Tris{N-[(anthracen-9-yl)methyleneamino]thioureato}cobalt(III) tetrahydrate

In the title complex, [Co(C16H12N3S)3]·4H2O, the central CoIII atom is in a distorted octahedral coordination environment. There are three N-[(anthracen-9-yl)methyleneamino]thioureate ligands coordinated to the CoIII atom via three imine N and three thioamide S atoms. The Co—S and Co—N bond distances are in expected ranges [2.2194 (8)—2.2545 (8) and 1.926 (2)—1.985 (2)Å, respectively]. The endocyclic S—Co—N bond angles in the five-membered chelate rings range from 82.91 (7) to 85.33 (7)°. The structure contains four water molecules which are disordered over 12 sites and link the complex molecules into a three-dimensional network through N—H⋯O, O—H⋯O, O—H⋯N, and O—H⋯S hydrogen bonds.

This work was supported financially by the Natural Science Foundation of Jiangsu Province Education office (grant No. 04KJB150015). The authors also thank Dr Zaichao Zhang for his support.

Comment
The thiosemicarbazone derivatives and their transition metal complexes have received considerable attention because of their biological and pharmaceutical properties. These compounds have been previously investigated for their antifungal (Horton et al., 2003), antibacterial (He et al., 2003), antimicrobial (Pawar et al., 2004), antiamoebic (Ozden et al., 2005), antiparasitic (Navarrete-Vazquez et al., 2001) and antitumor activities (Kabanos et al., 1992). Although many thiosemicarbazones and their transition metal complexes have been studied (Rodriguez-Arguelles et al., 2004), there is no information available on the structural characterization of anthracene thiosemicarbazone derivatives. The pharmacological or coordinative information on the anthracene thiosemicarbazone derivatives and their complexes are also unknown (Casas et al., 2000).
There are four disordered water molecules in the structure which are located over twelve sites with partial occupancyies and take part in a bridging role, linking the complex molecules into a three-dimensional network through N-H···O, O-H···O, O-H···N, and O-H···S type hydrogen bonds (details are given in Table 1).
Dark brown prismatic crystals suitable for X-ray analysis were obtained.

Tris{N-[(anthracen-9-yl)methyleneamino]thioureato}cobalt(III) tetrahydrate
Crystal data [Co(C 16   Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ.