6533b870fe1ef96bd12d0656

RESEARCH PRODUCT

Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid. Synthesis, spectroscopic characterization, in vitro antimicrobial activity and X-ray crystallography

subject

description

Triorganotin(IV) complexes of the 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid (HL), Me 3 SnL(H 2 O), ( 1 ), [ n -Bu 3 SnL] 2 (H 2 O), ( 2 ), Ph 3 SnL(MeOH), ( 3 ), were synthesized by reacting the amino acid with organotin(IV) hydroxides or oxides in refluxing methanol. The complexes have been characterized by elemental analysis, 1 H, 13 C and 119 Sn NMR, IR, Raman and 119 Sn Mossbauer spectroscopic techniques. Single crystal X-ray diffraction data were obtained for compounds ( 2 ) and ( 3 ). Ph 3 SnL(MeOH) presents a trigonal bipyramidal structure with the organic groups on the equatorial plane and the axial positions occupied by a ligand molecule, coordinated to tin through the carboxylate, and a solvent molecule, MeOH. A similar structure is proposed for Me 3 SnL(H 2 O) on the basis of analytical and spectroscopic data. The tributyltin(IV) derivative, [ n -Bu 3 SnL] 2 (H 2 O), is characterized by two different tin sites with similar tbp geometry featured by butyl groups on the equatorial plane. Sn(1) and Sn(2) atoms are axially bridged by a ligand molecule binding through the N(4) and the carboxylate group; the two coordination spheres are saturated by another ligand molecule, binding the metal through the carboxylate group, and a water molecule, respectively. Antimicrobial tests on compounds 1 and 2 showed in vitro activity against Gram-positive bacteria.