Proton-induced reversible modulation of the luminescent output of rhenium(I), iridium(III), and ruthenium(II) tetrazolate complexes
MetadataShow full item record
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, provide a useful tool for varying the main structural and electronic properties of the starting tetrazolate complexes. In this paper, we demonstrate how the use of a simple protonation–deprotonation protocol enables us to reversibly change, to a significant extent, the light-emission output and performance of a series of Re(I)-tetrazolate-based phosphors of the general formulation fac-[Re(N^N)(CO)3L], where N^N denotes diimine-type ligands such as 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) and L represents a series of different 5-aryl tetrazolates. Indeed, upon addition of triflic acid to these neutral Re(I) complexes, a consistent blue shift (Δλmax ca. 50 nm) of the emission maximum is observed and the protonated species also display increased quantum yield values (4–13 times greater than the starting compounds) and longer decay lifetimes. This alteration can be reversed to the initial condition by further treating the protonated Re(I) complex with a base such as triethylamine. Interestingly, the reversible modulation of luminescent features by the same protonation–deprotonation mechanism appears as a quite general characteristic of photoactive metal tetrazolate complexes, even for compounds in which the 2-pyridyl tetrazolate ligands coordinate the metal center with a bidentate mode, such as the corresponding Ir(III) cyclometalates [Ir(C^N)2L] and the Ru(II) polypyridyl derivatives [Ru(bpy)2L]+. In these cases, the protonation of the starting materials leads to red-shifted and more intense emissions for the Ir(III) complexes, while almost complete quenching is observed in the case of the Ru(II) analogues.
This research was supported under Australian Research Council's Discovery Projects funding scheme DP0986999
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/ic402187e
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 ...
Synthesis, photophysical and electrochemical investigation of dinuclear tetrazolato-bridged rhenium complexesWright, Phillip; Muzzioli, S.; Werrett, Melissa; Raiteri, Paolo; Skelton, B.; Silvester, Debbie; Stagni, S.; Massi, Massimiliano (2012)Starting from anionic tetrazole-based ligands, namely 5-(4’-cyanophenyl)tetrazolate and 5-(4’-pyridyl)tetrazolate, mononuclear and dinuclear complexes of fac-[Re(CO)3(phen)]+ (phen = 1,10-phenanthroline) were prepared and ...
Ligand-induced structural, photophysical, and electrochemical variations in tricarbonyl rhenium(I) tetrazolato complexesWright, Phillip; Affleck, M.; Muzzioli, S.; Skelton, B.; Raiteri, Paolo; Silvester, Debbie; Stagni, S.; Massi, Massimiliano (2013)Treatment of [Re(CO)5X] (X = Cl, Br) with 2-(2-tert-butyltetrazol-5-yl)pyridine yielded neutral mononuclear complexes by exchange of two CO ligands for the chelating tetrazolato ligand. Treatment of [Re(CO)5Br] with ...