Synthesis, structural investigation, antibacterial and DFT studies of complexes derived from a cholesteryl dithiophosphonate ligand with some thio-metallolane and thio-metallocane heterocycles of As(III) and Sb(III)

摘要

The synthesis and characterization of six new O-cholesteryl-dithiophosphonates containing thio-metalloheterocycles of As(III) and Sb(III); (CH2S)(2)As[S2P(cholesteryl)(4-MeOC6H5)] (2), (CH2S)(2)Sb[S2P(cholesteryl)(4-MeOC6H5)] (3), O(CH2CH2S)(2)As [S2P(cholesteryl)(4-MeOC6H5)] (4), O(CH2CH2S )(2)Sb[S2P(cholesteryl) (4-MeOC6H5)] (5), S(CH2CH2S)(2)As [S2P(cholesteryl)(4-MeOC6H5)] (6), and S(CH2CH2S)(2)Sb[S2P(cholesteryl)(4-MeOC6H5)] (7) are reported. 2-7 have been prepared from the reaction between the triethylammonium salt of O-3 beta-cholest 5 en 3 yl (4-methoxyphenyl) dithiophosphonate (1) and five and eight membered chloro-metalloheterocycles of As(III) and Sb(III). The obtained compounds have been characterized by elemental analyses, IR and NMR (H-1, C-13, and P-31) spectroscopy. The P-31 NMR data suggest that the dithiophosphonate ligand presents, in solution, a bidentate coordination. The structures of 3 and 4 were determined by X-ray single crystal analysis, that correspond to the first examples of such determinations in Group 15 dithiophosphonates, showing an anisobidentate coordination mode of the dithiophosphonate moiety. Sb(III) and As(III) in compounds 3 and 4 present tetracoordination and pentacoordination, respectively. The pentacoordination in 4 is achieved through a 1,5 transannular As center dot center dot center dot O interaction. Antibacterial assays were performed and the activity was correlated with the electronic distribution and molecular shape, employing their geometrical structures, Mulliken partial charges, dipole moments and Molecular Electrostatic Potential maps from DFT calculations.