Organotin(IV) Derivatives of Some O,C,O-Chelating Ligands

Abstract

The series of organotin(IV) complexes L1-3SnPhnCl3-n, where L1-3 are O,C,O-chelating ligands (called the pincer ligands), 2,6-bis(alkoxymethyl)phenyl-, 2,6-(ROCH2)2C6H3- (L1, R = Me, L2, R = i-Pr, L3, R = t-Bu, n = 3−0), have been synthesized and characterized by 1H, 13C, and 119Sn NMR spectroscopy, MS-ESI spectrometry, and elemental analysis. The structure of selected compounds L1SnPh3 (1), L1SnPh2Cl (2), L1SnPhCl2 (3), L1SnCl3 (4), L2SnPhCl2 (7), and L3SnPhCl2 (11) was studied by X-ray crystallography and 119Sn CP/MAS NMR spectroscopy in the solid state. The determination of crystal structures reveals the similarity of all the shapes of coordination polyhedra. The deformations of the shapes of coordination polyhedra depend on the degree of donor−acceptor Sn−O interaction (from very weak (interatomic distance Sn−O 2.963(1) Å) to medium-strong (2.475(1) Å)), which increases with increasing Lewis acidity of the tin atom in the L1-3SnPhnCl3-n entities and decreases with increasing steric demands of substituents R (from Me to t-Bu). NMR spectroscopy indicates a similar structural arrangement of the studied compounds in solution.