In an attempt to prepare the heavieranalogue of NHC-stabilized borenium cation, we have prepared a silylene-coordinated borenium equivalent (1a), which can be viewed as a contact ion pair of borenium and triflate. The triflate anion coordinates to the oxophilic silicon center, leaving the boron center existing in a trigonal-planar geometry in the solid state and in solution. Nucleophilic substitution
acid–base adduct formation between N-heterocyclic silylenes and silyl arenium ions. They were isolated in high yields as their [B(C6F5)4]− salts. These salts are stable at room temperature and were characterized by NMR spectroscopy supported by the results of density functional computations of molecular structures and NMR chemicalshifts. NICScalculations suggest for the imidazolium ions 7 only a modest
2-硅咪唑鎓N杂环甲硅烷基和甲硅烷基芳烃离子之间的路易斯酸碱加成反应合成了7号离子和2个硅咪唑啉鎓离子8号离子。以[B(C 6 F 5)4 ] -盐的形式高收率分离。这些盐在室温下稳定,并通过NMR光谱进行表征,并由分子结构的密度泛函计算和NMR化学位移的结果所支持。NICS计算表明,对于咪唑鎓离子7而言,其芳香度中等。尽管使用的取代基R 1和R 2庞大,甲硅烷基离子7和8表现为经典的路易斯对,并且没有显示出意外的反应性。
Electronic and steric properties of stable silylene ligands in metal(0) carbonyl complexes
作者:Thomas A. Schmedake、Michael Haaf、Bryan J. Paradise、Anthony J. Millevolte、Douglas R. Powell、Robert West
DOI:10.1016/s0022-328x(01)00765-3
日期:2001.11
substitution of silylenes 1 and 2 for carbonyl ligands in simple metal carbonyl complexes: M(1)2(CO)4 and M(2)2(CO)4 (M=Cr, Mo, W), Fe(1)(CO)4 and Ru(1)2(CO)3. X-ray crystal structures are reported. Infrared and NMR spectroscopy were used to probe the electronicproperties of stable silylene ligands. Based on these data, the stable silylene 1 behaves electronically very much like triaryl phosphines.
Pentamethylcyclopentadienyl-substituted hypersilylsilylene: reversible and irreversible activation of CC double bonds and dihydrogen
作者:Kinga I. Leszczyńska、Peter Deglmann、Carsten Präsang、Volker Huch、Michael Zimmer、David Schweinfurth、David Scheschkewitz
DOI:10.1039/d0dt02943b
日期:——
complexes with regards to the ability to activate small molecules. Here, we report synthesis and full characterisation of the persistent (hypersilyl)(pentamethylcyclopentadienyl)silylene Cp*[(Me3Si)3Si]Si: as well as its unique reactivity. Silylene Cp*[(Me3Si)3Si]Si: activates dihydrogen to give the corresponding dihydrosilane Cp*[(Me3Si)3Si]SiH2 at particularly mild conditions as well as ethylene to afford
Compounds of Germanium and Tin, 22 – Reactions of a Silyene with a Germylene and a Stannylene: Formation of a Digermene with an Unusual Arrangement of the Substituents and of a Stannane
The reaction of the diaminosilylene :Si(tBuNCH2CH2NtBu) (5) with the diaminogermylene :Ge(tBuNCH2CH2NtBu) is thought to proceed via a germasilene silylgermylene rearrangement and dimerisation to furnish the (Z)−1,2-diamino-1,2-disilyldigermene (Z)-9. The X-ray structure analysis of (Z)-9 reveals a long GeGe bond length of 245 pm and a large trans-bent angle of 42°. Air-oxidation of (Z)-9 takes place