Structural Diversity of Labile Indium(III) Solvates

Group 13 organometallic and coordination compounds have been reported as efficient optoelectronic materials and as convenient diamagnetic solid solvents for dilution studies of single-molecule magnets.  In this work, we sought anhydrous indium(III) starting materials that are soluble in organic solvents and sufficiently labile to undergo facile ligand substitution. We started by synthesizing the previously reported [InCl₃(thf)₂] (1) by an alternative route and then moved to the dehydration of InCl₃·4H₂O using triethyl orthoformate in thf, a route previously established by our research group. For In³⁺, this revealed a versatile reaction system that produced not only the expected  [InCl₃(thf)₃] (2) but also the previously unknown [In₂Cl₄(OEt)₂(thf)₄] (3) and [In₄(EtOH)₂(OEt)₄(thf)₂(OH)₂Cl₆]·2thf (4) under slightly different experimental conditions. The products were characterized by single-crystal X-ray diffraction, except for 3, whose data still require further refinement. These complexes will be used as precursors in the synthesis of magnetic diluents and luminescent materials.