Synthesis, Characterisation, Electrochemistry and Ion-Binding Studies of Ruthenium(II) and Rhenium(I) Bipyridine/Crown Ether Receptor Molecules

被引：39

作者：

Boricha, Vinod P. ^{[1
,2
]}

Patra, Subrata ^{[1
,2
]}

Chouhan, Yogendra S. ^{[1
,2
]}

Sanavada, Pankaj ^{[1
,2
]}

Suresh, E. ^{[1
,2
]}

Paul, Parimal ^{[1
,2
]}

机构：

[1] Cent Salt & Marine Chem Res Inst, Analyt Sci Div, Bhavnagar 364002, Gujarat, India

[2] CSIR, New Delhi 110001, India

来源：

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY | 2009年 / 09期

关键词：

Receptors; Ruthenium; Rhenium; Crown compounds; Electrochemistry; CRYSTAL-STRUCTURES; CATION-BINDING; COOPERATIVE BINDING; FLUORESCENT SENSORS; CARBONYL-COMPLEXES; ANION RECOGNITION; POTASSIUM CATION; BIPYRIDYL; LUMINESCENT; SPACER;

D O I：

10.1002/ejic.200801099

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

A number of molecular receptors containing a ruthenium(II)/rhenium(I) bipyridine moiety as fluorophore and a crown ether, connected to the 4,4'-positions of the bipyridine/phenanthroline unit through >C=O and -HC=N- spacers, as ionophore have been synthesised and characterised. The luminescence and electrochemical properties of these receptors have been studied. The cation-binding properties of these molecules have been investigated with the cations Na+, K+, Rb+, Mg2+, Ca2+, Zn2+, Cd2+, Hg2+, Pb2+ and Cu2+ and the recognition event monitored by H-1 NMR spectroscopy, luminescence, the oxidation potential of the metal ion and UV/Vis absorption studies. The emission intensities of complexes 1-3 are strongly quenched by the addition of Pb2+, Cu2+, Hg2+ and Na+, whereas a significant enhancement of the emission intensities is observed for 4 in the presence Of Cu2+ and Hg2+ and for 5 in the presence of Cd2+ and Hg2+. Luminescence titrations for 1-5 with the above-mentioned metal ions have been carried out. The binding constants (K-s) and stoichiometry of the complexes have, been calculated from titration data, with values of K-s ranging from 9.97 x 10(3) to 1.28 x 10(2) M-1 in the decreasing order Pb2+ > Na+ > Cu2+ > Hg2+ > Cd2+. The stoichiometries found for 1-3 and 5 are in the range 1.85-2.09 and for 4 0.99-1.04. A H-1 NMR spectroscopic scopic study with selected metal ions exhibits significant spectral changes for the protons attached to the crown moiety; a few significant changes are also noted in the aromatic region. Among the ions studied, the highest change is observed with Na+ and Pb2+, whereas K+ does not show any significant change. The electrochemical study exhibits a significant cathodic shift of the Oxidation potentials of the Ru-II centre in the presence of Na+ and Pb2+, thereby indicating complexation of these ions with the crown moiety. The electronic spectra, however, do not show significant spectral changes with various metal ions except for that of the Re-I complex 6, which exhibits some change upon addition of Na+. The results obtained are presented and discussed in light of selectivity and intramolecular energy-transfer. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

引用

页码：1256 / 1267

页数：12

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