Synthesis and crystal structure of Sr ₂ Cu(OH) ₄ [B(OH) ₄ ] ₂

Abstract

Single crystals of distrontium copper(II) tetrahydroxide bis(tetrahydroxidoborate), Sr 2 Cu(OH) 4 [B(OH) 4 ] 2 , were obtained by an ammonia evaporation method at room temperature. The compound crystallizes in the triclinic system, space group P 1 , and is isotypic with the calcium analogue henmilite, Ca 2 Cu(OH) 4 [B(OH) 4 ] 2 . The {Cu(OH) 4 } units form a deformed square lattice in the ac plane, giving rise to a quasi-two-dimensional arrangement of Cu II ions. An intricate network of O—H...O hydrogen bonds of medium strengths with the [B(OH) 4 ] units as the primary donor groups consolidate the framework structure.