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, crystal structures and magnetic properties of 1D polymeric [MnIII(salen)N3] and [MnIII(salen)Ag(CN)2] complexes

Abstract: The syntheses, crystal structures and variable temperature (5–300 K) magnetic susceptibility measurements of two salen complexes of manganese(III) [where H2salen = N,N′-bis(salicylidene)-1,2-diaminoethane] having azido and dicyano argentate(I) as bridging ligands are reported. Both complexes belong to one-dimensional systems in which the azido functions as μ-(1,3) and Ag(CN)2− as ⋯NC– Ag–CN⋯ bridging ligands. The azido-bridged compound is antiferromagnetic with an intrachain interaction constant J = −4.52(4) cm−1 (Weng model) or J = −5.19(8) cm−1 (Fisher model), and it is a candidate to observe the Haldane gap in a S = 2 system. The silver cyanide bridged complex shows single ion behaviour of the Mn(III) ion, perhaps in combination with a very weak antiferromagnetic interaction.

Highly Ordered Mesoporous TiO2–Fe2O3 Mixed Oxide Synthesized by Sol–Gel Pathway: An Efficient and Reusable Heterogeneous Catalyst for Dehalogenation Reaction

Abstract: Highly ordered two-dimensional (2D) hexagonal TiO2–Fe2O3 mixed-oxide material MFT-1, which is composed of very tiny nanoparticles, is synthesized using sodium dodecylsulfate (SDS) as a structure-directing agent. Interestingly, synthesis of an ordered mesophase was not possible using SDS as a template for mesoporous pure Fe2O3 or TiO2 phases. This mesoporous iron–titanium mixed-oxide material has been characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), N2 sorption, ultraviolet–visible light diffuse reflectance spectroscopy (UV–vis DRS) studies. N2 sorption analysis revealed high surface areas (126–385 m2 g–1) and narrow pore size distributions (3.1–3.4 nm) for different samples. UV–vis DRS spectra and wide-angle powder XRD patterns indicate that the material is composed of α-Fe2O3 and anatase TiO2 phases. This TiO2–Fe2O3 mixed-oxide material can act as a very efficient and reusable catalyst in the de...

Detection of Hg2+ and F− Ions by Using Fluorescence Switching of Quantum Dots in an Au‐Cluster–CdTe QD Nanocomposite

Abstract: A single probe of an Au nanocluster-CdTe quantum dots nanocomposite has been developed by using tripeptide-capped CdTe quantum dots (QD) and bovine serum albumin (BSA) protein-conjugated Au25 nanocluster (NC) for detection of both Hg(2+) ion and F(-) ion. The formation of Au-NC-CdTe QD nanocomposite has been confirmed by TEM, steady state and time resolved spectroscopy, CD and FTIR studies. A significant signal off (74 % PL quenching at 553 nm) phenomenon of this nanocomposite is observed in presence of 6.56×10(-7) M Hg(2+) ion, due to salt-induced aggregation. However, a dramatic PL enhancement (128 %) of the Au-NC-CdTe QD nanocomposite is observed in presence of 8.47×10(-7) M F(-) anion. The calculated limit of detections (LOD) of Hg(2+) ion concentration and F(-) ion concentration are found to be 9 and 117 nM, respectively, which are within the safety range set by the United States Environment Protection Agency. Thus, the simple Au-NC-CdTe QD optical-based sensor is very useful to detect both toxic cations and anions.

Monometallic and Bimetallic Ruthenium(II) Complexes Derived from 4,5-Bis(benzimidazol-2-yl)imidazole (H3Imbzim) and 2,2′-Bipyridine as Colorimetric Sensors for Anions: Synthesis, Characterization, and Binding Studies

Abstract: Mixed-ligand monometallic and bimetallic ruthenium(II) complexes of compositions [(bpy)2Ru(H3Imbzim)](ClO4)2·2H2O (1) and [(bpy)2Ru(H2Imbzim)Ru(bpy)2](ClO4)3·CH2Cl2 (2), where H3Imbzim = 4,5-bis(benzimidazol-2-yl)imidazole and bpy = 2,2′-bipyridine, have been synthesized and characterized using standard analytical and spectroscopic techniques. The X-ray crystal structures of both compounds have been determined and showed that 1 crystallized in the triclinic form with space group P1 and 2 is in the monoclinic form with space group P2(1)/m. The anion binding properties of complexes 1 and 2, as well as those of the parent H3Imbzim, were thoroughly investigated in an acetonitrile solution using absorption, emission, and 1H NMR spectral studies, which revealed that both of the metalloreceptors act as sensors for F−, for AcO−, and, to some extent, for H2PO4−. At a relatively lower concentration of anions, a 1:1 hydrogen-bonded adduct was formed; however, in the presence of an excess of anions, stepwise deproto...

Radiative contribution to neutrino masses and mixing in μνSSM

Abstract: In an extension of the minimal supersymmetric standard model (popularly known as the μνSSM), three right handed neutrino superfields are introduced to solve the μ-problem and to accommodate the non-vanishing neutrino masses and mixing. Neutrino masses at the tree level are generated through R−parity violation and seesaw mechanism. We have analyzed the full effect of one-loop contributions to the neutrino mass matrix. We show that the current three flavour global neutrino data can be accommodated in the μνSSM, for both the tree level and one-loop corrected analyses. We find that it is relatively easier to accommodate the normal hierarchical mass pattern compared to the inverted hierarchical or quasi-degenerate case, when one-loop corrections are included.