Reactivity of copper(I) complexes with tripodal ligands towards O2: Structures of a precursor [L3CuI(NCCH3)](BF4), L3 = tris(3-isopropyl-4,5-trimethylenepyrazolyl)methane and of its oxidation product [L3CuII(m-OH)2CuIIL3](BF4)2 with strong antiferromagnetic spin-spin coupling
The mol. structure of the highly oxygen-sensitive complex [L3CuI(NCCH3)](BF4) (1, L3 = tris(3-isopropyl-4,5-trimethylenepyrazolyl)methane) reveals approx. sym. coordination by the fac-tridentate (tripodal) ligand and a rather short CuI-N(acetonitrile) distance of 1.865(5) \AA. In CH2Cl2 at -78° the colorless compd. reacts with O2 to yield a labile purple intermediate (lmax 517 nm) - presumably a peroxodicopper(II) complex - which decomps. at -30°. No such intermediate was obsd. on reaction of the CuI complex of bis(2-pyridylmethyl)benzylamine with O2 at -80°. However, an EPR spectrum with g‖ = 2.17 and g$\bot$ = 2.03 without 63,65Cu hyperfine splitting was obsd. at low temps. Exposure of the precursor 1 to air under ambient conditions yields dinuclear [L3CuII(m-OH)2CuIIL3](BF4)2 (2), which exhibits an EPR detectable dissocn. into monomers in CH2Cl2 soln. The structure of the hexakis(dichloromethane) solvate of 2 with Cu-Cu and Cu-O distances of 3.055 and 1.94 \AA, resp., is typical for dihydroxo-bridged dicopper compds. with square-pyramidal CuII configuration (t = 0.03), adopting an anti arrangement. In agreement with the relatively wide Cu-O-Cu angles of 103.5°, an anal. of the temp. dependence of the magnetic susceptibility revealed a rather strong (J = -633 cm-1) antiparallel spin-spin coupling. The effect is ascribed to the steric bulk of the ligand L3. [on SciFinder(R)]
%0 Journal Article
%1 Kaim.2005b
%A Kaim, Wolfgang
%A Titze, Christoph
%A Schurr, Thilo
%A Sieger, Monika
%A Lawson, Max
%A Jordanov, Jeanne
%A Rojas, Dario
%A Garcia, Ana M.
%A Manzur, Jorge.
%D 2005
%J Zeitschrift fuer Anorganische und Allgemeine Chemie
%K acetonitrile antiferromagnetic complex complex;copper copper coupling dinuclear dinuclear;magnetic hydroxy methane mononuclear prepn property structure structure;crystal trimethylenepyrazolyl
%N 13-14
%P 2568--2574
%R 10.1002/zaac.200500053
%T Reactivity of copper(I) complexes with tripodal ligands towards O2: Structures of a precursor [L3CuI(NCCH3)](BF4), L3 = tris(3-isopropyl-4,5-trimethylenepyrazolyl)methane and of its oxidation product [L3CuII(m-OH)2CuIIL3](BF4)2 with strong antiferromagnetic spin-spin coupling
%V 631
%X The mol. structure of the highly oxygen-sensitive complex [L3CuI(NCCH3)](BF4) (1, L3 = tris(3-isopropyl-4,5-trimethylenepyrazolyl)methane) reveals approx. sym. coordination by the fac-tridentate (tripodal) ligand and a rather short CuI-N(acetonitrile) distance of 1.865(5) \AA. In CH2Cl2 at -78° the colorless compd. reacts with O2 to yield a labile purple intermediate (lmax 517 nm) - presumably a peroxodicopper(II) complex - which decomps. at -30°. No such intermediate was obsd. on reaction of the CuI complex of bis(2-pyridylmethyl)benzylamine with O2 at -80°. However, an EPR spectrum with g‖ = 2.17 and g$\bot$ = 2.03 without 63,65Cu hyperfine splitting was obsd. at low temps. Exposure of the precursor 1 to air under ambient conditions yields dinuclear [L3CuII(m-OH)2CuIIL3](BF4)2 (2), which exhibits an EPR detectable dissocn. into monomers in CH2Cl2 soln. The structure of the hexakis(dichloromethane) solvate of 2 with Cu-Cu and Cu-O distances of 3.055 and 1.94 \AA, resp., is typical for dihydroxo-bridged dicopper compds. with square-pyramidal CuII configuration (t = 0.03), adopting an anti arrangement. In agreement with the relatively wide Cu-O-Cu angles of 103.5°, an anal. of the temp. dependence of the magnetic susceptibility revealed a rather strong (J = -633 cm-1) antiparallel spin-spin coupling. The effect is ascribed to the steric bulk of the ligand L3. [on SciFinder(R)]
@article{Kaim.2005b,
abstract = {The mol. structure of the highly oxygen-sensitive complex [L3CuI(NCCH3)](BF4) (1, L3 = tris(3-isopropyl-4,5-trimethylenepyrazolyl)methane) reveals approx. sym. coordination by the fac-tridentate (tripodal) ligand and a rather short CuI-N(acetonitrile) distance of 1.865(5) {\AA}. In CH2Cl2 at -78° the colorless compd. reacts with O2 to yield a labile purple intermediate (\textgreek{l}max 517 nm) - presumably a peroxodicopper(II) complex - which decomps. at -30°. No such intermediate was obsd. on reaction of the CuI complex of bis(2-pyridylmethyl)benzylamine with O2 at -80°. However, an EPR spectrum with g‖ = 2.17 and g$\bot$ = 2.03 without 63,65Cu hyperfine splitting was obsd. at low temps. Exposure of the precursor 1 to air under ambient conditions yields dinuclear [L3CuII(\textgreek{m}-OH)2CuIIL3](BF4)2 (2), which exhibits an EPR detectable dissocn. into monomers in CH2Cl2 soln. The structure of the hexakis(dichloromethane) solvate of 2 with Cu-Cu and Cu-O distances of 3.055 and 1.94 {\AA}, resp., is typical for dihydroxo-bridged dicopper compds. with square-pyramidal CuII configuration (\textgreek{t} = 0.03), adopting an anti arrangement. In agreement with the relatively wide Cu-O-Cu angles of 103.5°, an anal. of the temp. dependence of the magnetic susceptibility revealed a rather strong (J = -633 cm-1) antiparallel spin-spin coupling. The effect is ascribed to the steric bulk of the ligand L3. [on SciFinder(R)]},
added-at = {2022-06-15T11:26:56.000+0200},
author = {Kaim, Wolfgang and Titze, Christoph and Schurr, Thilo and Sieger, Monika and Lawson, Max and Jordanov, Jeanne and Rojas, Dario and Garcia, Ana M. and Manzur, Jorge.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2efde9d684da35614ffebc9aefc739ecf/huebleriac},
doi = {10.1002/zaac.200500053},
interhash = {d396307cc93cf406e0e1d7951bb683be},
intrahash = {efde9d684da35614ffebc9aefc739ecf},
issn = {0044-2313},
journal = {Zeitschrift fuer Anorganische und Allgemeine Chemie},
keywords = {acetonitrile antiferromagnetic complex complex;copper copper coupling dinuclear dinuclear;magnetic hydroxy methane mononuclear prepn property structure structure;crystal trimethylenepyrazolyl},
number = {13-14},
pages = {2568--2574},
timestamp = {2022-06-15T09:26:56.000+0200},
title = {Reactivity of copper(I) complexes with tripodal ligands towards O2: Structures of a precursor [L3CuI(NCCH3)](BF4), L3 = tris(3-isopropyl-4,5-trimethylenepyrazolyl)methane and of its oxidation product [L3CuII(\textgreek{m}-OH)2CuIIL3](BF4)2 with strong antiferromagnetic spin-spin coupling},
volume = 631,
year = 2005
}