New metal-organic frameworks (MOFs) based on zinc and cadmium ions, terephthalic acid, and flexible ligands 1,5-bis(imidazol-1-yl)pentane or 1,6-bis(imidazol-1-yl)hexane were prepared and characterized by X-ray diffraction, thermorgavimetric analysis and IR spectroscopy. The imidazolyl ligands were prepared by a new robust procedure involving the reaction between imidazole and 1,5-dibromopentan...

In the title mononuclear complex, [Cu(C(8)H(7)O(2))(2)(C(7)H(6)N(2))(2)], the Cu(II) atom lies on an inversion centre and is coordinated by two O atoms of two monodentate 4-methyl-benzoate ligands and two N atoms of two benzimidazole ligands in a square-planar geometry. The mol-ecules are linked into chains running parallel to the b axis by inter-molecular N-H⋯O hydrogen bonds and by π-π stacki...

two n4-type schiff base ligands named n,n'-bis(2-pyridylmethylidene)-1,2-diiminoethane (l1) and n,n'-bis(2-pyridylmethylidene)-1,3-diiminopropane (l2) have been synthesized by the reaction of pyridine-2-carbaldehyde with ethylenediamine and propylenediamine, respectively. the binding abilities of l1 and l2 in dichloromethane towards cu2+, cd2+, co2+, ni2+, zn2+ and pb2+ ions were evaluated by p...

A conserved histidine serves as the axial ligand to the Mg of bacteriochlorophylls in the photosynthetic reaction center (RC) and many other photosynthetic systems. The histidine axial ligands to each and both bacteriochlorophylls of the special-pair primary electron donor of the Rhodobacter sphaeroides RC have been replaced with glycine to create a cavity. In each case, RCs assemble and a norm...

One of the difficulties in preparing accurate ambient-temperature model complexes for heme proteins, particularly in the ferric state, has been the generation of mixed-ligand adducts: complexes with different ligands on either side of the heme. The difference in the accessibility of the two sides of the heme in the H93G cavity mutant of myoglobin (Mb) provides a potential general solution to th...

The activity of Prunus dulcis (sweet almond) β-glucosidase at the expense of p-nitrophenyl-β-d-glucopyranoside at pH 6 was determined, both under steady-state and pre-steady-state conditions. Using crude enzyme preparations, competitive inhibition by 1-5 mM imidazole was observed under both kinetic conditions tested. However, when imidazole was added to reaction mixtures at 0.125-0.250 mM, we d...

In the structure of the title compound, [Cd(C(9)H(7)N(2)O(2)S)(2)(C(10)H(8)N(2))(2)], the complex mol-ecules are located on a crystallographic twofold rotation axis and the Cd(II) ion is octa-hedrally coordinated by two chelating 2,2'-bipyridine ligands and two O atoms from the carboxyl-ate groups of two 2-(benzimidazol-2-ylsulfan-yl)acetate ligands. The two carboxyl-ate ligands adopt a cis con...

To tune the lanthanide luminescence in related molecular structures, we synthesized and characterized a series of lanthanide complexes with imidazole-based ligands: two tripodal ligands, tris{[2-{(1-methylimidazol-2-yl)methylidene}amino]ethyl}amine (Me(3)L), and tris{[2-{(imidazol-4-yl)methylidene}amino]ethyl}amine (H(3)L), and the dipodal ligand bis{[2-{(imidazol-4-yl)methylidene}amino]ethyl}a...

The title coordination polymer, {[Li2(C8H2N2O8)(H2O)2]·2.5H2O} n , is built up from mol-ecular ribbons propagating in the c-axis direction of the ortho-rhom-bic unit cell; the ligand bridges two Li(+) ions using both its N,O,O'-bonding sites and adjacent Li(+) ions are bridged by pairs of water mol-ecules. The coordination geometry of the metal ion is distorted trigonal bipyramidal, with the li...