The heterocyclic ligands [1,2,4]triazolo-[1,5-a]pyrimidine (tp) and 5,7-dimethyl-[1,2,4]triazolo-[1,5-a]pyrimidine (dmtp), react withdiorganotin dichlorides giving the addition compounds Me2SnCl2(tp)2, Et2SnCl2(tp)2, Me2SnCl2(dmtp)2, Et2SnCl2(dmtp)2,Bu2SnCl2(dmtp), Ph2SnCl2(dmtp). The organotin:ligand stoichiometry goes from 1:2 to 1:1 by increasing the steric hindrance of theorganic groups bound to tin. The compounds have been characterized by means of infrared, 119Sn Mo¨ssbauer and 1H AND 13CNMR spectroscopy.The ligands presumably coordinate to tin classically through the nitrogen atom at the position 3. The 1:1 complexes adopt trigonalbipyramidal structures, with the organic groups on the equatorial plane and the ligand in the apical position. All-trans octahedral structuresare inferred for the 1:2 complexes, except for Et2SnCl2(tp)2, characterized by a skew-trapezoidal structure.119Sn Mo¨ssbauer measurements, at room temperature, in concomitance with DFT calculations, performed on isomeric structures ofR2SnCl2(tp)2 (R = Me, Et), allowed us to conclude that the all-trans octahedral coordination induces self-assembly in the solid state,possibly accomplished through p–p stacking interactions among the planar ligands coordinated to the organotin(IV) compound, whilethe skew-trapezoidal structure attributed to Et2SnCl2(tp)2, induces the formation of monomeric adducts in the solid state.In vitro antimicrobial tests showed that [n-Bu2SnCl2(dmtp)] has interesting properties as anti Gram-positive and antibiofilm agent.
|Numero di pagine||9|
|Rivista||Journal of Organometallic Chemistry|
|Stato di pubblicazione||Published - 2006|
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