Structures and relationship between the 119SnNMR chemical shifts and pKa of their parent acids in organotin (I∇) carboxylates
Abstract
Ten di-n-butyltin(I∇) carboxylates [(nBu2Sn-OCOR′)2O]2 and nBu2Sn(OCOR′)2 (R′ = CCl3, CHCl2, CH2Cl, PhCH = CH, and 2,2,3,3-tetramethylcyclopropyl) were synthesized and characterized by IR, 1H, 13C, 119Sn NMR spectroscopy and elemental analysis. Together with other series of organotin(I∇) carboxylates, their structural features were discussed. The relationship between the 119Sn NMR chemical shifts in the organotin(I∇) carboxylates [(nBu2SnOCOR′)2O]2, nBu2Sn(OCOR′)2, nBu3SnOCOR′, Ph3SnOCOR′ and the pKa values of their parent acids R′COOH was studied. The results have shown that the log[-δ(119Sn)] of the same series of carboxylates is linearly related to the pKa of R′COOH. It seems that the better is the linearity between the log[−δ(119Sn)] and the pKa, the more analogous are the structures of the same series of carboxylates. © 1996 John Wiley & Sons, Inc.
