The interest in calixarenes has been related to their ability as receptors for neutral molecules.In the present paper,molecular mechanics and molecular dynamics simulations were used to investigate the molecular recognition of bis(amidopyridine)-linked calix\arene and a series of aliphatic dicarboxylic acids.The computational results indicate that multiple hydrogen bonds were formed between the amide of host molecule and dicarboxylic acids guest molecules with different chain lengths,the binding capacity increased with the chain length increasing.The further study results show that average binding energy obtained by molecular dynamic simulation can be in agreement with the experimental binding constants.Meanwhile,the binding energy,which was calculated from the stable conformation gained by dynamic simulation in vacuum and in solution,agrees with the result of the experiment as well.
Preparations of new pyrethroid esters(5, 6) containing a pyridine ring in the acid moiety were described. The α and β form of α cyano 3 phenoxybenzyl esters 6 were separated chromato graphically. These compounds were screened for insecticidal activities against Mythimna separata(W. ) and Aphis fabae and for miticidal activity against Tetranychus urticae . Compound 5 showed 85% mortality against Mythimna separata(W. ) at 250 mg/L, and 6 β had more miticidal activity on Tetranychus urticae than fenvalerate at a mass fraction of 200 mg/L.
