%0 Journal Article %1 Bulak.2011b %A Bulak, Ece %A Varnali, Tereza %A Schwederski, Brigitte %A Sarkar, Biprajit %A Hartenbach, Ingo %A Fiedler, Jan %A Kaim, Wolfgang. %D 2011 %J Dalton Transactions %K chloro complex complex;platinum crystal cyclic gold methylimidazolylquinoxaline platinum prepn structure voltammetry %N 12 %P 2757--2763 %R 10.1039/c0dt01282c %T 2,3-Bis(1-methylimidazol-2-yl)quinoxaline (bmiq), a new ligand with decoupled electron transfer and metal coordination sites: The very different redox behaviour of isoelectronic complexes with [PtCl2] and [AuCl2]+ %V 40 %X The potentially ambidentate heterocyclic ligand 2,3-bis(1-methylimidazol-2-yl)quinoxaline (bmiq) was obtained from 2,3-bis(1-methylimidazol-2-yl)glyoxal and 1,2-diaminobenzene. Its coordination to PtCl2 and to the isoelectronic [AuCl2]+ in [AuCl2(bmiq)](AuCl4) occurs via the imine N donors of the imidazolyl groups, giving seven-membered chelate rings with boat conformation. According to the spectroelectrochem. (UV-visible-NIR, ESR), the reversible electron addn. to the [PtCl2(bmiq)] and the free ligand takes place in the (non-coordinated) quinoxaline part of the mol., similarly as for related complexes of dipyrido[3,2-a:2',3'-c]phenazines (dppz), 2,3-bis(2-pyridyl)quinoxalines (bpq) and 2,3-bis(dialkylphosphino)quinoxalines (QuinoxP). DFT calcns. confirm the exptl. results (structures, spectroscopy) and also point to the coordination potential of the quinoxaline N atoms. The electron addn. to [AuCl2(bmiq)]+ takes place not at the ligand but at the metal site, according to exptl. and DFT results. [on SciFinder(R)]

@article{Bulak.2011b, abstract = {The potentially ambidentate heterocyclic ligand 2,3-bis(1-methylimidazol-2-yl)quinoxaline (bmiq) was obtained from 2,3-bis(1-methylimidazol-2-yl)glyoxal and 1,2-diaminobenzene. Its coordination to PtCl2 and to the isoelectronic [AuCl2]+ in [AuCl2(bmiq)](AuCl4) occurs via the imine N donors of the imidazolyl groups, giving seven-membered chelate rings with boat conformation. According to the spectroelectrochem. (UV-visible-NIR, ESR), the reversible electron addn. to the [PtCl2(bmiq)] and the free ligand takes place in the (non-coordinated) quinoxaline part of the mol., similarly as for related complexes of dipyrido[3,2-a:2',3'-c]phenazines (dppz), 2,3-bis(2-pyridyl)quinoxalines (bpq) and 2,3-bis(dialkylphosphino)quinoxalines (QuinoxP). DFT calcns. confirm the exptl. results (structures, spectroscopy) and also point to the coordination potential of the quinoxaline N atoms. The electron addn. to [AuCl2(bmiq)]+ takes place not at the ligand but at the metal site, according to exptl. and DFT results. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Bulak, Ece and Varnali, Tereza and Schwederski, Brigitte and Sarkar, Biprajit and Hartenbach, Ingo and Fiedler, Jan and Kaim, Wolfgang.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2fd752b2375d2dd41e93f3b1029051b67/huebleriac}, doi = {10.1039/c0dt01282c}, interhash = {c9b9214acfee8559c897e03e2a2ebe44}, intrahash = {fd752b2375d2dd41e93f3b1029051b67}, issn = {1477-9226}, journal = {Dalton Transactions}, keywords = {chloro complex complex;platinum crystal cyclic gold methylimidazolylquinoxaline platinum prepn structure voltammetry}, number = 12, pages = {2757--2763}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {2,3-Bis(1-methylimidazol-2-yl)quinoxaline (bmiq), a new ligand with decoupled electron transfer and metal coordination sites: The very different redox behaviour of isoelectronic complexes with [PtCl2] and [AuCl2]+}, volume = 40, year = 2011 }