Gottfried Huttner

ansa-metallocene derivatives: XI. Synthesis and crystal structure of a chiral ansa-titanocene derivative with trimethylene-bridged tetrahydroindenyl ligands☆

The chiral ansa-zirconocene derivative ethylenebis(4,5,6,7-tetrahydro-1-indenyl)-zirconium(IV) dichloride has been prepared by reaction of dilithiobis(indenyl)ethane with ZrCl4 and subsequent hydrogenation. The product has been shown to be the 1-R,S rather than meso-metal-ring linkage stereoisomer by an X-ray determination of the molecular structure.

ansa-Metallocene derivatives : Molecular structure and proton magnetic resonance spectra or methylene- and ethylene-bridged dicyclopentadienyltitanium compounds

Abstract The molecular structure of the methylene-bridged titanocene dichloride, CH2(C5H4)2TiCl2, and that of the novel, ethylene-bridged derivative, (CH2)2-(C5H4)2TiCl2 have been determined by X-ray diffraction methods. In these molecules the cyclopentadienyl ligands are highly restricted in their torsional mobility. An angle of 65° between the two ring planes, a CCC angle of 97.5° at the methylene carbon atom, and other geometrical data, indicate a high degree of strain in the methylene-bridged derivative, whereas the ligand geometry of the ethylene-bridged derivative does not deviate significantly from that of unbridged titanocene dichloride. 1H NMR spectra for ansa-titanocene derivatives of general type (CH2)n-C5H4)2TiX2 (n = 1–3, X = Cl, CH3, CO) are reported; the varying degrees of splitting between the high-field and the low-field portions of an A2B2 resonance pattern due to the cyclopentadienyl hydrogen atoms are interpreted in terms of bonding goemetries.

ansa-metallocene derivatives : XII. Diastereomeric derivatisation and enantiomer separation of ethylenebis(tetrahydronindenyl)-titanium and -zirconium dichlorides

Abstract Derivatisation of racemic ethylene-bridged bis(4,5,6,7tetrahydro-1-indenyl)-titanium and -zirconium dichlorides with O-acetyl- r -mandelic acid affords diastereomers which can be separately crystallised. Crystal and molecular structures of these diastereomers reveal different chelate ring conformations in the crystalline state. The separated diastereomers have been converted, via their dimethyl derivatives, into the corresponding titanocene and zirconocene dichloride enantiomers, the optical purity of these enantiomers has been demonstrated by their reconversion into the acetyl- r -mandelate derivatives.

Nackte hauptgruppenelemente als trigonal planar gebundene μ3-brückenliganden

Abstract In (LnM)2X-Hal compounds which contain a trigonally planar coordinated bridging element (X = P, As, Sb) stabilized by two 16-electron LnM fragments the halogen may be substituted by monovalent organometallic groups. In the resulting molecules the bridging X atoms are coordinated to three metal atoms in a trigonal planar fashion. The syntheses and properties of 12 species of this type (I–IX) are described. The reaction of Na2W2(CO)10 with XCl4 (X = Ge, Sn) leads to [(Co)5W]3(μ3-X) compounds containing trigonally planar coordinated Ge (X) and Sn (XI), respectively. The trigonal planar coordination of the Main Group elements X is confirmed by eight X-ray analyses.

The structure of (C 5 H 5 ) 2 W(CO) 2 a compound containing a bent trihapto-cyclopentadienyl ligand

Abstract The crystal and molecular structure of the complex (C5H5)2W(CO)2 has been determined by X-ray analysis R1 = 0.063). The structure contains a trihapto-cyclopentadienyl ligand, bent along its 1,3-axis by 20°. By this unusual structure, a 20-electron valence configuration of the central metal is avoided.

R—P-verbrückte eien-cluster-hydride

Abstract Trinuclear clusters RPFe 3 (CO) 9 H 2 (R = Ph, p -C 6 H 4 OCH 3 , C 6 H 11 , t-Bu CH 2 CH 2 CN) are obtained in fair yields by treatment of Fe 3 (CO) 12 with primary phosphanes, RPH 2 . X-ray structure analysis of PhPFe 3 (CO) 9 H 2 reveals a trigonal pyramidal frame-work for the cluster with an iron triangle at the base and the phosphorus atom at the apex. Two of the three FeFe bonds are bridged by hydrogens. Reaction of C 5 H 5 (CO) 2 MnP(C 6 H 5 )H 2 with Fe 3 (CO) 12 gives an improved yield of the known trinuclear heterometallic cluster C 5 H 5 (CO) 2 MnFe 2 (CO) 6 PC 6 H 5 .

Gezielte synthesen von zweifach μ3-verbrückten dreikernigen eisenclustern Fe3(CO)9(μ3-S)(μ3-X) (X = PR, AsR, SO) aus [Fe3(CO)9(μ3-S-t-C4H9)]−

Abstract The cluster anion [Fe 3 (CO) 9 (μ 3 -S-t-C 4 H 9 )] − , which is easily obtained by deprotonation from the cluster compound Fe 3 (CO) 9 (μ 2 -H)(μ 3 -S-t-C 4 H 9 ), reacts with XCl 2 by elimination of t-C 4 H 9 Cl and Cl − to give the clusters Fe 3 (CO) 9 (μ 3 -S)(μ 3 -X) (X = PR: I, X = AsR: II, X = SO: III), in which one edge of the iron triangle is opened. The μ 3 -PR-bridged clusters I can also be obtained by reactions of SCl 2 with the anions [Fe 3 (CO) 9 (μ 3 -PR)] 2− , prepared from Fe 3 (CO) 9 (μ 2 -H) 2 (μ 3 -PR) by deprotonation. The geometry of I and II is exemplified by X-ray structure analyses. Experimental evidence for a reaction pathway, proposed for the high yield syntheses of I, is discussed.

Syntheses and characterisation of [Os3(CO)11(PRH2)], [(μ2-H)Os3(CO)10(μ2-PRH)] (R = C6H5, p-CH3OC6H4, C6H11) and [(μ2-H)2Os3(CO)9(μ3-PR)] (R = C6H5, C6H11). Interconversion of cluster-bound phosphine and phosphido ligands. Crystal and molecular structures of [(μ2-H)Os3(CO)10(μ2-P(C6H5)H)] and [(μ2-H)2Os3(CO)9(μ3-PC6H5)]

Abstract Monoorganophosphines react with Os3(CO)12 in presence of trimethylamine oxide to give the phosphine-substituted cluster [Os3(CO)11(PRH2)] and the phosphido-bridged hydrido cluster [(μ2-H)Os3(CO)10(μ2-PRH)] (R = C6H5, p-CH3OC6H4, C6H11). The thermolysis of [Os3(CO)11(PRH)2)] gave, under different conditions, [(μ2-H)Os3(CO)10(μ2-PRH)] and [(μ2-H)2Os3(CO)9(μ3-PR)], and the thermolysis of [(μ2-H)Os3(CO)10(μ2-PRH)] gave [(μ2-H)2Os3(CO)9(μ3-PR)] (R = C6H5, C6H11). All the compounds have been studied by IR, NMR (31P and 1H) and mass spectrometry. The structures of [(μ2-H)Os3(CO)10(μ2-P(C6H5)H)] and [(μ2-H)2Os3(CO)9(μ3-PC6H5)] have been determined by X-ray crystallography. The results obtained for the system Os3(CO)12/PRH2 demonstrate a stepwise transformation of a terminally bonded PRH2 ligand to a doubly bridging μ2-PRH unit and finally to a triply bridging μ3-PR group by successive hydrogen transfer and CO substitution processes.

Phosphor-, arsen- und antinon-metallacyclen als komplexliganden

Abstract Complexes of the type L n M(PRCl 2 (L n M = (CO) 5 Cr or C 5 H 5 (CO) 2 Mn) give on treatment with Fe 2 (CO) 9 a series of chemically interrelated mixed metal clusters. In the present paper the synthesis, properties and structure of (CO) 5 Cr(PPh)Fe 2 (CO) 8 as well as its As- and Sb-homologues are described.

Dihalogenphosphankomplexe als metallorganische synthesebausteine

Abstract The dichlorophosphanes (R)P(Cl) 2 react with Fe 2 (CO) 9 to give (CO) 4 FeP(R)(Cl) 2 (I) in high yields. When treated with Fe 2 (CO) 9 in 2.5 M excess, compounds I give the μ 2 -chloro-μ 2 -chlorophosphido-bridged dinuclear molecules II, Fe 2 (CO) 6 (μ 2 Cl)(μ 2 -PRCl). Further treatment of II with Fe 2 (Co) 9 results in the formation of the trinuclear clusters IV, Fe 3 (CO) 10 (μ 3 -PR). Zinc reduction of II leads to V, Fe 4 (CO) 11 (μ 4 -PR) 2 . All of these reactions lead to fairly high yields for a variety of substituents R. The product selectivity is effectively controlled by the stoichiometry. The syntheses and properties of the main products I, II, IV and V, as well as those of the dinuclear side-products [(CO) 2 (Cl)(RPCl 2 )Fe(μ 2 -PRCl)] 2 (III), [(CO) 3 Fe(μ 2 -PRCl)] 2 (VI), and the trinuclear species (CO) 9 Fe 3 (μ 3 -PR) 2 (VII), are discussed.