Kinetic studies and modeling of a self-replicating system
摘要:
The design, synthesis, and study of a molecular template, 11a, that catalyzes its own formation from simpler components, 9 and 10d, is described. Autocatalysis is shown by the following: (1) the increase in rate of reaction of 9 and 10d in the presence of lla; (2) the reduction in rate of reaction in the presence of 2,6-bis(acetylamino)pyridine inhibitor; and (3) the reduction in rate of reaction when a component incapable of template behavior, 10h, is substituted for 10d. Three kinetic pathways are elucidated: (1) the background bimolecular reaction (eq 6); (2) the preassociative mechanism (eq 7); and (3) the template termolecular process (eq 8). A kinetic model for the replication process is introduced, and equilibrium and rate constants are determined. Predictions for the shapes of the product growth curves are made.
Kemp's triacid attached to octa-O-methyl resorc[4]arenes: conformations in solution and comparative binding studies with various 2-amino pyridines
作者:Ion Stoll、Andreas Mix、Alexander B. Rozhenko、Beate Neumann、Hans-Georg Stammler、Jochen Mattay
DOI:10.1016/j.tet.2008.01.138
日期:2008.4
We synthesized the new supramolecular host molecules 7 and 13 based on functionalized resorcarenes bearing Kemp's triacid. Conformations in solution have been investigated and the influence of intra-and intermolecular hydrogen bonds from the triacid was shown by low temperature and DOSY NMR experiments. The results of host 7 are supported by DFT calculations. The binding behaviour of 7 towards different 2-amino pyridincs in chloroform has been investigated by NMR titrations. The association constants reach from K 207 M-1 for 2-amino-5-cyano pyridine to K=1551 M-1 for 2-amino-4-methyl pyridine. The association constants of the formed complexes of 7 with 2-amino pyridines were compared with those of the simple host systems 14 and 15 in order to evaluate the influence of the attached resorcarene host. (c) 2008 Elsevier Ltd. All rights reserved.