North Eastern Hill University

About: North Eastern Hill University is a education organization based out in Shillong, Meghalaya, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 2318 authors who have published 4476 publications receiving 48894 citations.

Synthesis, Spectroscopic and Molecular Studies of Half‐Sandwich η6‐Arene Ruthenium, Cp* Rhodium and Cp* Iridium Metal Complexes with Bidentate Ligands

Abstract: The bidentate ligand benzoyl(2-pyridyl)thiourea (L1) was prepared by reaction of benzoyl isothiocyanate with primary amine (2-aminopyridine) but the reaction with secondary amine bis(2-pyridyl)amine, yielded the unexpected product bis(2-pyridyl)benzoylamine (L2). Mononuclear complexes of the general formula [(η6-arene)Ru(L)Cl]+ {where, L = L1, arene = benzene (1); p-cymene (2); L = L2, arene = benzene (5); p-cymene (6)} and [Cp*M(L)Cl]+ {where, L = L1, M = Rh (3), Ir (4); L = L2, M = Rh (7), Ir (8)}, respectively, were formed by reaction of the ligands L1 and L2 with precursor complexes [(η6-arene)Ru(μ-Cl)Cl]2 and [Cp*M(μ-Cl)Cl]2 (M = Rh, Ir). The cationic complexes were characterized by FT-IR, UV/Vis, and 1H-NMR spectroscopy as well as mass spectrometry. X-ray crystallographic studies of these complexes reveal piano-stool-like arrangements around the metal atoms with six-membered metallacycles in which L1 and L2 act as a N, S- and N, N' chelating ligands, respectively.

Exact solution of return hysteresis loops in a one-dimensional random-field ising model at zero temperature

Abstract: Minor hysteresis loops within the main loop are obtained exactly in the one-dimensional ferromagnetic random-field Ising model at zero temperature. Numerical simulations of the model show excellent agreement with the exact results.

Phytoplankton diversity of two floodplain lakes (pats) of Manipur, northeastern India

Abstract: Phytoplankton communities of Utra and Waithou pats (floodplain lakes) of Manipur, studied during November 2002 - October 2004, revealed 62 and 61 species, and indicated monthly richness between 27-45 (38 � plus or minus 4) and 32-46 (39 � plus or minus 4) species respectively with distinct qualitative importance of Chlorophyta (29 � plus or minus 4 and 28 � plus or minus 3 species). Phytoplankton (154 � plus or minus 31 n/l and 164 � plus or minus 34 n/l) comprised between 43.8 � plus or minus 3.0 % and 41.5 � plus or minus 3.0 % of net plankton abundance respectively of these two lakes. Chlorophyta (115 � plus or minus 23 n/l and 113 � plus or minus 21 n/l), the dominant quantitative component (74.4 � plus or minus 4.1% and 67.5 � plus or minus 4.8%), indicated importance of the demids. Bacillariophyta (33 � plus or minus 9 n/l and 37 � plus or minus 12 n/l) formed sub-dominant group, and Dinophyta > Euglenophyta > Chrysophyta showed very low densities. Various abiotic factors registered relatively limited influence on richness and abundance of phytoplankton as well as on abundance of individual groups in Utra Pat than in Waithou Pat. Multiple regression depicted higher cumulative influence of fifteen abiotic factors on the stated biotic parameters in these pats. Both richness and abundance of Phytoplankton recorded significant monthly variations, showed insignificant temporal variations between two lakes and followed indefinite annual patterns in each pat. Phytoplankton communities of the sampled pats are characterized by higher species diversity, higher evenness and lower dominance.