Copper(II) diamino acid complexes: quantum chemical computations regarding diastereomeric effects on the energy of complexation.
[reaction: see text] Quantum chemical calculations were used to rationalize the observed enantiodifferentiation in the complexation of alpha-amino acids to chiral Cu(II) complexes. Apart from Cu(II)[bond]pi interactions and steric repulsions between the anchoring cholesteryl-Glu moiety and an aromatic amino acid R group, hydrogen bonding also plays a role. In fact, in the case of tryptophan, C[double bond]O...H[bond]N hydrogen bonding between the glutamate moiety and the tryptophan N[bond]H group compensates for the loss of intramolecular hydrogen-bonding and diminished Cu(II)[bond]pi interactions.
Zuilhof
Han
H
Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands. han.zuilhof@wur.nl
Morokuma
Keiji
K
D000599:Amino Acids, Diamino / Q000737:chemistry*; D002784:Cholesterol / Q000031:analogs & derivatives; D003300:Copper / Q000737:chemistry*; D018698:Glutamic Acid / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D010649:Phenylalanine / Q000737:chemistry; D011789:Quantum Theory; D013237:Stereoisomerism; D013816:Thermodynamics; D014364:Tryptophan / Q000737:chemistry
D000599:Amino Acids, Diamino; D018698:Glutamic Acid; D010649:Phenylalanine; D003300:Copper; D014364:Tryptophan; D002784:Cholesterol