Methylation of Ir(III)-tetrazolato complexes: An effective route to modulate the emission outputs and to switch to antimicrobial properties
Embargo Lift Date
MetadataShow full item record
Two neutral cyclometalated Ir(iii)-tetrazolato complexes that differ by variations of the substituents on either the phenylpyridine or the tetrazolate ligand have been converted into the corresponding methylated and cationic analogues. NMR ( 1 H and 13 C) characterization of the Ir(iii) complexes provided the results in agreement with the chemo- and regioselective character of methylation at the N-3 position of the Ir(iii)-coordinated tetrazolato ring. This evidence was further corroborated by the analysis of the molecular structures of the cationic complexes obtained by X-ray diffraction. In view of the photophysical properties, the addition of a methyl moiety to neutral Ir(iii) tetrazolates, which behave as sky-blue or orange phosphors, caused a systematic red shift of their phosphorescence output. The transformation of neutral Ir(iii) tetrazolates into cationic Ir(iii)-tetrazole complexes was screened for any eventual antimicrobial activity in vitro against Gram negative (E. coli) and Gram positive (D. radiodurans) microorganisms. While both kinds of complexes were not active against E. coli, the conversion of the neutral Ir(iii) tetrazolates into the corresponding methylated and cationic Ir(iii)tetrazole derivatives determined the turn-on of a good to excellent antimicrobial activity toward Gram positive Deinococcus radiodurans, a non-pathogenic bacterium that is listed as one of the toughest microorganisms in light of its outstanding resistance to radiation and oxidative stress.
Showing items related by title, author, creator and subject.
Negatively charged Ir(III) cyclometalated complexes containing a chelating bis-tetrazolato ligand: Synthesis, photophysics and the study of reactivity with electrophilesFiorini, V.; Zacchini, S.; Raiteri, Paolo; Mazzoni, R.; Zanotti, V.; Massi, Massimiliano; Stagni, S. (2016)The bis-tetrazolate dianion [1,2 BTB]2−, which is the deprotonated form of 1,2 bis-(1H-tetrazol-5-yl)benzene [1,2-H2BTB], is for the first time exploited as an ancillary N^N ligand for negatively charged [Ir(C^N)2(N^N)]−-type ...
Werrett, M.; Huff, G.; Muzzioli, S.; Fiorini, V.; Zacchini, S.; Skelton, B.; Maggiore, A.; Malicka, J.; Cocchi, M.; Gordon, K.; Stagni, S.; Massi, Massimiliano (2015)The irreversible reaction of methyl triflate with neutral Re(I) tetrazolato complexes of the type fac-[Re(diim)(CO)3(L)], where diim is either 1,10-phenanthroline or 2,2′-bipyridine and L is a para substituted 5-aryltetrazolate, ...
Proton-induced reversible modulation of the luminescent output of rhenium(I), iridium(III), and ruthenium(II) tetrazolate complexesWerrett, Melissa; Muzzioli, S.; Wright, Phillip; Palazzi, A.; Raiteri, Paolo; Zacchini, S.; Massi, Massimiliano; Stagni, S. (2014)One of the distinct features of metal–tetrazolate complexes is the possibility of performing electrophilic additions onto the imine-type nitrogens of the coordinated five-membered ring. These reactions, in particular, ...