Ligand substitution reactions on aquapentachloro- and hexachloroplatinic acid - Synthesis and characterization of tetrachloroplatinum(IV) complexes with heterocyclic N,N donors

摘要

Reactions of aquapentachloroplatinic acid, (H3O)[PtCl5(H2O)].2(18C6).6H(2)O (1) (18C6 = 18-crown-6), and H-2[PtCl6].6H(2)O (2) with heterocyclic N,N donors (2,2'-bipyridine, bpy; 4,4'-di-tert-butyl-2,2'-bipyridine, tBu(2)bpy; 1,10-phenanthroline, phen; 4,7-diphenyl-1,10-phenanthroline, Ph(2)phen; 2,2'-bipyrimidine, bpym) afforded with ligand substitution platinum(IV) complexes [PtCl4(Nboolean ANDN)] (Nboolean ANDN = bpy, 3a; tBu(2)bpy, 3b; Ph(2)phen, 5; bpym, 7) and/or with protonation of N,N donor yielding (R(2)phenH)(2)[PtCl6] (R = H, 4a; Ph, 4b) and (bpymH)(+) (8). With UV irradiation Ph(2)phen and bpym reacted with reduction yielding platinum(II) complexes [PtCl2(Nboolean ANDN)] (Nboolean ANDN = Ph(2)phen, 6; bpym, 9). Identities of all complexes were established by microanalysis as well as by NMR (H-1, C-13, Pt-195) and IR spectroscopic investigations. Molecular structures of [PtCl4(bpym)].MeOH (7) and [PtCl2(Ph(2)phen)] (6) were determined by X-ray diffraction analyses. Differences in reactivity of bpy/bpym and phen ligands are discussed in terms of calculated structures of complexes [PtCl5(Nboolean ANDN)](-) with monodentately bound N,N ligands (Nboolean ANDN = bpy, 10a; phen, 10b; bpym, 10c). [References: 35]