Preparation and Characterisation of Bis (η5-Cyclopentadienyl) N,N-Disubstituted Dithiocarbamato Chloro Oxotungsten (VI) Complexes

Bis (η⁵-cyclopentaienyl) N,N-disubstituted dithiocarbamato chloro oxotungsten (VI) complexes of the type η⁵-Cp₂WO(S₂CNR₂)Cl and η⁵-Cp₂WO(S₂CNRR')Cl (where R=Me, Et and i-Pr and R'=Cyhx) have been prepared by the reaction of bis (η⁵-cyclopentadienyl) oxotungsten (VI) dichloride with sodium salts of dithiocarbamic acids in refluxing tetrahydrofuran. Infrared spectral studies demonstrate that in these complexes dithiocarbamate ligands are bidentate. Therefore, tungsten (VI) atom may be assigned a coordination number 6 in all these complexes. Elemental analyses of these compounds have also been carried out. Electronic spectra have been recorded for all the six complexes.     

Studies on the Preparation and Properties of Thiol Derivatives of Biscyclopentadienyl Molybdenum (VI) and Bisindenyl Molybdenum (VI) Oxide Dichloride

Biscyclopentadienyl molybdenum (VI) oxide dichloride (I) and bisindenyl molybdenum (VI) oxide dichloride (II) react with various thiols in tetrahydrofuran and from the complexes of the type (C₃H₅)₂MoO (R₂) and (C₉H₇)₂MoO (R₂) wherein R may be S CH₈, S C₂H₅, S C₃H^N₇, S C₃H₇, S C₄Hⁿ₉, or S C₄H₃ or S C₃H₁₁. The preparation, thermal stabilities, physical characteristics and infrared spectra of these complexes have been studied in this paper.     

Synthesis and structures of fulvene-bridged diruthenium complexes

Three diruthenium carbonyl complexes, namely (η ³:η ⁵-C₅H₄C(CH₂)₂)Ru₂(CO)₅ (1), (η ³:η ⁵-C₅H₄C(CHCH₂)(C₂H₅))Ru₂(CO)₅ (2), and (η ¹:η ⁵-C₅H₄C₅H₈)Ru₂(CO)₆ (3), were obtained from the reactions of C₅H₄C(Me)₂, C₅H₄C(Et)₂, and C₅H₄C(CH₂)₄, respectively, with Ru₃(CO)₁₂ in refluxing xylene. The complexes were characterized by elemental analysis, IR and ¹H NMR spectra. Single-crystal X-ray diffraction analysis for complexes 1 and 2 revealed that the fulvene ligands bridge two ruthenium atoms in η ³:η ⁵ fashion.     

Bis-η5-cyclopentadienyl and Bis-η5-methylcyclopentadienylN,N-dialkyldithiocarbamato(chloro)titanium(IV) compounds

Summary Titanium(IV)N,N-dialkyldithiocarbamates of the type ⁵-Cp₂Ti (S₂CNR₂)Cl and (⁵-MeCp)₂Ti(S₂CNR₂)Cl (R = Me, Et and i-Pr) have been prepared by the reaction of di--cyclopentadienyldichlorotitanium(IV) and bis-n-methylcyclopentadienyldichlorotitanium(IV) with sodium salts of dithiocarbamic acids in refluxing dichloromethane. Molecular weight, conductance and i.r. studies show these complexes to be monomeric nonelectrolytes in which the dithiocarbamate ligands are bidentate. Therefore, pentacoordination may be assigned to titanium(IV) atom in all six complexes. Electronic and proton n.m.r. studies spectra have also been recorded for the complexes.     

Mono- and bisphenoxy derivatives of bis(indenyl) titanium(IV)

A series of (C₉H₇)₂Ti(OAr)Cl and (C₉H₇)₂Ti(OAr)₂ complexes whereAr=C₆H₅,p-ClC₆H₄, α-C₁₀H₇ or β-C₁₀H₇, have been synthesised by the reaction of bis(indenyl) titanium(IV) dichloride with an appropriate phenol in a 1:1 and 1:2 molar ratio in refluxing benzene in the presence of triethylamine. The new derivatives have been characterized on the basis of their elemental analyses, conductance measurements and spectral (IR,¹H-NMR and electronic) studies.     

Synthesis and structures of bridged biscyclopentadienyl diiron complexes

Three diiron carbonyl complexes, namely [(η ⁵-C₅H₄)(η ³-C(CH₂)₂)]Fe₂(CO)₅ (1), [(C₂H₅)₂C(η ⁵-C₅H₄)₂]Fe₂(μ-CO)₂(CO)₂ (2), and [(CH₂)₄C(η ⁵-C₅H₄)(η ⁵-C₅H₃)(C₅H₉)]Fe₂(μ-CO)₂(CO)₂ (3), have been synthesized by the reactions of C₅H₄C(Me)₂, C₅H₄C(Et)₂, and C₅H₄C(CH₂)₄, respectively, with Fe(CO)₅ in refluxing xylene. The complexes have been characterized by elemental analysis, IR, and ¹H NMR spectra. The molecular structures of the complexes have been determined by single-crystal X-ray diffraction. The structures of the complexes indicate that fulvenes can be bound to transition metal centers by diverse modes.     

Simulation of molecular and electronic structure of η5-π-complexes of fullereneI h -C 60 with half-sandwich XCp species (X=Si, Ge, Sn)

The molecular and electronic structure of hypothetical complexes of unsubstituted fullerene C₆₀ withI _h symmetry and its cyclopentadienyl type derivatives were simulated by the MNDO/PM3 method taking the C₆₀(XC[) _n molecules (n=1, 2, 10, 12; X=Si, Ge, Sn) and η⁵-C₆₀H₅XCp (X=Ge, Sn), respectively, as example. The complexes 12η⁵-πC₆₀(XCp)₁₂ and η⁵-πC₆₀XCp withI _h andC _5v symmetry, respectively, were found to be the most stable compounds. The energies of the X−C₆₀ bonds in these complexes are close to those of X−Cp bonds in bis(cyclopentadienyl) complexes XCp₂ and are substantially higher than the energies of similar bonds in complexes of unsubstituted fullerene η¹-πC₆₀(XCp)⁻ and η⁵-πC₆₀(XCp)⁺. Geometric parameters and spin densities in radicals C₆₀XCp and biradicals C₆₀(XCp)₂ and C₆₀H₁₀ were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2155–2165, November, 1998.     

Reaction of a naphthalene complex C10H8Yb(THF)2 with cyclopentadienyl-substituted alcohols and amines as a convenient synthetic route to the half-sandwich complexes of divalent ytterbium

The reactions of ytterbium naphthalene complex C₁₀H₈Yb(THF)₂ with 2-cyclopentadienylethanol, 1-cyclopentadienylpropan-2-ol, 3-cyclopentadienyl-1-butoxypropan-2-ol, and cyclopentadienyldimethylsilyl-tert-butylamine were studied. The bivalent ytterbium complexes with chelate bifunctional cyclopentadienyl ligands [(η⁵−C₅H₅)CH₂CH₂(η¹−O)]Yb(THF), [(η⁵−C₅H₅)CH₂CH₂(η¹−O)]Yb(DME). [(η⁵−C₅H₅)CH₂CH(Me)(η¹−O)]Yb(THF), [(η⁵−C₅H₅)CH₂CH(CH₂OC₄H₉)(η¹−O)]Yb(THF), and [(η⁵−C₅H₅)SiMe₂(η¹−N(Bu¹))]Yb(THF) were obtained and characterized. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 742–745, April, 2000.     

Reaction of <Emphasis Type="Italic">N,N</Emphasis>′-bis(trimethylsilyl)dicyandiamide with bis(η<Superscript>5</Superscript>-cyclopentadienylvanadium) dichloride

1,3,5-Tris[bis(η⁵-cyclopentadienyl)chlorovanadium]melamin is prepared in high yield by the reaction of N,N′-bis(trimethylsilyl)dicyandiamide with bis(η⁵-cyclopentadienylvanadium) dichloride in tetrahydrofuran. As side products, trimethylchlorosilane and cyclopentadiene formed. Reaction of N,N′-bis(trimethylsilyl) dicyandiamide with benzoyl chloride results in the formation of tris(benzoyl)melamin.     

Microwave assisted synthesis,spectroscopic and antibacterial studies of bis(cyclopentadienyl)hafnium(IV) derivatives with benzil bis(aroyl hydrazones)

The reactions of (η⁵-C₅H₅)₂HfCl₂ with benzil bis(hydrazones) (LH₂), derived from benzil and aromatic acid hydrazides (benzoic, 2-chlorobenzoic, 4-chlorobenzoic, 2-methylbenzoic or 4-methoxybenzoic) have been studied in anhydrous tetrahydrofuran in the presence of n-butylamine by both conventional methods and by microwave heating. Binuclear complexes of type [{(η⁵-C₅H₅)₂HfCl}₂(L)] were obtained in both cases. Tentative structural conclusions are drawn for the reaction products based upon analyses, electrical conductance, magnetic moment and spectral (UV–vis, IR, ¹H NMR and ¹³C NMR) data. A FAB-mass spectrum of one compound was also recorded to confirm the binuclear structures. Studies were conducted to assess the growth inhibiting potential of the complexes and free ligands against various bacterial strains.