The synthesis and structure of a dianionic species with a bond between pentacoordinated tin atoms: bonding properties of the tin–tin bond

Abstract

The first dianionic compound bearing a bond between two pentacoordinated tin atoms, a distannate, was synthesized in a stable form by using two sets of an electron-withdrawing C,O-bidentate ligand on each tin atom. The structure of the distannate was determined by NMR spectroscopy and X-ray crystallographic analysis. The Sn-Sn bond of the distannate was shown to be a single bond featuring high s-character. The J(Sn-Sn) coupling constant was larger than that of Sn(sp)-Sn(sp) bonds found in most hexaorganodistannanes. This bond feature was also supported by computational studies. The Sn-Sn bond was cleaved by treatment with hydrochloric acid, which shows a different reactivity to the homonuclear bonds of pentacoordinated disilicates and digermanates.

Preparation of seven-coordinated hypervalent tin(iv)-fused azobenzene and applications for stimuli-responsive π-conjugated polymer films

“…Tin (Sn) is one of the heavy group 14 elements, and it is known that the hypervalent tin( iv ) compounds have various coordination numbers, five, 15–22 six, 23–29 seven, 30–35 and eight. 36 Therefore, their structural features and physical properties have been explored.…”

“…8,9 In the main group elements, the highly-coordinated states can be classified as hypervalent states beyond the octet rule, where hypervalent compounds are characterized by the formation of relatively polarized three-center four-electron (3c-4e) bonds without d orbitals. [10][11][12][13][14] Tin (Sn) is one of the heavy group 14 elements, and it is known that the hypervalent tin(IV) compounds have various coordination numbers, five, [15][16][17][18][19][20][21][22] six, [23][24][25][26][27][28][29] seven, [30][31][32][33][34][35] and eight. 36 Therefore, their structural features and physical properties have been explored.…”