Bis(N-sec-butyl-N-n-propyldithiocarbamato-κ2 S,S′)(1,10-phenanthroline-κ2 N,N′)zinc(II)

Two independent but very similar molecules comprise the asymmetric unit of the title compound, [Zn(C8H16NS2)2(C12H8N2)]. The N2S4 donor set about Zn is defined by two symmetrically chelating dithiocarbamate ligands and a 1,10-phenanthroline ligand. Distortions from the ideal octahedral coordination geometry arise from the restricted bite angles of the ligands. The main feature of the crystal packing is the formation of tetrameric supramolecular aggregates mediated by C—H⋯S interactions. Disorder was found in each of the sec-butyl groups. This was resolved over two positions in each case with the major components of the disorder having site occupancies in the range 0.551 (6)–0.725 (5).

Two independent but very similar molecules comprise the asymmetric unit of the title compound, [Zn(C 8 H 16 NS 2 ) 2 -(C 12 H 8 N 2 )]. The N 2 S 4 donor set about Zn is defined by two symmetrically chelating dithiocarbamate ligands and a 1,10phenanthroline ligand. Distortions from the ideal octahedral coordination geometry arise from the restricted bite angles of the ligands. The main feature of the crystal packing is the formation of tetrameric supramolecular aggregates mediated by C-HÁ Á ÁS interactions. Disorder was found in each of the sec-butyl groups. This was resolved over two positions in each case with the major components of the disorder having site occupancies in the range 0.551 (6)-0.725 (5). 302 restraints H-atom parameters constrained Á max = 1.32 e Å À3 Á min = À0.59 e Å À3 Table 1 Hydrogen-bond geometry (Å , ). Symmetry codes: (i) x À 1; y; z; (ii) Àx þ 2; Ày þ 1; Àz þ 1.
We thank UKM (UKM-GUP-NBT-08-27-111 and UKM-ST-06-FRGS0092-2010), UPM and the University of Malaya for supporting this study. The presence of C-H···S interactions, Table 1, lead to the formation of tetrameric supramolecular aggregates in the crystal structure of (I). The S8 atom is pivotal in these. The molecules comprising the asymmetric unit are connected by the C-H···S8 interaction involving the C28-H28a atom. The dimeric aggregates thus formed are linked via the C-H···S8 interaction involving the C50-H50 atom, Fig. 3. Globally, the molecules pack into layers parallel to (0 1 1) and inter-digitate, Fig. 4.
The solution was kept at 273 K for an hour. Zinc chloride (10 mmol) dissolved in ethanol (50 ml) was added to give a white precipitate. This was collected and redissolved in chloroform (50 ml). The solution was mixed with a solution of 1,10-phenanthroline (10 mmol) dissolved in ethanol (10 mol). The yellow solution was set aside for the growth of crystals.

Refinement
H-atoms were placed in calculated positions (C-H 0.95 to 1.00 Å) and were included in the refinement in the riding model approximation, with U iso (H) set to 1.2 to 1.5U equiv (C).
All sec-butyl groups were found to be disordered. For each group, the site occupancies were refined. The major component had site occupancy factor of 0.551 (6) for the C5-containing group, 0.725 (5) for the C13-group, 0.587 (6) for the C33-group, and 0.557 (6) for the C41-group. For both the ordered n-propyl and disordered sec-butyl groups, the 1,2-related C-C distances were tightly restrained to 1.500±0.005 Å and the 1,3-related ones to 2.51±0.01 Å. Within the S 2 C-NC 2 fragment, the S 2 C-N distances were restrained to 1.35±0.01 Å and the N-C alkyl distances to 1.45±0.01 Å. Finally, all anisotropic displacement parameters were refined individually except for the C33' and C36' atoms which were refined isotropically.
supplementary materials sup-2 Additionally, the anisotropic displacement parameters for the carbon atoms of both the ordered n-propyl and disordered sec-butyl groups were tightly restrained to be nearly isotropic.