cis-Aquachloridobis(1,10-phenanthroline-κ2 N,N′)cobalt(II) chloride 2.5-hydrate

In the title complex, [CoCl(C12H8N2)2(H2O)]Cl·2.5H2O, the CoII ion is coordinated by four N atoms of two bis-chelating 1,10-phenanthroline (phen) ligands, one water molecule and a chloride ligand in a distorted octahedral environment. The dihedral angle between the two phen ligands is 84.21 (3)°. In the crystal structure, complex molecules and chloride ions are linked into centrosymmetric four-component clusters by intermolecular O—H⋯Cl hydrogen bonds. Of the 2.5 solvent water molecules in the asymmetric unit, two were refined as disordered over two sites with fixed occupancies of ratios 0.50:0.50 and 0.60:0.40, while another was refined with half occupancy.

In the title complex, [CoCl(C 12 H 8 N 2 ) 2 (H 2 O)]ClÁ2.5H 2 O, the Co II ion is coordinated by four N atoms of two bis-chelating 1,10-phenanthroline (phen) ligands, one water molecule and a chloride ligand in a distorted octahedral environment. The dihedral angle between the two phen ligands is 84.21 (3) . In the crystal structure, complex molecules and chloride ions are linked into centrosymmetric four-component clusters by intermolecular O-HÁ Á ÁCl hydrogen bonds. Of the 2.5 solvent water molecules in the asymmetric unit, two were refined as disordered over two sites with fixed occupancies of ratios 0.50:0.50 and 0.60:0.40, while another was refined with half occupancy.
Related literature 1,10-Phenanthroline is a versatile ligand capable of forming highly stable complexes with transition metal ions, see: Nobufumi (1969). Metal complexes functionalized with 1,10phenanthrolines have been used as catalyst for the enantio selective hydrolysis of N-protected amino acid esters and in enantio selective reduction of acetophenone, see: Weijnen et al. (1992). For some examples of the applications of substituted phenanthroline compounds, see Garuti et al. (1989). For the crystal structures of related cobalt complexes of 1,10phenanthroline, see: Sun & Feng (2006); Zhong et al. (2006). For the crystal structure of the title complex with thioacetamide solvent rather than water, see: Zhong et al. (2007). For the use of metal complexes of 1,10-phenanthroline in developing new diagnostic and therapeutic agents that can recognize and cleave DNA, see: Arai et al. (2005); Mü ller et al. (1987). Oxovanadium complexes of dimethyl-substituted phenanthroline will induce apoptosis in human cancer cells, and may be useful for the treatment of cancer, see: Rama Krishna et al. (2000). Weijnen et al. (1992); Nobufumi (1969).
Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97.  (Nobufumi, 1969). Complexes of 1,10-phenanthroline are frequently employed for catalytic reactions. For example metal complexes functionalized with 1,10-phenanthrolines have been used as catalyst for the enantio selective hydrolysis of N-protected amino acid esters and in enantio selective reduction of acetophenone (Weijnen, et al. 1992). The synthesis of some phenanthroline -2,9-disubstituted compounds along with their in vitro antimicrobial properties against gram-positive and gram -negative bacteria and fungi have been reported (Garuti et al.,1989). Metal complexes of 1,10-phenanthroline have been found to be attractive species for developing new diagnostic and therapeutic agents that can recognize and cleave DNA (Müller et al., 1987, Arai et al., 2005. Experimental evidence has been provided to prove oxovanadium complexes of dimethyl substituted phenanthroline will induce apoptosis in human cancer cells, and may be useful for the treatment of cancer (Rama Krishna, et al. 2000).
The molecular structure of the cation is shown in Fig. 1. The asymmetric unit contains one complex cation a chloride anion and 2.5 molecules of solvent water. The Co II ion is coordinated in a distorted octahedral environment by four nitrogen atoms of two 1,10-phenanthroline ligands, a chloride ion, and a water molecule. The dihedral angle between the two phen ligands is 84.21 (3) °. In the crystal structure, complex molecules and chloride ions are linked into centrosymmetric four component clusters by intermolecular O-H···Cl hydrogen bonds. .

Experimental
Cobalt(II) chloride hexahydrate was thoroughly grinded and exposed to microwave radiation for 30s. The dehydrated cobalt(II) chloride (0.05 mol) was dissolved in 100 ml of acetone. 1,10-phenanathroline monohydrate (0.1 mol) was dissolved in 100 ml of acetone. The solution of 1,10-phenanathroline was slowly added with constant stirring to the solution of cobalt(II) chloride and allowed to react for two hours. After completion of the reaction, a reddish orange coloured solution was formed. The stirring was stopped and the reaction mixture was allowed to settle for one hour. The reddish orange coloured product was filtered and washed with acetone and dried over a desicator. Single crystals were obtained by slow evaporation of a methanolic solution of the title complex.

Refinement
H atoms bonded to C atoms were placed in calculated position and included in the refinement in a riding-model approximation with C-H = 0.93Å and U iso (H) = 1.2U eq (C). The H atoms bonded to the coordinated water molecule were refined with isotropic displacement parameters. Of the 2.5 solvent water molecules is the asymmetric unit two were refnied as disordered over two sites with fixed occupancies of ration 0.5:0.5 and 0.60:0.40 while another was refined as a partial occupancy of 0.50. The H atoms of the solvent water molecules were not located nor included in the refinement but were included in the molecular formula.