Abstract

Heterometallic chromium(III) Cr^III[(SQ-Cat)SbPh₃]₃ (I), copper(II) Cu^II[(SQ-Cat)SbPh₃]₂ (II), and zinc I₂Zn(Q-Cat)SbPh₃ (III) and IZn(SQ-Cat)SbPh₃ (IV) complexes, where SQ is the corresponding o-semiquinone radical anion, and Cat is the catecholate dianion (mono- and direduced forms of the quinone fragment), are synthesized on the basis of the mononuclear triphenylantimony(V) quinone-catecholate complex (Q-Cat)SbPh₃, which was derived from 4,4'-di-(6-tert-butyl-3-methylbenzo-1,2-quinone) (Q-Q). The one-electron oxidation and one-electron reduction of chromium complex I afford the paramagnetic derivatives [Cr^III[(Q-Cat)SbPh₃][(SQ-Cat)SbPh₃]₂]⁺ (I⁺) and [Cr^III[(Cat-Cat)SbPh₃][(SQ-Cat)SbPh₃]₂]^– (I^–), respectively, which are easily detected by EPR spectroscopy. The EPR spectroscopy data and measurements of the temperature dependence of the magnetic susceptibility of copper complex II indicate in favor of the localization of the lone electron on the organic ligand, which can be explained by the antiferromagnetic metal–ligand exchange in this complex (J(SQ-Cu) = –157 cm^–1, J(SQ-SQ) = –10.0 cm^–1). The coordination of (Q-Cat)SbPh₃ as neutral o-quinone to zinc iodide with the formation of complex III increases significantly the oxidation ability of the quinone fragment in this complex (E^Red1 = 0.43 V for III and –0.45 V for (Q-Cat)SbPh₃ vs. Ag/AgCl/KCl(sat.)), and the complex can oxidize the iodide anion to iodine with the formation of paramagnetic derivative IV, whose EPR spectrum is characteristic of complexes of the M(SQ-Cat) type. The redox properties of complexes I and III are studied by cyclic voltammetry.

中文翻译：

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基于三苯基锑（邻苯二酚）的杂金属配合物

摘要

异金属铬（III）Cr ^III [（SQ-Cat）SbPh ₃ ] ₃（I），铜（II）Cu ^II [（SQ-Cat）SbPh ₃ ] ₂（II）和锌I ₂ Zn（Q-Cat ）SbPh ₃（III）和IZn（SQ-Cat）SbPh ₃（IV）配合物，其中SQ是相应的邻半醌自由基阴离子，Cat是儿茶酚酸二阴离子（醌片段的单还原形式）。在单核三苯基锑（V）醌-儿茶酚酸酯配合物（Q-Cat）SbPh ₃的基础上合成的，该配合物衍生自4,4'-di-（6-叔丁基-3-甲基苯并1,2-醌）（QQ）。铬配合物I的单电子氧化和单电子还原得到顺磁性衍生物[Cr ^III [（Q-Cat）SbPh ₃ ] [（SQ-Cat）SbPh ₃ ] ₂ ] ⁺（I ⁺）和[Cr ^III [（Cat-Cat）SbPh ₃ ] [（SQ-Cat）SbPh ₃ ] ₂ ] ^-（I ^–）分别很容易通过EPR光谱法进行检测。EPR光谱数据和铜络合物II的磁化率的温度依赖性测量表明有利于孤立电子在有机配体上的定位，这可以通过该复合物中的反铁磁金属-配体交换来解释（J（SQ-Cu）= –157 cm ^–1，J（SQ-SQ）= –10.0厘米^–1）。（Q-Cat）SbPh ₃作为中性邻醌与碘化锌的配合物与配合物III的形成显着提高了该配合物中醌片段的氧化能力（III的E ^Red1 = 0.43 V，（-）为–0.45 V Q-Cat）SbPh ₃与Ag / AgCl / KCl（sat。）相比，该配合物可将碘化物阴离子氧化为碘，形成顺磁性衍生物IV，其EPR谱是M（SQ-Cat）类型配合物的特征。通过循环伏安法研究了配合物I和III的氧化还原性质。