Microwave-assisted synthesis and characterization of novel symmetrical substituted 19-membered tetrathiadiaza metal-free and metallophthalocyanines and investigation of their biological activities

This work reports on a new symmetrically substituted metal-free phthalocyanine and its transition metal complexes which were prepared by a condensation of N,N′-[propan-1,3-diilbis(tiyoetan-2,1-diil)]bis(4-methylbenzenesulfonamid) (1) and 1,2-bis (2-iodomercaptoethyl)-4,5-dicyanobenzene (2) with NiCl2, ZnCl2, CoCl2, CuCl2,and PbO salts in 2-(dimethylamino)ethanol, respectively. The phthalocyanines bearing thia and aza donor atoms at the peripheral position were characterized by IR, UV–Vis, 1H NMR, 13C NMR, Mass spectra, and elemental analysis data. The thermal behaviors of 4–9 were investigated by TG/DTA. Novel phthalocyanines were also investigated for enlightening their possible biological activities by employing antimicrobial (antibacterial and antifungal), antineoplastic and antioxidative assays. Of all tested, four samples exhibited antimicrobial activity against test microorganisms, among which, Branhamella catarrhalis was the most sensitive one with a MIC value around 0.312 mg/mL followed by a yeast, Candida albicans (MIC. 0.625 mg/mL). Due to their colored nature, the samples were found not to be applicable for antioxidative and antineoplastic assays.