cis-Diammine[3-(3-chloro-7-methoxy-9,10-dihydroacridin-9-ylideneamino)propan-1-amine-κ²N,N′]platinum(II) dinitrate

Abstract

The title complex salt, [Pt(C 16 H 17 N 3 )(NH 3 ) 2 ](NO 3 ) 2 , is of interest with respect to anticancer activity. The secondary amine of 9-aminoacridine coordinates with the platinum(II) atom, leading to imine-platinum complex cation formation. The crystal structure displays extensive N-HÁ Á ÁO and N-HÁ Á ÁN hydrogen bonding and weak C-HÁ Á ÁCl and C-HÁ Á ÁO hydrogen bonding. Structure descriptionPlatinum has been widely used for chemotherapy since cisplatin was approved by the US Food and Drug Administration in 1978 (Galanski et al., 2005). Unfortunately, due to the widespread use of platinum drugs, patients began to develop drug resistance (Shen et al., 2012). Non-classical platinum drugs, for example, platinum-intercalator conjugates are thought to be an alternative solution to overcome cisplatin resistance (Johnstone et al., 2014;Baruah et al., 2004;Martins et al., 2001). We attempted to synthesize a 9-aminoacridine derivative linked with monofunctional platinum via a three-carbon alkyl chain. During the platination reaction between the primary amine and cis-[Pt(NH 3 ) 2 (Odonor)Cl] + (O-donor = O1-DMF and NO 3 À ), an unexpected product formed predominantly. We grew crystals of the compound to investigate the structure via X-ray diffraction of the crystal.The secondary amine of 9-aminoacridine replaced the chloride to form a platinumnitrogen complex. The platinum complex (Fig. 1) has a square-planar geometry and the three-carbon alkyl chain became part of a newly formed six-membered ring with Pt, N13 and N9. The longer bond lengths of N13-Pt [2.053 (9) Å ] and N9-Pt [1.993 (8) Å ] appears to compensate for the smaller bond angle of ], allowing the six-membered ring to adopt a conformation similar to a chair conformation. The bond