Organotin adducts of indomethacin: synthesis, crystal structures and spectral characterization of the first organotin complexes of indomethacin

The complexes [Me-2(Indo)SnOSn(Indo)Me-2](2), (1) [Bu-2(Indo)SnOSn(Indo)Bu-2](2), (2), where Hindo is indomethacin, have been prepared and structurally characterized by means of Sn-119 Mossbauer, vibrational, and NMR (H-1 and C-13) spectroscopy. The crystal structures of the complexes [Me-2(Indo)SnOSn(Indo)Me-2](2) (.) 2C(4)H(8)O(2), 3 and 2 have been determined by X-ray crystallography. Each structure is centro-symmetric and features a central rhombus Sn2O2 unit with two additional tin atoms linked at the O atoms. Pairs of tin atoms are bridged by bidentate carboxylate ligands and by a monoatomic bridging oxygen. C-H --> pi, pi --> pi, stacking interactions, inter and intramolecular hydrogen bonds stabilize the structures 2 and 3. Complexes 2 and 3 are self-assembled via pi --> pi. C-H-pi and stacking interactions. (C) 2004 Elsevier Ltd. All rights reserved.