The complexation reaction of Co2+ (M) and the 1,1-diethyl-3-(4-methoxybenzoyl)thiourea (L) ligand in the binary mixtures: acetonitrile-dimethylsulfoxide (MeCN-DMSO), acetonitrile-dichloromethane (MeCN-DCM), water-dimethylsulfoxide (H2O-DMSO) and acetonitrile-water (MeCN-H2O), was investigated using a conductometric method at temperatures of (288.15, 298.15, 308.15 and 318.15) K. In all cases, the conductance data showed that the stoichiometry of the neutral complex formed between M and L is 1:3 [M:3L], which indicates that the Co2+ ion was oxidized to Co3+ during the reaction. The best estimate of the stability constant, log10 K f, = 3.31 for the [CoL3] complex, was observed with the MeCN-DCM (20:80 %) binary mixture at 298.15 K. The values of the thermodynamic parameters (i.e., ?Gc� and ? Sc�) for the formation of the [CoL3] complex were obtained from the temperature dependence of the stability constant via van't Hoff plots. The results show that, in most cases, the [CoL3] complexes are enthalpy destabilized but entropy stabilized. The values and signs of the thermodynamic parameters are affected by the nature and composition of the mixed solvents but are independent of the temperature. � 2015 Springer Science+Business Media New York.

In the title compound, C14H18N2O2S, the piperidine ring has a chair conformation. Its mean plane is twisted with respect to the 4-methoxybenzoyl ring, with a dihedral angle of 63.0 (3). The central N-C( S)-N(H)-C( O) bridge is twisted with an N-C-N-C torsion angle of 74.8 (6). In the crystal, molecules are linked by N-H...O and C-H...O hydrogen bonds, forming chains along the c-axis direction. Adjacent chains are linked by C-H...φ interactions, forming layers parallel to the ac plane. The layers are linked by offset φ-φ interactions [intercentroid distance = 3.927 (3) Å ], forming a supramolecular three-dimensional structure.

In the title compound, C13H16N2O2S, the pyrrolidine ring has a twisted conformation on the central - CH2-CH2- bond. Its mean plane is inclined to the 4-methoxybenzoyl ring by 72.79 (15)°. In the crystal, molecules are linked by N - H⋯O and C - H⋯O hydrogen bonds to the same O-atom acceptor, forming chains along [001]. The chains are linked via slipped parallel π-π interactions [inter-centroid distance = 3.7578 (13) Å], forming undulating slabs parallel to (100).