ChemInform Abstract: INTERLIGAND STERIC EFFECTS IN METAL COMPLEXES IN SOLUTION STUDIED THROUGH THE RESIDUAL CIRCULAR DICHROISM OF THE D-D TRANSITIONS: APPLICATION TO TETRAAMINECOBALT(III)-AMINO ACID COMPLEXES

1981 ◽  
Vol 12 (16) ◽  
Author(s):  
R. JOB ◽  
P. E. SCHIPPER
Keyword(s):  
Circular Dichroism ◽  
Amino Acid ◽  
Metal Complexes ◽  
Steric Effects ◽  
Amino Acid 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.

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