Crystal structure of dichlorido(1,2-phenylenediamine-κ2 N,N′)platinum(II)

In the crystal structure of the title compound, almost planar [PtCl2{(C6H4)(NH2)2}] molecules are stacked into columns along the c axis, suggesting Pt⋯Pt interactions.


Chemical context
The title compound, dichlorido(1,2-phenylenediamine-2 N,N 0 )platinum(II) [PtCl 2 {(C 6 H 4 )(NH 2 ) 2 }], (I), which was originally prepared by Connors et al. (1972), is a member of the family of derivatives of cis-diamminedichloridoplatinum(II), cis-[PtCl 2 (NH 3 ) 2 ] (cis-platin). Since the discovery of the antitumor activity of cis-platin (Rosenberg et al., 1965), numerous derivatives and analogues of cis-platin have been prepared and investigated. However, reports on the corresponding crystal structures are rather scarce, probably because of the difficulty in obtaining crystals suitable for X-ray analysis, in part owing to poor solubility. Although the antitumor activity (Connors et al., 1972;Meischen et al., 1976) and the chemical stabilities (Kö ckerbauer & Bednarski, 1996) of the title compound have been reported, its crystal structure has not been determined so far. In the course of our study of the deprotonation and redox properties of a platinum complex with 1,2-phenylenediamine as a ligand (Konno & Matsushita, 2006a,b), we have successfully obtained single crystals of the title compound and report here its crystal structure. ISSN 2056-9890

Figure 1
A view of the molecular structure of compound (I), showing the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level for non-H atoms. [Symmetry code: (i) Àx + 1, y, Àz + 1 2 .] intermolecular N-HÁ Á ÁCl hydrogen bonds between adjacent molecules in the column ( Fig. 2 and Table 2). Intercolumnar hydrogen bonds also help to stabilize the crystal packing of the columns (Fig. 3, and Table 2).

Synthesis and crystallization
Compound (I) was prepared using a method modified from that described by Connors et al. (1972)

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3. One reflection (010)

Funding information
Funding for this research was provided by: Ministry of Education, Culture, Sports, Science and Technology, MEXT-Supported Program for the Strategic Research Foundation at Private Universities (award No. S1311027).