Syntheses and crystal structures of two heterometallic iodoplumbates containing mixed-valence copper(I/II)

Abstract

Mixed-valence copper(I/II) atoms have been introduced successfully into a Pb/I skeleton to obtain two heterometallic iodoplumbates, namely poly[bis(tetra-n-butylammonium) [bis(μ₃-dimethyldithiocarbamato)dodeca-μ₃-iodido-hexa-μ₂-iodido-tetracopper(I)copper(II)hexalead(II)]], {(C₁₆H₃₆N)₂[Cu₄^ICu^IIPb₆(C₃H₆NS₂)₂I₁₈]}_n, (I), and poly[[μ₃-iodido-tri-μ₂-iodido-iodido[bis(1,10-phenanthroline)copper(I)]copper(I)copper(II)lead(II)] hemiiodine], {[Cu^ICu^IIPbI₅(C₁₂H₈N₂)₂]·0.5I₂}_n, (II), under solution and solvothermal conditions, respectively. Compound (I) contains two-dimensional anionic layers, which are built upon the linkages of Cu^II(S₂CNMe₂)₂ units and one-dimensional anionic Pb/I/Cu^I chains. Tetra-n-butylammonium cations are located between the anionic layers and connected to them via C-H...I hydrogen-bonding interactions. Compound (II) exhibits a one-dimensional neutral structure, which is composed of [PbI₅] square pyramids, [Cu^II₄] tetrahedra and [Cu^IIN₄I] trigonal bipyramids. Face-to-face aromatic π-π stacking interactions between adjacent 1,10-phenanthroline ligands stabilize the structure and assemble compound (II) into a three-dimensional supramolecular structure. I₂ molecules lie in the voids of the structure.

Keywords: 1,10-phenanthroline; copper; crystal structure; hydrogen-bonding interactions; iodoplumbates; mixed valence; π–π stacking interaction.