Discussion On New In-Situ Synthesis Of Coordination Polymers For 4,7-Disubstituted Benzothiadiazole Ligands

In situ reaction,as a convenient synthesis method,can be used to obtain complexes with special structures which are difficult to obtain under conventional conditions.21,3-benzothiadiazole?BTD?is a typical planar molecule and is easily modified by structural modification,which is widely used to construct conjugated organic molecules.In this paper,a novel benzimidazole or benzimidazole derivative was designed and synthesized from the prec ursor of benzimidazole with classical coordination elements?such as carboxyl group or azacaryl ring?,and the corresponding coordination polymer was prepared by in-situ reaction under similar conditions.This thesis contains two parts that were as follow:1)A new reaction was found to synthesize O2 and O3 of benzimidazole derivatives with 2,1,3-benzimidazole-4,7-dicarboxylic acid?O1?as precursors and the reaction mechanism was investigated.Through experiments and molecular simulation analysis to explore the reaction mechanism,we found that Cd???is an indispensable factor in the reaction that directly converts BTD into BID through the in-situ alcohol generation strategy,which plays an important role in the activation of thiadiazole ring and sulfur departure by the insertion of alcohol through coordination interaction.At the same time,two novel Cd???BID class coordination polymers with O2 or O3 as in situ ligands were synthesized by in situ reaction of O1 as ligand and Cd???metal salt.We found that this new in situ alcohol substitution strategy can be used to prepare benzimidazole metal organic frames with different honeycomb cavities by modifying different alcohols by experiments.2)With aromatic ring type of BTD derivatives:2,1,3-benzothiadiazole-4,7-2?2-aminopyridine??N1?as precursors,two new compounds:semi-cyclized product N2 and fully cyclized hetero-[5]-spironene compound N3 were synthesized by Cu???catalytic intromolecular C-H activation reaction.Based on the successful synthesis of the above compounds and the analysis of the coordination between copper and substrate in the activation mechanism of C-H bond in the molecule catalyzed by Cu???,two Cu???coordination polymers with N2 or N3 as the in-situ ligands were designed and synthesized by using N1 as ligand and metal salts of Cu through in-situ reaction.In the process of in situ synthesis of complex C_N3,both the precursor N1 underwent in situ ligand formation reaction,and the Cu???ion underwent in situ metal ion REDOX reaction and was transformed into the central metal ion Cu???of the complex.