Preparation And Characterization Of Ordered Mesoporous Carbon Nitride And Its Utilization In Organic Reactions

Ordered mesoporous carbon nitride(OMCN) is a novel superior material and has been widly used as electrode materials because of its porous structure and amine-containing molecules. On the other hand, its use for organic catalysis reports has not been concentrated ever. We start our work with the preparation of ordered mesoporous carbon nitride by a novel method, and the material was obtained with considerable nitrogen content, higher specific surface properties and ordered pore size distribution. Utilizing the material as a functionalized support, OMCN-supported copper nanoparticles(Cu NPs-OMCN) was prepared and used as a highly efficient catalyst for the coupling reaction of terminal alkynes to synthesize symmetrical and unsymmetrical 1,3-diynes. Furthermore, the one-pot synthesis of 2,5-disubstituted furans and thiophenes from terminal alkynes were also developed.Firstly, the precursor of carbon nitride was prepared from the polymerization of 2,4,6-trichloro-1,3,5-triazine and benzidine in the presence of SBA-15 as the template. Then the ordered mesoporous carbon nitride was obtained through 700 oC heating treatment and then Cu NPsOMCN was also prepared by using the liquid loading method to immobilize the copper nanoparticles.Then, the material was characterized by BET, EA, HRTEM, XRD and XPS. The analysis results showed that the precursors had a better template integration for SBA-15, and the prepared mesoporous carbon nitrides had the ordered mesoporous structure with a pore size distribution in 4.3 nm, specific surface area and nitrogen content range are 741 m2/g and 9.28 % respectively. Nitrogen mainly existed in N-C and N=C. The electrochemical measurements showed that the ordered mesoporous carbon nitride materials and its supported copper nanoparticles had a certain activity of electrochemical oxygen reduction.Finally, the Cu NPs-OMCN catalyst was evaluated with the coupling reaction of terminal alkynes to prepare symmetrical and unsymmetrical 1,3-diynes by using Cs2CO3 as a base, DMSO as solvent at 80 oC. Significant ligand/support-effect as well as good yields were observed. Furthermore, the metal/ligand dual-immobilized nanoparticle catalyst showed much better recyclability: the catalyst could be recycled for 3 times at least without obvious decrease in catalytic activities and no additional fresh ligands are required. Based on the results, the one-pot synthesis of 2,5-disubstituted furans and thiophenes from terminal alkynes were developed.In summary, the ordered mesoporous carbon nitride material was prepared and used to support and modify the copper nanoparticles, which showed a high catalytic activity in synthesis of symmetrical and unsymmetrical 1,3-diynes from terminal alkynes. Furthermore, the one-pot synthesis of 2,5-disubstituted furans and thiophenes from terminal alkynes were developed. And both of the reactions showed good functional group tolerance and wide substrates scope under the mild reaction conditions.