(1,2,3,4-Tetrahydroisoquinoline-2-carbodithioato-κ2 S,S′)(thiocyanato-κN)(triphenylphosphane)nickel(II)

The NiII atom in the mononuclear title compound, [Ni(C10H10NS2)(NCS)(C18H15P)], exists within a S2PN donor set that defines a distorted square-planar geometry. A significant asymmetry in the Ni—S bond lengths support the less effective trans effect of SCN− over PPh3.

The Ni II atom in the mononuclear title compound, [Ni(C 10 H 10 NS 2 )(NCS)(C 18 H 15 P)], exists within a S 2 PN donor set that defines a distorted square-planar geometry. A significant asymmetry in the Ni-S bond lengths support the less effective trans effect of SCN À over PPh 3 .

Related literature
For general background to dithiocarbamates and their biological activity, see: Gunay et al. (1999); Hogarth (2005); Ozkirimli et al. (2005). Nickel complexes of phosphine ligands have been studied for their anticancer activity, see: Jarret et al. (1993). Nickel(II) dithiocarbamates can react with Lewis bases such as phosphines as well as hard bases such as nitrogenous ligands, see: Srinivasan et al. (2009);Travnicek et al. (2008). For the preparation of the title compound, see: Valarmathi et al. (2011).

Experimental
Crystal data [Ni(C 10  the results are presented here. The X-ray study confirmed the molecular structure and atomic connectivity for (I), as illustrated in Fig. 1.
The structure consists of distorted square planar metal coordination with NiS 2 PN chromophore. Deviation of the plane from a perfect square is caused by the small bite angle subtended by the sulfur atoms of the chelating dithiocarbamate at the nickel atom. The Ni-S bond distances [2.218 (1) and 2.162 (1) Å, respectively] are significantly different, due to the different trans influences exerted by phosphine and NCS -. PPh 3 being a good π-acceptor has a greater trans influence and hence the Ni-S bond trans to P is longer than the one trans to NCS anion.
The shortening of Ni-P distance is due the strong back bonding in nickel atom. The C-P-C angles deviate appreciably from the normal tetrahedral angle due to the crowding of the phenyl rings. The short Ni-N distance, 1.867 (2) Å, shows the effective bonding between the nickel atom and NCS -. The Ni-N-C angle 170.9 (2)° indicates deviation from the linearity and is due to steric compulsions of the bulky PPh 3 group.
The C-S bond lengths are 1.707 (3) and 1.717 (3) Å which are shorter than the typical single bond value of 1.81 Å and longer than C=S distance of 1.69 Å, indicating partial double bond character. The short thioureide C-N distance, 1.315 (3) Å indicates that the π-electron density is delocalised over the S 2 CN moiety and that this bond has partial double bond character.
In addition to the van der Waals interactions, the molecular structure is influenced only by intramolecular C-H···S hydrogen bonds involving sulphur atoms S1 and S2. (Fig. 2 and Table 1).

Experimental
Compound (I) was prepared according to the literature procedure (Valarmathi et al., 2011). Single crystals of (I) were obtained by slow evaporation of dichloromethane and ethanol (2:1) solution of (I) at room temperature.
supplementary materials sup-2 Refinement H atoms were placed in idealized positions and allowed to ride on their parent atoms, with C-H distances of 0.93-0.97 Å, and Uiso(H) = 1.2U eq (C) for H atoms.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 > 2sigma(F 2 ) is used only for calculating R-factors(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 )