On/Off Fluorescent Chemosensor for Selective Detection of Divalent Iron and Copper Ions: Molecular Logic Operation and Protein Binding

Here, naphthalene diamine-based β-diketone derivative (compound LH) was successfully used as a dual signaling probe for divalent cations, Fe2+ and Cu2+ ions, in bimodal methods (colorimetric and fluorometric). It showed fluorescent enhancement for Fe2+ ion by photoinduced electron transfer mechanism and fluorescence quenching for Cu2+ ion by charge-transfer process. Binding stoichiometry for [LH-(Fe2+)2] and [LH-(Cu2+)2] was found to be 1:2 by Job's plot method and, the binding constants were calculated as 1.6638 × 1010 and 9.22929 × 108 M-1, respectively. Compound LH exhibited OR and XOR logic gate behavior with H+, Fe2+, and Cu2+ as inputs. Further, the compound LH and bovine serum albumin binding interaction showed quenching of fluorescence by Förster resonance energy-transfer mechanism.

Three-component 1D and 2D metal phosphonates: structural variability, topological analysis and catalytic hydrocarboxylation of alkanes

New metal–organic materials were synthesized based on diphosphonates. They possess interesting structural/topological features, and exhibit substantial catalytic activity in the hydrocarboxylation of alkanes.

The synthesis of three new Cu5, Cu8 and Cu12 clusters via the use of a semi-flexible aminotriazine-based bis-methylpyridine ligand

The use of a semi-flexible aminotriazine-based bis-methylpyridine ligand afforded three new Cu₅, Cu₈ and Cu₁₂ complexes.

Di-, tri- and tetranuclear molecular vanadium phosphonates: a chloride encapsulated tetranuclear bowl

Synthesis and characterization of three dinuclear, two dinuclear and one tetranuclear vanadium phosphonates is being reported. These include a chloride encapsulated tetranuclear bowl-shaped complex.

Reaction of N-heterocyclic silylenes with thioketone: formation of silicon-sulfur three (Si-C-S)- and five (Si-C-C-C-S)-membered ring systems

Three- and five-membered rings that bear the (Si-C-S) and (Si-C-C-C-S) unit have been synthesized by the reactions of LSiCl (1; L=PhC(NtBu)2 ) and L'Si (2; L'=CH{(CCH2 )(CMe)(2,6-iPr2 C6 H3 N)2 }) with the thioketone 4,4'-bis(dimethylamino)thiobenzophenone. Treatment of 4,4'-bis(dimethylamino)thiobenzophenone with LSiCl at room temperature furnished the [1+2]-cycloaddition product silathiacyclopropane 3. However, reaction of 4,4'-bis(dimethylamino)thiobenzophenone with L'Si at low temperature afforded a [1+4]-cycloaddition to yield the five-membered ring product 4. Compounds 3 and 4 were characterized by NMR spectroscopy, EIMS, and elemental analysis. The molecular structures of 3 and 4 were unambiguously established by single-crystal X-ray structural analysis. The room-temperature reaction of 4,4'-bis(dimethylamino)thiobenzophenone with L'Si resulted in products 4 and 5, in which 4 is the dearomatized product and 5 is formed under the 1,3-migration of a hydrogen atom from the aromatic phenyl ring to the carbon atom of the CS unit. Furthermore, the optimized structures of probable products were investigated by using DFT calculations.

DNA interaction studies of new nano metal based anticancer agent: validation by spectroscopic methods

A new nano dimensional heterobimetallic Cu-Sn containing complex as a potential drug candidate was designed, synthesized and characterized by analytical and spectral methods. The electronic absorption and electron paramagnetic resonance parameters of the complex revealed that the Cu(II) ion exhibits a square pyramidal geometry with the two pyrazole nitrogen atoms, the amine nitrogen atom and the carboxylate oxygen of the phenyl glycine chloride ligand located at the equatorial sites and the coordinated chloride ion occupying an apical position. (119)Sn NMR spectral data showed a hexa-coordinated environment around the Sn(IV) metal ion. TEM, AFM and XRD measurements illustrate that the complex could induce the condensation of CT-DNA to a particulate nanostructure. The interaction of the Cu-Sn complex with CT-DNA was investigated by UV-vis absorption and emission spectroscopy, as well as cyclic voltammetric measurements. The results indicated that the complex interacts with DNA through an electrostatic mode of binding with an intrinsic binding constant K(b) = 8.42 x 10(4) M( - 1). The Cu-Sn complex exhibits effective cleavage of pBR322 plasmid DNA by an oxidative cleavage mechanism, monitored at different concentrations both in the absence and in the presence of reducing agents.

Octanuclear aluminum(III) and iron(III) phosphonate cages encapsulating two Na(I) ions

Hydrothermal reactions of aluminum(III) nitrate or iron(III) nitrate with N,N-dimethylaminomethane-1,1-diphosphonic acid (H(4)L) and sodium hydroxide lead to two novel isostructural octanuclear metal phosphonate cages encapsulating two Na(I) ions, namely, [Al(8)Na(2)(HL)(2)(H(2)L)(10)(H(2)O)(6)] x 20 H(2)O (1) and [Fe(8)Na(2)(HL)(2)(H(2)L)(10)(H(2)O)(6)] x 22 H(2)O (2). The molecular structure of 1 can be viewed as a three-in-one cluster, in which a central zeolite D6R SBU lookalike aluminophosphonate cage is capped by two symmetry-related aluminophosphonate tetrahedral cages above and below and such a tetrahedral cage, being composed of four zeolite S6R SBU lookalike aluminophosphonate rings, further hexadentately traps one Na(+) ion in its cavity.