatechol Ligands

The dicatechol ligand bis[3‐(2,3‐dihydroxyphenoxy)propyl]‐amine hydrochloride, DIPACE (6), reduces the 99m[TcO4]− ion to lower valent 99mTc and subsequently forms a complex with the reduced 99mTc. The structure of benzylbis[3‐(2,2‐dimethyl‐1,3‐benzodioxol‐4‐yloxy)propyl]amine (4) is determined by X‐ray crystallography.
Synthesis of Monosubstituted [1.1.1]Propellanes
Authors: Bothe Harald , Schl üter Arnulf‐Dieter
Published: July 2007

The synthesis (up to the 10‐g scale) and purification of alkyl‐ and methoxyalkyl‐substituted [1.1.1]propellanes are described.
The Azo/Nitrene Route to cis,cis‐Trialkyltriaziridines, 1 Synthesis of syn‐Azo Azides of Defined Proximity
Authors: Marterer Wolfgang , Klingler Otmar , Thiergardt Regina , Knothe Lothar , Prinzbach Horst
Published: July 2007

Bi‐ and polycyclic syn‐azo azide substrates H, 5, 14 and I, 15–18, 36, 41d, respectively, of varying rigidity and proximity (with the potential nitrene nitrogen atom in the π plane of the azo function) are prepared in order to synthesize kinetically stabilized cis,cis‐trialkyltriaziridines.
Photochemical Transformations, 75. The Azo/Nitrene Route to cis,cis‐Trialkyltriaziridines, 21b) Photolysis of syn‐Azo Azides of Defined Proximity – Attempts for N3 → N3X Ring Enlargement
Authors: Marterer Wolfgang , Klingler Otmar , Thiergardt Regina , Beckmann Eberhard , Fritz Hans , Prinzbach Horst
Published: July 2007

The as yet unknown route to triaziridines by the addition of nitrenes to the π side of the NN bond is achieved intramolecularly by the photolysis (thermolysis) of syn‐azo azide substrates with high proximity; the yields reflect the sterical (and possibly inductive) influences of the skeleton. The product composition is rather independent of the exciting light; intramolecular azo → azide energy transfer is assumed. The kinetic skeleton stabilization of the triaziridines permits the synthesis of 17 (18) by the thermolysis of 7 (8) at 200°C with the product composition deviating only marginally from that of the photolysis. Attempts towards enlargement of the triaziridines to N3X rings (XCHR, O, NR) lead exclusively to products of intramolecular fragmentation.
A Macrocyclic Tetraazapolyene – Synthesis and Configuration
Authors: Thilgen Carlo , Vögtle Fritz
Published: July 2007

The new macrocyclic bis(azine) 2 forming yellow microcrystals has been prepared in 72% yield by treating the diketone 1 with hydrazine hydrate under high‐dilution conditions. In contrast to the UV/Vis spectrum of the “open‐chain” azine 4, that of 2 shows characteristic features of a polyene chromophore containing (Z)‐configurated double bonds.
Tellurium Cations by Lewis Acid‐Base Reactions: Syntheses and Crystal Structures of (Te24⊕)Zr2Br210⊖ and (TeBr3p⊕)(Zr2Br9⊖)
Authors: Beck Johannes
Published: July 2007

ZrBr4 reacts with Te2Br in a sealed evacuated ampoule at 210°C in quantitative yield to afford (Te24⊕)(Zr2Br210⊖) as blueblack, moisture‐sensitive crystals. The crystal‐structure determination shows, that (Te4)(Zr2Br10) consists of planar, nearly square Te24⊕ and Zr2Br210⊖ ions, that form edge‐sharing double octahedra. Both ions possess crystallographic 2/m (C2h) symmetry. At temperatures above 250°C (Te4)(Zr2Br10) decomposes with cleavage of Te –Te bonds into (TeBr3⊕)(Zr2Br9⊖), which forms yellow, hygroscopic crystals. (TeBr3)(Zr2Br9) can also be obtained by the reaction of two equivalents of ZrBr4 with TeBr4 at 260°C. The crystal structure is built of Zr2Br9⊖ ions, that form face‐sharing double octahedra, and of pyramidal TeBr3⊕ ions. Each TeBr3⊕ ion exhibits three Te – Br contacts to two different Zr2Br9⊖ ions, resulting in a strongly deformed octahedral coordination for the Te atom. The Zr2Br9 double octahedra and the TeCl6 octahedra are connected by common edges and corners to infinite chains.
On the Reactivity of [(Mes)Os(CO)Cl2] Toward Grignard Reagents. Unexpected Formation and X‐ray Crystal Structure of [(Mes)Os(cyclohexene)(CO)]
Authors: Werner Helmut , Stahl Stefan , Schulz Michael
Published: July 2007

Reaction of [(Mes)Os(CO)Cl2] (3) with PhLi in benzene gives the diphenylosmium compound [(Mes)OsPh2(CO)] (6) whereas with PhMgBr [(Mes)OsPh(CO)Br] (7) is obtained. Treatment of 3 with TolMgBr in benzene or ether affords almost exclusively the monoaryl complex [(Mes)OsTol(CO)Br] (8). Compound 3 reacts with C6H11MgCl to give both [(Mes)Os(C6H11)2(CO)] (9) and [(Mes)Os(C6H10)(CO)] (10) in 60 and 30% yield, respectively. With C6H11MgBr, complex 10 is mainly obtained. Reaction of 7 and 8 with Na/Hg in THF/EtOH gives nearly quantitatively the arylhydridoosmium complexes [(Mes)Os‐C6H4R(CO)H] (14, 15). The analogous hydrido methyl compound [(Mes)OsCH3(CO)H] (13) reacts with CCl4 to produce [(Mes)OsCH3(CO)Cl] (17), which is not accessible from 3 and LiCH3 or CH3MgX. The X‐ray structure analysis of 10 reveals that the cyclohexene is coordinated in the endo configuration.
Synthese von Imidodiphosphaten des Aluminiums, Galliums, Indiums, Zinns und Titans
Authors: Mazzah Ahmed , Gosink Hans‐Jürgen , Liebermann Johannes , Roesky Herbert W.
Published: July 2007

Synthesis of Imidodiphosphates of Aluminum, Gallium, Indium, Tin, and Titanium.

Me3SiN[P(O)Cl2]2, (1) and Me3SnN[P(O)Cl2]2 (2) are synthesized from NaN[P(O)Cl2]2 and Me3SiCl or Me3SnCl, respectively. Treatment of 1 with AlCl3, GaCl3 InCl3, Me2SnCl2, and TiCl4 yields (3), (4), (5), (6), and (7), respectively. Reaction of LiN[P(O)Ph2]2 with TiCl4 leads to (8). NMR spectra demonstrate that the tetrachloroimidodiphosphate ligand coordinates through the oxygen atoms towards the metal atom.
[K{V4O4(μ‐O)4(μ‐O2CCH2tBu)4}] [O2CCH2tBu] · 2 tBuCH2CO2H, ein Kaliumkomplex eines „anorganischen Kronenethers”︁
Authors: Priebsch Wolfgang , Rehder Dieter , Oeynhausen Maren Von
Published: July 2007

[K{V4O4(μ‐O)4(μ‐O2CCH2tBu)4}][O2CCH2tBu] · 2 tBuCH2CO2H, a Potassium Complex of an “Inorganic Crown Ether”

The reaction of VOCl3 with Ag/KO2CCH2tBu yields the title compound (characterized by crystal and molecular structure analyses), which is the first oligonuclear vanadium complex with monofunctional carboxylate containing Vv centres exclusively. The potassium ion is coordinated by two planes of O2;−: the four μ‐oxo bridges of the puckered V4(μ‐O)4 ring and the plane spanned by the eight oxygen functions of the bridging carboxylate ligands, from wich it protrudes only slightly.
Small and Medium Rings, 74. Syntheses and Photoelectron Spectra of 7‐Azanorbornadiene and Related Compounds An Analysis with Fragment Orbitals
Authors: Altenbach Hans‐Josef , Martin Hans‐Dieter , Mayer Bernhard , Müller Monika , Constant Dieter , Vogel Emanuel
Published: July 2007

The He(I) photoelectron spectra (PE) of 7‐azanorbornane (5), 7‐azanorbornene (6), and 7‐azanorbornadiene (7) as well as of related urethanes have been recorded. The syntheses of these bicyclic compounds are described in detail. A most convenient analysis of the PE spectroscopic results is based on the procedure of Heilbronner‐Schmelzer on an ab initio STO‐3G level. This method allows to construct fragment orbitals elucidating the orientation of the nitrogen lone pair, the through‐space interaction with π bonds, and the participation of σ bond orbitals. The result is remarkable: whereas the direct interaction of localized lone‐pair and π orbitals is significant in both syn;‐ and anti‐orientation, the interaction of a localized lone pair with a precanonical fragment π orbital is completely different in the two geometries. In 6;‐syn a considerable interaction matrix element FantiΨnπ=−0.71 eV comes to the fore, whereas the corresponding parameter in 6;‐anti turns out to be almost zero, FantiΨnπ=+ 0.09 eV. Since 6;‐syn is calculated to be more stable than 6;‐anti, it is this invertomer, 6;‐syn, which is likely to be responsible for the main bands in the PE spectrum of 6. The comparatively large experimental split between the first two PE bands of 6 (0.98 eV) is in accord with the 6;‐syn geometry and compares well with the calculated band separation of 1.26 eV for 6;‐syn.
Bisaxial koordinierte (Tetraphenylporphinato)eisen(II)‐Komplexe
Authors: Mezger Martin , Hanack Michael , Hirsch Andreas , Kleinw ächter Jörg , Mangold Klaus‐Michael , Ramaswami Subramanian L.
Published: July 2007

Bisaxially Coordinated (Tetraphenylporphinato)iron(II) Complexes

The coordination behavior of (tetraphenylporphinato)iron(II) (TPPFe) has been studied with the preparation of the monomeric complexes TPPFe(L)2 with Lpy (pyridine), pyz (pyrazine), 2,6‐dimepyz (2,6‐dimethylpyrazine), bpy (4,4′‐bipyridine), bpyac [1,2‐bis(4‐pyridyl)acetylene], dabco (1,4‐diazabicyclo [2.2.2]octane), and BzINC (benzyl isocyanide). Pure TPPFe has been obtained by thermal decomposition of TPPFe(py)2. The monomeric complexes TPPFe(L)2 with Lpyz, bpy, bpyac, and dabco can be transformed into the bridged systems [TPPFe(L)]n by heating them in toluene or chlorobenzene. The bridged structure of the complexes [TPPFe(L)]n has been confirmed by IR and TG/DTA investigations and especially by Mößbauer spectroscopy. In comparison with the corresponding (phthalocyaninato)iron compounds the bridged TPPFe complexes exhibit lower semi conducting properties even after doping with iodine.
OrganosubstituierteBicyclen undMonocyclen aus 2,5‐Dihydro‐1,2,5‐oxasilaboratolaten
Authors: Köster Roland , Seidel Günter , Müller Gerhard
Published: July 2007

OrganosubstitutedBicyclic and Monocyclic Compounds from 2,5‐Dihydro‐1,2,5‐oxasilaboratolates1a)

The potassium salts of the cyclic anions of (A: R, R′ = CH3; B: R = C2H5, R′ = CH3; C: R = C6H5, R′ = CH3 react with [(CH3)2NCH2]Br in THF to yield the bicyclic compounds 1a (X‐ray crystal structure analysis), 1b/1b' (endo/exo‐C2H5), and 1c/1c' (endo/exo‐C6H5). D (RCH3, R'=C6H5) reacts with [(CH)32NCH2]Br to form a 1:4 mixture of 1d together with the heterocycle (3d) with elimination of (CH3)2N‐C3H7. – From A – D and CIP(C6H5)2 the six‐membered heterocycles (2a−d) are obtained in yields of ca. 90%.
Addition anorganischer und organischer Nucleophile an den Vinyliden‐Liganden des Clusters FeCo2(CO)9(μ3‐CCH2)
Authors: Albiez Thomas , Heineke Daniel , Vahrenkamp Heinrich
Published: July 2007

Addition of Inorganic and Organic Nucleophiles to the Vinylidene Ligand of the Cluster FeCo2(CO)9(μ3‐CCH2)

The CCH2 ligand of the cluster FeCo2(CO)9(μ3‐CCH2) (1) is electrophilic at the terminal C atom. Soft inorganic nucleophiles [Nu – PR3, (CH3)2SO, CN−, SCN−] are added to form the zwitterionic complexes FeCo2(CO)9(μ3‐C–CH2–Nu) (4, 7, 8), as proved by the structure determination of FeCo2(CO)9(μ3‐CCH2 – PMe3) (4a). The products are of low thermal stability. Upon heating, the PR3 derivatives rearrange to the CO substitution products FeCo2(CO)8(PR3)(μ3‐CCH2) (5, 6). C–C coupling is achieved by addition of malonic ester anion derivatives [X – CH – CO2Me] (XMeO2C, CN, Br). The anionic addition product for XMeO2C (10a) can be protonated to form HFeCo2(CO)9[μ3 CCH2 – CH(COOMe)2] (11) which liberates H2 upon warming resulting in FeCo2(CO)9[μ3‐CCH – CH(COOMe)2] (12). Thus, a substitution of a vinylidene H atom has been performed by an HX addition/H2 elimination sequence. Phosphorus ylides R3PCHX [XH, SiMe3, Cl, CHO, C(O)Ph, COOR] are also added with CC coupling to yield the complexes FeCo2(CO)9(μ3‐CCH2 – CHX – PR3) (15, 16). The structure determination of the compound with XEtO2C and RPh (16c) proves that these complexes differ from the complexes 4 just by insertion of one methylene unit.
Diazadienkomplexe elektronenarmer übergangsmetalle: Synthese, Eigenschaften und Struktur von CpTi(diazadien)Cl
Authors: Scholz Joachim , Thiele Karl‐Heinz , Dietrich Andreas , Schumann Herbert
Published: July 2007

Diazadiene Complexes of Electron‐Deficient Transition Metals: Synthesis, Properties, and Structure of CpTi(diazadiene)Cl

The electron‐deficient 1,4‐diazadiene (DAD) complex CpTi‐(DAD)Cl (3), [DAD=1],4‐bis(4‐methoxyphenyl)‐2,3‐dimethyl‐1,4‐diazabutadiene] is prepared either by reduction of CpTiCl3 (1) with magnesium in the presence of free DAD (2) or by the reaction of 1 with Na2DAD. NMR spectroscopic and X‐ray diffraction analysis of 3 indicate that the bonding of the DAD ligand has σ2,π‐metallacyclopentene rather than η4;‐π character. As a result of steric repulsion between the Cp ring and methyl groups of the DAD ligand 3 exhibits a supine (exo) geometry for DAD coordination is solid state. Substitution reaction of 3 affords the novel complex CpTi(DAD)R (RCH2Ph).
Darstellung und Struktur von Thallium(I)‐2,4,6‐tris(trifluormethyl)thiophenolat, einer Verbindung mit faltblattartig‐polymerem Aufbau
Authors: Labahn Dieter , Phol Ehmke , Herbst‐Irmer Regine , Stalke Dietmar , Roesky Herbert W. , Sheldrick George M.
Published: July 2007

Preparation and Structure of Thallium(I) 2,4,6‐Tris(trifluoromethyl thiophenolate, a Compound with a Folded Polymeric Structure

The title compound, thallium(I) 2,4,6‐tris(trifluoromethyl)thiophenolate (1) has been prepared by using either TlOEt and (CF3)3C6H2SH or Tl2CO3 and (CF3)3C6H2SNa. A single X‐ray structural analysis shows a folded polymeric structure for 1; the crystal lattice incorporates half of a 1,4‐dioxane molecule per Tl atom. This compound has a surprisingly high kinetic stability compared to known thallium(I) thiolates.
Additionsreaktionen an intramolekular basenstabilisierte GeN‐ und GeS‐Doppelbindungen
Authors: Veith Michael , Detemple Astrid , Huch Volker
Published: July 2007

Addition Reactions of Intramolecularly Base‐Stabilized GeN and GeS Double Bonds.

The GeN bond of 1 adds hydrogen chloride, ethanol, tert‐butyl alcohol, methyllithium, and methyl iodide to form 3–6 and 8. The GeS bond in 2 analogously adds methyl iodide to yield 10. In the resulting products the electropositive part of the polar reactand is bound to nitrogen or sulfur, while the electronegative one is on the germanium atom. In the lithium derivative 6 and in the iodine derivative 8 Li and I can be replaced by hydrogen to form two isomers of the same composition 7 and 9, which differ only in the positions of the hydrogen and methyl groups with respect to Ge or N. The X‐ray structure analyses on 4, 9, and 10 reveal that the germanium atom is fourfold coordinated by two nitrogen atoms and two other ligands. The intramolecular nitrogen base of the silazyl moiety in 1 and 2 is, thus, expelled from the coordination sphere of germanium by insertion of the double bonds into polar σ bonds, and the tricyclic molecule is changed to a bicyclic one. Thus these “base stabilized π bonds” in 1 and 2 behave as normal unsaturated systems.
Beiträge zur Chemie des Phosphors, 215. Einfache Darstellung des Pentaphosphacyclopentadienid‐Ions, cyclo‐P⊖5, durch Abbau von rotem Phosphor mit Kaliumdihydrogenphosphid
Authors: Baudler Marianne , Etzbach Thomas
Published: July 2007

Contributions to the Chemistry of Phosphorus, 215. – Simple Preparation of the Pentaphosphacyclopentadienide Ion, cyclo‐P⊖5, by Degradation of Red Phosphorus with Potassium Dihydrogenphosphide

The pentaphosphacyclopentadienide ion 1 is easily obtained in the form of a KP5 solution by the reaction of red phosphorus with potassium dihydrogenphosphide (1.9:1) in boiling dimethylformamide. The IR absorption at ṽ = 815 cm−1 previously observed for NaP5/[18]crown‐6/THF solutions is not to be assigned to 1. The formation of 1 in the degradation process of red phosphorus is discussed.
Reaktion von KSi mit M(CO)6 (MCr, Mo, W) und Cr(CO)5NMe3 – Struktur von [K(DME)2]2[Cr2(CO)10] (DME=1,2‐Dimethoxyethan)
Authors: Hey‐Hawkins Evamarie , Schnering Hans Georg Von
Published: July 2007

Reaction of KSi with M(CO)6 (MCr, Mo, W) and Cr(CO)5NMe3 – Crystal Structure of [K(DME)2]2[Cr2(CO)10] (DME=1.2‐Dimethoxyethane)

M(CO)6 (MCr, Mo, W) and Cr(CO)5NMe3 are reduced by KSi in DME during several days with formation of the anions [M2(CO)10]2⊖. These can be obtained from a DME/toluene solution as pale yellow or orange crystals of [K(DME)2]2[M2(CO)10] [MCr (1), Mo (2), W (3)]. A crystal structure determination of the chromium compound shows that strong interactions between the [Cr2(CO)10]2⊖ and the K⊕ ions exist in the solid state, leading to the formation of one‐dimensional polymeric chains. 2 and 3 are isomorphous to 1 (powder diffraction, Rietveld method).
Chiral Organometallic Reagents, III. On the Configurational Stability of α‐Bromoalkyllithium Compounds
Authors: Hoffmann Reinhard W. , Bewersdorf Martin
Published: July 2007

The carbenoids 2 undergo at ‐110°C a bromine/lithium exchange reaction with 1,1‐dibromo alkanes. This leads to partial equilibration of the carbenoids 2 during their generation from the 1,1‐dibromo compound 1. In the absence of the precursor 1, the carbenoids 2 have been found to be configurationally stable at ‐110°C.
4,9,14,19‐Tetrafunctionalized Pagodanes de novo Synthesis – Functional Group Manipulations
Authors: Melder Johann‐Peter , Prinzbach Horst
Published: July 2007

Various 4,9,14,19‐tetrafunctionalized pagodanes are prepared by a de novo route commencing from appropriately substituted isodrin analogues (3, 4). With the 14,19‐dimethoxypagodane‐4,9‐dicarboxylic esters 30/31, isolated after 16 one‐pot operations (ca. 40 functional changes) in ca. 6.5% overall yield (ca. 84% per operation, ca. 93% per functional change), the scope for further functional group manipulations on the pagodane sphere is explored (e.g. diketone dicarboxylic ester 35, dimethoxy diketone 37, tetraketone 41). In two face‐to‐face dibenzo substrates (17, 49), clean photoequilibration with the corresponding syn‐o,o'‐dibenzo isomers (19, 50) (75: 25 and 80: 20, resp.) is observed upon direct excitation (λ=254 nm).
Photolysis of Diazo(pentamethyldisilanyl)methyl Ketones in the Presence of Carbonyl Compounds: Trapping of the Acylsilene Intermediates
Authors: Maas Gerhard , Alt Mechthild , Schneider Klaus , Fronda Antonio
Published: July 2007

UV photolysis of diazo(pentamethyldisilanyl)methyl ketones 1b – d generates acylsilenes (3‐oxo‐1‐sila‐1‐propenes) 3 as reactive intermediates, which can be trapped by enolizable carbonyl compounds in an ene‐type reaction. With non‐enolizable carbonyl compounds or ethyl acetate, they undergo a [4 + 2] cycloaddition. In contrast to the photolysis in the absence of these carbonyl compounds, a Wolff rearrangement of 1b – d (or the derived carbenes) to silyl ketenes 5b – d is observed as a competitive reaction.
Bis[2,3‐naphthalindiolato(2–)](pyrrolidiniomethyl)silicat‐Acetonitril‐Solvat: Synthese sowie Kristall‐ und Molekülstruktur eines zwitterionischen λ5‐Spirosilicats
Authors: Tacke Reinhold , Sperlich Jöurg , Strohmann Carsten , Mattern Güunter
Published: July 2007

Bis[2,3‐naphthalenediolato(2—)](pyrrolidiniomethyl)silicate Acetonitrile Solvate: Synthesis and Crystal and Molecular Structure of a Zwitterionic λ5‐Spirosilicate

The zwitterionic spirocyclic bis[2,3‐naphthalenediolato[2–)](pyrrolidiniomethyl)silicate (3) was synthesized and the crystal and molecular structure of its acetonitrile solvate 3 · CH3CN investigated. 3 was prepared by reaction of trimethoxy(pyrrolidinomethyl)silane (8) or dimethoxy(methyl)(pyrrolidinomethyl)silane (8) or dimethoxy(methyl)(pyrrolidinomethyl)silane (9) with 2,3‐dihydroxynaphthalene in acetonitrile. Reaction 9 → 3 involves a remarkable Si—C cleavage with formation of CH4. The pentacoordinate silicon atom of 3 · CH3CN is surrounded by 4 oxygen atoms and 1 carbon atom, the latter being in an equatorial position. The coordination polyhedron can be described as a distorted trigonal bipyramid (the structure is displaced by 20.5% from the trigonal bipyramid towards the square pyramid). The crystal lattice of 3·CH3CN contains centrosymmetric dimers of 3, built up by intermolecular N—H … O hydrogen bonds.
Darstellung, Struktur und Komplexierung von 2,2′,5,5′‐Tetrahydro‐1,1′‐bi(1H‐1,2,5‐phosphadiborol)‐Derivaten
Authors: Drieß Matthias , Frankhauser Pascal , Pritzkow Hans , Siebert Walter
Published: July 2007

Synthesis, Structure, and Complexation of 2,2′,5,5′‐Tetrahydro‐1,1′‐Bi(1H‐1,2,5‐phosphadiborole) Derivatives

Reactions of (Z)‐1,2‐diborylethenes [HC — B(Cl)R]2 with LiPH2 and LiP(SiMe3)2 lead to the 2,5‐dihydro‐1H‐1,2,5‐phosphadiboroles 1a — d in good yields. 1a, b react with (Me3C)2Hg to give yellow 2a (56%) and 2b (90%), which are also obtained from 1c, d and TlCl or C2Cl6, respectively. The constitution of 2b is established by an X‐ray structure analysis. 2a reacts with Cr(CO)3(CH3CN)3 to yield the bis(pentacarbonyl)chromium complex 4a, whereas 2b and Fe(CO)3(C8H14)2 form the bis(tricarbonyliron) compex 5b. Spectroscopic studies and X‐ray structure analyses of 4a and 5b show that in 4a the chromium atom is η1‐bound to phosphorus, whereas in 5b the iron interacts with all atoms of the folded C2B2P ring.
Chemie des Dicyans: Reaktionen von Diiminosuccinonitril (DISN) mit Sulfenylchloriden und Chlortrimethylsilan sowie Cyclisierung zu Trifluormethyl‐substituierten 2H‐Imidazolen
Authors: Sundermeyer Jörg , Roesky Herbert W.
Published: July 2007

Chemistry of Cyanogen: Reactions of Diiminosuccinonitrile (DISN) with Sulfenyl Chlorides, Chlorotrimethylsilane and Ring Closure to Trifluoromethyl‐Substituted 2H‐Imidazoles

4,5‐Dicyano‐2‐hydroxy‐2‐(trifluoromethyl)‐2H‐imidazole (1) is easily prepared by treating DISN with trifluoroacetic anhydride. In the presence of 4‐(dimethylamino)pyridine, however, the O‐acylated derivative 2 is formed in excellent yield, while the reaction of 1 with chlorotrimethylsilane affords the O‐silylated product 6. A bi‐1,2,5‐thiadiazole of the formula S2(CN)4Cl2 (5) is the final reaction product, when DISN is treated with sulfur dichloride in the presence of “naked” chloride ions. On the other hand the non‐heterocyclic N‐sulfenyl derivative 4 has readily been obtained, when DISN is treated with F3CSCl instead. Finally a procedure is described to convert DISN into the corresponding N‐silylated diimine 3.
Synthese und Strukturen von Imidotitanverbindungen — Steuerung der Bildung monomerer und dimerer Spezies durch Änderung der Basizität des Lösungsmittels
Authors: Roesky Herbert W. , Raubold Thomas , Witt Michael , Bohra Rakesh , Noltemeyer Mathias
Published: July 2007

Synthesis and Structures of Imidotitanium Compounds — Directing the Monomer‐Dimer Formation by Changing the Basicity of the Solvents

The reaction of (i‐Pr)2PN(SiMe3)2 (1) with elemental sulfur leads to (i‐Pr)2P(S)N(SiMe3)2 (2). Compound 2 reacts with TiCl4 with elimination of chlorotrimethylsilane to yield the adducts [(i‐Pr)2P(S)NTiCl2‐MeCN]2 (3) and (i‐Pr)2P(S)N = TiCl2.3py (4), crystallized from MeCN or pyridine, respectively. Compound 3 crystallises in the space group Pbca, 4 in the space group p&1macr;.
Metallkomplexe mit biologisch wichtigen Liganden, LX. Metallkomplexe von 3′‐Azido‐3′‐desoxythymidin (AZT) und 3′‐Isocyan‐3′‐desoxythymidin
Authors: Pill Thomas , Polborn Kurt , Kleinschmidt Andrea , Erfle Volker , Breu Walter , Wagner Hildebert , Beck Wolfgang
Published: July 2007

Metal Complexes of Biologically Important Ligands, LX. — Metal Complexes of 3′‐Azido‐3′‐deoxythymidine (AZT) and 3′‐Isocyano‐3′‐deoxythymidine

Metal complexes of N‐3‐deprotonated 3′‐azido‐3′‐deoxythymidine (AZT — H+), (AZT — H+)AuPR3 (R = Me, Et, Ph) (2, 3, 4), trans‐(AZT — H+)2Pd(NH3)2 (5), [(n‐Bu3P)(AZT — H+) M(μ‐Cl)2M(AZT — H+)(n‐Bu3P)] (M = Pd, Pt) (6, 7), trans‐(Ph3P)2Pd(AZT — H+)2 (8), cis‐(Ph3P)2Pt(AZT— H+)(Cl) (9), and complexes of 3′‐isocyano‐3′‐deoxythymidine (L), (Et3P)(L)‐ PdCl, (11), magnified image (12), (n‐Bu3P)(L)PtCl2 (13), [(Ph3P)2(L)PtCl](BF4) (14), (η5‐C5Me5)(L)RhCl2 (15), and (η5‐C5Me5)(L)IrCl2 (16) have been prepared and characterized by IR and NMR spectra, 2 by X‐ray crystallography. 2, 4, and 9 show an anti‐HIV activity very similar to AZT; 2 exhibits antiinflammatory activity.
Redox Properties of Diphosphanes
Authors: Niemann Jürgen , Schoeller Wolfgang W. , von der Gönna Volker , Niecke Edgar
Published: July 2007

Diphosphanes undergo electrochemical one‐electron oxidation. In case amino groups are at the phosphorus, the resulting distonic diphosphane radical cations disproportionate readily into a dication and a diphosphane; the former separates into two phosphenium cations.
Nitro‐ und Allyloxy‐substituierte helicale [2.2]Metacyclophane: Synthese, Circulardichroismus und Röntgen‐Kristallstrukturanalysen
Authors: Knops Peter , Windscheif Paul‐Michael , Vögtle Fritz , Roloff Albrecht , Jansen Martin , Nieger Martin , Niecke Edgar , Okamoto Yoshio
Published: July 2007

Nitro‐ and Allyloxy‐Substituted Helical [2.2]Metacyclophanes: Synthesis, Circular Dichroism and Crystal Structures

The preparations of the title compound 3a, intraannularly nitro‐functionalized, of the extraannularly substituted reference compound 3b, and of the sulfone 4 are described. Enantiomeric resolution of these helical phanes was accomplished on (+)‐PTrMA and cellulose tris(3,5‐dimethylphenyl)carbamate by HPLC. Racemization of the enantiomers of 3b is faster than that of the previously reported extraannularly substituted phanes. The crystal structure of 3a as well as that of the allyl ether 3d show severe distortions of the benzene rings; the CD spectrum of 3a is pointing at an intramolecular charge‐transfer complex, an effect that cannot be evaluated from the CD spectrum of 3b.
Synthesis and Properties of (Phthalocyaninato)ruthenium(II) with Bisaxially Coordinated Azanaphthalenes
Authors: Hanack Michael , Kang Young‐Goo
Published: July 2007

(Phthalocyaninato)ruthenium(II) (PcRu) reacts with different azanaphthalenes such as quinoxaline, 2‐methylquinoxaline, quinazoline, phthalazine, quinoline, pyrido[2,3‐b]pyrazine, pteridine, isoquinoline and 1,5‐naphthyridine to form the corresponding bisaxially coordinated PcRuL2 complexes 1–9. The IR, 1H‐NMR, UV/Vis, TG/DTA, and FD‐MS data are discussed in detail for all the complexes prepared.