Two new CrIII(bpb)(H2O)X complexes derived from [Cr(bpb)(N3)2]− or [Cr(bpb)(CN)2]− (bpb2− = 1,2-bis(pyridine-2-carboxamido)benzenate, X− = hydroxo or azide)

Two new Cr(III) complexes, Cr(bpb)(H₂O)(OH)]·3H₂O (1) and Cr(bpb)(H₂O)(N₃)]·H₂O (2) have been synthesized and structurally characterized. Both complexes were unexpectedly obtained as single crystals during the reactions of Cr(bpb)(CN)₂]⁻ or Cr(bpb)(N₃)₂]⁻ with Ni(L)](ClO₄)₂ (L = 3,10-dimethyl-1,3,6,8,10,12-hexaazacyclotetradecane) or MX₂·nH₂O (M = Cu, Ni and Mn, X = Cl⁻ and ClO₄ ⁻). Complex 1 crystallizes in the triclinic system, space group P-1, formula CrC₁₈H₂₁N₄O₇ with a = 7.1543(17) ?, b = 12.420(3) ?, c = 12.955(3) ?, α = 115.021(5)°, β = 95.544(5)°, and γ = 101.575(5)°. Complex 2 crystallizes in the monoclinic system, space group P2₁/c, formula CrC₁₈H₁₆N₇O₄ with a = 11.7171(9) ?, b = 9.4999(7) ?, c = 16.8799(13) ?, and β = 97.449(2)°. Both complexes exhibit distorted octahedral coordination environment with four nitrogen atoms of bpb²⁻ situated at the equatorial plane (Cr–N bond distances range from 1.961(3) to 2.1088(15) ?), and the remaining two trans-positions occupied by terminal ligands H₂O/HO and H₂O/N₃ in 1 and 2, respectively. It is noteworthy that a hydrogen-bonded folded ladder-like structure involving twelve O atoms in 1 and a chair-like hexagonal hydrogen-bonded cluster containing six O atoms are formed.