Search

The first example of 12-vertex metallapolyhedra, namely, tris-phosphorus-containing closo-metallacarborane ruthenium(II) cluster , was synthesized and structurally studied. A principal possibility of the use of aliphatic amines as one-electron reducing agents converting carborane ruthenium(III) complexes to structurally close ruthenium(II) compounds was experimentally demonstrated. [ABSTRACT FROM AUTHOR]

The effect of tin( IV) monocathecholate 36CatSnR• nTHF (36Cat is 3,6-di- tert-butylcatehol dianion; R = Me, Et, Ph, or Cl; n = 1 and 2) on the radical polymerization of methyl methacrylate and {itn}-butyl methacrylate was studied. The role of the complexes in the synthesis of the corresponding polymers is mainly determined by the structure of tin o-semiquinone derivatives formed directly in the polymerization process. Tin( IV) monocatecholates can control the synthesis of polymers via the mechanism of reversible inhibition and, in certain cases, exert an accelerating effect on the polymerization of methacrylic monomers like Lewis acids. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of bromine-containing exo- nido-clusters of a general formula exo-5,6,10-[Br(PhP)Ru]-5,6,10-(μ-H)-10-H-7,8-R- nido-7,8-CBH (R = H, Me) was developed using the reactions of RuBr(PPh) with [K][7,8-R-7,8- nido-CBH]. Replacement of the phosphine ligands in the starting exo- nido-cluster (R = H) with the diphosphine ones afforded a series of diamagnetic (18-electron) closo-bromoruthenacarboranes, 3-Br-3,3-[κ-PhP(CH)PPh]-3-H- closo-3,1,2-RuCBH ( n = 3−5). A mild thermal method of the halide ligands exchange (Cl → Br) upon heating of diamagnetic chlorine-containing complexes 3,3-[κ-PhP(CH)PPh]-3-H-3-Cl- closo-3,1,2-RuCBH ( n = 3−5) with excess of CBr in benzene (70-80 °C) was suggested for the synthesis of paramagnetic (17-electron) bromine-containing ruthenacarboranes, 3-Br-3,3-[κ-PhP(CH)PPh]- closo-3,1,2-RuCBH ( n = 3, 4) or 3-Br-3,3,8-[κ-Ph(CH)PPh]-μ-[InlineMediaObject not available: see fulltext.]. Paramagnetic chlorine-containing clusters 3-Cl-3,3-[κ-PhP(CH)PPh]- closo-3,1,2-RuCBH ( n = 2−4) were alternatively used as the starting compounds in the exchange reaction. Complexes with dppp and dppb (dppp is 1,3-bis(diphenylphosphino)propane, dppb is 1,4-bis(diphenylphosphino)butane) were used as examples to study the thermal reactions (toluene, 110 °C) leading in the presence of CBr to paramagnetic mono( P- o-phenylene)- and bis( P, P- o-phenylene)cycloboronated clusters, 3-Br-3,3,8-[κ-Ph(CH)PPh]-μ-[InlineMediaObject not available: see fulltext.] and 3-Br-3,3,4,8-[κ-Ph(CH)P]-μ-[InlineMediaObject not available: see fulltext.] ( n = 3, 4). The compounds obtained were characterized by NMR spectroscopy (in the case of diamagnetic complexes), ESR spectroscopy and mass spectrometry (in the case of paramagnetic compounds). X-ray diffraction experiments were carried out for two cycloboronated paramagnetic complexes. [ABSTRACT FROM AUTHOR]

Characteristic features of synthesis of various polymers with participation of the tin complex imSQSnBuCl, where imSQ is the 4,6-di- tert-butyl- N-(2,6-diisopropylphenyl)- o-iminobenzoquinone radical anion, were studied. It was shown that for a number of monomers, this complex acts as an iniferter, i.e., it can not only initiate the polymerization, but can also regulate the chain growth of macromolecules. The effect of the conditions of the process on the possibility of obtaining macromolecular products with a narrow polydispersity was estimated. [ABSTRACT FROM AUTHOR]

Chelate exo- nido-ruthenacarboranes exo-5,6,10-[RuCl(PhP(CH)PPh)]-5,6,10-(μ-H)-10-H-7,8-R,R′- nido-7,8-CBH (R, R′ = H, PhCH) were synthesized by the direct method using the reaction of ClRu(PPh)(PhP(CH)PPh) with [7,8-R,R′- nido-7,8-CBH][K] in benzene. Unsubstituted exo-nido-ruthenacarborane (R, R′ = H) was used in situ for the synthesis of the dinuclear Ru-Cu exo-closo cluster of the formula exo-closo-(PhP)Cu(μ-H)Ru(PhP(CH)PPh)(η-CBH). The isomerism of the complex and the crystal structure were studied by NMR spectroscopy and X-ray diffraction. The catalytic activity of the cluster in the atom transfer radical polymerization of methyl methacrylate was investigated. [ABSTRACT FROM AUTHOR]