Indian Association for the Cultivation of Science

About: Indian Association for the Cultivation of Science is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Excited state & Catalysis. The organization has 3867 authors who have published 10457 publications receiving 220098 citations.

Synthesis of copper sulfides of varying morphologies and stoichiometries controlled by chelating and nonchelating solvents in a solvothermal process

Abstract: Different morphological patterns of copper sulfide crystals, e.g., flowers, distorted rods (rice, grainlike morphology), and spaghetti-like and spherical microparticles have been successfully synthesized using different organic solvents, namely, ethylenediamine, ethyleneglycol, and ethanol, by a solvothermal process. From the experimental results, it has been revealed that the solvents played an important role to control the morphology and composition of copper sulfide crystals.

A successive layer-by-layer assembly of supramolecular frameworks driven by a novel type of face-to-face π+–π+ interactions

Abstract: The solid-state complex [PTPH3](NO3)3·2(HNO3) (1) has been synthesized and characterized by X-ray studies, where PTPH3 is the triply protonated form of 4′-(4-pyridyl)-2,2′:6′,2′′-terpyridine (PTP). The solid-state structure of the complex reveals that the π+–π+ interactions are the major driving force in the crystal packing while π+–π, π–π and π–anion interactions assist the overall stabilization of self-assembly. Complex 1 exhibits two different π-stack layers, where layer 1 is generated through π+–π+ interactions and the mutual forces of π+–π+ and π+–π form layer 2. The interaction energies of the main driving forces (π+–π+, π+–π and π–anion interactions) observed in the crystal structure have been calculated using dispersion-corrected density functional theory (DFT-D). An analysis of the Hirshfeld surface of complex 1 shows the intermolecular interactions involved within the crystal structure and corresponding quantitative information are presented by fingerprint plots.

Highly luminescent organic : Inorganic hybrid mesoporous silicas containing tunable chemosensor inside the pore wall

Abstract: New multifunctional luminescent hybrid mesoporous silicas (LHMS) containing a tunable chemosensor diimine moiety inside the pore wall have been synthesized. XRD and TEM image analyses indicate the formation of highly ordered 2D hexagonal mesophase from a 1:3 mixture of diimine organosilica and tetraethyl orthosilicate (TEOS) assisted by the supramolecular assembly of cetyltrimethylammonium bromide (CTAB); the use of diimine organosilica precursor alone leads to disordered mesophase. 13C CP MAS, 29Si MAS NMR, and UV−visible spectroscopic data show the incorporation of bridging organic diimine in the solid mesoporous materials. N2 sorption data suggest high BET surface areas together with type IV isotherms for the LHMS samples. These hybrid mesoporous materials show very strong affinity for metal cations (Fe3+, Zn2+, etc.), which could be utilized for possible application to metal ion chemosensors. All the LHMS samples exhibit very strong photoluminescence at room temperature and strong dependence of emissi...

pH-controlled reversible assembly of peptide-functionalized gold nanoparticles.

Abstract: The assembly/disassembly process of carboxylated peptide-functionalized gold nanoparticles (peptide-GNPs) was studied within the pH interval of 2.5 to 10. The assembly process was not well controlled at pH 2.5, leading to the formation of 3D structures of GNPs, whereas at pH 4 we observed controlled assembly with the formation of only a network of 1D chains. In the pH range of 2.5 to 4, the assembly proceeded with the formation of a combination of two extremes (i.e., having both 1D and 2D nanostructures). The assembly process was reversed on changing the pH of the medium to 10. The assembly/disassembly process was monitored using UV−vis spectroscopy and finally confirmed by TEM analysis. This assembly resulted from the intermolecular H-bonding between two carboxylic acid groups of peptides bound to the two adjacent GNPs and were confirmed by FTIR spectroscopy.