Authors:Ian Hoffman, Kurt Ungar, Marc Bean, Jing Yi, René Servranckx, Calin Zaganescu, Nils Ek, Xavier Blanchard, Gilbert Le Petit, Guy Brachet, Pascal Achim, and Thomas Taffary
Radioxenon concentration data collected at International Noble Gas Experiment (INGE) monitoring sites in the Northern Hemisphere
are demonstrably impacted by emissions from medical isotope (MI) production facilities at Chalk River (CRL), Ontario and Fleurus,
Belgium [Saey, J Environ Radioact 100(5):396–406, 2009]. Temporary cessation at these European MI facilities in the latter
half of 2008 allowed an opportunity to assess the relative impact of distant MI facilities at INGE monitoring stations. In
particular, the concentration distributions at the measurement sites and calculated sensitivities to the putative emission
locations through atmospheric transport modelling (ATM) of meteorological Source Receptor Sensitivity (SRS) computations were
used to study MI impacts.
[NiL3]X2 (where L=N-phenylethane-1,2-diamine and X=I− and ClO4−), [NiL2X2] (X is Cl−, Br−, NCS−, 0.5SO42− or 0.5SeO42−) and [NiL2(H2O)2](NO3)2 have been synthesized from solution and their thermal study has been carried out in the solid phase. [NiL2Cl2] upon heating undergoes irreversible endothermic phase transition (142–152C, ΔH=0.35 kJ mol−1) without showing any visual colour change. This phase transition is assumed to be due to conformation changes of the diamine
chelate rings. NiLCl2 and NiL2.5I2 have been prepared pyrolytically from [NiL2Cl2] and [NiL3]I2 respectively in the solid state. [NiL2(H2O)2](NO3)2 upon heating undergoes deaquation-anation reaction without showing any visual colour change. [NiL2X2] (X is Cl−, Br−, NCS−), [NiL2(H2O)2](NO3)2 and [NiL2(NO3)2] possess trans-octahedral configuration, whereas, [NiL2X2] (X is 0.5SO42− or 0.5SeO42−) are having cis-octahedral configuration. Amongst the complexes, only NiLCl2 shows unusually high (5.1 BM at 27C) magnetic susceptibility value.
Authors:J. Kameníček, F. Březina, R. Pastorek, and Z. Šindelář
Ni(II) Schiff base complexes of compositions NiL ROH (R=Me, Et, Pr, i-Pr) and NiL′·ROH (R=Me, Et, Pr, i-Pr, Bu) were prepared and investigated by methods of thermal analysis. The thermal decomposition of NiL·ROH led to NiL (plateau in TG curve), whereas NiL′·ROH underwent a similar decomposition only in an inert atmosphere (N2); thermal decomposition in air involved alcohol fragmentation, followed by a mass increase due to oxidation by atmospheric oxygen. The activation energy of alcohol fragmentation was calculated.
We introduce the concept of nil-McCoy rings to study the structure of the set of nilpotent elements in McCoy rings. This notion extends the concepts of McCoy rings and nil-Armendariz rings. It is proved that every semicommutative ring is nil-McCoy. We shall give an example to show that nil-McCoy rings need not be semicommutative. Moreover, we show that nil-McCoy rings need not be right linearly McCoy. More examples of nil-McCoy rings are given by various extensions. On the other hand, the properties of α-McCoy rings by considering the polynomials in the skew polynomial ring R[x; α] in place of the ring R[x] are also investigated. For a monomorphism α of a ring R, it is shown that if R is weak α-rigid and α-reversible then R is α-McCoy.
Formation of nitrogen ligated complexes of types NiL6X2, NiL4X2, NiL2X2 and NiL1X2 (whereL=pyridine, 2-, 3- and 4-methyl-pyridine andX=F, Cl, Br, I) have been studied by traditional preparative methods, i.e. from solutions and by solid-gas phase chemisorption.
Quaternary mixed complexes were obtained by chemisorption from heated intermediates. The complexes thus formed were further
analysed by simultaneous TG-DTG-DTA. Effects of the ligands on stoichiometry and thermal properties of the complexes are discussed.
Authors:Agnieszka Jabłońska-Wawrzycka, Małgorzata Zienkiewicz, Barbara Barszcz, and Patrycja Rogala
molar ratio Ni:L was 1:2. It was left to stand at RT for a few days and the resulting fine blue crystals were filtered off, and washed. The complex was dried in vacuum box. Yield 46%.
Preparation of cobalt complex ( 1
Authors:J. Gálvez, J. Palazón, G. López, and G. García
The preparation of Ni(CN)21.5M (M=morpholine) and the thermal study of this and NiBr23M, Nil24M and Ni(NCS)24M are described. The thermal treatment of these compounds leads to the isolation of Ni(CN)2M, Ni(CN)20.5M, NiBr22M, Nil23M, Nil21.5M, Ni(NCS)22M and Ni(NCS)2M. With the exception of NiBr22M and Ni(NCS)22M, all intermediate species are reported here for the first time. Magnetic and spectral studies have been carried out to determine the mode of coordination and stereochemistry of the complexes. The thermal study includes the determination of stability, apparent activation energy and reaction orders, and reaction enthalpies.
Authors:P. M. Madhusudanan, K. K. Mohammed Yusuff, and C. G. Ramachandran Nair
Thermogravimetric (TG), derivative thermogravimetric (DTG) and differential thermal analysis (DTA) curves of CuL2 and NiL2 (L−=diethyl dithiocarbamate anion) in air are studied. The main decomposition temperature ranges are: For CuL2, DTG 250–350°, DTA 300–320° and for NiL2, DTG 290–390°, DTA 360–400°. Mass loss considerations at the main decomposition stages indicate conversion of the complex to sulphides. Mathematical analysis of TG data shows that first order kinetics are applicable in both cases. Kinetic parameters (energy and entropy of activation and preexponential factor) are reported.