2010
Do Spiroarsoranes Exhibit Polytopal Equilibrium in Solution Antonio R.Tapia-Benavides, Luis H. Mendoza-Huizar, Francisco Pérez-Garca, Hugo Tlahuext, Alejandro Alvarez and Margarita Tlahuextl. Inorg. Chem., 2010, 49 (4), pp 14961502. DOI: 10.1021/ic901740
Abstract
The spiroarsoranes 5-phenyl-1,6-dioxa-4,9-diaza-5?5-arsaspiro[4.4]nonane (6), (3R,8R)-3,8-dimethyl-5-phenyl-1,6-dioxa-4,9-diaza-5?5-arsaspiro[4.4]nonane (7), (2S,7S)-2,7-dimethyl-5-phenyl-1,6-dioxa-4,9-diaza-5?5-arsaspiro[4.4]nonane (8), and (3S,8S)-3,8-dimethyl-(2R,7R)-2,5,7-triphenyl-1,6-dioxa-4,9-diaza-5?5-arsaspiro[4.4]nonane (9) were prepared by reaction of phenylarsonic acid and the correspondig amino alcohol. The presence of polytopal ? ? equilibrium in 6?9 was demonstrated by HPLC and NMR studies. NBO computations at the MP2/6-31+G(2d,2p) level indicate that methyl substitution in C2 or C3 of the oxazarsolane ring determines the predominance of ? or ? stereoisomers. GIAO B3LYP/6-311++G(2d,2p) computations were used to assign experimental 1H and 13C NMR spectra.
Mercury Ions Removal from Aqueous Solution Using an Activated Composite Membrane
ELECTROCHEMICAL STUDY ABOUT ZINC ELECTRODEPOSITION ONTO GCE AND HOPG SUBSTRATES