%0 Journal Article %1 Berger.1998 %A Berger, Sascha %A Klein, Axel %A Kaim, Wolfgang %A Fiedler, Jan. %D 1998 %J Inorganic Chemistry %K bipyridazine bipyridine carbonyl complex complex;methylpyrazinium complex;tetraazaphenanthrene diimine electroredn electroredn;bipyridine electroredn;bipyrimidine electroredn;electroredn electroredn;spectroelectrochem methylbipyridinium methylpyrazinium rhenium %N 21 %P 5664--5671 %R 10.1021/IC980268F %T Variable Reduction Sequences for Axial (L) and Chelate Ligands (N$\cap$N) in Rhenium(I) Complexes (N$\cap$N)Re(CO)3(L)n %V 37 %X The rhenium(I) compds. (N$\cap$N)Re(CO)3(MQ)(PF6)2 (N$\cap$N = 2,2'-bipyridine (bpy), 2,2'-bipyrimidine (bpym), 3,3'-bipyridazine (bpdz), or 1,4,7,10-tetraazaphenanthrene (tap) and MQ+ = N-methyl-4,4'-bipyridinium) undergo four 1-electron redn. steps which could be analyzed using cyclic voltammetry, EPR, IR, and UV/visible spectroelectrochem. Due to the rather low-lying p* orbital of tap, the corresponding compd. shows electron uptake by N$\cap$N each time before MQ+ is reduced. The opposite is obsd. for the complexes of the other chelate ligands N$\cap$N, however, and the p*(N$\cap$N) orbital approaches the p*(MQ+) level in the order bpy \textless bpym \textless bpdz. Remarkably, the redn. processes of MQ+ and bpdz in (bpdz)Re(CO)3(MQ)(PF6)2 are sepd. by only 74 mV as deduced from IR spectroelectrochem. anal. On redn. of the related compd. (bpy)Re(CO)3(mpz)(PF6)2 (mpz+ = N-methylpyrazinium), the 1st two electrons are added to the axial ligand which has a lower-lying p* orbital than MQ+ and cannot undergo intramol. twisting. on SciFinder(R)

@article{Berger.1998, abstract = {The rhenium(I) compds. [(N$\cap$N)Re(CO)3(MQ)](PF6)2 (N$\cap$N = 2,2'-bipyridine (bpy), 2,2'-bipyrimidine (bpym), 3,3'-bipyridazine (bpdz), or 1,4,7,10-tetraazaphenanthrene (tap) and MQ+ = N-methyl-4,4'-bipyridinium) undergo four 1-electron redn. steps which could be analyzed using cyclic voltammetry, EPR, IR, and UV/visible spectroelectrochem. Due to the rather low-lying \textgreek{p}* orbital of tap, the corresponding compd. shows electron uptake by N$\cap$N each time before MQ+ is reduced. The opposite is obsd. for the complexes of the other chelate ligands N$\cap$N, however, and the \textgreek{p}*(N$\cap$N) orbital approaches the \textgreek{p}*(MQ+) level in the order bpy {\textless} bpym {\textless} bpdz. Remarkably, the redn. processes of MQ+ and bpdz in [(bpdz)Re(CO)3(MQ)](PF6)2 are sepd. by only 74 mV as deduced from IR spectroelectrochem. anal. On redn. of the related compd. [(bpy)Re(CO)3(mpz)](PF6)2 (mpz+ = N-methylpyrazinium), the 1st two electrons are added to the axial ligand which has a lower-lying \textgreek{p}* orbital than MQ+ and cannot undergo intramol. twisting. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Berger, Sascha and Klein, Axel and Kaim, Wolfgang and Fiedler, Jan.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/28217fa3f40af9ab028e98a9cd32f59d6/huebleriac}, doi = {10.1021/IC980268F}, interhash = {3ed6fdb8b9d9e13987330b3c14b43a4c}, intrahash = {8217fa3f40af9ab028e98a9cd32f59d6}, issn = {0020-1669}, journal = {Inorganic Chemistry}, keywords = {bipyridazine bipyridine carbonyl complex complex;methylpyrazinium complex;tetraazaphenanthrene diimine electroredn electroredn;bipyridine electroredn;bipyrimidine electroredn;electroredn electroredn;spectroelectrochem methylbipyridinium methylpyrazinium rhenium}, number = 21, pages = {5664--5671}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Variable Reduction Sequences for Axial (L) and Chelate Ligands (N$\cap$N) in Rhenium(I) Complexes [(N$\cap$N)Re(CO)3(L)]n}, volume = 37, year = 1998 }