摘要
Silicones can be cross-linked to materials with a wide variety of properties.In this work,the ringed oligomers of [SiO(OH)_2]nas well as the stacked structures of trimer and the linear strands of the dimer and trimer were investigated systematically at B3 LYP/6-311 + + G(d,p) level combined with the conductor-like screening model(CPCM).This theoretical model reveals that,(1) SiO(OH)_2 will condense to stable ringed structures with SiO tetrahedrons;(2) in the ringed octamer [SiO(OH)_2]8,the macrocycle begins to pucker drastically;(3) from the linear strands of SiO rings it can be seen that the longer the chain is,the greater the energies decrease;(4) in [SiO(OH)_2]n(n ≥5) and in the strands of ringed oligomers,the highest occupied molecular orbitals(HOMOs) are primarily the n orbitals of the lone-pair electrons of oxygen atoms,so there are no delocalized π bonds.
Silicones can be cross-linked to materials with a wide variety of properties.In this work,the ringed oligomers of [SiO（OH）2]nas well as the stacked structures of trimer and the linear strands of the dimer and trimer were investigated systematically at B3 LYP/6-311 ＋ ＋ G（d,p） level combined with the conductor-like screening model（CPCM）.This theoretical model reveals that,（1） SiO（OH）2 will condense to stable ringed structures with SiO tetrahedrons;（2） in the ringed octamer [SiO（OH）2]8,the macrocycle begins to pucker drastically;（3） from the linear strands of SiO rings it can be seen that the longer the chain is,the greater the energies decrease;（4） in [SiO（OH）2]n（n ≥5） and in the strands of ringed oligomers,the highest occupied molecular orbitals（HOMOs） are primarily the n orbitals of the lone-pair electrons of oxygen atoms,so there are no delocalized π bonds.
基金
National Natural Science Foundations of China(Nos.21502136 and 21571137)
Natural Science Foundation of Shandong Province,China(No.ZR2012BL10)
the University Science and Technology Project of Shandong Province,China(No.J13LD05)
