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: Catalysis & Excited state. The organization has 3867 authors who have published 10457 publications receiving 220098 citations.

Metal–organic frameworks derived from bis-pyridyl-bis-amide ligands : Effect of positional isomerism of the ligands, hydrogen bonding backbone, counter anions on the supramolecular structures and selective crystallization of the sulfate anion

Abstract: Three new metal–organic frameworks, namely [Co(μ-L1)2(Cl)2]n1, [Cd(µ-L1)2(NO3)2]n2 and [{Co(μ-L1′)(H2O)4}.SO4·3(H2O)]n3 (L1 = N,N′-bis-(4-pyridyl)isophthalamide, L1′ = N,N′-bis-(3-pyridyl)isophthalamide) have been synthesized and characterized. The single crystal structures of 1–3 and the free ligand L1 are discussed in the context of the effect of positional isomerism of the ligands, hydrogen bonding backbone and counter anions on the supramolecular structural diversities observed in these MOFs. Selective crystallization of the sulfate anion from a mixture of L1′, CoSO4, Co(NO3)2, Co(ClO4)2, Co(OAc)2, Co(BF4)2 was evident from the isolation of 3 which was confirmed by powder X-ray diffraction, elemental analysis and IR data.

Peptide-assisted synthesis of gold nanoparticles and their self-assembly.

Abstract: A novel gold nanoparticle-tripeptide (GNP-tripeptide) conjugate was prepared by peptide in-situ redox technique at ambient temperatureusing a newly designed tripeptide. This new tripeptide was nso designed that it has a C-terminus tyrosine residue, which reduced Au+3 to Au, and the terminally located free amino group was bound to the gold nanoparticle (GNP) surface resulting in highly stable Au colloids. The average diameter of the tripeptide-stabilized GNP is 8.7 +/- 2.3 nm. Tripeptide bound gold nanoparticles formed three-dimensional assemblies in the presence of an excess of similar or disimilar tripeptides. The aggregation of GNPs results in a red shift in the surface plasmon resonance from lambda max = 527 to 556 nm. The effect of the solvent, concentration, and nature of the tripeptides on the assembly process were investigated by TEM and UV-visible spectroscopy.