Halogenated rhenacarboranes: optoelectronic behavior of the iodinated rhenacarborane complex anion [3,3,3-(CO)3-8-I-closo-3,1,2-ReC2B9H10]−

The rhenacarborane complex anions [3,3-(CO)2-3,3-Cl2-closo-3,1,2-ReC2B9H11]− and [3,3,3-(CO)3-8-I-closo-3,1,2-ReC2B9H10]− have been isolated and structurally characterized. The latter has been shown to have a rich optoelectronic behavior, with quasi-reversible two-electron or two reversible, sequential one-electron oxidations in MeCN and CH2Cl2, respectively. A cyclic oxidation product (shown) has been implicated in this redox chemistry, and a related exciplex species is believed to be responsible for long-lived blue phosphorescence of the monoanion in 2-methyltetrahydrofuran at 77 K (λem = 455 nm, τ = 1.65 ms).