Bis(2-amino-4-phenyl-1,3-thiazol-3-ium) tetrachloridopalladate(II)

The title compound, (C9H9N2S)2[PdCl4], consists of two monoprotonated 2-amino-4-phenyl-1,3-thiazole molecules and one tetrachloridopalladate anion. The organic molecules exhibit a dihedral angle between the main rings planes of 31.82 (9)°. In the anion, the PdII atom is located on a crystallographic centre of symmetry with a square-planar geometry. In the crystal, the anions and cations are connected through bifurcated N—H⋯Cl hydrogen bonds, and these interactions lead to hydrogen-bonded tapes of cations and anions along [100].

The title compound, (C 9 H 9 N 2 S) 2 [PdCl 4 ], consists of two monoprotonated 2-amino-4-phenyl-1,3-thiazole molecules and one tetrachloridopalladate anion. The organic molecules exhibit a dihedral angle between the main rings planes of 31.82 (9) . In the anion, the Pd II atom is located on a crystallographic centre of symmetry with a square-planar geometry. In the crystal, the anions and cations are connected through bifurcated N-HÁ Á ÁCl hydrogen bonds, and these interactions lead to hydrogen-bonded tapes of cations and anions along [100].

S1. Introduction
The thiazole ring system is an important structural motif found in numerous molecules with potential biological activities, for instance; as antiinfective agents (Annadurai et al., 2012;Alam et al., 2011). On the other hand, in recent years there has been a growing interest in organic derivatives of transition metals in order to modify the biological properties of these organic compounds. Thus, in this opportunity we would like to report the crystal structure of bis-(2-amino-4-phenyl-1,3thiazolium) tetrachloropalladate (II).
The PdCl 2 (25 mg, 0.14 mmol) was dissolved in 1 mL of concentrated HCl and then diluted with 5 mL of methanol. To the resulting mixture a methanol (5mL) solution of 2-amino-4-phenyl-1,3-thiazole (50 mg, 0.28 mmol) was added. The reaction mixture was stirred for four hours at room temperature, after which time the resulting solution was allowed to slowly evaporate to produce brown X-ray diffraction quality crystals after few days.

S2.2. Refinement
Crystal data, data collection and structure refinement details are summarized in Table 1.
All H atoms were included in calculated positions (C-H = 0.93 Å), and refined using a riding model with Uiso(H) = 1.2 Ueq of the carrier atom. H atoms on N were located in a Fourier map and refined isotropically with Uiso(H) = 1.2 × Ueq(N).
13 badly-fitted reflections were omitted from the final refinement.

S3. Results and discussion
The title compound, [C 9 H 9 N 2 S] 2 [PdCl 4 ], is centrosymmetric and consists of two monoprotonated 2-amino-4-phenyl-1,3thiazole molecules and one tetrachloropalladate anion. This compound, crystallized in the triclinic P-1 space group. The asymmetric unit is composed of one monoprotaned 2-amino-4-phenyl-1,3-thiazole and half of the tetrachloropalladate anion, the other half is generated by application of an inversion centre. The dihedral angle between the planes of the phenyl and thiazole rings in the cation is of 31.82 (9)°.This value is larger than those reported in other compounds containing the 2-amino-4-phenyl-1,3-thiazole molecule, protonated (Form et al., 1974;Jin et al., 2013;Jin et al., 2011)  The palladium atom of the anion is in a special position (0.5, 0, 1), Wyckoff site 1d, and exhibits a square-planar geometry with Pd-Cl distances of 2.3031 (5) and 2.3061 (6) Å. The cation and the anion are linked by a bifurcate hydrogen bond between the chloride atoms and the hydrogen of the thiazole ring (Figure 1). The NH and NH 2 groups exhibit N-H···Cl hydrogen bonds with the chloride atoms generating a linear arrangement in the orientation [100] ( Figure 2).

Figure 1
Molecular structure of title compound with displacement ellipsoids at the 40% probability. Hydrogen atoms are drawn as spheres of arbitrary radius.

Figure 2
Linear arrangement due hydrogen bond patterns in crystal structure of the title compound.