Four coordinate tin complexes: Synthesis, characterization, thermodynamic and theoretical calculations
摘要:
In this work, two new Sn(IV) complexes, [SnLx]Cl-2 where (L-x)(2-) is the deprotonated form of 5-A-salabza-H-2 = N,N'-bis(salicylidene)-2-aminobenzylamine and A = 5-OMe, 5-H, 5-NO2, 5-Br, were synthesized and fully characterized by UV-Vis, FT-IR, H-1 NMR, C-13 NMR, Sn-119 NMR spectroscopies, mass spectrometry and elemental analysis. The thermodynamic formation constants of the complexes were determined spectrophotometrically at 25 degrees C in acetonitrile. The trend of formation constants of the complexes are as: 5-OMe > 5-H > 5-NO2 > 5-Br and Ph2SnCl2 > Me2SnCl2 > n-Bu2SnCl2. DFT/B3LYP molecular orbital calculations were carried out for the 5-H substituent isomer, [SnL2](2+), in an attempt to explain the structure of complexes. The optimized resulting geometries, vibrational frequencies and the NMR resonances of the complexes are discussed. (C) 2013 Elsevier B.V. All rights reserved.