title: Proton-induced cis-trans conversion of a platinum(II) center coordinated by L-cysteinatocobalt(III) metalloligands.
abstract: Treatment of LambdaL-[Co(L-cys-N,S)(en)2]+ (l-H2cys = L-cysteine) with [PtCl4]2- in water, followed by the addition of acid, gave an S-bridged CoIII2PtII trinuclear complex ([1]4+), which was reversibly converted to its deprotonated complex ([2]2+) in an aqueous solution. While [1]4+ formed only a trans isomer, [2]2+ existed as a mixture of trans and cis isomers. The selective formation of a cis isomer was achieved by treatment of [1]4+ or [2]2+ with phthalic acid in water, which afforded a unique CoIII4PtII2 hexanuclear complex ([3]4+). Complex [3]4+ was reverted back to [1]4+ by treatment with aqueous HCl, accompanied by the complete cis-to-trans conversion.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Zentaro
authors.initials: Z
authors.lastname: Matsumoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Aridomi
authors.forename: Asako
authors.initials: A
authors.lastname: Igashira-Kamiyama
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kawamoto
authors.forename: Takumi
authors.initials: T
authors.lastname: Konno
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D011522:Protons; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods; D013237:Stereoisomerism
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D011522:Protons; D003035:Cobalt; D010984:Platinum; D003545:Cysteine