Synthesis And Properties Of A Series Of Photoacidogenic Agent

Photoacidogenic agent（PAG）are a class of compounds that react or dissociate under light.The final formed photoproducts include specific light controllable acidic substances,which can cause specific chemical reactions of acid sensitive substances.They are a class of fine chemical products of great importance and high industrial value,and are widely used in UV curable coatings,adhesives,printing inks,varnishes,and dental composites.In addition,due to the emergence of"chemical amplification"technology,photoacidogenic agent are increasingly used as core components of chemical amplification photoresists in the microelectronic industry,3D printing,and the construction of microfluidic systems.In recent years,the research on the structure activity relationship between molecular structure and compound type on the acid production performance of photoacidogenic agents,and the development of novel compounds with high amplification mechanisms,has become a hot topic in the field of photoacidogenic agents.In this paper,a series of sulfonic acid esters（12 types）and sulfonium salts（5types）have been designed and synthesized,which contain different types of main photosensitive and acid generating groups with different structures.Among them,9 are new types of photoacidogenic agents.The synthesis method of the series of compounds is simple and easy to operate,easy to separate and post process,with high yield and purity.The structure of the above photoacidogenic agents was determined by¹H NMR,¹³C NMR,¹⁹F NMR,and melting point.In this study,the basic properties of17 synthesized PAGs were investigated,including solubility,thermal stability,UV absorption,fluorescence absorption,photodegradation,and acid production.The results show that all PAGs synthesized have a certain solubility in common organic solvents and good thermal stability,which can well meet the requirements of use and storage.UV absorption investigation results showed the maximum absorption peak(λ_max)of the solvent on the synthesized PAG is not obvious,while the size of substituents and conjugated systems has a significant impact on some PAGs;The fluorescence absorption investigation results showed that fluorescence was detected in all the synthesized PAGs,but the fluorescence of the sulfonium salts PAG and PAG6a-f was relatively lower,which had a small impact on the acid production efficiency and theoretically had better acid production performance.In addition,the sulfonic acid esters PAG showed positive solvent achromatic emission related to solvent polarity.In addition,using Rhodamine B as an acid sensor,a spectrophotometric method for the detection of exposure acid production was established,and the decomposition and acid production performance of each PAG were investigated.The results show that when exposed to a 254 nm light source,the decomposition yield of PAG is greater than its acid production quantum yield,and the type of compound,molecular structure,and fluorescence have certain effects on the decomposition and acid production performance.The acid production efficiency of sulfonium salts PAG is relatively higher.Cations have a decisive impact on the decomposition and acid production performance of the sulfonium salt PAG,while anions have no significant impact.Among sulfonic acid ester PAGs,the photosensitive portion of PAG 6a-f has higher transparency and lower fluorescence,and has stronger photon absorption and conversion capabilities compared to PAG 3a-f;PAG molecules with low conjugated structures and acid producing portions of electron donor groups have higher photon efficiency.PAG 3c and 6c molecules contain electron donor groups and large conjugated structures,forming a typical D-π-A structure,improving the photon utilization efficiency of the compound,resulting in higher decomposition and acid production efficiency.Overall,the acid production efficiency of most PAGs has reached over 10%,especially that of PAG 6f,PAG 10a-d,and PAG 12.They are excellent photoacidogenic agents with high development and application value.