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11.
The apparent molar volumes V of KCl, BaCl2, K2SO4, LaCl3, Co(en)3Cl3 [Tris(ethylenediamine)cobalt(III) chloride], K3Co(CN)6, K3Fe(CN)6, K4Fe(CN)6, and Ba3[Co(CN)6]2 have been determined at 25°C in both light and heavy water. The V values in D2O are systematically lower and increase more rapidly with salt concentration than the V in H2O. The volume of transfer from H2O to D2O as well as the partial molar volume at infinite dilution in both solvents have also been calculated. These results together with literature values for other electrolytes were used to estimate both of these quantities for D2O solutions of individual ions. The predictions of ion hydration models and ion-ion interactions are compared with experimental observations. 相似文献
12.
Enza Di Gregorio Luciano Lattuada Alessandro Maiocchi Silvio Aime Giuseppe Ferrauto Eliana Gianolio 《Chemical science》2021,12(4):1368
The set-up of reversible binding interactions between the hydrophobic region of macrocyclic GBCAs (Gadolinium Based Contrast Agents) and SO3−/OH containing pyrene derivatives provides new insights for pursuing relaxivity enhancements of this class of MRI contrast agents. The strong binding affinity allows attaining relaxation enhancements up to 50% at pyrene/GBCA ratios of 3 : 1. High resolution NMR spectra of the Yb-HPDO3A/pyrene system fully support the formation of a supramolecular adduct based on the set-up of hydrophobic interactions. The relaxation enhancement may be accounted for in terms of the increase of the molecular reorientation time (τR) and the number of second sphere water molecules. This effect is maintained in blood serum and in vivo, as shown by the enhancement of contrast in T1w-MR images obtained by simultaneous injection of GBCA and pyrene derivatives in mice.The set-up of reversible binding interactions between the hydrophobic region of macrocyclic gadolinium based contrast agents and SO3−/OH containing pyrene derivatives provides new insights for pursuing relaxivity enhancement of MRI contrast agents. 相似文献
13.
Antonia Sacchi Paolo De Caprariis Luciano Mayol Giovanni De Martino 《Journal of heterocyclic chemistry》1995,32(3):1067-1069
4-Hydroxy-3-phenylprolines were synthesized via 1-acetyl-2,2-diethoxycarbonyl-2,3-dihydro-3-phenyl-1H-pyrrole. Reversed phase hplc resulted in the isolation of the products which were characterized by 1H and 13C nmr spectroscopy. 相似文献
14.
Silva Julio Cezar Soares de Lima Silva Diogo Ferreira Ferreira Luciano de Almeida-Filho Adiel Teixeira 《4OR: A Quarterly Journal of Operations Research》2022,20(1):139-164
4OR - Even though sovereign bonds represent low-risk alternatives that give investors a healthy income, the risk assessment process for these bonds is still considered subjective because of the... 相似文献
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Rosenberg Edward Freeman William Carlos Zinnia Hardcastle Kenneth Yong Jin Yoo Milone Luciano Gobetto Roberto 《Journal of Cluster Science》1992,3(4):439-457
The general relationships between trinuclear cluster reactivity and the ligand dynamical processes in these systems are explored. Three specific mechanistic studies are presented: (1) the rate and stereochemistry of ligand addition to 3-imidoyl complexes, (2) the factors influencing the rate of carbon-hydrogen bond activation in 3-alkyne complexes, and (3) the origin of anomalously large kinetic deuterium isotope effect in metal to ligand and ligand to metal hydrogen transfer in trinuclear and binuclear complexes. In all three cases, the current state of the mechanistic studies are summarized and the possible rate of specific ligand dynamical processes in controlling the mechanism are put forth. 相似文献
20.
Eric Steiner Carl Djerassi Ernesto Fattorusso Silvana Magno Luciano Mayol Circo Santacroce Donato Sica 《Helvetica chimica acta》1977,60(2):475-481
Two acetylenic steroids, cholest-5-en-23-yn-3β-ol ( 5 ) and 26,27-dinorcholest-5-en-23-yn-3β-ol ( 3 ), and another unsaturated steroidalcohol, stigmasta-5,23-dien-3β-ol ( 7 ), were isolated from the sponge Calyx nicaaensis. The structures of these two acetylenic steroids were established by synthesis. Several attempts to synthesize the marine steroids alcohol calysterol ( 1 ), with a cyclopropene-containing side chain, starting from cholest-5-en-23-yn-3β-ol are also recorded. Addition of ethyl-diazo-acetate to the triple bond was performed, but the reduction to the methyl derivative yielded decomposition products. 相似文献