Organic–inorganic hybrid chains and layers constructed from copper-aminecations and early transition metal (Nb, Mo) oxyfluoride anions

Abstract

Under hydrothermal conditions in HF-containing media, the combination of early (Nb⁵⁺, Mo⁶⁺) and late (Cu²⁺) transition metals with four different organic amine ligands yields eight novel hybrid compounds with chain and layer structures. The eight new compounds were synthesised from a systematic series of reactions and can be subdivided into four pairs, the topologies of which are essentially unique to each ligand, containing in each case a Cu-based cationic species, but alternately either [MoO₂F₄]²⁻ or [NbOF₅]²⁻, in an isomorphous manner, as the anionic moiety. The overall structures of theses materials reflect the influences of the organo amine ligands. [Cu(C₂H₄N₄)₂][MoO₂F₄].H₂O (1) and [Cu(C₂H₄N₄)₂][NbOF₅].H₂O (2) exhibit an infinite copper fluoride amine chain, while the anionic moieties act as ‘decoration’ to the chain. [Cu(C₃H₄N₂)₄][MoO₂F₄] (3) and [Cu(C₃H₄N₂)₄][NbOF₅] (4) form infinite 1D chains with alternating cationic and anionic units. [Cu₂F₂(C₁₀H₉N₃)₂][MoO₂F₄] (5) and [Cu₂F₂(C₁₀H₉N₃)₂] [NbOF₅] (6) contain a dimeric copper fluoride complex, bridged through anions to form a 1D infinite chain. [Cu(C₁₀H₈N₂)₂(H₂O)₂][MoO₂F₄] (7) and [Cu(C₁₀H₈N₂)₂(H₂O)₂][NbOF₅] (8) contain a 2D interpenetrated network formed from the copper-4,4′-bipy complex, with open channels which accommodate the oxyfluoride anions via hydrogen bond interactions.