Molecular structures of organotin tropolonato complexes with tin coordination numbers 5–7, seen by single‐crystal x‐ray diffraction and solid‐ and solution‐state ¹¹⁹Sn NMR

Abstract

Abstract Organotin tropolonato complexes of the type R 3 Sn(trop) 1 [R = Bu (b), Ph (c)], R 2 Sn(trop) 2 2 [R = Me (a), Bu (b), Ph (c)] and RSn(trop) 3 3 [R = Bu (b), Ph (c)] were studied by single‐crystal X‐ray diffraction (1c, 2a,b, 3b), 13 C and 119 Sn MAS NMR and 119 Sn NMR in solution. The tin coordination numbers from 5 to 7, as determined for the solid state, are retained in solution. The different distorted octahedral surroundings ( cis ‐like arrangement of the methyl groups in 2a; trans ‐like arrangement of the butyl groups and weak intermolecular association in 2b) of the tin atoms in solid compounds 2 are reflected both by the 119 Sn chemical shift anisotropies and the magnitude of the coupling constants | 1 J ( 117/119 Sn, 13 C)|. The molecular structures of 2a and 2b become more similar to each other in solution, as indicated by differences in the isotropic 119 Sn chemical shifts in solution and in the solid state, and even more obvious by changes in the magnitude of the corresponding coupling constants | 1 J ( 117/119 Sn, 13 C)|. Copyright © 2001 John Wiley & Sons, Ltd.