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Abstract: The reaction of dipotassio‐tetrasilan‐1,4‐diide (4) with anhydrous SnCl2 at low temperature results in the formation of a five‐membered cyclic potassio chlorostannate(II) ([(18‐C‐6)K](1)). By careful cation exchange reactions, it was transformed into the sodium chlorostannylenoid 2 (by using Na2[B12Cl12]) or into the non‐stabilized cyclic bissilylstannylene 3 (through applying Li[Al(OC(CF3)3)4]). The increasing Lewis basicity of the bissilylstannylene 3 was analyzed by combined methods of DFT calculations and NMR spectroscopy and substantiated by the synthesis of the corresponding iron carbonyl complexes 7 and 8 from the chlorostannate 1 and the stannylene 3, respectively. [ABSTRACT FROM AUTHOR]

An isolable dicoordinatedialkylsilylene, 2,2,5,5-tetrakis(trimethylsilyl)silacyclopentane-1,1-diyl(6), was found to react with CO2and ArNCX(X = O, S) smoothly to give the corresponding bis(silyl)carbonate,4-imino-1,3-dioxasiletane and 4-imino-1,3-dithiasiletane derivativesin high yields, respectively. The molecular structures of these productswere determined by X-ray crystallography. All these reactions areparallel to those of a hypercoordinate silylene with η5-pentamethylcyclopentadienyl ligands, decamethylsilicocene, reportedby Jutzi et al. and are suggested to involve similarly the formationof the corresponding SiX doubly bonded compounds (X = O, S)at the initial steps. Mechanistic details of the multistep reactionof a model dialkylsilylene with CO2were investigated usingDFT calculations. [ABSTRACT FROM AUTHOR]

Abstract: AgOTf (OTf=trifluoromethanesulfonate) shows the reactivity differences when it reacts with carborane complexes [MCl2{(PPh2)2(C2B10H10)}] (M=Ni (2), Pd (3)). The reaction of AgOTf with the palladium complex 3 affords [Pd2(μ-OTf)2{(PPh2)2(C2B9H10)}2] (4) in high yields, while corresponding reaction between the nickel complex 2 and AgOTf leads to the formation of binuclear complexes [Ni{(PPh2)2(C2B9H10)}](μ-Cl)2[Ag{(PPh2)2(C2B10H10)}] (5) and [Ag2(μ-Cl)2 {(PPh2)2 (C2B10H10)}2] (6). The carborane cage of complexes 4 and 5 were broken to form nido-carboranes. It is believed the group 10 metals themselves play an important role in opening the closo-carborane skeleton. Directly stirring [(PPh2)2(C2B10H10)] with AgOTf afforded [Ag2(μ-OTf)2{(PPh2)2(C2B10H10)}2] (7), which is also used to react with 2 and 3. The reaction between 2 and 7 gives only 4 in high yields, however, stirring the mixture of 3 and 7 affords [Pd2(μ-Cl)2{(PPh2)2(C2B9H10)}2] (8), [Pd{(PPh2)2(C2B9H10)}2] (9) and 6. All these complexes have been characterized by IR, 1H NMR, 11B NMR and elemental analyses. Complexes 2, 4–9 have also been determined by single-crystal X-ray diffraction analyses. [ABSTRACT FROM AUTHOR]

A sterically demanding TBS-substituted oligosilane ( 4 , TBS = t -butyldimethylsilyl) was stepwisely formed by reactions of oligosilanyl potassium compound and the corresponding chlorosilane. Although a well-established method, the ring closure reaction of compound 4 in the presence of t -BuOK and 18-Cr-6 with SiX 4 (X = Cl, Br) failed. The silyl potassium compound was then transformed to silyl Grignard compound 5 , which can be used to react with SiX 4 to give the dihalocyclopentasilanes ( 6 , X = Cl; 7 , X = Br) successfully. The molecular structures of 3 – 7 have been confirmed by X-ray single-crystal analyses. [ABSTRACT FROM AUTHOR]

The reaction of silylene (I) with aromatic nitriles bearing electron-donating substituents on the phenyl ring (II) leads to the desired 1,4-diaza-2-siloles (III), whilst the reaction with aromatic nitriles with strong electron-withdrawing substituents (IV) affords 1,3-diaza-2-siloles (V). [ABSTRACT FROM AUTHOR]