Synthesis of 5-vinyl-2-norbornene through Diels-Alder reaction of cyclopentadiene with 1,3-butadiene in supercritical carbon dioxide

An efficient method for the synthesis of 5-vinyl-2-norbornene from cyclopentadiene and 1,3-butadiene was developed.The Diels-Alder reaction of cyclopentadiene with 1,3-butadiene proceeded smoothly in supercritical carbon dioxide in the absence of any polymerization inhibitor to produce the corresponding5-vinyl-2-norbornene in satisfactory yield with high selectivity.

Theoretical Study on the Structures and Properties of Phenobarbital Imprinted Polymers

Recently, the investigation of novel molecularly imprinted polymers（MIPs） has attracted a lot of interest and becomes a fascinating field. The phenobarbital（PHN） was taken as an imprinted molecule and the 2-vinyl-4,6-diamino-1,3,5-triazine（VDAT） was considered as a functional monomer in this study. The geometry optimization, natural bond orbital（NBO） charge, and molecular electrostatic potential（MEP） of PHN and VDAT were studied at the M062 X level belonging to one of the hybrid density functional theories. Furthermore, we discussed the bonding conditions of PHN molecular imprinted polymers（PHN-MIPs） via the hydrogen bond length and atoms in molecules（AIM） theory. The rebinding property of PHN-MIPs was also researched. The results of MEP and NBO charge analysis were coincident. The stability property was excellent when the ratio of PHN and VDAT was 1：4. Except the classic hydrogen bonds, non-classical hydrogen bonds also existed in the imprinted polymers. By simulating the rebinding energies between the pentobarbital（PNT）, barbital（BAR）, and PHN-MIPs after the elution of PHN, the rebinding property of PHN-MIPs to PHN was excellent when PNT and BAR existed all at once. This research can provide theoretical reference for the synthesis and characterization of novel PHN-MIPs.