INVESTIGADORES
VALLEJOS Margarita De Las Mercedes
congresos y reuniones científicas
Título:
Microsolvation of Morpholine, a bidentate base. The importance of cooperativity
Autor/es:
VALLEJOS, MARGARITA; LAMSABHI, AL MOKHTAR; PERUCHENA, NÉLIDA M.; MÓ, OTILIA; YÁÑES, MANUEL
Lugar:
Barcelona
Reunión:
Congreso; VIIIth Congress on Electronic Structure: Principles and Applications. ESPA 201; 2012
Resumen:
The structure, relative energies and bonding in morpholine(water)n
(n = 1-4) clusters have been investigated at the
B3LYP/6-311+G(3df,2p)//B3LYP/6-311+G(d,p) level of theory. Cooperative effects
have been analyzed through the use of structural, energetic and electron
density indexes. Our analysis shows that these effects are crucial to
trace the relative stability of the complexes formed. In all cases water
molecules prefer to self-associate forming chains in which each individual
molecule behaves as a HB donor and HB acceptor. The chain so formed behaves in
turn as HB donor and HB acceptor with respect to morpholine, being the most
stable arrangements those in which the NH group of morpholine behaves
simultaneously as HB donor and HB acceptor. Higher in energy lie complexes in
which the HB acceptor continues to be the NH group, but the HB donor is a CH group,
or alternative structures in which the HB acceptor is the ether-like oxygen of
morpholine and the HB donor its NH group. Cooperativity increases with
the number of solvent molecules, but there is a clear attenuation effect. Thus,
whereas the additive interaction energy on going from dihydrated to trihydrated
species increases by a factor of 3, this increase is about half on going from
trihydrated to tetrahydrated complexes