Synthesis And Ion Recognition Of Calix[4]Pyrrole Schiff Base Compounds

Calixpyrrole following calixarene has drawn highly attention in the field of molecular recognition as another functionied supramolecular host compounds. On one hand, a calix[4]pyrrole molecule has four NH bonds which can lock the anion and play a role in identifying anion, on the other hand, the calixpyrrole Schiff base compounds which were obtained by the parent going through the steps of esterification, amidation and aromatic aldehydes after dehydration condensation can be a good role in coordination with various transition metal ions. Therefore, calixpyrrole as a new neutral organic ions receptors aroused great interest and attention in the field of supramolecular chemistry. Based on a series of methods of the early synthesis of calixpyrrole Schiff base, we received a total of 58 calixpyrrole compounds and focused on studing it’s characteristics of identifying ion and made some more meaningful experimental results.1. Both the hydroxyl group and o-hydroxyacetophenone can react with two pyrrole pentanone in methanesulfonic acid and methanol acid catalyzed reaction conditions to generate different configurations of disubstituted product:1,2-cis-disubstituted calix[4]pyrrole mother and 1,3-trans-disubstituted parent calix[4]pyrrole. Derived on the basis of the parent’s total of 34 calixpyrrole synthesized compounds, we cultivated 9 crystal compounds, and all compounds were characterized by NMR, IR, LS-MS, melting, etc.2. O-hydroxyacetophenone with two pyrrole pentanone and also generates one kind of mono-substituted calix[4]pyrrole precursor in methanesulfonic acid and methanol acidic catalytic reaction conditions, then we changed the cup strategy through two of pyrrole-pentanone and nitroacetophenone in trifluoroacetic acid and dichloromethane catalytic conditions after first into a cup chain to give 7-nitro-synthesized mono-substituted precursor, and wherein the mono-substituted parent acetone derivatized. A total of 25 calixpyrrole compounds were synthesized,10 crystal compounds were cultivated, and all compounds were characterized by NMR, IR, LS-MS, melting, etc.3. We have studied the ion recognition properties of calix[4]pyrrole compounds on the basis of synthesis. The research is divided into two parts:select disubstituted calix[4]pyrrole Schiff base (mostly meta-1,2-cis-disubstituted 5-chloro,5-bromo Schiff base, ortho 1,3-trans-disubstituted 5-chloro,5-bromo Schiff base), the research is characterized by UV analysis and NMR titration method to research their recognition of cations; select disubstituted calix[4]pyrrole Schiff base (mostly meta-1,2-cis-disubstituted 5-bromo Schiff base, ortho-1,3-trans-disubstituted 5-bromo Schiff base), the research is also characterized by UV analysis and NMR titration method to research their recognition of anions. We found that calix[4]pyrrole Schiff base have a strong ability to identify metal Mn2+, Zn2+, Ni2+, Cu2+ in cation recognition experiments, and F" has better effect in anion recognition experiment. At the same time, we have raised the single crystal of five calix[4]pyrrole Schiff base metal complexes, and all compounds were characterized by IR, LS-MS, X-rays, melting, etc.