Synthese und kristallstrukturuntersuchung von bis[dicarbonyl(μ-trifluormethylisocyanid)-(η-pentamethylcyclopentadienyl)molybdän)], [Mo(CO)2(μ-CNCF3)(η-Cp)]2 und dessen isomerisierung zu Cp(CO)2Mo(μ-F3CNCCNCF3)Mo(CO)2Cp

Trifluoromethyl isocyanide adds to the metal—metal triple bond of bis[dicarbonyl(η-pentamethylcyclopentadienyl)molybdenum] forming Mo₂Cp₂(CO)₄(η²-μ-CNCF₃) as the first isolated product. Further addition of trifluoromethyl isocyanide at 0°C leads to the formation of [Mo(CO)₂(μ-CNCF₃)(η-Cp)]₂, which according to crystal structure analysis contains two bridging CF₃NC ligands. During the isomerization of this compound in dichloromethane solution at room temperature or in the solid state above 110°C molybdenum—molybdenum bond cleavage and carbon—carbon bond formation occurs, leading to Cp(CO)₂Mo(μ-F₃CNCCNCF₃)Mo(CO)₂Cp, which contains 1,1,1,6,6,6-hexafluoro-2,5-diaza-2,3,4-hexatriene as bridging ligand.     

Methylierung eines schwefelreichen dimolybdänkomplexes: darstellung,trennung und charakterisierung von (C5Me5)2Mo2(μ-SCH3)2(μ-S)2 in zwei isomeren formen

The methylation reaction of (C₅Me₅)₂Mo₂(μ-S₂)(μ-S)₂ (Ia) leads to two isomers of composition (C₅Me₅)₂Mo₂(SMe)₂S₂ (IV and IVb) which were separated by column chromatography. As an intermediate product of this reaction the iodine-containing adduct (C₅Me₅)₂Mo₂S₄I₂ is formed. All compounds were investigated by means of ¹H and ⁹⁵Mo NMR spectroscopy as well as by an X-ray structure analysis in the case of IVa. Thus, the SCH₃ ligands in IV are found to be arranged in a trans position. As a further result a cleavage of the η²-disulfur bridge, originally present in Ia, has been found to occur in the second step of the reaction sequence.     

Metallkomplexe mit verbrückenden dimethylphosphidoliganden: VI. Zweikernkomplexe mit substituierten vinyldimethylphosphan-brückenliganden durch templatsynthese aus [(C5H5Co)2(μ-PMe2)2(μ-H)]+ und alkinen. Die kristallstruktur von [(C5H5Co)2(μ-PMe2)(μ-η4-Me2PC(CO2Me)CHC(OMe)O)]BF4

The hydrido-bridged dinuclear complex [(C₅H₅CO)₂(μ-PMe₂)₂(μ-H)]BF₄ (I) reacts with C₂(CO₂Me)₂ to produce a mixture of (C₅H₅Co)₂[μ-η⁴-Me₂PC(CO₂Me)C(CO₂Me)PMe₂] (II) and [(C₅H₅Co)₂(μ-PMe₂)(μ-η⁴-Me₂PC(CO₂Me)-CHC(OMe)O)]BF₄ (III). The X-ray structural analysis of III reveals that besides a dimethylphosphido bridge the cation contains a substituted vinyldimethylphosphine ligand which behaves as a 6-electron donor group and is coordinated via phosphorus and oxygen to the first cobalt and via the CC bond the second cobalt atom. The reactions of I with HC₂CO₂Me and CH₃C₂CO₂Me also give mixtures of products which contain the neutral component, (C₅H₅Co)₂[μ-η⁴-Me₂PCRC(CO₂Me)PMe₂] (IV: R  H; VII: R  CH₃), i.e., the structural analogue of II. The ionic products V, VI (obtained from HC₂CO₂Me) and VIII, IX (obtained from CH₃C₂CO₂Me) have been characterized by IR and NMR spectroscopy. {(C₅H₅Co)₂[μ-η⁴-PMe₂C(CH₃)C(CO₂Me)PMe₂](μ-H)}BF₄ (VIII) has independently been prepared by treatment of VII with HBF₄.     

Transformationen von clustern mit dem (μ3-RP)Fe3(CO)9-Gerüst. Synthese und reaktionen von [(μ3-RP)Fe3(CO)9]2−

The clusters (μ₃-RP)Fe₃(CO)₁₀ (1) or (μ₃-RP)Fe₃(CO)₉(μ₂-H)₂ (2) can reversibly be transformed into the cluster anions [(μ₃-RP)Fe₃(CO)₉ (μ₂-H)]⁻ (3) and [(μ₃-RP)Fe₃(CO)₉]²⁻ (4). The pyrophoric clusters 4 react with the divalent electrophile CH₂I₂ to give the complexes (μ₃-η²-RP=CH₂)Fe₃(CO)₁₀ (5), which contain a cluster-stabilized phosphaalkene, RP=CH₂, as a ligand. With monovalent electrophiles R′X, such as Me₂SO₄, compound 4 (R = anisyl), yields, upon protolytic work-up, the complexes (μ₃-η³-R′P-anisyl)Fe₃(CO)₉(μ₂-H) (6) in which the phosphorus-bound aryl residue of the μ₂-bridging phosphide ligand (R′P-anisyl) forms an η²-coordination to the third iron atom of the cluster. The η²-coordination of the aryl substituent may be reversibly released by two-electron ligands L under formation of (μ₂-R′P-anisyl)(μ₂-H)Fe₃(CO)₉L (7). In addition, the transformation sequence of 5 into 6 is accomplished by an H⁻, H⁺ addition sequence. The experiments are documented by analytic and spectroscopic data as well as by X-ray analyses.     

Reaction of Mo(CO)6 with Alkoxide: Synthesis and Structure of the Mo(0)-OR Complex [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2C6H5)3]

The reaction of molybdenum hexacarbonyl with C6H5CH2OC6H4ONa and Et4NBr in CH3CN at 60 ℃ afforded the di-nuclear Mo(0) compound [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2- C6H5)3] 1. 1 crystallizes in monoclinic, space group P21/c with a=15.359(2), b=18.378(3), c=24.952(2)(A), β=102.268(4)°, V=6882.3(16) (A)3, Mr=1348.34, Z=4, Dc=1.301 g/cm3, F(000)=2832 and μ= 0.424 mm-1. The final R=0.0606 and wR=0.1552 for 9396 observed reflections (Ⅰ ＞ 2σ(Ⅰ)). 1 contains a [Mo2O3]3- core in triangular bi-pyramidal configuration and each Mo atom adopts a distorted octahedral geometry with three carbon atoms from carbonyls and three μ-O atoms from C6H5CH2OC6H4O- bridging ligands. The Mo…Mo distance is 3.30(8) (A), indicating no metalmetal bonding. A formation pathway via forming a di-molybdenum(0) di-bridging OR compound [Mo2(μ-OR)2(CO)8]2- has been figured out and the reaction of Mo(CO)6 with alkoxide has also been discussed.     

In Situ Generation of the Fulvalene Ligand via C–H Activation by Gray Antimony and Its Incorporation into the Tetrahedral Cluster [(μ,η5:η5-C10H8) (η5-C5H5)M3(CO)6(μ3-Sb)] (M=Mo or W)1

The first tetrahedral clusters containing a single naked antimony atom have been prepared by the thermolysis of [CpM(CO)₃]₂ (M=Mo or W) in the presence of gray antimony at 180°C in toluene in a sealed Carius tube. X-ray structural characterization revealed that, in addition to the incorporation of Sb in the cluster, it has also affected coupling of two Cp rings to form [(, ⁵: ⁵-C₁₀H₈)( ⁵-C₅H₅)-M₃(CO)₆( ₃-Sb)]. It is only the second example of in situ formation of the fulvalene ligand for group-6 metal. Simultaneous with the C–C coupling reaction, a mirror of Sb forms on the reaction tube; this indicates that SbH₃ is formed in the hydrogen abstraction step, which then subsequently decomposes at the tube wall.     

Zweikernige η5-pentamethylcyclopentadienyl-rhenium-komplexe mit einer chalkogenbrücke. Die molekülstruktur von [(η5-C5Me5)Re(CO)2]2(μ-Se)

We report the synthesis and characterisation of binuclear η⁵-pentamethylcyclopentadienylrhenium complexes, [(η⁵-C₅Me₅)Re(CO)₂]₂(μ-E) (E = S (2), Se (3), Te (4)), containing a chalcogen bridge in addition to a ReRe bond. According to the X-ray structural analysis, 3 possesses approximately C₂ molecular symmetry; the C₅Me₅ ring ligands occupy trans positions with respect to the central Re₂Se unit [d(ReRe) 3.032(1) Å, ∢ ReSeRe 74.9(1)°]. As expected, the complexes of the now complete series [CpRe(CO)₂]₂(μ-E) (E = O (1), S (2), Se (3), Te (4)) show a high degree of similarity in their corresponding mass, IR, ¹H and ¹³C NMR spectra.     

Ti-Verbindungen mit fulvalenbrücken: Die struktur von [CpTiMe2]2(C10H8)

X-ray analysis for the orange-yellow thermally unstable crystalline compound [CpTiMe₂]₂(C₁₀H₈) (3(Me)), which results from methylation of [CpTiCl₂]₂(C₁₀H₈), confirms the presence of a fulvalene bridge. The two CpTiMe₂ fragments in 3(Me) are trans with respect to the fulvalene group.     

Tieftemperatur-flüssigphasefluorierung von pentafluorphenyl-element-Verbindungen. Darstellungen und eigenschaften von (C6F5)3AsF2, (C6F5)3SbF2, (C6F5)2SeF2, (C6F5)2SeO,C6F5TeF3 und Cs[(C6F5)3EF3] (E = As,Sb) [1]

The fluorination reactions of (C₆F₅)₃E (E = As, Sb) with elemental flourine yield (C₆F₅)₃EF₂ in high yields. From the reactions of (C₆F₅)₃EF₂ with CsF the new salts Cs[(C₆F₅)₃EF₃] are obtained. (C₆F₅)₂SeF₂ and C₆F₅TeF₃ are formed for the first time by reacting (C₆F₅)₂SeF and (C₆F₅)₂TeF₂ with elemental flourine and XeF₂, respectively. (C₆F₅)₂SeF₂ rapidly reacts with glass, and the new compound (C₆F₅)₂SeO is isolated. The preparations, properties and ¹⁹F NMR spectra of the new compounds are described.     

The Potential of the Diarsene Complex [(C5H5)2Mo2(CO)4(μ,η2-As2)] as a Connector Between Silver Ions

The reaction of the organometallic diarsene complex [Cp₂Mo₂(CO)₄(μ,η²-As₂)] ( B ) (Cp = C₅H₅) with Ag[FAl{OC₆F₁₀(C₆F₅)}₃] (Ag[FAl]) and Ag[Al{OC(CF₃)₃}₄] (Ag[TEF]), respectively, yields three unprecedented supramolecular assemblies [(η²- B )₄Ag₂][FAl]₂ ( 4 ), [(μ,η¹:η²- B )₃(η²- B )₂Ag₃][TEF]₃ ( 5 ) and [(μ,η¹:η²- B )₄Ag₃][TEF]₃ ( 6 ). These products are only composed of the complexes B and Ag^I. Moreover, compounds 5 and 6 are the only supramolecular assemblies featuring B as a linking unit, and the first examples of [Ag^I]₃ units stabilized by organometallic bichelating ligands. According to DFT calculations, complex B coordinates to metal centers through both the As lone pair and the As−As σ-bond thus showing this unique feature of this diarsene ligand.     

The Synthesis of the Arene Clusters Ru6C(CO)14(η6-Arene) (Arene = C6H5CHMe2, C6H5C4H9, C6H5C3H7, and C6H5C3H5)

On reaction with Ru₃(CO)₁₂, isopropenylbenzene and 4-phenyl-l-butene undergo hydrogenation, to yield the clusters, Ru₆C(CO)₁₄(⁶-C₆H₅CHMe₂) 1 and Ru₆C(CO)₁₄(⁶-C₆H₅C₄H₉) 2, respectively. With allylbenzene, both hydrogenation and isomerization occurs affording Ru₆C(CO)₁₄(⁶-C₆H₅C₃H₇) 3 and Ru₆C(CO)14(⁶-C₆H₅C₃H₅) 4. The structures of 1 and 2 have been established by single crystal X-ray diffraction. One of the Ru–Ru bond lengths in 2 is unusually long and extended Hückel molecular orbital calculations have been used in an attempt to rationalize this feature.     

REACTIONS OF [η5−RC5H4 (CO)2Mo]2 (Mo≡Mo) WITH (μ-PhSe)2Fe2 (CO)6. SYNTHESIS AND CHARACTERIZATION OF SELENOLATO-BRIDGED TRANSITION METAL COMPLEXES [η5−RC5H4Mo (CO) (μ-SePh)]2 (R ˭ MeCO,MeO2C) AND η5−RC5H4MoFe2 (CO)4 (μ3-Se) [μ,η1: η2−C(0)Ph] (μ-SePh)2 (R ˭ H,MeCO, EtO2C)

Abstract

Mo≡Mo triply bonded dimers [η⁵?RC₅H₄ —react with (μ,-PhSe)₂Fe₂ (CO)₆ in boiling xylene to give selenolato-bridged bimetallic complexes [η⁵?RC5H₄Mo(CO) (μ-SePh)]₂ (R ? MeCO, MeO₂C). However, irradiation of a benzene solution of —(R ? H, MeCO, EtO₂C) and (μ-PhSe)₂Fe₂ (CO)₆ with a 400W high pressure mercury lamp gave rise to selenolato-bridged trimetallic clusters η⁵?RC₅H₄MoFe₂(CO)₂ (μ₃-Se) [μ,η:η²?C (O) Ph] (μ-SePh)₂ (R ? H, MeCO, EtO₂C). All products were characterized by elemental analysis and spectroscopic methods, as well as by an X-ray diffraction analysis of the product η⁵?MeCOC₅H₄MoFe₂(CO)₄ (μ-Se)[μ;η¹:η²?C(O)Ph](μ-SePh)₂.     

Synthesis of a vinylcarbynetetrairon complex. Crystal and molecular structure of [(C5H5)2(CO)2Fe2(μ-CO)]2- (μ-C5H3)+BF4−

The diiron vinyl ether carbyne complex [(C₅H₅)(CO)Fe]₂(μ-CO)- (μ-CCHCHOCH₂CH₃)⁺ BF₄⁻ (1) reacted with the diiron ethenylidene complex [(C₅H₅)(CO)Fe]₂(μ-CO)(μ-CCH₂) (2) to yield the tetrairon complex [(C₅H₅)₂(CO)₂Fe₂(μ-CO)]₂(μ-C₅H₃⁺BF₄⁻ (3) which was characterized by spectroscopy and by single crystal X-ray diffraction.     

过渡金属卡宾配合物 VI:单、双核锰和双核铼的铁硫原子簇卡宾配合物-π-C5H5(CO)2MnC(C6H5)(μ-S)(μ-C6H5S)Fe2(CO)6和[π-C5H5(CO)2MC(C6H5)]2(μ-S)2Fe2(CO)6(M=Mn,Re)的合成和波谱

本文报道了锰和铼的阳离子卡拜配合物[π-C5H5(CO)2MCC6H5]BRr4(M=Mn, Re)分别与(μ-苯硫)六羰基二铁和双(μ-锂硫)六羰基二铁阴离子反应生成标题化合物. 产物的组成和结构由元素分析, IR, ^1H NMR和MS分析, 以及7的单晶X射线结构分析确定的. 文中还对合成和波谱研究结果进行了讨论.     

Übergangsmetall-Fulven-Komplexe: XXXI. Die Reaktivität des [η5-(C5H4CHO)M(CO)3]−-Anions (M  Mo,W) gegenüber Carbonsäurechloriden

The reactivity of the (η⁵-formylcyclopentadienyl)M(CO)₃ anions (M  Mo, W) towards acyl chlorides has been studied. Acetyl chloride reacts with the anions to give two different types of substituted cyclopentadienyl complexes: [M(Cl)(η⁵-C₅H₄CH₂OC(O)CH₃)(CO)₃] and [M(η¹-CH₃CO)(η⁵-CH₃CO)(η⁵-C₅H₄CH₂OC(O)CH₃)(CO)₃]. The reaction of the anions with benzoyl chloride only yields the chloro complexes [M(Cl)(η⁵-C₅H₄CH₂OC(O)C₆H₅)(CO)₃]. The molecular structure of [W(Cl)(η⁵-C₅H₄CH₂OC(O)CH₃)(CO)₃] has been determined by X-ray diffraction studies.     

Probing the aromaticity of the [(H(t)Ac)3(μ2-H)6], [(H(t)Th)3(μ2-H)6],(+), and [(H(t)Pa)3(μ2-H)6] clusters

In this study we report about the aromaticity of the prototypical [(H(t)Ac)(3)(μ(2)-H)(6)], [(H(t)Th)(3)(μ(2)-H)(6)](+), and [(H(t)Pa)(3)(μ(2)-H)(6)] clusters via two magnetic criteria: nucleus-independent chemical shifts (NICS) and the magnetically induced current density. All-electron density functional theory calculations were carried out using the two-component zeroth-order regular approach and the four-component Dirac-Coulomb Hamiltonian, including scalar and spin-orbit relativistic effects. Four-component current density maps and the integration of induced ring-current susceptibilities clearly show that the clusters [(H(t)Ac)(3)(μ(2)-H)(6)] and [(H(t)Th)(3)(μ(2)-H)(6)](+) are non-aromatic whereas [(H(t)Pa)(3)(μ(2)-H)(6)] is anti-aromatic. However, for the thorium cluster we find a discrepancy between the current density plots and the classification through the NICS index. Our results also demonstrate the increasing influence of f orbitals, on bonding and magnetic properties, with increasing atomic number in these clusters. We think that the enhanced electron mobility in [(H(t)Pa)(3)(μ(2)-H)(6)] is due the significant 5f character of its valence shell. Also the participation of f orbitals in bonding is the reason why the protactinium cluster has the shortest bond lengths of the three clusters. This study provides another example showing that the magnetically induced current density approach can give more reliable results than the NICS index.     

Chalcogen–acetylide interaction and unusual reactivity of coordinated acetylide with water: synthesis and characterisation of [(η5-C5R5)Fe3(CO)6(μ3-E)(μ3-ECCH2RI)] (R=H,Me; RI=Ph,Fc; E=S,Se) and [(η5-C5R5)MoFe2(CO)6(μ3-S)(μ-SCCH2Ph)] (R=H,Me)

Photolysis of a benzene solution containing [Fe₃(CO)₉(μ₃-E)₂] (E=S, Se), [(η⁵-C₅R₅)Fe(CO)₂(CCR^I)] (R=H, Me; R^I=Ph, Fc), H₂O and Et₃N results in formation of new metal clusters [(η⁵-C₅R₅)Fe₃(CO)₆(μ₃-E)(μ₃-ECCH₂R^I)] (R=H, R^I=Ph, E=S 1 or Se 2; R=Me, R^I=Ph, E=S 3 or Se 4; R=H, R^I=Fc, E=S 5; R=Me, R^I=Fc, E=S 6 or Se 7). Reaction of [Fe₃(CO)₉(μ₃-S)₂]with [(η⁵-C₅R₅)Mo(CO)₃(CCPh)] (R=H, Me), under same conditions, produces mixed-metal clusters [(η⁵-C₅R₅)MoFe₂(CO)₆(μ₃-S)(μ-SCCH₂Ph)] (R=H 8; R=Me 9). Compounds 1–9 have been characterised by IR and ¹H and ¹³C-NMR spectroscopy. Structures of 1, 5 and 9 have been established crystallographically. A common feature in all these products is the formation of new C-chalcogen bond to give rise to a (ECCH₂R^I) ligand.     

STRUCTURE OF TRANS-SYN-BIS-[(η-(CH_3)_2CHC_5H_4)Mo (μ-S)(μ-SC(CH_3)_3)]

<正> Mr = 648.75, triclinic, space group P1 , a = 10.087(4), b = 12.686(5), c = 14.222(6) A, α= 104.83(3)°, β = 124.61(4)°, γ = 90.98(3)°, V = 1417.22A3, Z = 2, De = 1.520 Mg.m-3, (MoKα)= 0.71069A, μ(MoKα) = 11.597 cm-1, F(000) = 664, room temperature. Final R=0.0424 for 5705 observed reflections. In the molecule two metal atoms are bonded togetherin a cavity surrounded by Ugands. Pour sulphur atoms are in bridging positions and in the same plane perpendicular to the metal-metal vector with the two t-butylthiolato ligands being in mutu-syn positions.