Tetradentate Bis(o-iminobenzosemiquinonate(1-)) Radical Ligands and Their o-Aminophenolate(1-) Derivatives in Complexes
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- 作者：Kil Sik Min ; Thomas Weyhermü ; ller ; Eberhard Bothe ; and Karl Wieghardt
- 刊名：Inorganic Chemistry
- 出版年：2004
- 出版时间：May 3, 2004
- 年：2004
- 卷：43
- 期：9
- 页码：2922 - 2931
- 全文大小：281K
- 年卷期：v.43,no.9(May 3, 2004)
- ISSN：1520-510X
文摘
The coordination chemistries of the potential tetradentate ligands N,N'-bis(3,5-di-tert-butyl-2-hydroxyphenyl)ethylenediamine, H4[L1], the unsaturated analogue glyoxal-bis(2-hydroxy-3,5-di-tert-butylanil), H2[L2], and N,N'-bis(2-hydroxy-3,5-di-tert-butylphenyl)-2,2-dimethylpropylenediamine, H4[L3], have been investigated with nickel(II),palladium(II), and copper(II). The complexes prepared and characterized are [NiII(H3L1)2] (1), [NiII(HL2)2]·5/8CH2Cl2(2), [NiII(L3
)] (3), [PdII(L3)][PdII(H2L3) (4), and [CuII(H2O)(L4)] (5), where (L4)2- is the oxidized diimine form of(L3)4- and (L3)2- is the bis(o-iminosemiquinonate) diradical form of (L3)4-. The structures of compounds 1-5have been determined by single crystal X-ray crystallography. In complexes 1 and 2, the ligands (H3L1)- and(HL2)- are tridentate and the nickel ions are in an octahedral ligand environment. The oxidation level of the ligandsis that of an aromatic o-aminophenol. 1 and 2 are paramagnetic (
gr.gif">eff ~ 3.2 gr.gif">B at 300 K), indicating an S = 1ground state. The diamagnetic, square planar, four-coordinate complexes 3 and [PdII(L3)] in 4 each contain twoantiferromagnetically coupled o-iminobenzosemiquinonate(1-) 
radicals. Diamagnetic [PdII(H2L3)] in 4 forms aneclipsed dimer via four N-H···O hydrogen bonding contacts which yields a nonbonding Pd···Pd contact of 3.0846(4) Å. Complex 5 contains a five-coordinate CuII ion and two o-aminophenolate(1-) halves in (L4)2-. Theelectrochemistries of complexes 3 and 4a ([PdII(L3)] of 4) have been investigated, and the EPR spectra of themonocations and -anions are reported.
)] (3), [PdII(L3)][PdII(H2L3) (4), and [CuII(H2O)(L4)] (5), where (L4)2- is the oxidized diimine form of(L3)4- and (L3)2- is the bis(o-iminosemiquinonate) diradical form of (L3)4-. The structures of compounds 1-5have been determined by single crystal X-ray crystallography. In complexes 1 and 2, the ligands (H3L1)- and(HL2)- are tridentate and the nickel ions are in an octahedral ligand environment. The oxidation level of the ligandsis that of an aromatic o-aminophenol. 1 and 2 are paramagnetic (gr.gif">eff ~ 3.2 gr.gif">B at 300 K), indicating an S = 1ground state. The diamagnetic, square planar, four-coordinate complexes 3 and [PdII(L3)] in 4 each contain twoantiferromagnetically coupled o-iminobenzosemiquinonate(1-) radicals. Diamagnetic [PdII(H2L3)] in 4 forms aneclipsed dimer via four N-H···O hydrogen bonding contacts which yields a nonbonding Pd···Pd contact of 3.0846(4) Å. Complex 5 contains a five-coordinate CuII ion and two o-aminophenolate(1-) halves in (L4)2-. Theelectrochemistries of complexes 3 and 4a ([PdII(L3)] of 4) have been investigated, and the EPR spectra of themonocations and -anions are reported.