title: (trans-1,4-bis[(4-pyridyl)ethenyl]benzene)(2,2'-bipyridine)ruthenium(II) complexes and their supramolecular assemblies with beta-cyclodextrin.
abstract: Two novel ruthenium polypyridine complexes, [Ru(bpy)(2)Cl(BPEB)](PF(6)) and ([Ru(bpy)(2)Cl](2)(BPEB))(PF(6))(2) (BPEB = trans-1,4-bis[2-(4-pyridyl)ethenyl]benzene), were synthesized and their characterization carried out by means of elemental analysis, UV-visible spectroscopy, positive ion electrospray (ESI-MS), and tandem mass (ESI-MS/MS) spectrometry, as well as by NMR spectroscopy and cyclic voltammetry. Cyclic and differential pulse voltammetry for the mononuclear complex showed three set of waves around 1.2 V (Ru(2+/3+)), -1.0 V (BPEB(0/)(-)), and -1.15 (BPEB(-/2-)). This complex exhibited aggregation phenomena in aqueous solution, involving pi-pi stacking of the planar, hydrophobic BPEB ligands. According to NMR measurements and variable-temperature experiments, the addition of beta-cyclodextrin (betaCD) to [Ru(bpy)(2)Cl(BPEB)](+) leads to an inclusion complex, breaking down the aggregated array.
authors.affiliation: Instituto de Química, Universidade de São Paulo USP, Caixa Postal 26077, CEP 05513, São Paulo, SP, Brazil.
authors.forename: Sergio H
authors.initials: SH
authors.lastname: Toma
authors.forename: Miriam
authors.initials: M
authors.lastname: Uemi
authors.forename: Sofia
authors.initials: S
authors.lastname: Nikolaou
authors.forename: Daniela M
authors.initials: DM
authors.lastname: Tomazela
authors.forename: Marcos N
authors.initials: MN
authors.lastname: Eberlin
authors.forename: Henrique E
authors.initials: HE
authors.lastname: Toma
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000138:chemical synthesis*; D003505:Cyclodextrins / Q000138:chemical synthesis / Q000737:chemistry*; D017666:Deuterium Oxide; D004563:Electrochemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis*; D012428:Ruthenium / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism; D013696:Temperature; D047392:beta-Cyclodextrins
chemical_list: D003505:Cyclodextrins; D008024:Ligands; D009942:Organometallic Compounds; D047392:beta-Cyclodextrins; C095931:dichlorobis(2,2'-bipyridine)ruthenium; D015082:2,2'-Dipyridyl; D012428:Ruthenium; D017666:Deuterium Oxide; C031215:betadex