TY - JOUR
T1 - Macrocyclic vs. dendrimeric effect. A DFT study
AU - Soto-Castro, Delia
AU - Guadarrama, Patricia
PY - 2004/7/30
Y1 - 2004/7/30
N2 - Macrocycles up to 15 members with different heteroatoms (N, O, and S) and dendrimeric functionalized branches were assembled, resulting in unique "collective" supramolecular hosts with several active sites for transition metal ions complexation. The nature of the interactions between these kinds of systems and metal ions of the first transition series (Fe, Ni, Cu, Zn) was evaluated by calculations of the binding energies at the B3LYP/LACVP* level of theory, resulting in a preference of metal ions for macrocyclic cavity in terms of complexation; however, there is a favorable contribution in energy due to the cooperative effect of dendrimeric branches (DBs) in the inclusion process by means of long-range interactions between metal ions and the heteroatoms present in DBs. According to calculated binding energies, even when the complexation in the middle of DBs appears as a less favored situation, still competes with the complexation occurred in several known macrocycles traditionally used in the formation of inclusion complexes. The capability of macrocycles as host entities is related to some criteria like: (1) the compatibility in orbital symmetry between host and guest molecules; (2) the cavity dimensions and the negative charge inside; and (3) the hardness-softness affinity between host and guest molecules. When DBs are included in host systems, their flexibility seems to be very important, in addition to localized negative charge, which permits the occurrence of long-range interactions.
AB - Macrocycles up to 15 members with different heteroatoms (N, O, and S) and dendrimeric functionalized branches were assembled, resulting in unique "collective" supramolecular hosts with several active sites for transition metal ions complexation. The nature of the interactions between these kinds of systems and metal ions of the first transition series (Fe, Ni, Cu, Zn) was evaluated by calculations of the binding energies at the B3LYP/LACVP* level of theory, resulting in a preference of metal ions for macrocyclic cavity in terms of complexation; however, there is a favorable contribution in energy due to the cooperative effect of dendrimeric branches (DBs) in the inclusion process by means of long-range interactions between metal ions and the heteroatoms present in DBs. According to calculated binding energies, even when the complexation in the middle of DBs appears as a less favored situation, still competes with the complexation occurred in several known macrocycles traditionally used in the formation of inclusion complexes. The capability of macrocycles as host entities is related to some criteria like: (1) the compatibility in orbital symmetry between host and guest molecules; (2) the cavity dimensions and the negative charge inside; and (3) the hardness-softness affinity between host and guest molecules. When DBs are included in host systems, their flexibility seems to be very important, in addition to localized negative charge, which permits the occurrence of long-range interactions.
KW - Cooperative effects
KW - DFT calculations
KW - Dendrimeric effect
KW - Macrocyclic effect
KW - Monte Carlo conformational search
UR - http://www.scopus.com/inward/record.url?scp=3042647044&partnerID=8YFLogxK
U2 - 10.1002/jcc.20046
DO - 10.1002/jcc.20046
M3 - Artículo
SN - 0192-8651
VL - 25
SP - 1215
EP - 1226
JO - Journal of Computational Chemistry
JF - Journal of Computational Chemistry
IS - 10
ER -