Unique Use of Dibromo-L-Tyrosine Ligand in Building of Cu(II) Coordination Polymer-Experimental and Theoretical Investigations.

Although the crystals of coordination polymer {[CuCl(O,O'-L-BrTyr)]}n (1) (L-BrTyr = 3,5-dibromo-L-tyrosine) were formed under basic conditions, crystallographic studies revealed that the OH group of the ligand remained protonated. Two adjacent [CuCl(L-BrTyr)] monomers, bridged by the carboxylate group of the ligand in the bidentate bridging mode, are differently oriented to form a polymeric chain; this specific bridging was detected also by FT-IR and EPR spectroscopy. Each Cu(II) ion in polymeric compound 1 is coordinated in the xy plane by the amino nitrogen and carboxyl oxygen of the parent ligand and the oxygen of the carboxyl group from the symmetry related ligand of the adjacent [Cu(L-BrTyr)Cl] monomer, as well as an independent chlorine ion.

Low pH constructed Co(ii) and Ni(ii) 1D coordination polymers based on C-substituted analogues of zoledronic acid: structural characterization, and spectroscopic and magnetic properties.

Three novel coordination compounds based on α,α-disubstituted analogues of zoledronic acid with a cyclopropane (cpp) or cyclobutane (cbt) ring on the C carbon, isomorphous [Co(HcppZol)(HO)]·HO (1a), [Ni(HcppZol)(HO)]·HO (1b) and [Co(HcbtZol)(HO)]·HO (2a), were synthesized under hydrothermal conditions at low pH. Single-crystal X-ray diffraction analysis revealed that all the compounds had a 1D double zig-zag chain architecture with an 8 + 8 ring motif formed by alternately arranged symmetrical (-O-P-O-) bridges linking equivalent octahedral metal centres. Both the ligand coordination mode and chain architecture displayed by 1a, 1b and 2a are unique among 1D [M(HL)(HO) ]·HO coordination polymers based on nitrogen-containing bisphosphonates reported so far.

Amphoteric Ion-Exchange Membranes with Significantly Improved Vanadium Barrier Properties for All-Vanadium Redox Flow Batteries.

All-vanadium redox flow batteries (VRBs) have attracted considerable interest as promising energy-storage devices that can allow the efficient utilization of renewable energy sources. The membrane, which separates the porous electrodes in a redox flow cell, is one of the key components in VRBs. High rates of crossover of vanadium ions and water through the membrane impair the efficiency and capacity of a VRB.

Two isomorphous Co(ii) coordination polymers based on new α,α-disubstituted derivatives of zoledronic acid: synthesis, structures and properties.

Two novel α,α-disubstituted derivatives of zoledronic acid, namely 1-hydroxy-2-(1H-imidazol-1-yl)-2-methylpropylidene-1,1-diphosphonic acid (HL1) and 1-hydroxy-2-[1-(1H-imidazol-1-yl)cyclopropyl]ethylidene-1,1-diphosphonic acid (HL2) were synthesized and structurally characterized by single-crystal X-ray diffraction. The reaction of cobalt acetate with HL1 and HL2 carried out under hydrothermal conditions afforded two isomorphous Co(HL1)(HO)·6HO (1a) and Co(HL2)(HO)·6HO (2a) complexes. Both compounds are characterized by means of X-ray crystallography, IR and NIR-Vis-UV spectroscopic methods.

Crystal structure of di-cyclo-hexyl-ammonium nitrate(V).

In the title mol-ecular salt, C12H24N(+)·NO3 (-), the cyclohexyl rings adopt chair conformations with the exocyclic C-N bonds in equatorial orientations. In the crystal, a bifurcated N-H⋯(O,O) hydrogen bond links the cation to the anion; the ion pairs are linked via C-H⋯O hydrogen bonds, forming layers in the ac plane.

Dicyclohexylammonium bromoacetate: a low molecular mass organogelator with a one-dimensional secondary ammonium monocarboxylate (SAM) synthon.

The asymmetric unit of the title salt, C12H24N(+)·C2H2BrO2(-), contains a dicyclohexylammonium cation connected to a bromoacetate anion by means of an N-H...