Structure, EPR and UV-VIS and IR spectroelectrochemistry of reversibly reducible compounds [(C5Me5)IrCl(L)](PF6), L= 1,3-dimethyllumazine or 1,3-dimethylalloxazine
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)]
%0 Journal Article
%1 Heilmann.1996
%A Heilmann, Oliver
%A Hornung, Fridmann M.
%A Kaim, Wolfgang
%A Fiedler, Jan.
%D 1996
%J Journal of the Chemical Society, Faraday Transactions
%K EPR;crystal alloxazine complex complex;electrochem complex;flavin complex;pterin cyclopentadienyl cyclopentadienyl;EPR interaction iridium lumazine metal model;iridium model;spectroelectrochem prepn redn spectroelectrochem spectroelectrochem;lumazine spectroelectrochem;mol structure
%N 21
%P 4233--4238
%R 10.1039/FT9969204233
%T Structure, EPR and UV-VIS and IR spectroelectrochemistry of reversibly reducible compounds [(C5Me5)IrCl(L)](PF6), L= 1,3-dimethyllumazine or 1,3-dimethylalloxazine
%V 92
%X 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)]
@article{Heilmann.1996,
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{\textless}2) 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)]},
added-at = {2022-06-15T11:26:56.000+0200},
author = {Heilmann, Oliver and Hornung, Fridmann M. and Kaim, Wolfgang and Fiedler, Jan.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/288f1fd07a36d77993f3762901fa9bd14/huebleriac},
doi = {10.1039/FT9969204233},
interhash = {461f2f1f5b4d79e898e657f0be455135},
intrahash = {88f1fd07a36d77993f3762901fa9bd14},
issn = {0956-5000},
journal = {Journal of the Chemical Society, Faraday Transactions},
keywords = {EPR;crystal alloxazine complex complex;electrochem complex;flavin complex;pterin cyclopentadienyl cyclopentadienyl;EPR interaction iridium lumazine metal model;iridium model;spectroelectrochem prepn redn spectroelectrochem spectroelectrochem;lumazine spectroelectrochem;mol structure},
number = 21,
pages = {4233--4238},
timestamp = {2022-06-15T09:26:56.000+0200},
title = {Structure, EPR and UV-VIS and IR spectroelectrochemistry of reversibly reducible compounds [(C5Me5)IrCl(L)](PF6), L= 1,3-dimethyllumazine or 1,3-dimethylalloxazine},
volume = 92,
year = 1996
}