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Itanagar, India

North Eastern Regional Institute of Science and Technology is a science and technology oriented higher education institute in Nirjuli, Itanagar, in the Indian state of Arunachal Pradesh. Established in 1984, it is a deemed university, autonomous, fully funded and controlled by the Ministry of Human Resource Development, Department of Education, Government of India. Wikipedia.

Devi T.G.,North Eastern Regional Institute of Science and Technology
Journal of Raman Spectroscopy | Year: 2010

The vibrational relaxation and molecular reorientational processes in liquids have been studied in some carbonyl-containing molecules using the acetonitrile (ACN) solvent. The vibrational and reorientational processes have been studied in correspondence with correlation times. The screening effect due to dielectric has been studied and the Onsager reaction field model has been tested. The study shows that repulsive types of intermolecular forces play an important role in complex systems. Copyright © 2010 John Wiley & Sons, Ltd.

Jhajharia D.,North Eastern Regional Institute of Science and Technology | Singh V.P.,Texas A&M University
International Journal of Climatology | Year: 2011

Trends in maximum (Tmax), minimum (Tmin) and mean (Tmean) temperatures; diurnal temperature range (DTR = Tmax - Tmin); and sunshine duration at eight sites in Northeast (NE) India were investigated. Three sites observed decreasing trends in DTR corresponding to annual, seasonal (pre-monsoon and monsoon) and monthly (September) time scales. On the other hand, DTR increases were also observed at other three sites in monsoon and post-monsoon seasons as well as in the months of June, October and December. The sites showing DTR decreases (increases) witnessed either increasing trends in Tmin (Tmax) or decreasing trends in Tmax (Tmin), with Tmax (Tmin) showing either no trend or increasing at a smaller rate than Tmin (Tmax). Temperature remained practically trendless in winter and pre-monsoon seasons over NE India. However, temperature increases were observed in monsoon and post-monsoon seasons. Decreasing trends in sunshine duration were observed mainly on annual, seasonal (winter and pre-monsoon) and monthly (January, February and March) time scales. Concomitant decreases in sunshine duration may be one of the potential causes of the observed DTR decreases over NE India. © 2010 Royal Meteorological Society.

The bimetallic and heterometallic coordination oxalate precursors uranyl(II)diaquatris(oxalato)lanthanate(III)octahydrate (UOLa) and cobalt(II)uranyl(II)pentaquatris(oxalato) lanthanate(III)octahydrate (CoUOLa) have been synthesized and characterized by elemental analysis, IR, electronic spectral and powder X-ray diffraction (XRD) studies. Thermal decomposition studies (TG, DTG and DTA) in air showed that UOLa ultimately decomposed mainly to a mixture of U2O5, U3O8, La2O3 and La6UO12 at 1000 °C through the formation of several intermediates at 190, 496, and 770 °C. The presence of a trace of UO2, carbon and carbides of both uranium and lanthanum were also identified at end products. The precursor, CoUOLa lost all crystal and coordinated water molecules up to 235 °C, followed by slow decomposition of anhydrous species to a mixture of CoC2O4 and (UO2)2[La(C2O4)2.4]2 at 330 °C. The end products identified at 1000 °C is a mixture of CoO, LaO and U2O5 along with a trace of La2O3, LaCoO3, La2C3 and carbon. The unstable intermediate phases at 340 and 515 °C were also attributed during the fragmentation path of the precursor. The crystal structures of the major oxides identified in the end products in the mixture form of both the precursors are inferred from the powder XRD data. The kinetic parameters, E*, ln ko, ΔH and ΔS of all the dehydration and decomposition steps of the precursors are explored and discussed from DSC study in nitrogen. © 2010 Elsevier B.V. All rights reserved.

Bhuyan J.,North Eastern Regional Institute of Science and Technology
Dalton Transactions | Year: 2015

An overview of the chemistry of isoporphyrin, the tautomer of porphyrin, whose existence was predicated by the Noble laureate Woodward, is presented with emphasis on hydroxy-isoporphyrins of tetra-aryl derivatives. The chemistry of metalloisoporphyrin has been discussed since the discovery of the first metallo-isoporphyrin by Dolphin and co-workers, as no comprehensive article is available on this beautiful macrocycle. Attention is paid to the possible applications of metalloisoporphyrins as photosensitizers in photodynamic therapy, as a near infra-red dye and as a reactive agent for different atom transfer reactions. Some important findings about reactivity and theoretical results of hydroxy-isoporphyrins are discussed. Furthermore, the approaches of heme oxidation via isoporphyrin as an intermediate to understand the heme oxygenase mechanism are discussed. The metalloisoporphyrins are discussed reviewing coordination modes, structural changes, electronic properties and biological relevance. This journal is © The Royal Society of Chemistry.

Bhuyan J.,North Eastern Regional Institute of Science and Technology
Dalton Transactions | Year: 2016

The reactions of iron(iii) hydroxyisoporphyrin, chloro[5-(hydroxy)-5,10,15,20-tetrakis(4-methyl)-5,21H-porphinato]iron(iii) [Fe(4-Me-HTPI)(Cl)]-, 1 and chloro[5-(hydroxy)-5,10,15,20-tetrakis(4-methoxy-5,21H-porphinato]iron(iii) [Fe(4-OMe-HTPI)(Cl)]-, 2 with different O-, N- and S- nucleophiles have been performed to understand the reactivity of iron isoporphyrins with nucleophiles. The treatment of iron(iii) hydroxy isoporphyrin with alcohols is found to form ring opened 19-benzoyl-1-alkoxy-bilin iron complexes. When alkyl amines were used the formation of ring opened 19-benzoyl-1-alkylamine-bilin iron complexes was observed, but heterocyclic N-nucleophiles such as pyridine and imidazole form benzoyl bilinone iron complexes. No role of oxygen was found in these nucleophilic ring opening reactions. The treatment of a S-nucleophile such as PhSH is found to reduce iron(iii)-hydroxyisoporphyrin in the parent iron(iii) porphyrin compound. The ring opening products were characterized using electronic and ESI-mass spectroscopy. The mechanism for the formation of ring opening products is based on the formation of a tetrahedral intermediate at the carbon atom near the saturated meso carbon atom similar to the hydrolytic pathway of verdoheme conversion to biliverdin. © The Royal Society of Chemistry 2016.

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