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Ditopic Ligand (ditopic + ligand)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Site-Selective Internal Cross-Linking between Mercury(II)-Centered Vertices of an Octahedral Mercury(II) Capsule by a Rod-Shaped Ditopic Ligand,

ANGEWANDTE CHEMIE, Issue 1 2010
Shuichi Hiraoka Dr.
Ein oder zwei stabförmige Bissulfonat-Brückenliganden wurden durch positionsselektive Verdrängung innerer TfO, -Liganden in eine selbstorganisierte HgII -Kapsel eingebaut. Durch einen Ligandenaustausch der verbleibenden inneren TfO, -Liganden wurden TsO, -Liganden im Innern der resultierenden Kapsel angeordnet, in welcher der/die Bissulfonat-Ligand(en) zwei gegenüberliegende HgII -Ecken verbrücken (siehe Bild). Tf=Trifluormethansulfonyl, Ts=p -Toluolsulfonyl. [source]

A Rigid Molecular Scaffold Affixing a (Polypyridine)ruthenium(II)- and a Nickel(II)-Containing Complex: Spectroscopic Evidence for a Weakly Coupled Bichromophoric System

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2003
Yann Pellegrin
Abstract The synthesis of DppztBuSalH2 (7), a rigid conjugated ditopic ligand containing a Dppz (dipyrido[3,2- a:2,,3,- c]phenazine) skeleton and a salophen-type chelate, is reported. The complexes DppztBuSalNi (10), [Ru(bpy)2(DppztBuSalH2)]2+ (11), and [Ru(bpy)2(DppztBuSalNi)]2+ (12) have been prepared and characterised using common spectroscopic methods. Electrochemical, UV/Vis spectroelectrochemical and EPR studies were conducted on compounds 7, 10, 11, and 12. The singly reduced radical forms of 7 and 10 can be generated electrochemically, with the lone electron located on the low-lying phenazine ,*-molecular orbital. Complexes 11 and 12 show several reduction waves and electronic and EPR data obtained for the electrogenerated singly reduced species show them to be closely related to the radical species 7·, and 10·,, respectively. The presence of nickel(II) in compound 12 renders the addition of the second electron on the phenazine group reversible. Both 11 and 12 show common features on the cathodic side of their cyclic voltammograms, with reversible one-electron ruthenium-centred oxidation. An additional low-potential reversible-oxidation wave is observed for 12, and this is ascribed to oxidation of the nickel(II) ion. The combined spectroscopic data best describe the ruthenium-containing complexes as weakly coupled bichromophoric systems. Photophysical studies attest to the formation of a charge-separated state for 11, whereas a strong quenching is detected for 12. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

Dianion cyclization strategy for the synthesis of macrosilaheterocycles

HETEROATOM CHEMISTRY, Issue 5 2008
Maya S. Singh
A practical and efficient method for the preparation of silaheterocycles is described. The key step involves the initial formation of symmetrical chiral ditopic ligand, N,N,-1,2-cyclohexylenebis(salicylideneimine) followed by sequential deprotonation with NaH to form dianion intermediate, which reacts with diorganodichlorosilanes to furnish dibenzodioxadiazasilamacrocycles. The products were characterized by satisfactory elemental analyses and spectral (IR, 1H, 13C, 29Si NMR, and Mass) studies. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:455,460, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20460 [source]

Electrochemical functions of metallosupramolecular nanomaterials

THE CHEMICAL RECORD, Issue 4 2007
Masayoshi Higuchi
Abstract Self-assembly of metal ions and organic ligands results in the formation of extended or discrete metallosupramolecular structures. In case of neutral ditopic ligands such as bisterpyridines, extended metallosupramolecular coordination polyelectrolytes (MEPEs) are formed. Metal ion-induced self-assembly of 1,4-bis(2,2,:6,,2,-terpyridin-4,-yl)benzene with Fe(II) or Co(II) results in MEPEs with interesting electrochemical properties. These MEPEs reversibly change their color when oxidized or reduced. The heterometallic MEPE consisting of Fe(II) and Co(II) combines the properties of the individual MEPEs and therefore shows their different states: red-purple, blue, and transparent. On the other hand, complexation of cyclic phenylazomethines with metal ions results in discrete metallosupramolecular structures. We find that metal ion assembly to the organic module occurs in a stepwise fashion because of a difference in the basicity of the imine conformers, and the metal ion assembly can be controlled electrochemically. This example illustrates how metal ion binding can be controlled by the conformation of the receptor, an important step toward assembling organic ligands and metal ions in predictable ways. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 203,209; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20118 [source]