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Dynamic materials have been widely studied for regulation of cell adhesion that is important to a variety of biological and biomedical applications. These materials can undergo changes mainly through one of the two mechanisms: ligand release in response to chemical, physical, or biological stimuli, and ligand burial in response to mechanical stretching or the change of electrical potential. This study demonstrates an encrypted ligand and a new hydrogel that are capable of inducing and inhibiting cell adhesion, which is controlled by molecular reconfiguration. The ligand initially exhibits an inert state; it can be reconfigured into active and inert states by using unblocking and recovering molecules in physiological conditions. Since molecular reconfiguration does not require the release of the ligand from the hydrogels, inhibiting and inducing cell adhesion on the hydrogels can be repeated for multiple cycles. [ABSTRACT FROM AUTHOR]

The title compound, [Co(C12H8N2)(H2O)4]2(C10H2O8), consists of discrete tetra­aqua­(1,10-phenanthroline)cobalt(II) cations and 1,2,4,5-benzene­tetra­carboxyl­ate anions. The CoII atom is octa­hedrally coordinated by two N atoms of the 1,10-phenanthroline ligand and four O atoms of water mol­ecules. The anion lies on an inversion centre. A two-dimensional hydrogen-bonding network is formed by O atoms of benzene­tetra­carboxyl­ate and the coordinated water mol­ecules. [ABSTRACT FROM AUTHOR]

The article discusses the intermolecular structure of Bis(4-nitrobenzoato)bis(trimethylsilylmethyl)tin(IV). The geometry at the six-coordinate Sn atom is distorted octahedral with an approximately planar equatorial belt made up of the four O atoms of two carboxylate groups and the axial positions occupied by two trimethylsilylmethyl groups. The biological activity of diorganotin compounds depends mainly on the alkyl groups and the ligands The structure of the compound is analogous to that of bis(4 -methoxylbenzo ato)phenyl- (trimethylsilylmethyl)tin(IV). The carboxylate groups act as asymmetric chelating groups.

The novel title ZnII coordination polymer, poly[bis(μ-6-thioxo-1,6-dihydropyridine-3-carboxylato-κ2 S: O)zinc(II)], [Zn(C6H4NO2S)2] n, consists of two crystallographically independent zinc centers and two 6-mercaptonicotinate (Hmna−) ligands. Each ZnII atom is four-coordinated and lies at the center of a distorted tetrahedral ZnS2O2 coordination polyhedron, bridged by four Hmna− ligands to form a two-dimensional (4,4)-network. Each Hmna− ion acts as a bridging bidentate ligand, coordinating to two ZnII atoms through the S atom and a carboxyl O atom. The metal centers reside on twofold rotation axes. The coordination mode of the S atoms and N—H...O hydrogen-bonding interactions between the protonated N atoms and the uncoordinated carboxyl O atoms give the extended structure a wavelike form. [ABSTRACT FROM AUTHOR]

A nickel(II) coordination polymer, catena-poly[[aqua­tri­pyri­dinenickel(II)]-μ-isophthalato], [Ni(C8H4O4)(C5H5N)3(H2O)] n, obtained by reaction of m-bda, pyridine and Ni(NO3)2·6H2O under hydro­thermal conditions, where m-bda is isophthalic acid, was characterized by single-crystal X-ray diffraction. The NiII atom is six-coordinate and lies at the centre of a distorted octa­hedron, coordinated by two carboxylate O atoms from two m-bda ligands, three N atoms from three pyridine mol­ecules and one water mol­ecule. The carboxylate groups of m-bda link the NiII atoms, forming an extended one-dimensional zigzag chain. The chains are then knitted together, forming a two-dimensional supramolecular arrangement, via C—H⋯O hydrogen bonds between the H atoms of pyridine rings and the coordinated carboxylate O atoms of m-bda. [ABSTRACT FROM AUTHOR]

In the title compound, [Zn(C13H9N2O)2]·2C3H7NO, the ZnII ion is located on a twofold axis and chelated by two 2-(2- hydroxyphenyl)benzimidazole ligands with a distorted tetrahedral geometry. [ABSTRACT FROM AUTHOR]

The article discusses the intermolecular structure of (Bis[μ-bis(diphenylphosphino)methane-κ2P:P']-bis[(1,10-phenanthroline-κ2 N,N')copper(I)] bis(tetrafluoroborate) dichloromethane disolvate. In the structure, the two Copper centres are bridged by two bis(diphenylphosphino)methane (dppm) ligands to form a centrosymmetric eight-membered Cu2P4C2 ring. The coordination of polyhedron of each Cu atom is distorted tetrahedral. The four-electron-donor diphosphine ligand, bis(diphenyl- phosphino)methane (dppm), is a very efficient bridging bidentate ligand and can form polynuclear complexes with most metal ions.

The coordination environment of copper(II) in the title compound, [Cu(C6H4NO3)(NO3)(C12H8N2)], is square pyramidal; the basal plane comprises the two N atoms of 1,10-phenanthroline and the two O atoms of picolinate N-oxide, with the apical position occupied by a nitrate O atom. [ABSTRACT FROM AUTHOR]

The centrosymmetric mol­ecule of the title CdII complex, [Cd3(C10H7N6O)6], is located on a threefold axis. The pyridopyrimidine ligands bridge neighbouring Cd atoms, forming a trinuclear complex. π–π Stacking is observed between neighbouring complex mol­ecules. [ABSTRACT FROM AUTHOR]

The title cobalt(II) coordination polymer, [Co(C16H8O8)(C10H8N2)2] n, was obtained by the reaction of Co(OAc)2·4H2O (OAc is acetate), 4,4′-bipyridine (4,4′-bpy) and biphenyl-3,4,3′,4′-tetra­carboxylic acid (H4 L) under hydro­thermal conditions. Each CoII atom lies at the centre of a distorted octa­hedron, coordinated by four O atoms from three H2 L2− and two N atoms from two monodentate 4,4′-bpy ligands. Each H2 L2− ligand coordinates to three CoII centres through two carboxyl­ate groups, one acting as a bridging bidentate group and the other in a chelating bidentate fashion. Two Co atoms, two H2 L2− and four 4,4′-bpy ligands form a ring dimer node, and these nodes link into an extended broad chain along the c axis. [ABSTRACT FROM AUTHOR]