Tetranuclear Group 7/8 Mixed-Metal and Open Trinuclear Group 7 Metal Carbonyl Clusters Bearing Bridging 2-mercapto-1-methylimidazole Ligands

The reactivity of group 7 metal dinuclear carbonyl complexes [M2(CO)6(μ-SN2C4H5)2] (1, M = Re; 2, M = Mn) toward group 8 metal trinuclear carbonyl clusters were examined. Reactions of 1 and 2 with [Os3(CO)10(NCMe)2] in refluxing benzene furnished the tetranuclear mixed-metal clusters [Os3Re(CO)13(μ3-SN2C4H5)] (3) and [Os3Mn(CO)13(μ3-SN2C4H5)] (4), respectively. Similar treatment of 1 and 2 with Ru3(CO)12 yielded the ruthenium analogs [Ru3Re(CO)13(μ3-SN2C4H5)] (5), and [Ru3Mn(CO)13(μ3-SN2C4H5)] (6), but in the case of 2 a secondary product [Mn3(CO)10(μ-Cl)(μ3-SN2C4H5)2] (7) was also formed. Compounds 3–6 have a butterfly core of four metal atoms with the M (Mn or Re) at a wingtip of the butterfly and containing a noncrystallographic mirror plane of symmetry. This result provides a potential method for the synthesis of a series of new group 7/8 mixed metal complexes containing a bifunctional heterocyclic ligand. Compound 7 is a unique example of a 54-electron trimanganese complex having bridging 2-mercapto-1-methylimidazolate and chloride ligands. Interestingly, the reaction of 1 with Fe3(CO)12 at 70–75 °C furnished the tri- and dirhenium complexes [Re3(CO)10(μ-H)(μ3-SN2C4H5)2] (8) and [Re2(CO)6(N2C4H5)(μ-SN2C4H5)2] (9), respectively instead of the expected formation of the mixed-metal clusters. The former is an interesting example of a 52-electron trirhenium-hydridic complex containing bridging 2-mercapto-1-methylimidazolate ligand, while the latter can be viewed as a 1-methylimidazole adduct of 1. No mixed Fe–Re complexes were produced in this reaction. The molecular structures of the new compounds 3–5 and 7–9 were established by single-crystal X-ray diffraction analyses and the DFT studies of compounds 5, 7 and 8 are reported

Aminosilanetrithiol RSi(SH)(3): an experimental and quantum-chemical study

973 Program [2012CB821704]; National Nature Science Foundation of China [91027014]; Innovative Research Team Program [IRT1036, 20923004]; Deutsche Forschungsgemeinschaft (DFG)An interesting aminosilanetrithiol RSi(SH)(3) (R = N(SiMe3)-2,6-iPr(2)C(6)H(3)) has been prepared by the reaction of lithium aminosilanetrithiolate {RSi[SLi(THF)](3)}(2) with MeCOOH. Theoretical calculations indicate that the LP(N) -> sigma*(Si-S) and LP(S) -> sigma*(Si-S) electron donations remarkably contribute to the stabilization of the Si(SH)(3) part of the molecule. RSi(SH)(3) is the first example of a stable molecule containing three SH groups attached to one element

Synthesis of metallasiloxanes of group 13-15 and their application in catalysis

973 Program [2012CB821704]; National Nature Science Foundation of China [91027014, 20972129]; National Key Lab Foundation for PCOSS [20923004]; Innovative Research Team Program [IRT1036]Herein we report on the synthesis, characterization and catalytic application of metallasiloxanes of group 13-15. Reactions of R(Me)Si(OH)(2) (R = N(SiMe3)-2,6-iPr(2)C(6)H(3)) (A) with Bi(NEt2)(3), Sb(NEt2)(3), Ge[N(SiMe3)(2)](2) and AlMe3 afforded [R(Me)SiO2BiNEt2](2) (1), [R(Me)SiO2SbOSi(OH)(Me)R](2) (2), [R(Me)SiO2](3)(GeH)(2) (3), and [R(Me)SiO2AlMe(THF)](2) (4), respectively. Reactions of RSi(OH)(3) (B) with Bi(NEt2)(3) and AlMe3 produced complexes (RSiO3Bi)(4) (5) and (RSiO3)(2)[AlMe(THF)](3) (6). Compounds 1-6 have been characterized by IR and NMR spectroscopy, single crystal X-ray structure and elemental analysis. Each of the compounds 1, 2 and 4 features an eight-membered ring of composition Si2O4Bi2, Si2O4Sb2 and Si2O4Al2, while 3 and 6 exhibit a bicyclic structure with the respective skeletons of Si3O6Ge2 and Si2O6Al3. Compound 5 has a cubic core of Si4O12Bi4. Compounds 1-6 exhibit very good catalytic activity in the addition reaction of trimethylsilyl cyanide (TMSCN) with benzaldehyde. Compound 5 was found to be the best catalyst and its activity was probed in the reactions of TMSCN with a number of aldehydes and ketones

Unusual formation of a N-heterocyclic germylene via homolytic cleavage of a C-C bond

Deutsche Forschungsgemeinschaft [RO 224/60-1]; Danish National Research Foundation [DNRF93]; Centre for Materials Crystallography; Norwegian Research Council through the CoE Centre for Theoretical and Computational Chemistry (CTCC) [179568/V30]; China Scholarship Council; Norwegian Supercomputing Program (NOTUR) [NN4654K]Reaction of the monoanionic radical salt IP center dot-K+ (IP = (Py)CH(=NR); Py = C5H4N, R = 2,6-iPr(2)C(6)H(3); alpha-iminopyridine) with GeCl2(dioxane) afforded compound (IPGeCl)(2) (1) which produced red blocks of IPGe: (2), when treated with KC8 in toluene. 1 is a digermylene formed via C-C coupling between two carbon-centered radicals. 2 can be considered as an analogue of a N-heterocyclic carbene, which exhibits a five-membered GeC2N2 ring with one CQC double bond. 2 is formed by two-electron reduction of 1 with cleavage of the two Ge-Cl bonds and the central C-C single bond

Preparation of Organometallic Hydroxides and their Reactions with Lanthanide Compounds

International audienceThe preparation of soluble organometallic hydroxides is a key step in the preparation of organometallic oxides containing the heterobimetallic M-O-M' unit. Compounds of composition LMOH where M is a Main Group metal (Ca, Sr, Al, Ga, Ge, Sn) and transition metal (Zr, Hf) are summarized. The reactions of Cp3Ln (Ln = Yb, Dy, Er, Sm) with several hydroxides to yield compounds with the skeletons M(µ-O)Ln and M(µ-OH)Ln are reported. The application of the latter compounds in Є-caprolactone polymerization is discussed. An unforeseen formation of a chlorine-centered cluster of composition [(Me3Si)2NC(NCy)2SmCl2]5(THF)2 is reported

Preparation and reactions of sulfur-nitrogen ring systems

Two routes for the preparation of (CH3)2SnS2N2 are given, which are kinetically controlled reactions. The molecule (CH3)2SnS2N2 was characterized by X-ray analysis. It is an interesting starting material for the preparation of S2N2CO and S3N2O. The latter reacts with iminosulfur oxides and isocyanates under the formation of S3N3SO2F and S3N3SO2CF3. The structure of S3N3SO2F was established by X-ray analysis. The bonding properties are discussed. The cleavage of thin-nitrogen derivatives with S3N2Cl2 yields also five membered sulfurnitrogen rings. The structure and properties of P3N3F5NS3N2 and C3N3F2NS3N2 are reported. Six, eight and ten membered rings are formed by the reactions of (CH3)3Si–N = S = N–Si (CH3)3 with FSO2–N=S=O, these are S4N4O2 and S5N5+S3N3O4, respectively. The cation S5N5+ is a planar molecule, while the oxygen containing species are puckered. In S4N4O2 the oxygens are attached to one sulfur atom, which has a tetrahedral configuration. The structure of the silicon containing cyclic and bicyclic rings (CH3)2Si(NSN)2Si(CH3)2 and CH3Si(NSN)3SiCH3 were determined