161520-99-6Relevant articles and documents
Physico-chemical studies of new luminescent chemosensor for Cu2+
Jayabharathi, Jayaraman,Thanikachalam, Venugopal,Vennila, Munusamy,Jayamoorthy, Karunamoorthy
, p. 677 - 683 (2012)
The spectroscopic properties of (E)-2-(2-hydroxybenzylideneamino)-3- phenylpropanoic acid (HBDPPA) has been studied in a series of different solvents. As revealed by absorbance, and emission results, the molecule undergoes fast excited-state intramolecula
Deuterium isotope effect on 13C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids
Rozwadowski
, p. 881 - 886 (2007/10/03)
Deuterium isotope effects on 13C chemical shift of tetrabutylammonium salts of Schiff bases, derivatives of amino acids (glycine, L-alanine, L-phenylalanine, L-valine, L-leucine, L-isoleucine and L-methionine) and various ortho-hydroxyaldehydes in CDCl3 have been measured. The results have shown that the tetrabutylammonium salts of the Schiff bases amino acids, being derivatives of 2-hydroxynaphthaldehyde and 3,5- dibromosalicylaldehyde, exist in the NH-form, while in the derivatives of salicylaldehyde and 5-bromosalicylaldehyde a proton transfer takes place. The interactions between COO- and NH groups stabilize the proton-transferred form through a bifurcated intramolecular hydrogen bond. Copyright
Equilibrium studies of schiff bases and their complexes with Ni(II), Cu(II) and Zn(II) derived from salicylaldehyde and some α-amino acids
Demirelli, Havva,Koeseoglu, Fitnat
, p. 561 - 577 (2007/10/03)
The acid-base equilibria of Schiff bases derived from salicylaldehyde, glycine, alanine, serine, tyrosine, and phenylalanine, and their Ni(II), Cu(II) and Zn(II) complex formation equilibria were investigated by a potentiometric method in aqueous solution (t = 25°C, μ = 0.1 M, KCl). The data from the potentiometric titrations were evaluated by means of the BEST computer program. The order of the formation constant values of the Schiff bases was Sal-Ala > Sal-Gly > Sal-Ser > Sal-Phe > Sal-Tyr, which is the same order as the increasing log K 1 values of amino acids (and the log K 2 values of tyrosine) with the exception of an inversion between serine and phenylalanine. Also, it was seen that the stability constants, log β1 and log β2, of Schiff base-metal complexes vary for all the metal ions investigated, viz., Sal-Gly > Sal-Ala > Sal-Ser > Sal-Tyr > Sal-Phe with the exception of Sal-Gly in the copper complex. The effect of the nature of the amino acids on their formation, protonation and stability constants was also discussed.
Enantioselective Cyclopropanation of 1,1-Diphenylethylene and Diazoacetic Acid Ester with Copper Catalysts
Brunner, Henri,Miehling, Wolfgang
, p. 1237 - 1254 (2007/10/02)
Copper(II) compounds catalyze the reaction of 1,1-diphenylethylene with diazoacetic acid ethylester.The main product is 2,2-diphenylcyclopropane carboxylic acid ethylester.The formation of the carbene dimerization products fumaric and maleic acid diethylester can be suppressed by the continuous addition of diazoacetic ester to 1,1-diphenylethylene. 37 optically active ligands, partly new, were combined with copper(II)-acetate to give in-situ-catalysts.In five cases isolated copper complexes were used as catalysts.The best optical inductions in the formation of 2,2-diphenylcyclopropane carboxylic acid ethylester with up to 65.6percent ee were achived with Schiffbase ligands, which derive from salicylaldehyde and amino alcohols, obtained from amino acid esters and phenyl Grignard. - Keywords: Catalytic enantioselective cyclopropanation; Copper(II) catalysts; Optical induction.
