Simazine inclusion complexes with cucurbiturils (n = 6-8): experimental and molecular dynamics studies.

Simazine (SIM) inclusion complexes with cucurbit[n]uril, CBn, (n = 6-8), have been studied in both aqueous solutions and solid states. NMR measurements were taken in DMSO. The solid samples were examined using Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD). Molecular dynamics (MD) simulations were used to investigate the inclusion process at an atomic level and to examine the mechanism and stability of the complexes. The results showed that the SIM complexes with both CB[7] and CB [8] are highly stable in water, whereas the smaller cavity of CB[6] prevents the formation of an inclusion complex with SIM. The findings clearly demonstrate that, in addition to hydrophobic interactions, hydrogen bonding plays a significant role in stabilizing these complexes.