Syntheses and crystal structures of two new sodium borates [Na2(H2O)3][B5O8(OH)2] and Na[enH2][B7O10(OH)4

Abstract

Abstract Two new sodium borates [Na2(H2O)3][B5O8(OH)2] (1) and Na[enH2][B7O10(OH)4] (2) have been synthesized and their structures have been determined by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic system space group C2/c with a = 11.118(2), b = 16.442(2), c = 13.572(2) Å, β =112.90(1)°, V = 2285.4(5) Å3, and Z = 4. Compound 2 crystallizes in the triclinic space group P1̅, with a = 7.4974(9), b = 8.349(2), c = 11.746(2), α = 93.98(1), β = 97.25(1), γ = 101.18(1)°, V = 712.2(2) Å3, and Z = 2. Compound 1 possesses {Na2B5O8(OH)2·3H2O} n chains which form through the connection of the fundamental building blocks (FBBs) [B5O8(OH)2]2– by sharing Na+ ions, while compound 2 has infinite {Na[B7O10(OH)4]} n sheets which form via the connection of the FBBs [B7O10(OH)4]3– by common Na+ ions.