Ref document number : Country of ref document : CN. Kind code of ref document : A1. Country of ref document : CA.
|Published (Last):||9 October 2011|
|PDF File Size:||13.1 Mb|
|ePub File Size:||10.71 Mb|
|Price:||Free* [*Free Regsitration Required]|
This example emphasizes one of the questions raised by the description of the effects of the environment solvation,hydrogen bond, formation of clusters or supramolecular entities and their influence on the shape of the VCD spectra.
Le Barbu-Debus, A. Scherrer, A. Bouchet, D. Sebastiani, R. Vuilleumier, and A. Zehnacker Phys. Perez-Mellor, K. Le Barbu-Debus, and A. Zehnacker Chirality, , Declerck, A. Perez-Mellor, R. Guillot, DJ.
Aitken, M. Mons, and A. Zehnacker Chirality, , vol 31, Our recent VCD studies include cyclic dipeptides in the solid phase, like diketopiperazine peptides and those derived of cis or trans 2-aminocyclobutanecarboxylic acids ACBCs. The cyclo LL diphenylalanine is organised as dimers in the solid state, which are bound by a double hydrogen bridge.
This is however not the case for the LD dipeptides for which dispersion between the aromatic rings is the major interaction in the solid phase. Formation of cyclo LD diphenylalanine in the solid phase by thermal peptide bond formation in the linear LD diphenylalanine parent leads to the formation of a new chiral phase resulting from the synchronisation of the transient chirality of the -otherwise not chiral- subunit.
While the VCD spectrum of the cis derivative is described by that of the monomer in the solid phase, that of the trans requires inclusion of at least a tetramer. A dramatic enhancement in the VCD intensity of the trans derivative relative to the cis is observed.
We are also inteerested in the description of VCD spectra for molecules in strong interaction with their solvent. It was compared for 1-indanol insolution in DMSO to time-dependent methods resting on first-principles molecular dynamics MD simulations that fully account for anharmonicity, temperature and environment effects. Experimental and simulated VCD spectra of 1-indanol.