scholarly journals Metal Complexes of Amino Acids. IV. The Circular Dichroism of Tetrammine Cobalt (III) Complexes Containing Two Unidentate L-Amino Acid Ligands

1969 ◽  
Vol 42 (7) ◽  
pp. 2081-2083 ◽  
Author(s):  
Takaji Yasui ◽  
Junnosuke Fujita ◽  
Yoichi Shimura
Keyword(s):  
Amino Acids ◽  
Circular Dichroism ◽  
Amino Acid ◽  
Metal Complexes ◽  
Circular Dichroïsm

Circular dichroism spectra of amino acid complexes. II. Chelated amino acid complexes with the CoN5O chromophore

1970 ◽  
Vol 23 (9) ◽  
pp. 1735 ◽  
Author(s):  
CJ Hawkins ◽  
PJ Lawson
Keyword(s):  
Amino Acids ◽  
Circular Dichroism ◽  
Amino Acid ◽  
Visible Region ◽  
Optically Active ◽  
Circular Dichroism Spectra ◽  
Amino Acid Complexes ◽  
Similar Series ◽  
Cotton Effects ◽  
Circular Dichroïsm

The circular dichroism spectra of a series of optically active (α-aminocarboxylato)tetraamminecobalt(111) complexes have been measured in aqueous solution, and in the presence of salts of polarizable anions. The observed spectra in the visible region have been analysed to determine the signs of the Cotton effects of the three components of the 1A1g ↔ 1T1g cobalt(111) transition. For L-amino acids, the transition with A2g(D4h) parentage is negative, and the two transitions with Eg(D4h) parentage have opposite signs. Published circular dichroism spectra of complexes of the type [Co(en)2(L-am)]2+ were similarly interpreted in terms of a perturbed tetragonal chromophore, and it was shown that the vicinal effect of the L-amino acids imposed the same signs onto the component transitions as for the tetraammines and for a similar series of pentaamminecobalt(111) complexes.

Circular dichroism spectra of amino acid complexes. III. Copper(II) compounds

1970 ◽  
Vol 23 (11) ◽  
pp. 2237 ◽  
Author(s):  
CJ Hawkins ◽  
CL Wong
Keyword(s):  
Amino Acids ◽  
Circular Dichroism ◽  
Amino Acid ◽  
Sign Pattern ◽  
Circular Dichroism Spectra ◽  
Amino Acid Complexes ◽  
Rotational Strength ◽  
Conformational Effects ◽  
Cotton Effects ◽  
Circular Dichroïsm

The solution circular dichroism spectra of the 1 : 1 and 1 : 2 copper(II) complexes of a series of �-amino acids are reported for the region 12500-25000 cm-1. These spectra and spectra of the isolated 1 : 2 complexes dispersed in KBr disks have been interpreted as arising from three Cotton effects with a -,+,- sign pattern for the L configuration, except for the L-proline spectra, which were analysed in terms of a +,-,+ pattern. A tentative assignment is made for these Cotton effects, and the relative contributions of vicinal and conformational effects to the rotational strength are discussed.

Conformational dissymmetry. Circular dichroism of amino acid and peptide complexes

1979 ◽  
Vol 57 (1) ◽  
pp. 62-66 ◽  
Author(s):  
E. A. Sullivan
Keyword(s):  
Amino Acids ◽  
Circular Dichroism ◽  
Amino Acid ◽  
Solid State ◽  
Structural Features ◽  
Consistent Pattern ◽  
Amino Acid Complexes ◽  
Spectroscopic Assignment ◽  
Peptide Complexes ◽  
Circular Dichroïsm

A number of Pd(II) and Pt(II) complexes of amino acids and dipeptides have been isolated and characterized. The solution and solid-state circular dichroism of the amino acid complexes show a fairly consistent pattern, which is opposite to that shown by the dipeptide complexes. Some of the problems associated with the interpretation of the spectra in terms of spectroscopic assignment and structural features are discussed.

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