title: Synthesis, characterization, crystal structures and in vitro antistaphylococcal activity of organotin(IV) derivatives with 5,7-disubstituted-1,2,4-triazolo[1,5-a]pyrimidine.
abstract: New organotin(IV) complexes of 5,7-ditertbutyl-1,2,4-triazolo[1,5-a]pyrimidine (dbtp) and 5,7-diphenyl-1,2,4-triazolo[1,5-a]pyrimidine (dptp) with 1:1 and/or 1:2 stoichiometry were synthesized and investigated by X-ray diffraction, FT-IR and (119)Sn Mössbauer in the solid state and by (1)H and (13)C NMR spectroscopy, in solution. Moreover, the crystal and molecular structures of Et(2)SnCl(2)(dbtp)(2) and Ph(2)SnCl(2)(EtOH)(2)(dptp)(2) are reported. The complexes contain hexacoordinated tin atoms: in Et(2)SnCl(2)(dbtp)(2) two 5,7-ditertbutyl-1,2,4-triazolo[1,5-a]pyrimidine molecules coordinate classically the tin atom through N(3) atom and the coordination around the tin atom shows a skew trapezoidal structure with axial ethyl groups. In Ph(2)SnCl(2)(EtOH)(2)(dptp)(2) two ethanol molecules coordinate tin through the oxygen atom and the 5,7-diphenyl-1,2,4-triazolo[1,5-a]pyrimidine molecules are not directly bound to the metal center but strictly H-bonded, through N(3), to the OH group of the ethanol moieties; Ph(2)SnCl(2)(EtOH)(2)(dptp)(2) has an all-trans structure and the C-Sn-C fragment is linear. On the basis of Mössbauer data, the 1:2 diorganotin(IV) complexes are advanced to have the same structure of Et(2)SnCl(2)(dbtp)(2), while Me(2)SnCl(2)(dptp)(2) to have a regular all-trans octahedral structure. A distorted cis-R(2) trigonal bipyramidal structure is assigned to 1:1 diorganotin(IV) complexes. The in vitro antibacterial activities of the synthesized complexes have been tested against a group of reference pathogen micro-organisms and some of them resulted active with MIC values of 5μg/mL, most of all against staphylococcal strains, which shows their inhibitory effect.
authors: Dipartimento di Chimica Stanislao Cannizzaro, Università di Palermo, Palermo, Italy. assunta.girasolo@unipa.it
authors: Maria Assunta
authors: MA
authors: Girasolo
authors: Loredana
authors: L
authors: Canfora
authors: Piera
authors: P
authors: Sabatino
authors: Domenico
authors: D
authors: Schillaci
authors: Elisabetta
authors: E
authors: Foresti
authors: Simona
authors: S
authors: Rubino
authors: Giuseppe
authors: G
authors: Ruisi
authors: Giancarlo
authors: G
authors: Stocco
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D009947:Organotin Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D011743:Pyrimidines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D015204:Spectroscopy, Mossbauer; D013211:Staphylococcus aureus / Q000187:drug effects; D014230:Triazoles / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D009947:Organotin Compounds; D011743:Pyrimidines; D014230:Triazoles