Charge and electron transfer from metal-to-carbon bonds of Main Group organometallics MRn (M = Al, Ga, Zn) to aromatic N-heterocycles: Colored precursor compounds and radical complex formation
The coordinatively unsatd. compds. AlR3, GaR3 and ZnR2, R = iso-Pr, were reacted with linearly bridging pyrazine, tetramethylpyrazine or 4,4'-bipyridine ligands and with potentially chelating 2,2'-bipyridine. The primary reaction products are diamagnetic dinuclear complexes (bis-adducts) which are characterized by intense long-wavelength ligand-to-ligand charge transfer (LLCT) transitions s(M-R)$\rightarrow$ p*(L) and which may yield radical complexes after loss of R.bul.. The latter reaction is assumed to have a strong single electron transfer (SET) component. An isolable Al(II) species (bpy)AlCH(SiMe3)22 has been characterized unambiguously by ESR, UV-Vis and cyclic voltammetry as an Al(III) complex of the bpy radical anion. Irradn. into the fairly intense LLCT absorption bands (e \textgreater 3000 M-1 cm-1) of the dinuclear complexes between pyrazine and AliPr3 or GaiPr3 resulted in bleaching and formation of a mixt. of non-arom. products. Attempts are made to correlate charge transfer properties and radical formation with the geometrical and electronic structures of the precursor complexes. on SciFinder(R)
%0 Journal Article
%1 Hasenzahl.1994
%A Hasenzahl, Steffen
%A Kaim, Wolfgang
%A Stahl, Thomas.
%D 1994
%J Inorganica Chimica Acta
%K Group aluminum bond carbon charge gallium metal organometallic organometallic;Main organometallic;heterocycle reaction transfer zinc
%N 1-2
%P 23--34
%R 10.1016/0020-1693(94)04025-7
%T Charge and electron transfer from metal-to-carbon bonds of Main Group organometallics MRn (M = Al, Ga, Zn) to aromatic N-heterocycles: Colored precursor compounds and radical complex formation
%V 225
%X The coordinatively unsatd. compds. AlR3, GaR3 and ZnR2, R = iso-Pr, were reacted with linearly bridging pyrazine, tetramethylpyrazine or 4,4'-bipyridine ligands and with potentially chelating 2,2'-bipyridine. The primary reaction products are diamagnetic dinuclear complexes (bis-adducts) which are characterized by intense long-wavelength ligand-to-ligand charge transfer (LLCT) transitions s(M-R)$\rightarrow$ p*(L) and which may yield radical complexes after loss of R.bul.. The latter reaction is assumed to have a strong single electron transfer (SET) component. An isolable Al(II) species (bpy)AlCH(SiMe3)22 has been characterized unambiguously by ESR, UV-Vis and cyclic voltammetry as an Al(III) complex of the bpy radical anion. Irradn. into the fairly intense LLCT absorption bands (e \textgreater 3000 M-1 cm-1) of the dinuclear complexes between pyrazine and AliPr3 or GaiPr3 resulted in bleaching and formation of a mixt. of non-arom. products. Attempts are made to correlate charge transfer properties and radical formation with the geometrical and electronic structures of the precursor complexes. on SciFinder(R)
@article{Hasenzahl.1994,
abstract = {The coordinatively unsatd. compds. AlR3, GaR3 and ZnR2, R = iso-Pr, were reacted with linearly bridging pyrazine, tetramethylpyrazine or 4,4'-bipyridine ligands and with potentially chelating 2,2'-bipyridine. The primary reaction products are diamagnetic dinuclear complexes (bis-adducts) which are characterized by intense long-wavelength ligand-to-ligand charge transfer (LLCT) transitions \textgreek{s}(M-R)$\rightarrow$ \textgreek{p}*(L) and which may yield radical complexes after loss of R.bul.. The latter reaction is assumed to have a strong single electron transfer (SET) component. An isolable Al(II) species (bpy)Al[CH(SiMe3)2]2 has been characterized unambiguously by ESR, UV-Vis and cyclic voltammetry as an Al(III) complex of the bpy radical anion. Irradn. into the fairly intense LLCT absorption bands (\textgreek{e} {\textgreater} 3000 M-1 cm-1) of the dinuclear complexes between pyrazine and AliPr3 or GaiPr3 resulted in bleaching and formation of a mixt. of non-arom. products. Attempts are made to correlate charge transfer properties and radical formation with the geometrical and electronic structures of the precursor complexes. [on SciFinder(R)]},
added-at = {2019-07-15T13:41:23.000+0200},
author = {Hasenzahl, Steffen and Kaim, Wolfgang and Stahl, Thomas.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2d9ee0f23d6424807ea65c66cfa081e4f/b_schwederski},
doi = {10.1016/0020-1693(94)04025-7},
interhash = {622b62cb6c03a189b81e752e83a7e73d},
intrahash = {d9ee0f23d6424807ea65c66cfa081e4f},
issn = {0020-1693},
journal = {Inorganica Chimica Acta},
keywords = {Group aluminum bond carbon charge gallium metal organometallic organometallic;Main organometallic;heterocycle reaction transfer zinc},
number = {1-2},
pages = {23--34},
timestamp = {2019-07-15T11:42:10.000+0200},
title = {Charge and electron transfer from metal-to-carbon bonds of Main Group organometallics MRn (M = Al, Ga, Zn) to aromatic N-heterocycles: Colored precursor compounds and radical complex formation},
volume = 225,
year = 1994
}