Ligands, induced circular

A remarkable phenomenon of chiral ligand induced circular dichroism in CdSe quantum dots was reported by M. Balaz et The researchers... 

A and A" is the same achiral chromophore and B-j and Bj have the same configurational relationship to A in the composite complex as in their respective substituent complexes, the circular dichroism of AB-jBj... is simply the summation of the CD s of A B., A"Bj, etc. The purpose of this effort is to exhibit an achiral 1 chromophore upon which exchange of chiral ligands induces negligible perturbation in the configurational relationship of the chelating ligands, and thus to allow the utility of the predicted additivity to be demonstrated experimentally. 

The interaction of aspartic acid and other ligands with complexes of Tb " with edta and related ligands has also been studied and association constants determined. The complex formation between Tb " or Eu " and (r)-( — )-l,2-propanediaminetetraacetic add or (r,r)-trons-1,2-cyclohexanediaminetetraacetic acid has been similarly investigated. The pH dependence of the circularly polarized and total luminescence shows a drastic configurational change of the chelate system at pH 10.5-11, corresponding, it is believed, to formation of hydroxide complexes. Tlie technique of magnetic-field-induced circularly polarized emission has been introduced for lanthanide ions the mechanisms of lanthanide transition intensities are also discussed in the paper. 

Theory Induced Circular Dichroism Macromolecule-Ligand Interactions Studied By NMR Magnetic Circular Dichroism, Theory Nucleic Acids and Nucleotides Studied Using Mass Spectrometry Nucleic Acids Studied Using NMR ORD and Polarimetry Instruments Proteins Studied Using NMR Spectroscopy Peptides and Proteins Studied Using Mass... 

Cobalt(lll).—Complexes. Ammine complexes. Optical activity can be induced in the complexes [Co(NH3) ] and [Cofenlj] by means of outer-sphere association with chiral anions, e.g. (- - )-tartrate. Circular dichroism is observed in the d-d bands of the cations and it is suggested that this is due to (a) direct interaction between the chiral anion and the metal f/-orbitals and (b) the preferred conformation adopted by the inner-sphere ligands in the presence of a helical outer-sphere ligand. 

Quadrupole splitting (A q) correlates to electric field gradient and, based on model compounds, can identify some ligand types Can observe changes in ligand field induced by sample perturbation Can only detect iron sites Magnetic circular dichroism (MCD) spectra Require low temperature to observe (—2-70 K)... 

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