Experimental and ab initio structural study of estertin compounds, X sub(3SnCH) sub(2)CH sub(2CO) sub(2)Me: Crystal structures of Cl sub(3SnCH) sub(2)CH sub(2CO) sub(2)Me at 120 K and Br sub(3SnCH) sub(2)CH sub(2CO) sub(2)Me at 120 and 291 K

• Published in: Journal of molecular structure 2009-03, Vol.921 (1-3), p.244-250
• Main Authors: De Lima, Geraldo M, Milne, Bruce F, Pereira, Robson P, Rocco, Ana Maria, Skakle, Janet MS, Travis, Anthony J, Wardell, James L, Wardell, Solange MSV
• Format: Article
• Language: English
• Subjects: Bonding strength
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2008.12.064

The MeO sub(2CCH) sub(2)CH sub(2 ligand in X) sub(3)SnCH sub(2CH) sub(2)CO sub(2Me, (X = Cl, Br or I), acts as a C,O-chelating group, via the carbonyl group, both in the solid state and in solutions in non-coordinating solvents. The crystal structures of 1 (X = Cl), a redetermination at 120 K and of I (X = Br), at 298 and 120 K, are reported. Comparison of the intramolecular Sn[single bond]O bond lengths in solid 1 (X = Cl, Br or I) indicates that the strength of the Sn[single bond]O interaction increases in the order X = I Br Cl. Furthermore, the strength of the Sn[single bond]O bond is greater in Cl) sub(3)SnCH sub(2CH) sub(2)CO sub(2Me than in the corresponding ketotin compound, Cl) sub(3)SnCMe sub(2CH) sub(2)COMe, another chelated complex. Mixtures of 1 (X = Cl) and 1 (X = Br or I) undergo exchange reactions in solution, as shown by NMR spectra, to give all possible halide derivatives, (Cl sub(nX) sub(3)-nSnCH sub(2CH) sub(2)CO sub(2Me: n = 0-3: X = Br or I). A series of electronic structure calculations on ( 1: X = F, Cl, Br, I, SCN; R = Me) have been carried out at various levels of theory, including RHF and MP2. Hessian calculations have also been performed on these optimized geometries in order to obtain internal coordinate force constants. Comparisons of the theoretical and experimental structures of 1 (X = Cl, Br and I) are reported.)