title: Synthesis of a Bent 2-Silaallene with a Perturbed Electronic Structure from a Cyclic Alkyl(amino) Carbene-Diiodosilylene.
abstract: The cyclic alkyl(amino) carbene (cAAC) 1 reacted with SiI4 in toluene, affording the cAAC-silicon tetraiodide complex [(cAACMe)SiI4] (2, cAACMe = :C(CH2)(CMe2)2NAr, Ar = 2,6-iPr2C6H3). It further reacted with two equivalents of KC8 in toluene at room temperature to afford the first cAAC-diiodosilylene [(cAACMe)SiI2] (3). DFT calculations show that the Ccarbene-Si bond in 3 is formed by the donation of the lone pair of electrons on the Ccarbene atom to the SiI2 moiety, while the π-back-bonding of the lone pair of electrons on the Si atom to the Ccarbene atom is negligible. The presence of the lone pair of electrons on the silicon atom in 3 is also evidenced by its reaction with N3SiMe3 to form the cAAC-silaimine complex [(cAACMe)Si(NSiMe3)I2] (4). Compound 3 reacted with IiPrMe (:C{N(iPr)CMe}2) in n-hexane to form the NHC-cAAC-silyliumylidene iodide [cAACMe(SiI)IiPrMe]I (5), which was then reacted with two equivalents of KC8 in toluene to furnish [cAACMeSi(IiPrMe)] (6). The experimental and theoretical studies suggest that 6 can be described as a bent silaallene with a perturbed electronic structure, which can be attributed to the different donor-acceptor properties of cAACMe and IiPrMe. Compounds 3-6 were elucidated by NMR spectroscopy, X-ray crystallography, and theoretical studies.
authors: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371, Singapore.
authors: Yan
authors: Y
authors: Li
authors: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371, Singapore.
authors: Yuk-Chi
authors: YC
authors: Chan
authors: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371, Singapore.
authors: Yongxin
authors: Y
authors: Li
authors: Department of Chemistry, National Institute of Technology Calicut , NIT Campus P.O., Calicut 673601, India.
authors: Indu
authors: I
authors: Purushothaman
authors: Department of Chemistry, National Institute of Technology Calicut , NIT Campus P.O., Calicut 673601, India.
authors: Susmita
authors: S
authors: De
authors: Department of Chemistry, National Institute of Technology Calicut , NIT Campus P.O., Calicut 673601, India.
authors: Pattiyil
authors: P
authors: Parameswaran
authors: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371, Singapore.
authors: Cheuk-Wai
authors: CW
authors: So