Formation, dynamic behavior, and chemical transformation of Pt complexes with a rotaxane-like structure.
The reaction of [Pt(CH2COMe)(Ph)(cod)] (cod = 1,5-cyclooctadiene) with (ArCH2NH2CH2-C6H4COOH)+ (PF6)- (Ar = 4-tBuC6H4 or 9-anthryl) in the presence of cyclic oligoethers such as dibenzo[24]crown-8 (DB24C8) and dicyclohexano[24]crown-8 (DC24C8) produces {(ce)[ArCH2NH2CH2C6H4COOPt(Ph)(cod)]}+ (PF6)- (ce = DB24C8 or DC24C8, Ar = 4-tBuC6H4 or 9-anthryl) with interlocked structures. FABMS and NMR spectra of a solution of these compounds indicate that the Pt complexes with a secondary ammonium group and DB24C8 (or DC24C8) make up the axis and cyclic components, respectively. Temperature-dependent 1H NMR spectra of a solution of {(DB24C8)[4-tBuC6H4CH2NH2CH2-C6H4COOPt(Ph)(cod)]}+ (PF6)- ({(DB24C8)[4-H]}+ (PF6)-) show equilibration with free DB24C8 and the axis component. The addition of DB24C8 to a solution of {(DC24C8)[4-H]}+ (PF6)- causes partial exchange of the macrocyclic component of the interlocked molecules, giving a mixture of {(DC24C8)[4-H]}+ (PF6)-, {(DB24C8)[4-H]}+ (PF6)-, and free macrocyclic compounds. The reaction of 3,5-Me2C6H3COCl with {(DB24C8)[4-H]}+ (PF6)- affords the organic rotaxane {(DB24C8)(4-tBuC6H4CH2NH2CH2-C6H4COOCOC6H3Me2-3,5)}+ (PF6)- through C-O bond formation between the aroyl group and the carboxylate ligand of the axis component. The addition of 2,2'-bipyridine (bpy) to a solution of {(DB24C8)[4-H]}+ (PF6)- induces the degradation of the interlocked structure to form a complex with trigonal bipyramidal coordination, [Pt(Ph)(bpy)(cod)]+ (PF6)-, whereas the reaction of bpy with [Pt(OCOC6H4Me-4)(Ph)(cod)] produces the square-planar complex [Pt(OCOC6H4Me-4)(Ph)(bpy)].
Suzaki
Yuji
Y
Chemical Resources Laboratory (Mailbox R1-3), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Osakada
Kohtaro
K
D002264:Carboxylic Acids / Q000737:chemistry*; D003460:Crystallization; D015195:Drug Design; D007700:Kinetics; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008956:Models, Chemical; D009944:Organoplatinum Compounds / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D043862:Rotaxanes / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics; D014961:X-Ray Diffraction
D002264:Carboxylic Acids; D008024:Ligands; D009944:Organoplatinum Compounds; D000644:Quaternary Ammonium Compounds; D043862:Rotaxanes; D010984:Platinum