Molecular and electronic structure of octahedral o-aminophenolato and o-iminobenzosemiquinonato complexes of V(V), Cr(III), Fe(III), and Co(III).: Experimental determination of oxidation levels of ligands and metal ions
Molecular and electronic structure of octahedral o-aminophenolato and o-iminobenzosemiquinonato complexes of V(V), Cr(III), Fe(III), and Co(III).: Experimental determination of oxidation levels of ligands and metal ions
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DOI：
10.1021/ic010106a
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发表时间：
2001-08-13
影响因子：
4.6
通讯作者：
Wieghardt, K
中科院分区：
文献类型：
--
作者：
Chun, H;Verani, CN;Wieghardt, K
本文研究了配体2-苯胺基-4，6-二叔丁基苯酚H[L-AP]和NY“‘-bis{2-(4，6-di-tert-butylphenol}diethylenetriamine，H-2[(L-AP)N(L-AP)]与第一过渡金属离子V，Cr，Fe和Co的配位化学。这些配体是无害的，因为它们的氨基酚部分[L-AP](-)和[L-AP-H](2-)很容易被氧化成邻亚氨基对苯二酚。[L-isq](-)和邻亚氨基对苯二酚[L-isb]。本文报道了以下中性八面体配合物的晶体结构，并用X射线单晶衍射法测定了它们的晶体结构：[Cr-III(L-isq)(3)](1)，[Fe-III(L-isq)(3)](2)，[Co-III-H(L-isq)(3)](3)，[V-V(L-isq)(L-ap-H)(2)](4)，[V-V(L-AP-H)(2)(L-AP)](5)和[(VO)-O-V{(L-AP)N(L-AP-H)}}(6)。由变温磁化率测量和X波段电子顺磁共振谱确定它们具有基态：1，S=0；2，S=1；3，S=3/2；4，S=1/2；5，S=0；6，S=0。邻亚胺基苯并半喹啉自由基(S-rad=1/2)在分子内与t(2g)亚壳层的单个占据轨道发生强烈的反铁磁性偶联，但在含有t(2g)(6)亚壳层的3-含6a Co-III离子中却相互铁磁耦合。高质量的X射线结晶学结合EPR、UV、VIS和穆斯堡尔谱可以明确地确定配体和金属离子的氧化程度。并对其光谱和电化学性质进行了详细的研究。观察到了基于金属和配体的氧化还原化学。比较了它们的分子结构和电子结构，并与它们的邻半酮类似物进行了比较。
The coordination chemistry of the ligands 2-anilino-4,6-di-tert-butylphenol, H[L-AP], and NY " ' -bis{2-(4,6-di-tert-butylphenol}diethylenetriamine, H-2[(L-AP)N(L-AP)], has been studied with the first-row transition metal ions V, Cr, Fe, and Co. The ligands are noninnocent in the sense that the aminophenolato parts, [L-AP](-) and [L-AP-H](2-), can be readily oxidized to their o-iminobenzosemiquinonato, [L-ISQ](-), and o-iminobenzoquinone, [L-ISB], forms. The following neutral octahedral complexes have been isolated as crystalline materials, and their crystal structures have been determined by X-ray crystallography at 100 K: [Cr-III(L-ISQ)(3)] (1), [Fe-III(L-ISQ)(3)] (2), [Co-III-H(L-ISQ)(3)] (3), [V-V(L-ISQ)(L-AP-H)(2)] (4), [V-V(L-AP-H)(2)(L-AP)] (5), and [(VO)-O-V{(L-AP)N(L-AP-H)}} (6). From variable-temperature magnetic susceptibility measurements and X-band EPR spectroscopy it has been established that they possess the ground states: 1, S = 0; 2, S = 1; 3, S = 3/2; 4,S = 1/2; 5, S = 0; 6, S = 0. The o-iminobenzosemiquinonato radicals (S-rad = 1/2) couple strongly intramolecularly antiferromagnetically to singly occupied orbitals of the t(2g) subshell at the respective metal ion but ferromagnetic ally to each other in, 3-containing 6 a Co-III ion with a filled t(2g)(6) subshell. It is demonstrated that the oxidation level of the ligands and,metal ions can be unequivocally determined by high-quality X-ray crystallography in conjunction with EPR, UV, vis, and Mossbauer spectroscopies. The spectro- and electrochemistry of these complexes have also been studied in detail. Metal- and ligand-based redox chemistry has been observed. The molecular and electronic structures are compared with those of their o-semiquimonato analogues.