91 research outputs found
A new Cu(II) three-dimensional network with 4,4′-oxybis benzoic acid: structural diversity, EPR, and magnetism
No full textThe copper derivative [Cu4(oba)4(H2O)4]∙H2On(1) has been hydro(solvo)thermally synthesized by combining flexible 4,4′-oxybis benzoic acid (oba) and divalent copper nitrate. As a result of the potential coordination modes of carboxylate oxygens from the oba ligand, the aforementioned complex leads to the formation of an interesting 3D framework, as evidenced by single-crystal X-ray diffractometry. Concerning the topology in 1, the dimers [Cu2C4O8] are nodes of a 5-fold 4-connected uninodal net of the type lvt, with point symbol 42.84 and vertex symbol [4.4.84.84.88.88]. The encapsulation of the copper coordination polymer displays a moderate luminescent property. On temperature-dependent magnetic study, it reveals that the magnetic behaviour of 1 can be associated to a strong antiferromagnetic coupling between the two Cu(II) ions
Structural elucidation, EPR and magnetic property of a Co(III) complex salt incorporating 4,4′-bipyridine and 5-sulfoisophthalate
No full textThe cobalt(III) derivative [Co3(sip)4(bipy)2(H2O)10][Co(bipy)2(H2O)4]3(sip)2·20H2O (1) has been hydro(solvo) thermally synthesized by combining sodium 5-sulfoisophthalate (sipH2Na) as organic linker, divalent cobalt nitrate hexahydrate as metal salt and the flexible N-donor ancillary ligand bipy (4,4â2-bipyridine). Compound 1 is an ionic solid consisting of both cobalt containing cations and anions and also in addition 5-sulfoisophthalate anions. Cobalt containing cations in the crystal structure are mononuclear complex while cobalt containing anion is a discrete trinuclear species. The ÏâÏ interaction present in 1 results in chain supramolecular structure. The encapsulation of the cobalt compound displays a moderate luminescent property. On temperature dependent magnetic study, it is revealed that the corresponding effective magnetic moment is 5.27 B.M. at 300 K, which suggests isolated Co(III) species with S = 2 (theoretical value is 4.90 B M.) and thus 1 shows a rare paramagnetic behavior
A new Ni(II) coordination polymer formed by bulky bis(imidazole) and 4,4â2-oxybis(benzoic acid): Topological and spectral elucidation
No full textA new coordination polymer, [Ni(dia)(oba)(H2O)]·H2On(1), was synthetized under hydrothermal conditions from the N-donor ancillary ligand, 9,10-di(1H-imidazol-1-yl)anthracene) (dia) and the flexible aromatic carboxylate, 4,4â2-oxybis(benzoic acid) (oba) as organic linker. The two-dimensional framework of the polymer can be described as a 4-c uninodal net of topological type sql with point symbol 44.62. The structure well exhibits the rich coordination chemistry of dia and oba ligands as connectors; interestingly, two carboxylate groups of the oba ligand show Î1⁄41:η2and Î1⁄41:η1bridging coordination modes, connecting two Ni(II) ions possessing a six-connected NiN2O4 octahedral environment. EPR spectra for 1 were measured at different temperature and solvent. Variable temperature magnetic susceptibility confirms that a weak antiferromagnetic interaction among the Ni(II) ions exists. Thermal analysis has also been carried out to assess the thermal stability of 1 and its structural variation as a function of the temperature
Structural elucidation, EPR and magnetic interpretation of lanthanide (Ln = La, Nd, Sm) compounds with 4,4′-bipyridine and 2-sulfoterephthalate
No full textA series of three lanthanide compounds, namely, [La(stp)(bipy)(H2O)]·H2On(1), [Nd(stp)(bipy)(H2O)]·2H2On(2), and [Sm(stp)(bipy)(H2O)]·H2On(3) has been synthesized through the reaction of 2-sulfoterephthalic acid monosodium salt Na(H2stp), trivalent lanthanide nitrate [Ln(NO3)3·6H2O] and N-donor ancillary co-ligand, 4,4′-bipyridine (bipy). As a result of the potential coordination modes of the stp ligand and the bipy co-ligand, the aforementioned compounds are arranged in a 2-D network, as evidenced by single-crystal X-ray diffraction technique. In all the three compounds, the Ln ion presents a distorted tricapped trigonal-prismatic coordination geometry. The EPR measurements evidence a diamagnetic behaviour of compound 1 (La3+) whereas there exhibits a weak antiferromagnetic coupling between paramagnetic Ln3+ions (Nd3+and Sm3+) for compounds 2 and 3. This is also supported by the magnetic data obtained for compounds 1–3. The encapsulation of the lanthanide coordination polymers displays a moderate luminescent property
Bulky bis(imidazole) and 2-sulfoterephthalate Assisted 3-D Cu(II) and 2-D Mn(II) Coordination Polymers: Topology, Diversity in Metal Containing Nodes and Spectral Elucidation
No full textThis work presents the synthesis of a 3-D Cu(II) framework represented by a 4,6-c 2-nodal net of the type fsc employing the bifunctional template group sulfonate-carboxylate and the dia precursor (dia= 9,10-di(1H-imidazol-1-yl)anthracene). The high versatility of the N-donor and carboxylate ligands also yields a 2-D Mn chain described by a pcu primitive cubic net. The solvent-dependent EPR studies for both the CPs are also illustrated. Variable temperature magnetic susceptibility confirms that both ferromagnetic and antiferromanetic interactions coexist in 1 among the different geometrical arrangement of Cu(II) ions
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Exploring Bela, in Gujarat, India
No full textThis video explores the 3D laser scanning data obtained in Bela, a historic village located in Gujarat, India in 2021. This is part of the AHRC and DCMS funded project: 'A sustainable re-construction method for seismic-prone heritage areas of India based on advanced recording technologies'. In this project, we are using advanced recording technologies and social surveys to develop a sustainable re-construction method for seismic-prone heritage settlements of Gujarat. Capturing the built environment using 3D-laser-scanning-also known as LiDAR-gives an accurate, fast and comprehensive digital data set, measurable and coloured 3D point-cloud with a precision of millimetres, which has been combined with inhabitant’s interviews. This enhanced digital model of the case study, the village of Bela, offers a basis for damage assessments, improving the chances of a rapid and effective response in case of an earthquake, as well as offering a technical platform for risk mitigation measures and community engagement, aiming to increase resilience. The methodology is scalable and applicable to other identified heritage settlements in Gujarat, India. HOW TO CITE: © 3D for Heritage India NTU. 2021-2022. www.3D4heritageindia.wordpress.com Author: Dr Bernadette Devilat (NTU) using the 3D data processed by Dr Felipe Lanuza and obtained on-site by Mrudula Mane and Zeus Pithawalla (CHC CRDF), supported by Dr Jigna Desai from CHC CRDF; Aditya Singh and Tanvi Choudhari from the Hunnarshala Foundation; and Sukrit Sen from ICCROM
A Ni(II) dinuclear complex bridged by end-on azide-N and phenolate-O atoms: spectral interpretation, magnetism and biological study
No full textA potential tetradentate monoanionic N2O2 chelator, HL, derived from the condensation of o-vanillin and N,N-dimethylethylenediammine, has been reacted with nickel perchlorate and sodium azide to yield the dinuclear Ni(II) complex [Ni(L)(μ1,1-N3)Ni(L)(OH2)2]·ClO4 (1), where L = Me2N(CH2)2N♂CH-C6H3(O-)(OCH3). The complex has been characterized by X-ray diffraction anal. and different spectroscopic techniques. The coordination geometry around the Ni(II) centers is a distorted octahedron, with the azide ligand and the phenolato oxygen atom bridging in μ1,1 and μ2 mode, resp. The EPR spectra, recorded at liq. nitrogen temp. (77 K) and room temp. (298 K), show g factors of 2.080 and 2.085, in agreement with the structure detd. by X-ray diffraction anal. The VTM study confirms that there are ferromagnetic interactions between the bridging binuclear Ni(II) ions (S = 1). The evaluation of cytotoxic effects on different human cancer cell lines (A-549, MCF-7 and CaCo-2) suggests that both the ligand and complex 1 have potential anticancer properties. Furthermore, they also exhibit anti-mycobacterial activity against M. tuberculosis H37Rv (ATCC 27294) and M. tuberculosis H37Ra (ATCC 25177) strains. Mol. docking of HL with the enoyl acyl carrier protein reductase of M. tuberculosis H37Rv (PDB ID: 4U0K) has been examd., showing that HL forms two hydrogen bonds with Lys165 (1.94 and 2.53 Å) in its best docked pose. [on SciFinder(R)
Zinc Porphyrins Possessing Three p-Carboxyphenyl Groups: Effect of the Donor Strength of Push-Groups on the Efficiency of Dye Sensitized Solar Cells
No full textZinc porphyrins decorated with three p-carboxyphenyl anchoring groups and various “push” substituents of varied electron-donating strengths were prepared in good yields by facile and straightforward ways. The effect of electron-donating strength of the donor molecules on the overall power conversion efficiency was evaluated with the help of photophysical, electrochemical, photovoltaic spectroscopy and quantum chemical calculations. It is observed from the photophysical and Infrared (IR) spectroscopic data that multi-anchoring dyes are more stable and bind more strongly to the TiO2 surface than their one-anchor counterparts. The properties like a three-step synthesis, high overall yields, possible mass production on a gram-scale and strong binding affinities with TiO2 surfaces make them a suitable choice for commercial applications. Zn1NH3A, with electron donating and anti-aggregation characteristics, achieved the highest efficiency of 6.50%
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