2,9-Dimethyl-1,10-phenanthrolin-1-ium (6-carb-oxy-4-hy-droxy-pyridine-2-carboxyl-ato-κO,N,O)(4-hy-droxy-pyridine-2,6-dicarboxyl-ato-κO,N,O)zincate(II) 2.35-hydrate: a proton-transfer compound.

ABSTRACT

In the title compound, (C(14)H(13)N(2))[Zn(C(7)H(3)NO(5))(C(7)H(4)NO(5))]·2.35H(2)O, the Zn(II) atom is coordinated by two N atoms and four O atoms from the carboxyl-ate groups of the 4-hy-droxy-pyridine-2,6-dicarboxyl-ate and 6-carb-oxy-4-hy-droxy-pyridine-2-carboxyl-ate ligands, forming a distored octa-hedral geometry. In the anion, the two pyridine rings are inclined to one another by 87.75 (13)°. Two types of robust O-H⋯O hydrogen bond synthons, viz. R(2) (2)(16) and R(6) (6)(42), link the anions to form a two-dimensional network parallel to the bc plane. Furthermore, O-H⋯O, N-H⋯O, N-H⋯N and weak C-H⋯O hydrogen bonds connect the two dimensional networks, forming a three-dimensional structure. In the crystal, there are also C-H⋯π and π-π inter-actions [centroid-centroid distances of 3.5554 (18) and 3.7681 (18) Å], and C=O⋯π inter-actions [O⋯centroid distance = 3.117 (2) Å] present. One of the three crystal water molecules shows an occupancy of 0.35.