Substituent and Solvent Effects on the Electronic and Structural Properties of Silacyclopropylidenoids

Abstract

The isomeric structures, energies, and properties of the substituted silacyclopropylidenoids, SiC<sub>2</sub>H<sub>3</sub>RLiBr (R= –H, –CH<sub>3</sub>, –SiH<sub>3</sub>, –CN, –OH, –NH<sub>2</sub>), were studied by <em>ab initio</em> calculations at the MP2/6-311+G(d,p) level of theory. The calculations indicate that each of SiC<sub>2</sub>H<sub>3</sub>RLiBrs for R= –H, –CH<sub>3</sub>, –SiH<sub>3</sub>, –CN, –OH, –NH<sub>2 </sub>has three stationary structures: silacyclopropylidenoid (<strong>S</strong>), tetrahedral (<strong>T1</strong> or <strong>T2</strong>), and inverted (<strong>I</strong>). The conductor–like polarizable continuum model (CPCM) using various solvents (dimethyl sulfoxide (ε = 46.7), acetone (ε = 21.0), tetrahydrofuran (ε = 7.5), and diethyl ether (ε = 4.3)) has been applied to compute single point energies for title molecules. In addition, the molecular electrostatic potential maps, natural bond orbitals, and the frontier molecular orbitals of substituted silacyclopropylidenoids were calculated.