Computational Insight into Conformational Rearrangement and Intramolecular-H Bond Analysis of Some Calix[4]Arenes Including Acryloyl Moiety

Abstract

C alixarenes are macrocyclic compounds, which are utilized in important fields like pharmacy, engineering and medicine. They are applied as sensors in various areas of human activities, in medical applications and environmental protection (1, 2). Moreover, they are used in catalysis as well as in molecular recognition. Their cage-like structures play important role in host-guest mechanism in supramolecular chemistry (1, 2). In addition, the functionalization of Calixarenes by means of substituting methylene bridges with heteroatoms is quite important in order to discover new compounds (1, 2). Calixarenes attract much attention due to the rich conformational possibilities which come in four varieties: Cone, Partial Cone, 1,2-Alternate and 1,3-Alternate (3-6). The four forms of Calixarenes are mainly due to the free rotation of methylene groups. The determination of stable conformations could not always be achieved correctly by spectroscopic techniques such as IR and NMR. On the other hand, the current state of theory on predicting Calixerarene derivatives remains inconclusive or insufficient (7) hence there is still need for extensive theoretical work. Moreover, in literature, it has been highlighted that the determination of the conformational stability from experimental results of Calixarenes