title: A chelating diisocyanide ligand for cyclometalated Ir(III) complexes with strong and tunable luminescence.
abstract: We report the synthesis, structural characterisation and detailed photophysical description of three cationic cyclometalated iridium(III) complexes (2-4) bearing a chelating diisocyanide as the ancillary ligand (1 = 2,2''-diisocyano-1,1':3',1''-terphenyl). All compounds display irreversible reduction and oxidation potentials and emit from a triplet excited state centred on the cyclometalating ligands with lifetimes of several dozen microseconds, as commonly observed for other iridium(III) isocyanide complexes and further confirmed by DFT calculations. Room-temperature photoluminescence can be tuned from blue to orange upon variation of the cyclometalating ligands, and the related quantum yields range from around 30% in acetonitrile solution to nearly 80% in solid-state, as for complex 3 embedded in a 1% w/w poly(methyl methacrylate) matrix.
authors.affiliation: Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via P. Gobetti 101, 40129 Bologna, Italy. filippo.monti@isof.cnr.it nicola.armaroli@isof.cnr.it.
authors.forename: Filippo
authors.initials: F
authors.lastname: Monti
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy. letizia.sambri@unibo.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Baschieri
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy. letizia.sambri@unibo.it.
authors.forename: Elia
authors.initials: E
authors.lastname: Matteucci
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy. letizia.sambri@unibo.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mazzanti
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy. letizia.sambri@unibo.it.
authors.forename: Letizia
authors.initials: L
authors.lastname: Sambri
authors.affiliation: Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via P. Gobetti 101, 40129 Bologna, Italy. filippo.monti@isof.cnr.it nicola.armaroli@isof.cnr.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Barbieri
authors.affiliation: Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via P. Gobetti 101, 40129 Bologna, Italy. filippo.monti@isof.cnr.it nicola.armaroli@isof.cnr.it.
authors.forename: Nicola
authors.initials: N
authors.lastname: Armaroli