Crystal-to-crystal transformations in heterometallic yttrium(iii)–copper(i) iodide derivatives in a confined solvent-free environment: Influence of solvated yttrium cations on the nuclearity and dimensionality of iodocuprate clusters??

Dalton Transactions Pub Date: 2007-12-19 DOI: 10.1039/B709338A

Abstract

The solvated yttrium iodide precursors [Y(L)8]I3 (L = DMSO or DMF), prepared in situ by stirring YI3(PriOH)4 in DMSO or DMF, react with CuI in the presence of NH4I to give ionic hetero-metallic species [Y(DMSO)8][Cu2(μ-I)I4] (1) and [Y(DMF)8][Cu4(μ3-I)2(μ-I)3I2] (2) in excellent yields. Re-crystallization of 1 from DMF afforded the mixed-solvate complex [Y(DMSO)6(DMF)2][CuI3][I] (3). Compounds 2 and 3 undergo unique crystal-to-crystal transformation via progressive substitution of DMF by water molecules in a confined, solvent-free environment. Thus, crystals of 3 transform into [Y(DMSO)6(H2O)2][CuI3][I] (4), whereas a discrete ion-pair assembly of 2 is first converted into a 1-D zig-zag structure [Y(DMF)6(H2O)2]3+[Cu7(μ4-I)3(μ3-I)2(μ-I)4(I)]1∞3? (5) and finally into a 2-D sheet containing mixed-valent copper atoms, [Y(DMF)6(H2O)3]3+[CuI7CuII2(μ3-I)8(μ-I)6]2∞3? (6). The bi- and tetrafurcate H-bonding between water ligands on yttrium and iodides of the Cu–I cluster plays a pivotal role in the evolution of structures 4–6. Formation of a wide range of iodocuprate structures in 1–6, from discrete mono-, di- or tetranuclear units to one- and two-dimensional extended arrays, reflects the influence of solvated yttrium cations on the nuclearity and dimensionality of Cu–I clusters. TG-DTA-MS studies and DFT calculations for these complexes have also been carried out in order to determine their thermal stability and have insight about aforesaid transformations.

Graphical abstract: Crystal-to-crystal transformations in heterometallic yttrium(iii)–copper(i) iodide derivatives in a confined solvent-free environment: Influence of solvated yttrium cations on the nuclearity and dimensionality of iodocuprate clusters
Recommended Literature