title: 1,10-Phenanthrolin-1-ium nitrate-aqua-bis-(4-hydroxy-benzoato-κO,O')(nitrato-κO,O')(1,10-phenanthroline-κN,N')erbium(III)-1,10-phenanthroline-water (1/1/0.5/2).
abstract: In the title compound, C(12)H(9)N(2) (+)·NO(3) (-)·[Er(C(7)H(5)O(3))(2)(NO(3))(C(12)H(8)N(2))(H(2)O)]·0.5C(12)H(8)N(2)·2H(2)O, the water-mol-ecule-coordinated Er(III) ion is chelated by one 1,10-phenanthroline (phen) ligand, two 4-hy-droxy-benzoate anions and one nitrate anion in a monocapped square-anti-prismatic coordination geometry. The uncoordinating phen mol-ecule is approximately parallel to the 1,10-phenanthrolin-1-ium (Hphen) anion [dihedral angle = 3.3 (4)°]. The centroid-centroid distance of 3.801 (5) Å between pyridine rings suggests the existence of π-π stacking. The crystal structure contains an extensive network of classical O-H⋯O and N-H⋯O and weak C-H⋯O hydrogen bonds. C-H⋯π inter-actions between phen and 4-hy-droxy-benzoate is also present in the crystal structure. In the crystal, the uncoordinating phen is equally disordered over two sites about an inversion center.
authors.forename: Fwu Ming
authors.initials: FM
authors.lastname: Shen
authors.forename: Shie Fu
authors.initials: SF
authors.lastname: Lush