Synthese und Eigenschaften der heteronuklearen Metallatomcluster Re4(CO)12[μ3-GaRe(CO)5]4 und Re2(CO)3[μ-GaRe(CO)5]2

Synthesis and Properties of Heteronuclear Metal Atom Clusters Re₄(CO)₁₂[μ₃-GaRe(CO)₅]₄ and Re₂(CO)₈[μ-GaRe(CO)₅]₂ The title compounds were prepared by the reaction of gallium halides and dirhenium decacarbonyl. Crystals of the four-membered cluster Re₂(CO)₈[μ-GaRe(CO)₅]₂ gave at 300⁰C with aggregation of four Re atoms to an inner Re₄ tetrahedron the product Re₄(CO)₁₂(CO)[μ₃-GaRe(CO)₅]₄and with Ga₂I₃ shown by mass spectroscopic measurements the molecule ion Re₄(CO)₁₆+. In tetra-hydrofuran solution the cluster Re₄(CO)₁₂[μ₃-GaRe(CO)₅]₄ and the hydride Li[C₂H₅)₃BH] have formed the formyl complex Li₄{Re₄(CO)₁₂[μ₃ -GaRe(CO)₄(CHO)] ₄}, which was estimated by ¹H n. m. r. and i. r. spectroscopic data. Both synthesized gallium rhenium carbonyl clusters were characterized by i.r. spectroscopic measurements. The comparison of these results with those of the structurally known indium rhenium carbonyl clusters led to proposals of the molecule structure of the analogous gallium rhenium compounds.     

Darstellung von μ-Hydrido-μ-diphenylphosphido-bis(tetracarbonylrhenium) · 1/2 Xylol und Molekülstruktur des Derivates Re2(CO)6(PPh3)2(μ-H)(μ-PPh2) (Ph = C6H5)

Preparation of μ-Hydrido-μ-diphenylphosphido-bis(tetracarbonylrhenium) · 1/2 Xylene and Molecular Structure of the Derivative Re₂(CO)₆(PPh₃)₂(μ-H)(μ-PPh₂) (Ph = C₆H₅) The reaction of dirhenium decacarbonyl with diphenylphosphine in xylene solution gave at 190–200°C in a glas tube crystals of Re₂(CO)₈(μ-H)(μ-PPh₂) · 1/2 C₈H₁₀. The obtained adduct was reacted in the same solvent with an excess of triphenylphosphine to the derivative Re₂(CO)₆(PPh₃)₂(μ-H)(μ-PPh₂). Both diamagnetic dirhenium compounds with μ-H atom and μ-PPh₂ group were characterized by ¹H and ³¹P spectroscopic measurements. The molecular structure of the derivative was acertained by a single crystal X-ray analysis. Its result showed a three-membered Re₂(μ-P) ring as central molecular fragment. At these Re central atoms were attached two PPh₃ ligands in an unprefered cis-arrangement due to sterical reasons. A thermodynamic transinfluence of the (μ-P)? Re bond favoured the found positions of the PPh₃ ligands.     

Zur Selektivität des isolobalen Protonenaustausches im Hydrido/Phosphidoverbrückten Dirhenium-Komplex Re2(μ-H)(μ-PCyH)(CO)8

On the Selectivity of the Isolobal Proton Exchange in the Hydrido/Phsophido Bridged Dirhenium Complex Re₂(μ-H)(μ-PCyH)(CO)₈ H₂PCy and Re₂(CO)₁₀ in Xylene were heated in a sealed glass tube at 170°C for 18 h to afford Re₂(μ-H)(μ-PCyH)(CO)₈ in a yield of 30% and the cis/trans isomer pair Re₂(μ-PCyH)₂(CO)₈ in yields of 27% (trans) and 21% (cis). The isomer trans Re₂(μ-PCyH)₂(CO)₈ could be partially converted to the cis isomer by deprotonation with the non nucleophilic base DBU or by heating in xylene solution. The complex Re₂(μ-H)(μ-PCyH)(CO)₈ which is bifunctional relative to a proton abstraction was treated with equimolar amounts of DBU to generate [Re₂(μ-H)(μ-PCy)(CO)₈]^? under release of the more acidic proton from the PH group. Subsequently, this anion undergoes an isomerization to the thermodynamically more stable [Re₂(μ-PCyH)(CO)₈]^? by proton transfer. Such knowledge about the isomeric anions enabled us to synthesize selectively the monoaurated isomers Re₂(μ-AuPPh₃)(μ-PCyH)(CO)₈ and Re₂(μ-H)(μ₃-PCy(AuPPh₃))(CO)₈ in good yields by reaction with equimolar amounts of the electrophil ClAuPPh₃. In the presence of excess DBU and a twofold amount of ClAuPPh₃ the complex Re₂(μ-H)(μ-PCyH) · (CO)₈ formed the diaurated complex Re₂(μ-AuPPh₃)(μ₃-PCy(AuPPh₃))(CO)₈ (91%). Compared to the corresponding known dimanganese-gold isomers, each of the analogous dirhenium-gold complexes obtained showed no tendency for an isomerization process. Finally, the single crystal X-ray analyses of the three dirhenium-gold complexes led to the subsequent Re? Re bond lengths: 313,6(1) pm in Re₂(μ-H)(μ₃-PCy(AuPPh₃))(CO)₈, 316,8(2) pm in Re₂(μ-AuPPh₃)(μ₃PCy(AuPPh₃))(CO)₈ and 326,1(2) pm in Re₂(μ-AuPPh₃)(μ-PCyH)(CO)₈.     

Halogenverbrückte Heterometallatomcluster der drei Typen Re2(CO)4L2(μ-X)2(μ-Y) (L = (C6H5)3P; X = Br,I; Y = GaRe(CO)4ax-L), Re2(CO)6L2(μ-X)(μ-GaX2) (X = I) und Re3(CO)9L3(μ-X)3(μ-Y) (X = Cl)

Halogeno-Bridged Heteronuclear Metal Atom Clusters of the Three Types Re₂(CO)₄L₂(μ-X)₂(μ-Y) (L = (C₆H₅)₃P; X = Br, I; Y = GaRe(CO)₄ax-L), Re₂(CO)₆L₂(μ-X) (μ-GaX₂) (X = I), and Re₃(CO)₉L₃ (μ-X)₃(μ₃-Y) (X = Cl) The title compounds of the both types Re₂(CO)₄L(μ-X)₂(μ-Y) [L = (C₆H₅)₃P; X = Br, I; Y = GaRe(CO)₄ax-L] and Re₃(CO)₉L₃(μ-X)₃ (μ₃-Y) (X = Cl) were prepared by the reaction of GaX₃ (X = Cl, Br, I) and Re₂(CO)₈(ax-L)₂ in boiling mesitylene solution. The obtained substance Re₂(CO)₄L₂(μ-I)₂(μ-Y) and carbon monoxide gave the compound of the third type Re₂(CO)₆L₂(μ-I)(μ- GaI₂). The last-named single iodo-bridged dirhenium cluster could be therefore a precursor complex of the double iodo-bridged compound. The four diamagnetic substances were characterized by ³¹P n.m.r. spectroscopy and their molecular structures were acertained by X-ray measurements. The result of the single crystal X-ray analysis of Re₂(CO)₄L₂(μ-Br)₂ [μ-GaRe(CO)₄ax-L], a bridged coordination octahedron pair with a common face, and that of the edge-bridged pair Re₂(CO)₆L₂(μ-I)(μ-GaI₂) each possessing a Re? Re bond are especially treated in the present work.     

Heteronukleare Metallatomcluster der Typen X4−n[SnM(CO)4P(C6H5)3]n und M2(CO)8 [μ-Sn(X)M (CO)4P(C6H5)3]2 aus Umsetzungen von SnX2 mit M2(CO)8[P(C6H5)3]2 (X = Halogen; M = Mn,Re; n = 2, 3)

Heteronuclear Metal Atom Clusters of the Types X_4?n[SnM(CO)₄P(C₆H₅)₃]_n and M₂(CO)₈[μ-Sn(X)M(CO)₄P(C₆H₅)₃]₂ by Reaction of SnX₂ with M₂(CO)₈[P(C₆H₅)₃]₂ (X = Halogene; M = Mn, Re; n = 2, 3) The compounds of the both types X_4?n[SnM(CO)₄P(C₆H₅)₃]_n (n = 3; M = Mn; X = F, Cl, Br, I. n = 2: M = Mn, Re; X = Cl, Br, I) and M₂(CO)₈[μ-Sn(X)M(CO)₄P(C₆H₅)₃]₂ (M = Mn; X = Cl, I. M = Re; X = Cl, Br, I) are prepared by reaction of SnX₂ with M₂(CO)₈[P(C₆H₅)₃]₂ (M = Mn, Re). Their IR frequencies are assigned. In Re₂(CO)₈[μ-Sn(Cl)Re(CO)₄P(C₆H₅)₃]₂ the central molecule fragment contains a planar Re₂Sn₂ rhombus with a transannular Re? Re bond of 316.0(2) pm. Each of the Sn^IV atoms is connected with the terminal ligands Cl and Re(CO)₄P(C₆H₅)₃. These ligands are in transposition with respect to the Re₂Sn₂ ring. The mean values for the remaining bond distances (pm) are: Sn? Re = 274.0(3); Sn? Cl = 243(1), Re? C = 176(5), Re? P = 242.4(9), C? O = 123(5). The factors with an influence on the geometrical shape of such M₂Sn₂ rings (M = transition metal) are discussed.     

Heterometallatom-Koordinationsverbindungen Re2(μ-PPh2)2[mer-(CO)3]2-trans-[InX2(H2O)]2 und neue halogenhaltige drei- und vierkernige Rheniumcluster aus Reaktionen zwischen Re2[μ-PPh2)2(CO)8] und InX3 (X = Cl,Br, I)

Heterometallic Coordination Compounds Re₂(μ-PPh₂)₂[mer-(CO)₃]₂-trans-[InX₂(H₂O)]₂ and New Halogene Containing Three- and Four-Nuclear Rhenium Clusters from Reactions between Re₂(μ-PPh₂)₂(CO)₈ and InX₃ (X = Cl, Br, I) In sealed glass tubes equimolar amounts of Re₂(μ-PPh₂)₂(CO)₈ and InX₃ (X = Cl, Br, I) were reacted in the presence of xylene at 220°C to two types of products. The first type comprised the heterometallic coordination compounds Re₂(μ-PPh₂)₂(CO)₆[InX₂(H₂O)]₂ (X = Cl, Br, I) (yield 60%), and the second halogene containing rhenium complexes Re₃(μ₃-H)(μ₃-X)(μ-PPh₂)₃(CO)₆ (unsaturated three-membered metal ring with 46 VE) and Re₄(μ-H)(μ-X)(μ-PPh₂)₄(μ₄-PPh)(CO)₈ and additionally those substances as cis-IRe(CO)₄(PPh₂H), Re₂(μ-PPh₂)(μ-X)(CO)₈ (X = Cl, Br), Re₂(μ-I)₂[μ-(PPh₂)₂O](CO)₆ and Re₄(μ-Cl)₂(μ-PPh₂)₄(μ₄-PPh)(CO)₈ (four-membered metal ring with 66 VE with three Re? Re bonds) which have been observed in one or two of the three reaction systems. A proposal of the reaction course is discussed. The single X-ray analysis of Re₂(μ-PPh₂)₂[mer(CO)₃]₂-trans[InI₂(H₂O)]₂ · 2 Me₂CO shows for the two fold phosphido bridged dirhenium molecular fragment with 34 VE a Re? Re bond of 294.6(1) pm. From two possible transpositions of both In? Re bond vectors, the one found advantageously has sterical reasons. The average In? Re single bond length is 271.1(1) pm. The corresponding determination of the unsaturated three-membered ring compound Re₃(μ₃-H) (μ₃-Cl)(μ-PPh₂)₃(CO)₆ showed three Re? Re bond lenghts of comparable size, of which the mean value of 281.9(1) pm was significantly shortened by π electron delocalization effect compared to that of a saturated phosphido bridged three-membered rhenium ring compound. As it was recognized by further comparison, the structural data of the common molecular fragments in the three examined three-membered rhenium ring clusters (X = Cl, Br, I) are not dependent on the different kind of halogeno ligand atoms. Finally, the crystal structure determination of the substance Re₄(μ-H)(μ-Br)(μ-PPh₂)₄(μ₄-PPh)(CO)₈ shows the presence of square-pyramidal Re₄(μ₄-P) atomic arrangement, of which the planar basic plane has a sequence of up- and downwards orientated four diphenylphosphido bridging groups. The four measured Re? Re single bond lengths (mean value 302.7(3) pm change with the different kind of bridging atoms. The structural features observed are compared with those of a corresponding iodine derivative.     

Heterometallische Clusterkomplexe der Typen Re2(μ-PR2)(CO)8(HgY) und ReMo(μ-PR2)(η5-C5H5)(CO)6(HgY) (R = Ph,Cy; Y = Cl,W(η5-C5H5)(CO)3)

Heterometallic Cluster Complexes of the Types Re₂(μ-PR₂)(CO)₈(HgY) and ReMo(μ-PR₂)(η⁵-C₅H₅)(CO)₆(HgY) (R = Ph, Cy; Y = Cl, W(η⁵-C₅H₅)(CO)₃) Dinuclear complexes Re₂(μ-H)(μ-PR₂)(CO)₈ and ReMo(μ-H)(μ-PR₂)(η⁵-C₅H₅)(CO)₆ (R = phenyl, cyclohexyl) were deprotonated and reacted as anions with HgCl₂ to compounds of the both types Re₂(μ-PR₂)(CO)₈HgCl) and ReMo(μ-PR₂)(η⁵-C₅H₅)(CO)₆(HgCl). The heterometallic three-membered cluster complexes correspond to an isolobal exchange of a proton against a cationic HgCl⁺ group. For one of the products ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgCl) has been shown its conversion with NaW(η⁵-C₅H₅)(CO)₃ to ReMo(μ-PCy₂)(η⁵-C₅H₅)(HgW(η⁵-C₅H₅)(CO)₃) under substitution of the chloro ligand, par example. The newly prepared compounds were characterized by means of IR, UV/VIS and ³¹P NMR data. A complete determination of the molecular structure by single crystal analyses was done in the case of Re₂(μ-PCy₂)(CO)₈(HgCl) and of ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgCl) which both are dimer because of the presence of an asymmetric dichloro bridge, and of ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgW(η⁵-C₅H₅)(CO)₃). The structural study illustrates through comparison the influence of various metal types on an interaction between centric and edge-bridged frontier orbitals in three-membered metal rings.     

Zur Nucleophilie des sterisch anspruchsvollen Basenanions von Lithiumdiisopropylamid beim Protonenersatz gegen das isolobale AuPPh3-Kation in [(μ-H)(μ-PPh2) (CO)8Re2]

Nucleophilic Property of the Bulk Anion of the Base Lithium diisopropylamide at the Proton Exchange vs. the Isolobal AuPPh₃ Cation in [(μ-H) (μ-PPh₂) (CO)₈Re₂] The proton exchange in the starting material [(μ-H)(μ-PPh₂)(CO)₈Re₂] vs. the isolobal [AuPPh₃]⁺ cation when reacted with the steric expansive base LDA depending on reaction temperature leads to the three-membered metal ring substance [(μ-PPh₂)(CO)₈Re₂(AuPPh₃)] or the metallatetrahedron complex [(μ-C-(N i-Prop₂)O)(μ-PPh₂)(CO)₆Re₂(AuPPh₃)₂]. The tetrahedral cluster compound obtained through the nucleophilic property of LDA shows by means of cyclic voltammetry a reversible and a irreversible one-electron transfer redox step. The single crystal X-ray analysis of the compound with a tetrahedral Au₂Re₂ core gives following values of metal-metal bond lengths: Re? Re 312.2(2) pm, Au? Au 270.9(2) pm, and Au? Re 297.7(2) pm. The acyl diisopropylamido groups bridging the Re? Re bond is planar.     

Reaction of the unsaturated anion [Re3H4(CO)10]− with mercaptans. Synthesis and X-ray Characterization of the anion [ Re3H3 (CO)9(μ3-SBut)]−

The novel anion [Re₃H₃(CO)₉(μ₃-SBu^t)]^?, obtained by reaction of [Re₃H₄(CO)₁₀]^? with t-butyl mercaptan, has been characterized by IR, NMR and X-ray diffraction studies. It contains an equilateral Re₃ triangle (mean ReRe 3.091 Å), with nine terminal carbonyl groups, three for each metal atom, and a triply-bridging thiolate ligand (mean ReS 2.393 Å). The three hydrides are bridging on the edges of the triangle of metal atoms.     

Selektive Darstellung zweifach diorganophosphido-verbrückter Metallatetrahedrane [Re2(MPR3)2(μ-PR2)2(CO)6] mit Re2M2-Metallgerüst (M = Au,Ag)

Selective Preparation of Twofold Diorganophosphido-bridged Metallatetrahedranes [Re₂(MPR₃)₂(μ-PR₂)₂(CO)₆] with Re₂M₂ Metal Core (M = Au, Ag) The reaction of the in situ prepared salt Li[Re₂(AuPR)(μ-PR₂)(CO)₇Cl] (R = R′ = Cy ( 1 a ), R = Cy, R′ = Ph ( 1 b ), R = Ph, R′ = Cy ( 1 c ), R = Ph, R′ = Et ( 1 d ), R = Ph, R′ = Ph ( 1 e )) with one equivalent HPR in methanolic solution at room temperature yields the neutral cluster complexes [Re₂(AuPR)(μ-PR₂)(CO)₇(ax-HPR) (R = R′ = R″ = Cy ( 2 a ), Ph ( 2 b ), R = R′ = Cy, R″ = Et ( 2 c ), R = Cy, R′ = R″ = Ph ( 2 d ), R = Cy, R′ = Ph, R″ = Et ( 2 e ), R = R″ = Ph, R′ = Et ( 2 f ), R = Ph, R′ = Cy, R″ = Et (2 g)). Photochemically induced these complexes react in the presence of the organic base DBU in THF solution to give the doubly phosphido bridged anions Li[Re₂(AuPR)(μ-PR₂)(μ-PR)(CO)₆], which were characterized as salts PPh₄[Re₂(AuPR)(μ-PR₂)(μ-PR)(CO)₆] (R = R′ = R″ = Ph ( 3 a ), R = R′ = Ph, R″ = Cy ( 3 b ), R = Ph, R′ = Cy, R″ = Et ( 3 c ), R = R″ = Ph, R′ = Et ( 3 d )). These precursor complexes 3 then react with one equivalent of ClMPR (M = Au, Ag) to doubly phosphido bridged metallatetrahedranes [Re₂(MPR₃)₂(μ-PR₂)(μ-PR)(CO)₆] (M = Au, R = R′ = R″ = Ph ( 4 a ), M = Au, R′ = Et, R = R″ = Ph ( 4 b ), M = Au, R = R′ = Ph, R″ = Cy ( 4 c ), M = Au, R = Cy, R′ = Ph, R″ = Et ( 4 d ), M = Ag, R = R′ = R″ = Ph ( 4 e )). All isolated cluster complexes were characterized and identified by the following analytical methods: NMR- (¹H, ³¹P) and ν(CO) IR-spectroscopy and, additionally, complexes 2 b , 4 a and 4 e by X-ray structure analysis.     

An Unexpected Layered Structure in Inorganic Cyanide Clusters: [Cu4(μ3-OH)4][Re4(μ3-Te)4(CN)12]

Diffusion of aqueous solutions of K₄[Re₄Te₄(CN)₁₂] and CuCl₂ in the opposite direction through silica gel gives rise to the new polymer-like compound 1 . This complex has a layered structure built from the interconnected cubane-like cluster cations [Cu₄(μ₃-OH)₄]⁴⁺ and the cluster anions [Re₄Te₄(CN)₁₂]⁴⁻ (see picture).     

Tetrakis(μ2‐4‐aminobenzoato)di‐μ3‐oxido‐tetrakis[dibutyltin(IV)]

The molecule of the title compound, [Sn₄(C₄H₉)₈(C₇H₆NO₂)₄O₂], lies about an inversion centre and is a tetranuclear bis(tetrabutyldicarboxylatodistannoxane) complex containing a planar Sn₄O₂ core in which two μ₃‐oxide O atoms connect an Sn₂O₂ ring to two exocyclic Sn atoms. Each Sn atom has a highly distorted octahedral coordination. In the molecule, the carboxylate groups of two aminobenzoate ligands bridge the central and exocyclic Sn atoms, while two further aminobenzoate ligands have highly asymmetric bidentate chelation to the exocyclic Sn atoms plus long O...Sn interactions with the central Sn atoms. Each Sn atom is also coordinated by two pendant n‐butyl ligands, which extend roughly perpendicular to the plane of the Sn₄O₁₀ core. Only one of the four unique hydrogen‐bond donor sites is involved in a classic N—H...O hydrogen bond, and the resulting supramolecular hydrogen‐bonded structure is an extended two‐dimensional network which lies parallel to the (100) plane and consists of a checkerboard pattern of four‐connected molecular cores acting as nodes. The amine groups not involved in the hydrogen‐bonding interactions have significant N—H...π interactions with neighbouring aminobenzene rings.     

(PPh4)2[(SN)ReCl3(μ‐N)(μ‐NSN)ReCl3(THF)] – ein Nitrido‐Thionitrosyl‐Dinitridosulfato‐Komplex des Rheniums

(PPh₄)₂[(SN)ReCl₃(μ‐N)(μ‐NSN)ReCl₃(THF)] – a Nitrido‐Thionitrosyl‐Dinitridosulfato‐Complex of Rhenium The title compound has been prepared from PPh₄[Re^VIICl₄(NSCl)₂] with excess N(SiMe₃)₃ in dichloromethane solution to give red‐brown single crystals after recrystallisation from acetonitrile/THF solutions. As a by‐product PPh₄[ReNCl₄] is formed. (PPh₄)₂[(SN)ReCl₃(μ‐N)(μ‐NSN)ReCl₃(THF)] ( 1 ): Space group P2₁/n, Z = 4, lattice dimensions at –80 °C: a = 1024.1(1), b = 2350.2(1), c = 2315.4(2) pm, β = 94.09(1)°, R₁ = 0.0403. In the complex anion of 1 the rhenium atoms are connected by an asymmetric Re≡N–Re bridge as well as by a (NSN)^4–‐bridge to form a planar Re₂N(NSN) six‐membered heterocycle. Both rhenium atoms are coordinated by three chlorine atoms, one of them by a thionitrosyl ligand, the other one by the oxygen atom of a thf molecule.     

(PPh4)2[Cl2Re(N3S2)(μ‐NSN)(μ‐N≡ReCl3)]2 – ein Rhenium(VII)‐Komplex mit einer Nitrido‐, einer Dinitridosulfato(II)‐ und einer Rhena‐3,5‐dithia‐2,4,6‐triazino‐Funktion

(PPh₄)₂[Cl₂Re(N₃S₂)(μ‐NSN)(μ‐N≡ReCl₃)]₂ – a Rhenium(VII) Complex with a Nitrido, a Dinitridosulfato(II), and a Rhena‐3,5‐dithia‐2,4,6‐triazino Function The title compound has been prepared from PPh₄[Re^VIICl₄(NSCl)₂] with N(SiMe₃)₃ in dichloromethane solution to give red‐brown single crystals, which were suitable for a crystal structure determination. As a by‐product PPh₄[ReNCl₄] is formed. (PPh₄)₂[Cl₂Re^VII(N₃S₂)(μ‐NSN)(μ‐N≡Re^VIICl₃)]₂ ( 1 ): Space group P2₁/c, Z = 2, lattice dimensions at –80 °C: a = 1280.8(2), b = 1017.5(1), c = 2467.8(3) pm, β = 95.04(1)°, R = 0.049. The complex anion of 1 consists of a planar ReN₃S₂‐heterocycle which is connected with the second rhenium atom by a μ‐nitrido bridge as well as by a μ‐dinitridosulfato(II) ligand to form a planar Re₂(N)(NSN) six‐membered heterocycle. This [Cl₂Re(N₃S₂)(μ‐NSN)(μ‐N≡ReCl₃)]^– unit dimerizes via one of the N‐atoms of the (NSN)^4– ligand to give a centrosymmetric Re₂N₂ four‐membered ring.     

The new polynuclear titanium(IV) complex [(Cp*TiCl)(μ‐O)2(Cp*Ti)2(μ‐O)(μ‐O)2]2Ti (Cp* is η5‐C5Me5)

A new polynuclear titanium(IV) complex, dichloro­deca‐μ₂‐oxo‐hexa­kis­(penta­methyl­cyclo­penta­dien­yl)hexa­titanium(IV), [Ti₆(C₁₀H₁₅)₆Cl₂O₁₀], has been synthesized by hydro­lysis of a titanium complex bearing an N‐(2‐hydr­oxy‐3,5‐dimethyl­benz­yl)diethano­lamine Mannich ligand. The mol­ecule has two O‐bridged Ti₃O₃ rings linked to two similar rings through a tetra­hedrally O‐coordinated Ti atom. All Ti atoms except the central one are coordinated to penta­methyl­cyclo­penta­dien­yl (Cp*) ligands. The Cp* ligands are arranged with approximate symmetry with respect to the Ti/O/Cl core.     

Zur Darstellung phosphido‐chalkogenido‐verbrückter Dirheniumkomplexe vom Typ Re2(μ‐PCy2)(μ‐ER)(CO)8 (E = S,Se, Te; R = org. Rest)

Synthesis of Phosphido Chalcogenido Bridged Dirhenium Complexes of the Type Re₂(μ‐PCy₂)(μ‐ER)(CO)₈ (E = S, Se, Te; R = org. Residue) The reaction of Re₂(μ‐Br)(μ‐PCy₂)(CO)₈ with nucleophiles MER (M = Na, Li; E = S, Se, Te; R = org. residue) gives via substitution of the bromido bridge phosphido chalcogenido bridged dirhenium complexes of the general formula Re₂(μ‐PCy₂)(μ‐ER)(CO)₈. The new compounds were characterized by IR, ¹H and ¹³C NMR spectroscopic data and by elemental analyses. In addition the molecular structures for E = S, Se, Te and R = Ph as well as for E = S and R = H, n‐Bu, 2‐pyridyl have been established by single crystal X‐ray analysis. ¹³C NMR spectra of Re₂(μ‐PCy₂)(μ‐EPh)(CO)₈ (E = S, Se, Te) prove that the sulfur and selenium compounds are at room temperature dynamic molecules due to inversion of the pyramidal chalcogenido bridge. The tellurium compound, however, is rigid on the time scale of ¹³C NMR spectroscopy. Eventually the reactivity of the SH function of the novel complex Re₂(μ‐PCy₂)(μ‐SH)(CO)₈ was investigated by reaction with Re₂(CO)₈(MeCN)₂. In toluene at 90 °C the novel spirocyclic complex Re₂(μ‐PCy₂)(CO)₈(μ₄‐S)Re₂(μ‐H)(CO)₈ was formed by SH oxidative addition.     

A reactive and versatile trirhenium carbonyl cluster obtained by oxidation of [re3 (μ-H)4 (CO)10]−. Synthesis,x-ray characterization and reactivity of re3 (μ-H)3 (CO)10(NCMe)2

Oxidation of [Re₃(μ-H)₄(CO)₁₀]^? with CF₃SO₃H in acetonitrile gives the new complex Re₃(μ-H)₃(CO)₁₀(NCMe)₂. This contains a triangle of metal atoms with the edges bridged by the hydrides (mean ReRe 3.266 Å). The acetonitrile ligands, bound to two metals in a trans-diaxial manner, are easily replaced, giving a variety of derivatives.     

Reactions of the unsaturated anion [Re3H4(CO)10]− with car☐ylic acids and x-ray characterization of the anions [Re3H3(CO)10(μ-O2CR)]− (R = H,CF3)

The novel anions [Re₃H₃(CO)₁₀(μ-O₂CR)]^? (R = H, CH₃, CF₃), obtained by reaction of [Re₃H₄(CO)₁₀]^? with the corresponding car?ylic acids, have been characterized by IR and NMR spectra and by X-ray analysis of the formate and trifluoroacetate derivatives. They contain a triangle of rhenium atoms, with the car?ylate group diaxially bridging on the shorter ReRe edge.     

Synthese und Kristallstruktur eines μ-Methylen-μ-hydrido-dialanats [R2Al(μ-CH2)(μ-H)AlR2]− (R = CH(SiMe3)2)

Synthesis and Crystal Structure of a μ-Methylene-μ-hydrido-dialanate [R₂Al(μ-CH₂)(μ-H)AlR₂]^? (R = CH(SiMe₃)₂) tert-Butyl lithium reacts with the recently synthesized methylene bridged dialuminium compound [(Me₃Si)₂CH]₂Al? CH₂? Al[CH(SiMe₃)₂]₂ 2 in the presence of TMEDA under β-elimination; the thereby formed hydride anion is bound in a chelating manner by both unsaturated aluminium atoms forming a 3c–2e–Al? H? Al bond. The crystal structure of the product shows two independent molecules differing only slightly in bond lengths and angles, but significantly in conformation. While one of the Al₂CH heterocycles deviates little from planarity with a rough C₂ symmetry for the whole anion, the other one is folded with an angle of 21.1° and the arrangement of the substituents is best described by C_s symmetry.