Synthesis, Crystal Structure and Properties of Li₂Cu₅(PO₄)₄

Abstract

Abstract Li 2 Cu II 5 (PO 4 ) 4 has been obtained by various reactions starting from copper or Cu 2 O. Crystallization was achieved using I 2 as oxidant and mineralizer. The new orthophosphate crystallizes in space group P $\bar{1}$ , Z = 2, with a = 6.0502(3) Å, b = 9.2359(4) Å, c = 11.4317(5) Å, α = 75.584(2)°, β = 80.260(2)°, γ = 74.178(2)°, at 293 K. Its structure has been determined from X‐ray single‐crystal data and refined to R 1 = 0.022{ wR 2 = 0.058 for 4633 unique reflections with F o > 4 σ ( F o )}. From magnetic measurements μ eff = 1.51 μ B /Cu and θ P = –37.4 K have been determined. The Vis/NIR spectrum of aqua‐green Li 2 Cu 5 (PO 4 ) 4 shows a single broad band centered around $\bar{1}$ = 12000 cm –1 . Magnetic behavior and spectrum are discussed within the angular overlap model.