Synthesis and molecular structure of indium complexes based on 3,6-di-tert-butyl-o-benzoquinone. Looking for indium(i) o-semiquinolate

Abstract

The interaction of 3,6-di-tert-butyl-o-benzoquinone (3,6-Q) with indium in toluene leads to the tris-o-semiquinolate derivative (3,6-SQ)₃In (3,6-SQ - radical-anion of 3,6-Q). According to single-crystal X-ray diffraction analysis, this complex has a trigonal prismatic structure. Magnetic measurements revealed that the exchange interactions between odd electrons of the paramagnetic ligands in (3,6-SQ)₃In are antiferromagnetic in character. The treatment of (3,6-SQ)₃In with 2,2′-dipyridyl (Dipy) causes the displacement of one o-quinone ligand and the formation of the (3,6-SQ)In(Dipy)(3,6-Cat) (3,6-Cat - dianion of 3,6-Q) derivative containing mixed charged o-quinoid ligands. The reaction of InI with (3,6-SQ)K in THF solution is accompanied by a redox process and the potassium-indium(III) catecholate derivative was obtained as a result. The oxidation of InI with 3,6-Q in THF produces the dimeric In(III) iodo–catecholate complex [(3,6-Cat)₂In·2THF]InI₂. The same derivative can be synthesized by the interaction of indium metal with a mixture of I₂ and 3,6-Q.