Design, Synthesis And Performance Of Photoacid Generator With High Efficiency

As one kind of compounds, Photoacid Generator (PAG) can decompose and generate acid under external excitation (for example: light, heat, radial, plasm etc). Because the acid from PAG can be controlled by external condition, PAGs can be abroad used in many fields, such as photoresist, computer to plate (CTP), polymerization, exposure indicator. The systems containing PAGs and acid-sensitive polymer providing with potential high chemical amplification are more and more regarded as the imaging materials. At the same time, it is of much significance to explore the relationship of PAG's structure with performance, especially with acid-forming performance and farther to find excellent materials with the guide of above research results.According to literatures as far as we know, such an organic compound possessing a D(electron-donator)–π(conjugate)–A(electron-acceptor) structure has higher photon efficiency. On the base of the theory, in this research, a series of PAGs, including 8 kinds of s-triazinyl derivatives (Fig a) and 5 kinds of sulfonium salts (Fig b) have been designed and further prepared.In this work, these compounds'synthesis route, methods and conditions are investigated. s-Triazinyl derivatives are obtained by refluxing to dehydrate between substitutional benzene (naphthalene/anthracene) formaldehydes and 2,4-bis(trichloromethyl) -6-methyl -1,3,5-triazine with acetic acid, piperidine as catalyst and toluene as solvent.Sulfonium salts (PAG-S1 and PAG-S2) are obtained by methyl trifluoromethanesulfonate and key intermediates (m1s) which are prepared by Witting reaction between substitutional benzaldehydes and phosphorus ylides. Sulfonium salts PAG-S3 colud be easily prepared by the reaction of methyl trifluoromethanesulfonate and key intermediates S2a prepared by couplingreaction between 4-Methylthiophenylboronic acid and 10-bromo-9-phenyl anthracene.Sulfonium salts (PAG-S4 and PAG-S5) are also obtained with same method of PAG-S1 and PAG-S2 with two new intermediates S2b and S2c respectively. S2b and S2c are prepared by the reactions of unsubstitute and 2-tert-butylanthroquinon with Grignard reagents of 4-Bromothioanisole. All compounds'structure are confirmed by IR, 1HNMR, DSC and etc.More researches are focused on evaluations about above PAGs'solubility, thermol-stabilization, ultraviolet absorption and acid-forming performance under exposure after being dissolved in CH3CN.The results show that all PAGs have good solubility in common organic solvents, excellent thermol-stabilization, substituents and solvents influence on the PAGs'maximum absorption wavelength.Further more, according to the method ascertained in our laboratory, their acid-forming performance in acetonitrile under irradiation at 405 nm and 365nm are measured. The results indicate that the PAGs containing typical D-π-A structure, such as the compouds (PAG-T2,PAG-T1 and PAG-T3) containing diethylamine group, diphenylamine group, carbazolyl group, have higher acid-forming quantum efficiency, especially PAG-T1 and PAG-T2 over 50% and 70% at 405 nm respectively. They are excellent PAGs which have a good match with UV light and can be hopeful to be applied in 405nm imaging systems.