Complexes of indium(III) chloride with bidentate and terdentate nitrogen donors

Abstract

The reactions of indium(III) chloride with several nitrogen donors have been investigated and the far-infrared spectra (500–200 cm.^–1) of the resulting complexes measured. Of particular interest are the complexes InCl₃bipy_1·5, InCl₃phen_1·5,xMeCN (where x⩽ 1), InCl₃phen,H₂O, InCl₃terpy, and InCl₃paphy,2H₂O, where bipy = 2,2′-bipyridyl, phen = 1,10-phenanthroline, terpy = 2,2′,2″-terpyridyl and paphy = pyridine-2-aldehyde 2-pyridylhydrazone. While the last two complexes are of the type trans-[InCl₃L₃] and InCl₃B_1·5 are ionic, [InCl₂B₂]⁺[InCl₄B]^–, the structure of InCl₃phen(H₂O) is unknown, although it may be [InCl₂phen₂]⁺[InCl₄(H₂O)₂]^–. InCl₃bipy_1·5 reacts with an excess of Ph₄AsCl in acetonitrile under reflux to yield Ph₄As⁺[InCl₄bipy^–],MeCN. The complex InCl₃(pyrazine)_1·5, which is polymeric with bridging pyrazine molecules, has also been isolated. Factors affecting the structure and stoicheiometry of these and other indium(III) complexes are discussed.