Reactivity of a Tin(II)
(Iminophosphinoyl)(thiophosphinoyl)methanediide Complex Toward Sulfur:
Synthesis and <sup>119</sup>Sn Mössbauer Spectroscopic Studies
of [{(μ-S)SnC(PPh<sub>2</sub>NSiMe<sub>3</sub>)(PPh<sub>2</sub>S)}<sub>3</sub>Sn(μ<sub>3</sub>-S)]
posted on 2016-02-21, 16:04authored byJia-Yi Guo, Hong-Wei Xi, Israel Nowik, Rolfe H. Herber, Yongxin Li, Kok Hwa Lim, Cheuk-Wai So
Reaction of [(PPh<sub>2</sub>NSiMe<sub>3</sub>)(PPh<sub>2</sub>S)CSn:]<sub>2</sub> (<b>1</b>) with
elemental sulfur in toluene afforded [{(μ-S)Sn<sup>IV</sup>C(PPh<sub>2</sub>NSiMe<sub>3</sub>)(PPh<sub>2</sub>S)}<sub>3</sub>Sn<sup>II</sup>(μ<sub>3</sub>-S)] (<b>2</b>) and [CH<sub>2</sub>(PPh<sub>2</sub>NSiMe<sub>3</sub>)(PPh<sub>2</sub>S)] (<b>3</b>). Compound <b>2</b> comprises a Sn<sup>II</sup>S moiety coordinated with the
Sn<sup>IV</sup> and S atoms of a trimeric 2-stannathiomethendiide
{(PPh<sub>2</sub>NSiMe<sub>3</sub>)(PPh<sub>2</sub>S)CSn(μ-S)}<sub>3</sub>. Compound <b>2</b> has been characterized by NMR spectroscopy, <sup>119</sup>Sn Mössbauer studies, X-ray crystallography, and
theoretical studies. <sup>119</sup>Sn NMR spectroscopy and Mössbauer
studies show the presence of Sn<sup>IV</sup> and Sn<sup>II</sup> atoms
in <b>2</b>. X-ray crystallography suggests that the Sn<sup>II</sup>S moiety does not have multiple bond character. Theoretical
studies illustrate that the C<sub>methanediide</sub>–Sn bonds
comprise a lone pair orbital on each C<sub>methanediide</sub> atom
and an C–Sn occupied σ orbital.