%0 Journal Article %1 Klein.1996 %A Klein, Axel %A Vogler, Conny %A Kaim, Wolfgang. %D 1996 %J Organometallics %K bidiazine bromo chloro complex complex;EPR diimine halo redn rhenium substitution;electrochem substitution;rhenium substitution;substitution %N 1 %P 236--244 %R 10.1021/OM950500E %T The d in 18 + d Electron Complexes: Importance of the Metal/Ligand Interface for the Substitutional Reactivity of \dqRe(0)\dq Complexes (a-diimine-)ReI(CO)3(X) %V 15 %X The factors detg. the electron transfer-induced halide labilization in complexes (a-diimine)Re(CO)3(Hal), Hal = Cl and Br, were systematically studied via EPR and cyclic voltammetry in the presence of substituting ligands such as triphenylphosphine, cyanide, or acetonitrile. The a-diimines employed were the four isomeric bidiazines (bdz) 3,3'-bipyridazine, 2,2'-bipyrazine, and 2,2'- and 4,4'-bipyrimidine and the nonarom. a-diimines 1,4-di-tert-butyl-1,4-diaza-1,3-butadiene (dab) and 1,3-di-tert-butylsulfurdiimine (sdi). For comparison, (L)Re(CO3)Cl (L = 2,2'-bipyridine, 1,4,7,10-tetraazaphenanthrene, and h2-2,2',2''-terpyridine) and the new cationic species [(bdz)Re(CO)3(CH3CN)]+ were also studied. In a further expt., in situ EPR spectroelectrochem. was employed to study the primary paramagnetic intermediates during the redn. of the prototype compd., (bpy)Re(CO)3Cl, under a CO2 atmosphere. The susceptibility to substitution is dependent not on the redox potential but on the p MO coeffs. at the metal-coordinating nitrogen centers which are reflected by 14N, 185,187Re, and 31P EPR coupling consts. The most labile systems were thus found among the complexes of the small dab and sdi ligands, despite their facile redn. In contrast, the complexes of these nonarom. compds. showed an electrochem. reversible 1-electron oxidn. which, in comparison to the absorption max., allowed the authors to est. contributions to the reorganization energy of the MLCT excited state in two cases. For the reductive labilization, it is primarily the small but variable and EPR-detectable ligand-to-metal electron (spin) transfer at the metal/ligand interface which dets. the extent of activation in 18 + d valence electron intermediates. [on SciFinder(R)]

@article{Klein.1996, abstract = {The factors detg. the electron transfer-induced halide labilization in complexes (\textgreek{a}-diimine)Re(CO)3(Hal), Hal = Cl and Br, were systematically studied via EPR and cyclic voltammetry in the presence of substituting ligands such as triphenylphosphine, cyanide, or acetonitrile. The \textgreek{a}-diimines employed were the four isomeric bidiazines (bdz) 3,3'-bipyridazine, 2,2'-bipyrazine, and 2,2'- and 4,4'-bipyrimidine and the nonarom. \textgreek{a}-diimines 1,4-di-tert-butyl-1,4-diaza-1,3-butadiene (dab) and 1,3-di-tert-butylsulfurdiimine (sdi). For comparison, (L)Re(CO3)Cl (L = 2,2'-bipyridine, 1,4,7,10-tetraazaphenanthrene, and \textgreek{h}2-2,2',2''-terpyridine) and the new cationic species [(bdz)Re(CO)3(CH3CN)]+ were also studied. In a further expt., in situ EPR spectroelectrochem. was employed to study the primary paramagnetic intermediates during the redn. of the prototype compd., (bpy)Re(CO)3Cl, under a CO2 atmosphere. The susceptibility to substitution is dependent not on the redox potential but on the \textgreek{p} MO coeffs. at the metal-coordinating nitrogen centers which are reflected by 14N, 185,187Re, and 31P EPR coupling consts. The most labile systems were thus found among the complexes of the small dab and sdi ligands, despite their facile redn. In contrast, the complexes of these nonarom. compds. showed an electrochem. reversible 1-electron oxidn. which, in comparison to the absorption max., allowed the authors to est. contributions to the reorganization energy of the MLCT excited state in two cases. For the reductive labilization, it is primarily the small but variable and EPR-detectable ligand-to-metal electron (spin) transfer at the metal/ligand interface which dets. the extent of activation in 18 + \textgreek{d} valence electron intermediates. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Klein, Axel and Vogler, Conny and Kaim, Wolfgang.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2c2afe89097e7e022d3ddf6134369d15c/huebleriac}, doi = {10.1021/OM950500E}, interhash = {76dec298f33b43d8af8dc010eb221bf0}, intrahash = {c2afe89097e7e022d3ddf6134369d15c}, issn = {0276-7333}, journal = {Organometallics}, keywords = {bidiazine bromo chloro complex complex;EPR diimine halo redn rhenium substitution;electrochem substitution;rhenium substitution;substitution}, number = 1, pages = {236--244}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {The \textgreek{d} in 18 + \textgreek{d} Electron Complexes: Importance of the Metal/Ligand Interface for the Substitutional Reactivity of {\dq}Re(0){\dq} Complexes (\textgreek{a}-diimine-)ReI(CO)3(X)}, volume = 15, year = 1996 }