Synthesis and Characterization of Diorganotin Compounds {[R_2Sn(ON=CHC_6H_5)]_2O}_2 and Crystal Structure of {[(C_6H_5CH_2)_2Sn(ON=CHC_6H_5)]_2O}_2

摘要

Diorganotin compounds {[R_2Sn(ON=CHC_6H_5)]_2O}_2 [R=C_6H_5CH_2 (1), 2-FC_6H_4CH_2 (2), 4-FC_6H_4CH_2 (3), 2-ClC_6H_4CH_2 (4), 4-ClC_6H_4CH_2 (5)] were synthesized by the reaction of R_2SnO with HON=CHC_6H_5 in 1 : 1 molar ratio in refluxing anhydrous benzene or toluene. They were characterized by elemental analysis, IR, ~1H NMR and ~(119)Sn NMR spectroscopy. And two sets of ~(119)Sn chemical shifts were observed in the ~(119)Sn NMR spectra of these compounds, indicating the presence of two types of environment around the tin atoms. The crystal structure of compound 1 was determined by X-ray single crystal diffraction analysis. The results showed that the crystal of compound 1 belongs to a monoclinic system with space group P2_(1/c) and unit cell dimensions: a= 1.0718(9) nm, b= 1.9666(17) nm, c=2.0480(17) nm, β=96.4371(14)°, D_c=1.450 g/cm~3, Z=2, F(000)=1888, V=4.290(6) nm~3, μ = 1.206 mm~(-1), R_1 =0.0405, wR_2 = 0.0786. The compound 1 belongs to centrosymmetric dimer structure mode with a four-membered central endo-cyclic Sn_2O_2 unit in which the bridging oxygen atoms are tri-coordinated. Each bridging oxygen atom also connects with an exo-cyclic tin atom. The endo- and exo-cyclic tin atoms are both five-coordinated, and have coordination geometry of distorted trigonal bipyramid.