Metallkomplexe mit biologisch wichtigen Liganden, XL [1]. Iridium(III)-Komplexe mit 9-Methylguanin / Metal Complexes with Biologically Important Ligands, XL [1]. Iridium(III) Complexes with 9-Methylguanine

The dinitrogen-tetrafluoroborato complex (Ph 3 P) 2 (Cl)(N 2 )(H)IrFBF 3 reacts with 9-m ethylguanine in CH 2 Cl 2 to give [(Ph 3 P) 2 (Cl)(H)Ir(9-methylguanine)] + BF 4 - (2). From a solution of 2 in methanol the complex (Ph 3 P) 2 (Cl) 2 (H)Ir(9-methylguanine) (3) is obtained. The reaction of [(Ph 3 P) 2 (Cl)(N 2 )(H)IrOSO 2 C 4 F 9 ] with 9-methylguanine affords the com plexes [(Ph 3 P) 2 (Cl)(N 2 )(H)Ir(9-methylguanine)] + C 4 F 9 SO 3 - (5) and [(Ph 3 P) 2 (Cl)(H 2 O)(H)Ir(9-methylguanine)] + C 4 F 9 SO 3 - (6). The coordination of the guanine derivative to the iridium atom in 2, 5, 6 is discussed on the basis of the infrared spectra. The crystal structure of 3 was determined. 9-Methylguanine is coordinated via N (7). Intermolecular hydrogen bonding between the chloro-ligand and HN (1) of guanine leads to linear chains in the crystal.