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Ionic Compounds (ionic + compound)
Selected AbstractsLyophilization of Lipase Together with Ionic Compounds Generates Highly Enantioselective and Solvent-Sensitive Lipase in Organic Solvents.CHEMINFORM, Issue 24 2005Shin-ichi Ueji Abstract For Abstract see ChemInform Abstract in Full Text. [source] Density functional theory studies on the dissociation energies of metallic salts: relationship between lattice and dissociation energiesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 8 2001Chang Kon Kim Abstract The formation and physicochemical properties of polymer electrolytes strongly depend on the lattice energy of metal salts. An indirect but efficient way to estimate the lattice energy through the relationship between the heterolytic bond dissociation and lattice energies is proposed in this work. The heterolytic bond dissociation energies for alkali metal compounds were calculated theoretically using the Density Functional Theory (DFT) of B3LYP level with 6-311+G(d,p) and 6-311+G(2df,p) basis sets. For transition metal compounds, the same method was employed except for using the effective core potential (ECP) of LANL2DZ and SDD on transition metals for 6-311+G(d,p) and 6-311+G(2df,p) calculations, respectively. The dissociation energies calculated by 6-311+G(2df,p) basis set combined with SDD basis set were better correlated with the experimental values with average error of ca. ±1.0% than those by 6-311+G* combined with the LANL2DZ basis set. The relationship between dissociation and lattice energies was found to be fairly linear (r>0.98). Thus, this method can be used to estimate the lattice energy of an unknown ionic compound with reasonably high accuracy. We also found that the dissociation energies of transition metal salts were relatively larger than those of alkaline metal salts for comparable ionic radii. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 827,834, 2001 [source] ChemInform Abstract: Cyclodimerization of an Oxoboryl Complex Induced by trans Ligand Abstraction.CHEMINFORM, Issue 43 2010Holger Braunschweig Abstract The abstraction of Br from (I) induces instant cyclodimerization to the ionic compound (III). [source] Glycogen: A novel branched polysaccharide chiral selector in CEELECTROPHORESIS, Issue 6 2010Jiaquan Chen Abstract Various chiral selectors have been employed in CE and among them linear polysaccharides exhibited powerful enantioselective properties. Different from linear polysaccharides, the use of branched polysaccharides as chiral selectors in CE has not been reported previously. In this study glycogen belonging to the class of branched polysaccharides was used as a novel chiral selector for the enantiomeric separations for the first time. Since glycogen is electrically neutral, the method is applicable to ionic compounds. Eighteen chiral compounds including 12 basic drugs and six acidic drugs have been tested to demonstrate the potential of this chiral selector. BGE and selector concentrations and buffer pH were systematically optimized in order to obtain successful chiral separations. Among the tested compounds, the enantiomers of ibuprofen, which is an acidic drug, were successfully recognized by 3.0%,w/v glycogen with 90,mM Tris-H3PO4 buffer (pH 7.0). The enantiomers of basic drugs such as citalopram, cetirizine and nefopam were also baseline-resolved with 50,mM Tris-H3PO4 buffer (pH 3.0) containing 3.0% glycogen. Amlodipine belonging to basic compound only gave partial enantioseparation under the above-mentioned condition. [source] Constructor graph description of the hydrogen-bonding supramolecular assembly in two ionic compounds: 2-(pyrazol-1-yl)ethylammonium chloride and diaquadichloridobis(2-hydroxyethylammonium)cobalt(II) dichlorideACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010Ilia A. Guzei Covalent bond tables are used to generate hydrogen-bond pattern designator symbols for the crystallographically characterized title compounds. 2-(Pyrazol-1-yl)ethylammonium chloride, C5H10N3+·Cl,, (I), has three unique, strong, charge-assisted hydrogen bonds of the types N,H...Cl and N,H...N that form unary through ternary levels of graph-set interactions. Diaquadichloridobis(2-hydroxyethylammonium)cobalt(II) dichloride, [CoCl2(C2H8NO)2(H2O)2]Cl2, (II), forms five unique charge-assisted hydrogen bonds of the types O,H...Cl and N,H...Cl. These form graph-set patterns up to the quinary level. The Co complex in (II) resides at a crystallographic inversion center; thus the number of hydrogen bonds to consider doubles due to their G -equivalence, and the handling of such a case is demonstrated. [source] Organotin(IV) complexes with various donor ligands and their cytotoxicity against tumour cell lines.APPLIED ORGANOMETALLIC CHEMISTRY, Issue 12 2003Part(I): R2SnCl2 with Schiff bases; unusual CN bond cleavage of the bases, X-ray structures of the ionic products formed Abstract Several Schiff bases derived from salicylaldehyde and aminopyridines were found to coordinate with Me2SnCl2 in 1:1 or 1:2 (tin:base) molar ratio in diethylether, depending on the nature of the Schiff base used, to form complexes of the general formula Me2SnCl2·L or Me2SnCl2·2L respectively. These Schiff bases coordinate with Ph2SnCl2 in a similar manner, but if the reaction is carried out in chloroform or if the product formed in ether is dissolved in chloroform then colourless to pale yellow crystals precipitated. The latter were analysed and found to be due to the ionic compounds [H2NpyN,H+]2 [Ph2SnCl4]2, which were formed as a result of an unusual cleavage of the CN bond of the Schiff bases. The Schiff bases, their Me2SnCl2 complexes and the ionic compounds were analyzed physicochemically and spectroscopically. The crystal structures of two of the ionic compounds showed that the cation [H2NpyN,H+] binds with the anion [Ph2SnCl4]2, via hydrogen bonds. The Schiff bases, their Me2SnCl2 complexes and the ionic compounds were screened against the three tumour cell lines, L929, K562 and HeLa, and the results were compared with those of the anticancer drugs, cisplatin, carboplatin and oxaliplatin. Copyright © 2003 John Wiley & Sons, Ltd. [source] | ||||||||||