Crystal structure of di-aqua-bis-(4-tert-butyl-benzoato-κO)bis-(nicotinamide-κN (1))cobalt(II) dihydrate.

The asymmetric unit of the mononuclear cobalt complex, [Co(C11H13O2)2(C6H6N2O)2(H2O)2]·2H2O, contains one half of the complex mol-ecule, one coordinating and one non-coordinating water mol-ecule, one 4-tert-butyl-benzoate (TBB) ligand and one nicotinamide (NA) ligand; the Co atom lies on an inversion centre. All ligands coordinating to the Co atom are monodentate. The four nearest O atoms around the Co atom form a slightly distorted square-planar arrangement, with the distorted octa-hedral coordination completed by the two pyridine N atoms of the NA ligands at distances of 2.1638 (11) Å. The coordinating water mol-ecules are hydrogen bonded to the carboxyl O atoms [O ⋯ O = 2.6230 (17) Å], enclosing an S(6) hydrogen-bonding motif, while inter-molecular O-H⋯O hydrogen bonds link two of the non-coordinating water mol-ecules to the coordinating water mol-ecules and NA anions. The dihedral angle between the planar carboxyl-ate group and the adjacent benzene ring is 29.09 (10)°, while the benzene and pyridine rings are oriented at a dihedral angle of 88.53 (4)°. In the crystal, O-H⋯O and N-H⋯O hydrogen bonds link the mol-ecules, enclosing R 2 (2)(8), R 2 (2)(10) and R 4 (4)(12) ring motifs, forming layers parallel to (001). The C and H atoms of the tert-butyl group of the TBB ligand are disordered over two sets of sites with an occupancy ratio of 0.631 (5):0.369 (5).

Crystal structure of di-aqua-bis-(N,N-di-ethyl-nicotinamide-κN (1))bis-(2,4,6-tri-methyl-benzoato-κO (1))cobalt(II).

The centrosymmetric mol-ecule in the monomeric title cobalt complex, [Co(C10H11O2)2(C10H14N2O)2(H2O)2], contains two water mol-ecules, two 2,4,6-tri-methyl-benzoate (TMB) ligands and two di-ethyl-nicotinamide (DENA) ligands. All ligands coordinate to the Co(II) atom in a monodentate fashion. The four O atoms around the Co(II) atom form a slightly distorted square-planar arrangement, with the distorted octa-hedral coordination sphere completed by two pyridine N atoms of the DENA ligands. The dihedral angle between the planar carboxyl-ate group and the adjacent benzene ring is 84.2 (4)°, while the benzene and pyridine rings are oriented at a dihedral angle of 38.87 (10)°. The water mol-ecules exhibit both intra-molecular (to the non-coordinating carboxyl-ate O atom) and inter-molecular (to the amide carbonyl O atom) O-H⋯O hydrogen bonds. The latter lead to the formation of layers parallel to (100), enclosing R 4 (4)(32) ring motifs. These layers are further linked via weak C-H⋯O hydrogen bonds, resulting in a three-dimensional network. One of the two ethyl groups of the DENA ligand is disordered over two sets of sites with an occupancy ratio of 0.490 (13):0.510 (13).

Crystal structure of tri-aqua-(4-cyano-benzoato-κ(2) O,O')(nicotinamide-κN (1))zinc 4-cyano-benzoate.

The asymmetric unit of the title salt, [Zn(C8H4NO2)(C6H6N2O)(H2O)3](C8H4NO2), contains one complex cation and one 4-cyano-benzoate (CNB) counter-anion. The Zn(II) atom in the cation is coordinated by one 4-cyano-benzoate ligand, one nicotinamide (NA) ligand and three water mol-ecules, the CNB anion thereby coordinating in a bidentate O,O'-mode through the carboxyl-ate group. The latter, together with one water O atom and the N atom of the NA ligand, form a distorted square-planar arrangement, while the considerably distorted octa-hedral coordination sphere of the Zn(II) atom is completed by the two O atoms of additional water mol-ecules in the axial positions. The dihedral angles between the planar carboxyl-ate groups and the adjacent benzene rings in the two anions are 10.25 (10) and 5.89 (14)°. Inter-molecular O-H⋯O hydrogen bonds link two of the coordinating water mol-ecules to two free CNB anions. In the crystal, further hydrogen-bonding inter-actions are present, namely N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds that link the mol-ecular components, enclosing R 2 (2)(12), R 3 (3)(8) and R 3 (3)(9) ring motifs and forming layers parallel to (001). π-π contacts between benzene rings [centroid-to-centroid distances = 3.791 (1) and 3.882 (1) Å] may further stabilize the crystal structure.

Crystal structure of trans-di-aqua-bis-(4-cyano-benzoato-κO)bis-(nicotinamide-κN (1))cobalt(II).

In the title complex, [Co(C8H4NO2)2(C6H6N2O)2(H2O)2], the Co(II) atom is located on an inversion centre and is coordinated by two 4-cyano-benzoate (CNB) anions, two nicotinamide (NA) ligands and two water mol-ecules. The four O atoms in the equatorial plane form a slightly distorted square-planar arrangement, while the slightly distorted octa-hedral coordination sphere is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxyl-ate group and the adjacent benzene ring is 22.11 (15)°, while the pyridine and benzene rings are oriented at a dihedral angle of 89.98 (5)°. In the crystal, inter-molecular N-H⋯O and O-H⋯O hydrogen bonds link the mol-ecules, enclosing R 2 (2)(8) and R 4 (4)(8) ring motifs, forming layers parallel to (100). The layers are linked via C-H⋯O and C-H⋯N hydrogen bonds, resulting in a three-dimensional network. A weak C-H⋯π inter-action is also observed.