Syntheses, structural characterizations and properties of 12-MC-4 organotin(IV) metallacrowns: [12-MCRSn(IV)N(shi)-4] and [12-MCRSn(IV)N(Clshi)-4] (R = Et, Bu, Ph; H3shi = salicylhydroxamic acid; H3Clshi = 5-chlorosalicylhydroxamic acid)

Five 12-MC-4 organotin(IV) metallacrowns(MCs) with the types of [12-MCRSn(IV)N(shi)-4] (R = Et (1), Bu (2), Ph (3); H3Shi = salicylhydroxamic acid) and [12-MCRSn(IV)N(Clshi)-4] (R = Et (4), Bu (5), H3Clshi = 5-chlorosalicylhydroxamic acid) have been synthesized and characterized by elemental analyses, IR and TGA. X-ray single-crystal diffraction analyses were also carried out and showed that all complexes 1–5 contain a neutral 12-membered metallacrown ring which is formed by the succession of four repeating units of –[Sn–N–O]–, indicating the substituents on the tin(IV) atom are uninfluential in coordination of organotin(IV) centers with hydroxamic acid. Fluorescence properties of complexes 1–5 have been investigated, where complex 3 displays strong fluorescence emissions in the blue region. In addition, antitumor activities of complexes 4 and 5 have also been tested, and both the complexes exhibit weak activity towards human hepatocellular carcinoma cell line (Bel-7402) and Hela cell line.

Graphical abstractFive 12-MC-4 organotin(IV) metallacrowns(MCs) with the types of [12-MCRSn(IV)N(shi)-4] (R = Et (1), Bu (2), Ph (3); H3shi = salicylhydroxamic acid) and [12-MCRSn(IV)N(Clshi)-4] (R = Et (4), Bu (5), H3Clshi = 5-chlorosalicylhydroxamic acid) have been synthesized and characterized by elemental analyses, IR, TGA and X-ray single-crystal diffraction analyses, which showed that the substituents on the tin(IV) atom are uninfluential in coordination of organotin(IV) with hydroxamic acid. Fluorescence properties of complexes 1–5 have been investigated, where complex 3 displays strong fluorescence emissions in the blue region, antitumor activities of complexes 4 and 5 have also been tested, both the complexes exhibit weak activity towards human hepatocellular carcinoma cell line (Bel-7402) and Hela cell line.Figure optionsDownload full-size imageDownload as PowerPoint slide