Synthesis, spectral characterization and biological studies of some organotin(IV) complexes of L-proline, trans-hydroxy-L-proline and L-glutamine

New organotin(IV) complexes of the general formula R3Sn(L) (where R=Me, n-Bu and HL=L-proline; R=Me, Ph and HL=transhydroxy-L-proline and L-glutamine) and R2Sn(L)(2) (where R=n-Bu, Ph and HL=L-proline; R=Ph, HL=trans-hydroxy-L-proline) have been synthesized by the reaction of RNSnCL4-n (where n=2 or 3) with sodium salt of the amino acid (HL). n-Bu2Sn(Pro)(2) was synthesized by the reaction of n-Bu2SnO with L-proline under azeotropic removal of water. The bonding and coordination behavior in these complexes have been discussed on the basis of IR and Sn-119 Mossbauer spectroscopic studies in the solid-state. Their coordination behavior in solution has been discussed with the help of multinuclear (H-1, C-13 and Sn-119) NMR spectral studies. The Sn-119 Mossbauer and IR studies indicate that L-proline and trans-hydroxy-L-proline show similar coordination behavior towards organotin(IV) compounds. Penta-coordinate trigonal-bipyramidal and hexacoordinate octahedral structures, respectively, have been proposed for the tri- and diorganotin(IV) complexes Of L-proline and trans-hydroxy-L-proline, in which the carboxylate group acts as bidentate group. L-Glutamine shows different coordination behavior towards organotin(IV) compounds, it acts as monoanionic bidentate ligand coordinating through carboxylate and amino group. The triorganotin(IV) complexes of L-glutamine have been proposed to have trigonal-bipyramidal environment around tin. The newly synthesized complexes have been tested for their antiinflammatory and cardiovascular activities. Their LD50 values are >1000 mg kg(-1). (c) 2005 Elsevier B.V. All rights reserved.