%0 Journal Article %1 Knoedler.2002b %A Knoedler, Axel %A Wanner, Matthias %A Fiedler, Jan %A Kaim, Wolfgang. %D 2002 %J Journal of the Chemical Society, Dalton Transactions %K carbonyl crystal electrochem imidazolylglyoxal imidazolylglyoxal;rhenium prepn rhenium structure %N 15 %P 3079--3084 %R 10.1039/b202636h %T Coordination ambivalence of the electroactive bis-chelate ligand bis(1-methyl-2-imidazolyl)glyoxal (BIG) in mononuclear and dinuclear complexes with Re(CO)3Cl %X Bis(1-methyl-2-imidazolyl)glyoxal (BIG) (I) is reversibly reduced to an EPR, IR and UV-visible spectroelectrochem. detectable a-diketyl radical anion. As a ligand BIG can coordinate through the carbonyl oxygen centers O and O' and through the imine nitrogen atoms N and N' of the imidazolyl rings. For fac-(BIG)Re(CO)3Cl metal coordination occurs via both imine nitrogen centers, leading to a nonplanar seven-membered chelate ring with a free a-dicarbonyl moiety as evident from x-ray structural anal. For dinuclear (m-BIG)fac-Re(CO)3Cl2 three essentially different structural coordination alternatives A-C are possible in a bis-chelate situation: Sep. N,N'- and O,O'-coordination with one seven-membered and one five-membered chelate ring (A), N,O'- and N',O-coordination with two edge-sharing six-membered chelate rings (B), or N,O- and N',O'-coordination with two five-membered chelate rings and free rotation around the C(O)-C'(O') single bond. Spectroscopic, electrochem. and spectroelectrochem. results obtained for the mono- and di-nuclear complexes suggest the p-conjugated structure alternative B for (m-BIG)fac-Re(CO)3Cl2. on SciFinder(R)

@article{Knoedler.2002b, abstract = {Bis(1-methyl-2-imidazolyl)glyoxal (BIG) (I) is reversibly reduced to an EPR, IR and UV-visible spectroelectrochem. detectable \textgreek{a}-diketyl radical anion. As a ligand BIG can coordinate through the carbonyl oxygen centers O and O' and through the imine nitrogen atoms N and N' of the imidazolyl rings. For fac-(BIG)Re(CO)3Cl metal coordination occurs via both imine nitrogen centers, leading to a nonplanar seven-membered chelate ring with a free \textgreek{a}-dicarbonyl moiety as evident from x-ray structural anal. For dinuclear (\textgreek{m}-BIG)[fac-Re(CO)3Cl]2 three essentially different structural coordination alternatives A-C are possible in a bis-chelate situation: Sep. N,N'- and O,O'-coordination with one seven-membered and one five-membered chelate ring (A), N,O'- and N',O-coordination with two edge-sharing six-membered chelate rings (B), or N,O- and N',O'-coordination with two five-membered chelate rings and free rotation around the C(O)-C'(O') single bond. Spectroscopic, electrochem. and spectroelectrochem. results obtained for the mono- and di-nuclear complexes suggest the \textgreek{p}-conjugated structure alternative B for (\textgreek{m}-BIG)[fac-Re(CO)3Cl]2. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Knoedler, Axel and Wanner, Matthias and Fiedler, Jan and Kaim, Wolfgang.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2d671a45c80af888a69958146854f0455/huebleriac}, doi = {10.1039/b202636h}, interhash = {8fbcd16ba5e58af5521a4264893c1646}, intrahash = {d671a45c80af888a69958146854f0455}, issn = {1472-7773}, journal = {Journal of the Chemical Society, Dalton Transactions}, keywords = {carbonyl crystal electrochem imidazolylglyoxal imidazolylglyoxal;rhenium prepn rhenium structure}, number = 15, pages = {3079--3084}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Coordination ambivalence of the electroactive bis-chelate ligand bis(1-methyl-2-imidazolyl)glyoxal (BIG) in mononuclear and dinuclear complexes with Re(CO)3Cl}, year = 2002 }