In the title compound, {[Na(C(8)H(9)N(2)O(4))(H(2)O)]·0.5H(2)O}(n), the Na(+) ion is coordinated by two bridging water mol-ecules, one N atom and three O atoms from three 4-carb-oxy-2-propyl-1H-imidazole-5-carboxyl-ate (H(2)pimdc) ligands. Adjacent Na(+) ions are linked alternately by two water O atoms and two carb-oxy O atoms into a chain along [001]. These chains are connected through the coo...

Quantum chemical calculations (DFT, SCS-MP2) show that the relative energies of the four principal alanine conformations are only marginally altered by the introduction of a single fluorine substituent into the methyl group. The fluorine gauche effect and attractive interactions of fluorine to the O-H or N-H moieties (formation of hydrogen bridges) do stabilize particular conformers of 3-fluoro...

The D-glucose derived aziridine carboxylate 5 was obtained from (E)-ethyl-6-bromo-1,2-O-isopropylidene-3-O-benzyl-5-deoxy-alpha-D-xylo-5-eno-heptofuranuronate 4 through conjugate addition of benzylamine and in situ intramolecular nucleophilic expulsion of bromine. The regioselective aziridine ring-opening, using water as a nucleophile, resulted in the alpha-hydroxy-beta-aminoester 6, which was ...

I257E was obtained by site directed mutagenesis of nitrite reductase from Achromobacter cycloclastes. The mutant has no enzyme activity. Its crystal structure determined at 1.65A resolution shows that the side-chain carboxyl group of the mutated residue, Glu257, coordinates with the type 2 copper in the mutant and blocks the contact between the type 2 copper and its solvent channel, indicating ...

Thermodynamic parameters for the complex formation of Am(iii) and Eu(iii) with lactate were determined with UV-vis and time-resolved laser-induced fluorescence spectroscopy (TRLFS) in a temperature range between 25 and 70 °C. The reaction enthalpy decreased with increasing ionic strength. ATR FT-IR and NMR spectroscopy in combination with density functional theory (DFT) calculations revealed st...

Thermoresponsive polymeric surfactant CAE85 is a telechelic carboxyl group derivative of Pluronic P85 and its carboxyl end-groups undergo deprotonation into carboxylate groups upon micellization. Micelle formation and disintegration were studied here by means of small angle X-ray scattering, FTIR and Raman spectroscopy, quantum mechanical calculations and dynamical mechanical analysis. The depr...

In the crystal structure of the title coordination polymer, {[Zn(2)(C(17)H(8)O(10))(C(3)H(7)NO)(2)]·C(3)H(7)NO}(n), the mol-ecular build-ing block (MBB), viz. {Zn(2)(CO(2))(4)(C(3)H(7)NO)(2)}, comprises two zinc atoms, each bridged by three carboxyl-ate groups. These two Zn atoms exhibit different coordination environments: a distorted coordination intermediate between trigonal-pyramidal, and s...

The chemisorptive enantioselectivity of propylene oxide is examined on Pd(111) surfaces templated by chiral 2-methylbutanoate and 2-aminobutanoate species. It has been found previously that chiral propylene oxide is chemisorbed enantiospecifically onto Pd(111) surfaces modified by either (R)- or (S)-2-butoxide. The enantiomeric excess (ee) varied with template coverage, reaching a maximum of ap...

The title compound, C(12)H(9)N(2) (+)·C(7)H(4)ClO(3) (-)·C(12)H(8)N(2)·C(7)H(5)ClO(3), contains one phenanthrolinium (Hphen) cation, one phenanthroline (phen) mol-ecule, one 4-chloro-2-hydroxy-benzoate anion (hcba) and one 4-chloro-2-hydroxy-benzoic acid (Hhcba) mol-ecule in the asymmetric unit. The phen mol-ecule is approximately parallel to Hphen, making a dihedral angle of 1.98 (6)°. The cen...

As part of our continuing studies on heparin, the present paper uses 13C-n.m.r. spectroscopy to examine the acidity of heparin's uronic acid carboxylate groups. Heparin contains three different uronic acids. In porcine mucosal heparin these account for approx. 91, 7 and 2 mol% of the total uronic acid residues. These are alpha-L-idopyranosyluronic acid 2-sulphate, beta-D-glucopyranosyluronic ac...