Abstract
In an attempt to model possible metal-pterin or metal-flavin ligand interactions [(C5Me5)IrCl(L)](PF6) (L= 1,3-dimethyllumazine or 1,3-dimethylalloxazine) were prepd. and their structure, spectroscopy and spectroelectrochem. (EPR, IR, UV-visible) compared with results for the corresponding Rh analogs. The x-ray crystal structure of [(C5Me5)IrCl(DML)](PF6), DML = 1,3-dimethyllumazine, shows O4/N5 chelate coordination of Ir with a shorter bond to the N center [2.103(4) vs. 2.186(3) \AA], a slightly more unsym. situation than that found in the Rh analog. Electrochem. studies (cyclic voltammetry, polarog.) showed largely reversible 1-electron redn. processes to radical species [(C5Me5)IrCl(L)].bul. which allowed the authors to study the EPR, IR and UV-visible response to the redn. Although the EPR spectra of the Ir compds. remained unresolved, the low g factors (g\textless2) and particular line shapes revealed small but significant contributions from the heavy-metal center. Long-wavelength absorptions at $\sim$600 nm and low-energy shifts of the carbonyl stretching bands confirm the formulation [(C5Me5)IrIIICl(L-I)].bul. for the electronic situation. [on SciFinder(R)]
Users
Please
log in to take part in the discussion (add own reviews or comments).
