title: Discrimination of cis-trans isomers by dinuclear metal cryptates at physiological pH: selectivity for fumarate vs. maleate.
abstract: Cryptand L (L = N[(CH2)2NHCH2(2,6-C10H6)CH2NH(CH2)2]3N) and its dinuclear metal cryptates [Zn2L](NO3)4 (1) and [Cu2L](ClO4)4 (2) have been prepared, and the binding properties of the cryptates with fumarate and its cis isomer maleate were investigated using fluorescent spectra, (1)H NMR titrations and single crystal X-ray diffraction analysis for [(Cu2L)(fum)][ClO4]2 (3) (fum = fumarate). Thanks to the size and shape matching effect, the cryptates can selectively recognize fumarate at physiological pH, with an association constant almost 18-fold larger than that of maleate, forming a cradle-like cascade complex.
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/State Key Laboratory of Optoelectronic Materials and Technologies/School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China. lutongbu@mail.sysu.edu.cn.
authors.forename: Gao-Yi
authors.initials: GY
authors.lastname: Xie
authors.forename: Long
authors.initials: L
authors.lastname: Jiang
authors.forename: Tong-Bu
authors.initials: TB
authors.lastname: Lu
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry; D043844:Crown Ethers / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005650:Fumarates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D008298:Maleates / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D008968:Molecular Conformation; D011073:Polyamines / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D043844:Crown Ethers; D005650:Fumarates; D047028:Macrocyclic Compounds; D008298:Maleates; D008670:Metals; D011073:Polyamines; C030272:maleic acid