title: Conformation of 2-aminomethylpyrrolidine and 2-aminomethylpiperidine in ternary platinum(II) complexes: regulation of conformation of the diamine by the coexisting ligand.
abstract: Square-planar complexes with the formula [Pt(L(2))(L(1))](X)(2) x nH(2)O, where L(1) is S-2-aminomethylpyrrolidine (S-pyrda) or 2-aminomethylpiperidine (pipda) and L(2) is diammine (X=Cl), cyclobutane-1,1-dicarboxylato (cbdca) (X=none), 2,2'-bipyridine (bpy) (X=NO(3)), or 1,10-phenanthroline (phen) (X=Cl), were prepared and the nature of the coordination of L(1) was examined by (1)H-NMR spectroscopy and X-ray crystallography. These 2-aminomethylazacycloalkane derivatives form five-membered chelate rings condensed with an azacycloalkane ring in cis- or trans-configurations. The (1)H-NMR spectrum of complexes with S-pyrda as L(1) were consistent with cis-condensed rings in an S(N) conformation with any of L(2) group. However, (1)H-NMR spectra of the complexes with pipda as L(1) indicated trans-fused successive rings for the diammine and cbdca as L(2), but spectra for bpy and phen as L(2) were consistent with a conformation having cis-fused successive rings. X-Ray crystallography data for the two complexes with pipda as L(1) and cbdca (1) and bpy (2) as L(2) confirms the different coordination behavior in the solid state.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi, Japan. gmphiwin@gpo.kumamoto-u.ac.jp
authors.forename: Masafumi
authors.initials: M
authors.lastname: Goto
authors.forename: Yuuichiro
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Sumimoto
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tsuruda
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Kurosaki
mesh_terms: D018360:Crystallography, X-Ray / Q000379:methods; D003959:Diamines / Q000737:chemistry*; D008024:Ligands; D008968:Molecular Conformation; D010880:Piperidines / Q000737:chemistry*; D017671:Platinum Compounds / Q000737:chemistry*; D011759:Pyrrolidines / Q000737:chemistry*
chemical_list: D003959:Diamines; D008024:Ligands; D010880:Piperidines; D017671:Platinum Compounds; D011759:Pyrrolidines