Synthesis,characterization And Photoreaction Of Supermolecular Crystals Based On Dipyridine And Polyphenol

Supramolecular chemistry mainly studies the ordered molecular aggregation of two or more components bonded by the weak interaction between molecules.In recent years,the application prospect of supramolecular chemistry in medicine,information,materials and other fields has attracted wide attention of researchers.It has always been a hot topic for researchers to make rational use of molecular interactions to design novel structures and configuration-controllable supramolecular aggregates.Hydrogen bond is an important molecular intermolecular forces,because of its obvious orientation and the characteristics of high strength and its important use in the rational design and predictability of crystal structure.Based on 1,2-(4-pyridyl)ethylene(bpe)and three kinds of different organic resorcinol molecular,we got a set of similar structure of crystals and two groups of homogeneous polycrystalline through self-assembly and evaporation method are studied to obtain crystals with good quality.Three groups of crystals have different accumulation configuration and we also discuss the essential structure issues for[2+2]photodimerization reactions,explore the relationship between its structure and photodimerization reaction,the relationship between hydrogen bond and the thermal stability and the influence of different synthetic substructure substituent on the crystal.In addition,we studied the application of a widely used method in the crystal field names similar structure synthesis.All of these will provides an significant reference for the rational designs and predictability of crystal structure.The main contents of this paper are as follows:We selected 1,2,(4-pyridine)ethylene(bpe)to crystallize with 4-bromine resorcinol,4-chloride resorcinol,respectively and synthesized a group of crystals with similar structure by solvent evaporation method.Through uv irradiation,the single crystals underwent the single crystal to single crystal conversion to obtain two kinds of single crystal containing the four-member ring derivatives.We determine the structure of the four kinds of single crystal by X-ray single crystal diffraction and test its purity by powder X-ray diffraction.~1H NMR was used to confirm reaction process and yields of two kinds of similar single crystals.It's also testified that with the increase of double bond distance,photodimerization reaction completion time is longer.We selected 1,2,(4-pyridine)ethylene(bpe)to crystallize with 5-methyl resorcinol and synthesized a group of polymorphs with different double bond arrangement and differient packing mode by controlling experimental condition slightly.The structure of the two kinds of single crystal were determined by X-ray single crystal diffraction.It has been found that??stacking exists in one of them and it has played a key role in the formation of the single crystals.[2+2]photodimerization reactions were expected to occur in the polymorphs.1H NMR was used to confirm reaction process and yields of two kinds of similar single crystals.We found that the criss-cross aligned double bonds can be reacted through uv irradiation.And We also test its purity by powder X-ray diffraction.We selected 1,2,(4-pyridine)ethylene(bpe)to crystallize with 1,2,3-hydroxy phenol and obtained a set of pseudopolymorphism by controlling experimental condition slightly.And we determine the structure of two kinds of single crystal by X-ray single crystal diffraction.With the increase of hydrogen bonding donor,the direction of the hydrogen bond has make an obvious changes.The novel hydrogen bonding arrangement was studied through structure analysis and the effects of solvent influence on the crystal structure are also discussed.We analyze its purity and polymorphism by using X-ray diffraction and analyzed its thermal stability through thermal analysis.