Syntheses and crystal structures of organoindium(III) 1-D coordination polymers with bis(diphenylphosphino)alkane dioxides

Abstract

Bromomethyl-dibromo-indium(III), Br2InCH2Br, obtained from indium monobromide and methylene dibromide, reacts with hard and soft donor ligands to afford the corresponding indium(III) organometallic complexes. In this work, we investigated the conditions to prepare adducts of Br2InCH2Br using bis(diphenylphosphino)alkane dioxides acting as hard ligands. We report here the synthesis and crystal structures of two 1-D coordination polymers with the hard donor ligands Ph2P(O)(CH2)mP(O)Ph2 (m = 2, dppeO2 and m = 6, dpphO2). Compounds 1 and 2 with formulas [Br2In(CH2Br)(dppeO2)]n (1) and [Br2In(CH2Br)(dpphO2)]n (2) were characterized by IR and Raman spectroscopy and elemental analysis. We also obtained an ionic indium(III) compound with dppeO2 acting as a chelating ligand with formula [InBr2(dppeO2)2][InBr3(CH2Br)] (3). The crystal structures were determined for 1–3 using single crystal X-ray diffractometry. The geometry around the In(III) can be described as a trigonal bipyramid in 1 and 2, and the chains were packed onto the plane giving layers that are stabilized mainly by intermolecular interactions. Compound 3 has a square bipyramidal In(III) cation with formula [Br2L2In]+ and tetrahedral organoindium(III) anion with formula [Br3InCH2Br]–. Hirshfeld surface analysis employing 2-D fingerprint plots have been used to analyze intramolecular and intermolecular interactions present in the solid state of the structures.