PRODUCTS OF COMPLEXATION OF SnCl4 WITH SALICYLOYL-( β-, γ-PYRIDINOYL)HYDRAZONES OF 2- AND 4-METHOXYALDEHYDES, THEIR ANTIMICROBIAL ACTIVITY

Abstract

Complexes of different types: molecular chelates [SnCl4(HL1,2)]∙nCH3CN (I, II) and zwitterionic [SnCl4(L∙H3-6)] ∙ nCH3CN (III-VI) – were synthesized by interaction of SnCl4 withsalicyloyl-(HL1,2), β-,γ- pyridinoyl)hydrazones (НL3-6) of 2- and 4-methoxyaldehydes. Complexes I, II, unlike III-VI, are subjected to solvolysis in DMF by the reaction: [SnCl4(HL1,2)]∙+ДМФА → [SnCl3(HL1,2)(ДМФА)]∙+ Cl–. The mass spectra of I, II contains peaks of ions with m/z 36[HCl]+, 225[SnCl3]+ and hydrazone 270[HL1,2]+, spectra of III-VI – 36[HCl]+ and480[120SnCl3(L3-6)]+. In the IR spectra of I, II bands ν(C=O), ν(NH) are displaced to lower frequencies as compared to hydrazones; in the spectra of III-VI they are absent; in I–VI appear new ν(Sn–О) and ν(Sn–N), retained frequency νas(СН3)/νs(СН3), νas(CAr-O-C) and ν(ОH) (I, II). This indicated, that in I–VI realized bidentate coordination of hydrazones in different forms: ketone О(С=О)–N(CH=N) (I, II) or enol О(С–О)–N(CH=N) (III–VI) in the presence of a protonated (HN+Ру) pyridine nitrogen atom. Thermolysis of I–VI begins by dehydrochlorination, which for III–VI occurs at a higher temperature:~ 230(III, V) and 275 (IV, VI) with formationof the final product SnO2. A primary screening of hydrazones and II, V, VI on the manifestation of antimicrobial activity was conducted, it is shown that depending on the concentrationsof 25, 50 and 100 mcg/ml they able to significantly inhibit or induce the accumulation of biomass strains of E. coli, S. аureus, B. subtilis. It was found 100% inhibition complex II of all cultures and VI – only B. subtilis.