Triethyl-ammonium bis-(2-oxido-2,2-diphenyl-acetato-κO,O)anti-monate(III).

The coordination around the Sb atom in the title compound, (C(6)H(16)N)[Sb(C(14)H(10)O(3))(2)], is fourfold in a pseudo-trigonal-bipyramidal pattern in which one of the equatorial sites is occupied by the stereoactive lone pair of electrons. The four ligating atoms comprise the hydoxylate and carboxyl-ate O atoms from two independent benzilate ligands, each of which forms a five-membered chelating ring, spanning an axial and an equatorial site about the Sb atom. The hydroxy-late atoms occupy the two equatorial sites, and the carboxyl-ate atoms are in the pseudo-axial sites; the O-Sb-O angle is 147.72 (5)°. One carboxyl-ate group shows quite different bond lengths from those of the other group; one O atom is clearly the carbonyl atom and the other O atom the hydroxy-late atom. In the other ligand, there is less distinction in the C-O bonds. This is presumably related to the carbonyl O atom being the acceptor atom of a strong N-H⋯O hydrogen bond, which links the ammonium cation to the Sb complex anion.

S-methyldithiocarbazate and its Schiff bases: evaluation of bondings and biological properties.

Eight selective nitrogen-sulfur donor ligands have been synthesized from the condensation of S-methyldithiocarbazate (SMDTC) with aldehydes and ketones with a view to evaluating their antimicrobial and cytotoxic activities, and also to correlate the biological properties with the structure of the ligands. The compounds were all characterized by elemental analyses and other physicochemical techniques. SMDTC and the Schiff bases were screened for antimicrobial and cytotoxic activities. SMDTC showed very large inhibition zones (24-44 mm) against bacteria and fungi with a minimum inhibitory concentration (MIC) of 390-25,000 and 1562-6250 microg ml(-1), against different bacteria and fungi, respectively. Streptomycin and nystatin were used as the internal standards against bacteria and fungi, respectively. SMDTC along with its Schiff bases with pyridine-2-carboxaldehyde, acetylacetone and 2,3-butanedione were strongly antifungal and the MIC values were comparable to nystatin. Most of the Schiff bases were strongly cytotoxic. In particular, those with pyridine-2-carboxaldehyde and 2,3-butanedione have CD(50) values of 5.5, 1.9-2.0 microg ml(-1), respectively, against leukemic cells, while against colon cancer cells, the values were 3.7 and 2.0 microg ml(-1), respectively. The glyoxal Schiff base was strongly active only against leukemic cell with CD(50) value of 4.0 microg ml(-1). The present findings have been compared with standard drugs.