ORGANOSTANNATE DERIVATIVES OF DICYCLOHEXYLAMMONIUM HYDROGEN 2,6-PYRIDINEDICARBOXYLATE - SOLUTION SOLID-STATE C-13,SN-119 NMR AND IN-VITRO ANTITUMOR-ACTIVITY OF BIS(DICYCLOHEXYLAMMONIUM) BIS(2,6-PYRIDINEDICARBOXYLATO)DIBUTYLSTANNATE, AND THE CRYSTAL-STRUCTURE OF ITS MONOHYDRATE/

Bis(dicyclohexylammonium) bis(2,6-pyridinedicarboxylato)dibutylstannat e is assigned seven-fold coordination at tin on the basis of its Sn-11 9 CP/MAS NMR chemical shift (delta=-424.9 ppm). The assignment has bee n corroborated by a crystal structure determination of its monohydrate , whose tin atom has the trans-C2SnNO4 pentagonal bipyramidal [Sn-C = 2.040(9), 2.067(8) Angstrom; C-Sn-C = 168.9(5)degrees] geometry. One 2 ,6-pyridine-dicarboxylato group chelates to the tin atom (Sn-O = 2.234 (4), 2.260(4); Sn-N = 2.279(5) Angstrom) whereas the other binds throu gh only one carboxyl -CO2 end (Sn-O = 2.416(5), 2.441(5) Angstrom). Hy drogen bonds link the cation and the stannate into a linear chain para llel to the b-axis. The lattice water molecule is hydrogen-bonded to t he free carboxyl end, The anhydrous compound showed higher in vitro an titumor activity than those of carboplatin and cisplatin when screened against breast (MCF-7, EVSAT), colonic (WiDr), ovarian (IGROV) and re nal (A498) carcinoma, and melanoma (M19 MEL) cell lines. (C) 1997 by J ohn Wiley & Sons, Ltd.