Synthesis and comparative X-ray diffraction study of first ruthenocene-based pincer palladium complexes, PdCl[{2,5-(But 2PCH2)2C5H2}Ru(Cp′)] (Cp′ = C5H5 or C5Me5)

First ruthenocene-based palladium complexes PdCl[{2,5-(Bu^t ₂PCH₂)₂C₅H₂} Ru(Cp′)] (Cp′ = C₅H₅ (4) or C₅Me₅ (5)) were synthesized. Comparative single-crystal X-ray diffraction study of complexes 4 and 5 showed that the deviations of the cyclopentadienyl rings in these complexes from being parallel are 2.6 and 10.1°, respectively. In addition, the shift of the palladium atom relative to the plane of the metallated cyclopentadienyl ligand is 0.007 Å for 4 and 0.336 Å for 5. These differences in the structures of complexes 4 and 5 are due to close contacts between the pseudoequatorial tert-butyl groups at the phosphorus atoms and the unmetallated cyclopentadienyl ring. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1879–1884, November, 2006.     

Synthesis and structure of a product of interaction of acetonitrile with hydrogen bromide, [H2N=C(Me)−NH−C(Me)Br2]Br

A mixture of solid products was obtained upon absorption of dry HBr by MeCN. One of the products, [H₂N=C(Me)−NH−C(Me)Br₂]Br, was isolated as white single crystals and characterized by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2274–2277, November, 1998.     

Investigation into the formation of supramolecular compounds from mixed As/S-ligand complexes [(Cp*Mo)2As2S3] (Cp* = C5Me5) and copper halides

The coordination behavior of [(Cp*Mo)2As2S3] (3) (Cp* = C5Me5) toward Cu(I) halides was investigated. One dimensional polymers of the general formula [(Cp*Mo)2As2S3(CuHal)2]n (Hal = Cl, 4; Br, 5) and an oligomer of composition [{(Cp*Mo)2As2S3}3(CuI)7] (6) formed upon the reaction of 3 with the corresponding copper halide. All of the compounds were characterized by ESI-MS, elemental analysis, and single-crystal X-ray crystallography. The solid-state structures of 4 and 5 are isostructural and contain 1D S-shaped chains. This peculiar folding is achieved by alternating planar and folded Cu2Hal2 rings linked together by the central monosulfide bridge of the middle deck of the organometallic unit. The structure of 6 is characterized by a novel [CuI]7 aggregate, which forms a very flat Cu6I3S3 bowl along with three integrated peripheral [(Cp*Mo)2As2S3] building blocks. In contrast to earlier findings, the middle deck of the organometallic units consists in all structures of two trapezoidal AsS dumbbells and one monosulfide ligand.     

The oligoselenide metallacycle complex Cp*Re(NBut) (Se4) as an organometallic ligand. Preparation of the M(CO)5 (M=Cr,Mo, W) adducts [Cp*Re(NBut)(Se4){M(CO)5}2]

Transition Metal Chemistry -     

Synthesis of bisvinylidene complex of manganese Cp (OC)2Mn=C=CHC6H4CH=C=Mn(CO)2 Cp

Russian Chemical Bulletin -     

[{Me4C2(C5H4)2}Zr(BH4)2], a bis(tetra­hydro­borate) complex of a bridged zirconocene

Bis(tetra­hydro­borato)­[1,1,2,2‐tetra­methyl‐1,2‐ethyl­enebis­(η⁵‐cyclo­penta­dienyl)]­zirconium, (I), was synthesized by the reaction of the zirconocene dichloride with lithium tetra­hydro­borate. Crystals suitable for X‐ray structure analysis were obtained by recrystallization from toluene. The mol­ecule adopts an appproximate C_2v symmetry. Both tetra­hydro­borate ligands are η²‐coordinated and tilted by 18–19° out of the equatorial plane; the angle B1—Zr1—B2 is 104.7°. The cyclo­penta­dienyl rings show a normal η⁵‐coordinaton, with a centroid–Zr–centroid angle of 124.3°.     

New bridging tridentate bis-cyclopentadienyl ligands [C5Me4(CH2)n]2PPh (n = 1, 2) for organometallic synthesis

Preparative procedures were developed for the synthesis of new transmethylated bis-cyclopentadienyl ligands with phosphine-containing bridging fragments. These ligands were isolated as the dilithium salts Li₂[(C₅Me₄CH₂)₂PPh] (1) and Li₂[(C₅Me₄CH₂CH₂)₂PPh] (3). Phosphorus-substituted 3-ansa-zirconocene dichloride [(C₅Me₄CH₂)₂PPh]ZrCl₂ was synthesized starting from 1. The NMR spectroscopic data provide evidence for the absence of the Zr←P coordination interaction in solution. A straightforward approach to 5-ansa-zirconocene dichloride [(C₅Me₄CH₂CH₂)₂PPh]ZrCl₂ starting from lithium salt 3 and ZrCl₄ was shown to be impossible. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1775–1779, September, 2007.     

Chemistry of transition-metal clusters with mixed Sb/S ligands: evidence for a terminal Sb=S double bond in Cp*3Rh3Sb2S5 (Cp* = C5Me5)

The reaction of [Cp2*Rh2Cl4] (Cp* = C5Me5) with a slight excess of K(3)SbS(3) in boiling THF gave the neutral clusters [Cp*4Rh4S5] (1), [Cp*3Rh3Sb2S5] (2), and after salt metathesis [Cp*3Rh3SbSn]PF6 (3; n = 5 and 6). The structures of 1-3 are heterocubane clusters with CpRh, S, and Sb vertices but with sulfur inserted into one (1 and 2) or two (3) edges. X-ray diffraction analysis of 2 additionally reveals a very short Sb-S distance of 2.297(1) A within the novel mu3-Sb2S4 ligand. Density functional theory calculation of the model compounds [SSbS]3-, [HSSbS]2-, and [HSSbH2S]0 provided strong evidence for the existence of a stable terminal Sb=S double bond in 2.     

A heterobimetallic complex with an unsupported uranium(III)-aluminum(I) bond: (CpSiMe3)3U-AlCp* (Cp* = C5Me5)

A heterobimetallic complex with the first unsupported bond between an actinide and a group 13 element, (CpSiMe3)3U-AlCp* (Cp* = C5Me5) (1), was synthesized by reaction of (CpSiMe3)3U and 1/4(Cp*Al)4 in toluene. Density functional theory calculations indicate that the U-Al bond exhibits some covalent character resulting from a Cp*Al-->U charge-transfer.     

Synthesis, properties, and the crystal structure of the complex Cp2Yb(DAD)

The diazadiene complex of trivalent ytterbium, Cp₂Yb(DAD) (1) (DAD=Bu^t−N=CH−CH=N−Bu^t) was prepared according to three different procedures, namely, by oxidation of Cp₂Yb(THF)₂ with diazadiene in THF, by the reaction of Cp₂YbCl with DAD²⁻Na⁺ ₂ taken in a ratio of 2∶1, and by the reaction of Cp₂YbCl(THF) with DAD²⁻Na⁺ ₂ taken in a ratio of 1∶1. Complex1 was characterized by microanalysis, IR spectroscopy, magnetochemistry, and X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 384–386, February, 1999.     

Synthesis,spectroscopic investigation,structural characterization,and DFT calculations of [ReX2(N2COPh)(CH3PhCN)(PPh3)2] (X=Cl,Br)

Reactions of [ReX₂(η ²-N₂COPh-N′,O)(PPh₃)₂] with 3-methylbenzonitrile give two iso-structural complexes, [ReX₂(N₂COPh)(CH₃PhCN)(PPh₃)₂] (X?=?Cl, Br). The crystal and molecular structures of [ReCl₂(N₂COPh)(CH₃PhCN)(PPh₃)₂] (1) and [ReBr₂(N₂COPh)(CH₃PhCN)(PPh₃)₂]?·?CH₂Cl₂ (2) were determined. The electronic structures were examined with density functional theory (DFT). The spin-allowed electronic transitions were calculated with the time-dependent DFT method, and the UV-Vis spectrum has been discussed.     

Synthetic and X-ray structural and reactivity studies of Cp*RuIV complexes containing bidentate dithiocarbonate, xanthate, carbonate, and phosphinate ligands (Cp* = eta5-C5Me5)

The reaction of [Cp*RuCl2]2 (1; Cp* = eta5-C5Me5) with tetraalkyldithiuram disulfides (R2NC(S)SS(S)CNR2, R = Me, Et), isopropylxanthic disulfide ([iPrOC(S)S]2), and bis(thiophosphoryl) disulfide ([(iPrO)2P(S)S]2) led to the isolation of dark-red crystalline solids of Cp*RuIVCl2(eta2-dithiolate) complexes [dithiolate = S2CNR2, DTCR (2a, R = Me; 2b, R = Et), S2COiPr (3), and S2P(iPrO)2 (4)]. Dichlorido substitution in 2 and 3 with DTCEt and S2COiPr anions yielded RuIV derivatives containing bis(DTC) and mixed DTC-dithiocarbonate ligands. These are the first organoruthenium complexes of such ligands. The reaction of monophosphines with 2a resulted in monochlorido substitution, whereas the analogous reaction with 3 resulted in displacement of both chlorido ligands and reduction of the metal center to RuII. Reduction at Ru was also observed in the reaction of 2a with [CpCr(CO)3]2. Of these complexes, only 2 and 3 are air-stable in the solid state for an extended period. All of the complexes have been spectrally characterized, and selected compounds are also crystallographically characterized.     

Synthese und Insertionsreaktionen von Cp2′HfCl{As(SiMe3)2} (Cp′ = C5H4Me)

Synthesis and Insertion Reactions of Cp₂′HfCl{As(SiMe₃)₂} (Cp′ = C₅H₄Me) The reaction of Cp₂′HfCl₂ (Cp′ = C₅H₄Me) with Li(THF)_2,5As(SiMe₃)₂ (1 : 1) at room temperature gives the terminal hafnocene arsenido complex Cp₂′HfCl{As(SiMe₃)₂} ( 1 ) in high yield. 1 inserts CS₂ and PhNC into the Hf? As bond yielding Cp₂′HfCl{η²-S₂CAs(SiMe₃)₂} ( 2 ) and Cp₂′HfCl{η²-N(Ph)CAs(SiMe₃)₂} ( 3 ). The thermally sensitive complexes 1–3 were characterised spectroscopically and crystal structure determinations were carried out on 1 and 3 which shows the η² bonding mode of the N(Ph)CAs(SiMe₃)₂ ligand in the latter.     

钛配合物Cp2TiL,Cp2Ti2Cl2(μ-O)和Cp4Ti4Cl4(μ-O)4的合成与晶体结构研究(Cp=η5-C5H5,L=2,6-吡啶二羧酸盐)

利用溶剂热的方法将Cp2TiCl2(Cp=η5-C5H5)与2,6-吡啶二羧酸钠(L)反应,不同的反应时间得到了2个具有不同晶体空间群的化合物Cp2TiL(1a和1b),而在常温或低温下,Cp2TiCl2或CpTiCl3同羧酸盐或亚胺反应却得到了双核或四核氧桥联的钛化合物。     

Synthesis, crystal structure, and magnetic properties of hexanuclear [{MnL2}4{Nb(CN)8}2] and Nonanuclear [{MnL2}6{Nb(CN)8}3] heterometallic clusters (L=bpy, phen)

A hexanuclear cyano-bridged {MnII4NbIV2} cluster (1) bearing 2,2'-bipyridine (bpy) as the blocking ligand at manganese is obtained from the reaction of cis-[MnCl2(bpy)2] and K4[Nb(CN)8]. When the blocking ligand is 1,10-phenanthroline (phen), a nonanuclear cluster {MnII6NbIV3} (2) is obtained. The structure of [{Mn(bpy)2}4{Nb(CN)8}2] has been solved by single-crystal X-ray crystallography, whereas the phen derivative has been confirmed by means of the structure analysis of the corresponding WIV analogue [{Mn(phen)2}6{W(CN)8}3(H2O)2]. Magnetic measurements revealed S=9 and 27/2 spin ground states for these aggregates as a result of antiferromagnetic Nb-Mn interaction with JNb-Mn=-18.1 cm(-1) (1) and -13.6 cm(-1) (2).     

Synthesis of (C5Me5)2(C5Me4H)UMe, (C5Me5)2(C5H5)UMe, and (C5Me5)2UMe[CH(SiMe3)2] from cationic metallocenes for the evaluation of sterically induced reduction

To probe the correlation of unusual (C5Me5)(1-) reactivity with steric crowding in complexes such as (C5Me5)3UMe and (C5Me5)3UCl, slightly less crowded (C5Me5)2(C5Me4H)UX analogues (X = Me, Cl) were synthesized and their reactivity was evaluated. The utility of the cationic precursors [(C5Me5)2UMe](1+), 1, and [(C5Me5)2UCl](1+), 2, in the synthesis of (C5Me5)2(C5Me4H)UMe, 3, and (C5Me5)2(C5Me4H)UCl, 4, was also explored. Since the use of precursor [(C5Me5)2UMe][MeBPh3], 1a, is complicated by the equilibrium between 1a and (C5Me5)2UMe2/BPh3, the reactivity of [(C5Me5)2UMe(OTf)]2, 1b, (OTf = O3SCF3) prepared from (C5Me5)2UMe2 and AgOTf, was also studied. Both 1a and 1b react with KC5Me4H to form 3. Complex 4 readily forms by addition of KC5Me4H to [(C5Me5)2UCl][MeBPh3], generated in situ from (C5Me5)2UMeCl and BPh3. Complex 1b was preferred to 1a for the synthesis of (C5Me5)2(C5H5)UMe, 5, and (C5Me5)2UMe[CH(SiMe3)2], 6, from KC5H5 and LiCH(SiMe3)2, respectively. Complex 6 is the first example of a mixed alkyl uranium metallocene complex. Sterically induced reduction (SIR) reactivity was not observed with 3-6 although the methyl displacements from the (C5Me5)(1-) ring plane for 3 are the closest observed to date to those of SIR-active complexes. The (1)H NMR spectra of 3 and 4 are unusual in that all of the (C5Me4H)(1-) methyl groups are inequivalent. This structural rigidity is consistent with density-functional theory calculations.