Poly[[{µ2-5-[(di-methyl-amino)(thioxo)meth-oxy]benzene-1,3-di-carboxyl-ato-κ4 O 1,O 1':O 3,O 3'}(µ2-4,4'-di-pyridyl-amine-κ2 N 4:N 4')cobalt(II)] di-methyl-formamide hemisolvate monohydrate].

In the crystal structure of the title compound, {[Co(C11H9NSO5)(C10H9N3)]0.5C3H7NO·H2O} n or {[Co(dmtb)(dpa)]·0.5DMF·H2O} n (dmtb2- = 5-[(di-meth-yl-amino)-thioxometh-oxy]-1,3-benzene-dicarboxyl-ate and dpa = 4,4'-di-pyridyl-amine), an assembly of periodic [Co(C11H9NSO5)(C10H9N3)] n layers extending parallel to the bc plane is present. Each layer is constituted by distorted [CoO4N2] octa-hedra, which are connected through the µ 2-coordination modes of both dmtb2- and dpa ligands. Occupationally disordered water and di-meth-yl-formamide (DMF) solvent mol-ecules are located in the voids of the network to which they are connected through hydrogen-bonding inter-actions.

Crystal structure of a heterometallic coordination polymer: catena-poly[[[tetra-aqua-cobalt(II)]-µ-pyridine-2,6-di-carboxyl-ato-calcium(II)-µ-pyridine-2,6-di-carboxyl-ato] dihydrate].

In the crystal of the title polymeric complex, {[CoCa(C7H3NO4)2(H2O)4]·2H2O} n (1), the CoII ion is N,O,O'-chelated by two pyridine-2,6-di-carboxyl-ate anions in a distorted N2O4 octa-hedral geometry, and two carboxyl-ate O atoms of pyridine-2,6-di-carboxyl-ate anions bridge tetra-aqua-calcium(II) units to form polymeric chains propagating along the b-axis direction. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds, and offset π-π stacking inter-actions [inter-centroid distances = 3.551 (1) and 3.746 (1) Å] involving inversion-related pyridine rings link the polymeric chains and lattice water mol-ecules to form a supra-molecular three-dimensional framework.

Crystal structure of a heterometallic coordination polymer: poly[di-aqua-bis-(µ7-benzene-1,3,5-tri-carboxyl-ato)dicalcium(II)copper(II)].

In the title complex, [Ca2Cu(C9H3O6)2(H2O)2] n , the CaII and CuII cations are bridged by the benzene-1,3,5-tri-carboxyl-ate anions (BTC3-) to form the coordination polymer, in which each BTC3- anion bridges two CuII and five CaII cations with a µ7 coordination mode. The CuII cation, located at an inversion centre, is in a nearly square-planar geometry defined by four O atoms from four bridging BTC3- anions, while the CaII cation is in a distorted octa-hedral geometry defined by five O atoms from bridging BTC3- anions and one water mol-ecule. O-H⋯O hydrogen bonds between coordinating water mol-ecules and carboxyl groups further stabilize the structure; π-π stacking is also observed between parallel benzene rings, the centroid-to-centroid distance being 3.357 (2) Å.

Naked-eye detection of fluoride ion in water: a remarkably selective easy-to-prepare test paper.

A test paper for high-selectivity detecting fluoride ion in natural aqueous environments without any spectroscopic instrumentation was achieved by using Ru-bipy based quinonehydrazone as a chromo- and fluorogenic hybrid chemosensor.

A novel pyramidal multiple alkali metal cluster [K3(H2O)]3+ stabilized within a capsule containing 16-nitrogen donors.

A novel multiple alkali metal cluster K3(H2O)]3+ interior within a high-symmetry cubic capsule containing 16-nitrogen donors is achieved via self-assembly from twenty components.

Imidazolidinium-based robust crypt with unique selectivity for fluoride anion.

A new imidazolidinium based receptor exhibiting unique affinity and high selectivity for fluoride anion through steric requirements and the cooperativity of multiple intramolecular binding, has been designed, synthesized and structurally characterized.

Host-guest complexation of a fluorescent and electrochemical chemsensor for fluoride anion.

Host-guest complexation of a ferrocenenylphalene dyad 1, 1,1'-diaceylferrocenyl-3-hydroxyl-2-naphthoylhydrazone, as a fluorescent and electrochemical chemosensor for fluoride anion, was investigated. Crystal structure analysis revealed that the two naphthyl arms of compound 1 positioned in the same side about the ferrocene moiety and interacted through pi-pi stacking interactions. The intermolecular pi-pi stacking interactions and the C-H...pi interactions between the ferrocene moieties and the naphthalene rings linked the molecules together featuring a two-dimensional layered structure. Fluorescence titrations of compound 1 indicated that in the presence of F- and H2PO4-, the emission intensities enhanced significantly. Electrochemical titrations revealed that compound 1 sensed the F- anion in high selectivity with a cathodic shift of 120 mV, and had no sense in recognizing H2PO4- anion. 1H NMR titrations demonstrated that while compound 1 hydrogen-bonded to H2PO4- forming simple 1 : 1 host-guest complex, further addition of F- induced the deprotonation of compound 1.

A highly selective chromo- and fluorogenic dual responding fluoride sensor: naked-eye detection of F- ion in natural water via a test paper.

A highly selective and sensitive chromogenic and fluorogenic dual signal responding fluoride-sensor 1, comprising a Ru-bipy fluorophore (bipy = 2,2'-bipyridine) and a 2,4-dinitrophenylhydrazone chromophore was prepared and spectroscopically characterized. Uv-vis titrations with F- revealed the appearance of a new intense absorption band centered at about 580 nm which was accompanied by a dramatic change in color from yellow to magenta, with the association constant logK being 6.71 +/- 0.04. Fluorescence spectra showed that upon addition of F-, the emission intensities enhanced significantly without any change in the excited and emission wavelengths, suggesting a potential photoinduced electronic transfer (PET) signaling transduction mechanism. An easy-to-prepare test paper which was obtained by putting a filter paper into an acetonitrile solution of 1, can detect F- in aqueous media, indicating the potential application for detecting F- in natural aqueous environments without any spectroscopic instrumentation. Spectroscopic titrations of the free ligand were also studied for comparison.

Heterometallic compounds assembled from ferrocene-containing bisthiosemicarbazone clips.

Heteropolynuclear organometallic compounds have been constructed by using the ferrocene-based ligand H(2)L, [NH(2)SCNHN=C(CH(3))(C(5)H(4))](2)Fe. Reaction of the ligand H(2)L with the cobalt(II) salt gave a tetranuclear helicate Co(2)Fe(2) (1) with two ferrocene-based clips wrapped around the two cobalt atoms. The chiral helicates recognized the neighbors with same chirality through intermolecular hydrogen bonding between the thiosemicarbazone moieties to form a one-dimensional chiral channel. Reaction of the ligand H(2)L with the cadmium(II) salt afforded a tetranuclear dimeric compound Cd(2)Fe(2) (2), with two symmetric related parts bridged through two sulfur atoms. Reaction of the ligand H(2)L with the copper(I) salt, in the presence of triethylamine, resulted in a hexanuclear compound Cu(4)Fe(2) (3) with a crownlike Cu(4)S(4) octagon similar to that of S(8) sited inside and two ferrocene-containing ligands positioned outside. Electrochemical measurements were displayed to investigate the redox communications between the ferrocene moieties through metal centers.