Synthesis,spectra,and Theoretical Investigations Of 1,3,5-triazines Compounds As Ultraviolet Rays Absorber Based On Time-dependent Density Functional Calculations And 3D-QSPR

The 1,3,5-triazine ultraviolet?UV?absorbent is a novel UV absorbent developed in recent years.Due to its wide absorption spectra,high efficient,ourstanding thermostability and well compatibility with polymer materials,its development has been a hot spot for decades.In this paper,a series of 1,3,5-triazine compounds were synthesized by three synthetic routes which were the coupling reaction between the hydrochloride and substituted benzaldehyde,the Grignard coupling reaction and Friedel Crafts reaction used cyanuric chloride as material.The structure of aim compounds were characterized by 1H NMR,13 C NMR,HRMS,IR and UV absorption properties were tested.The computational chemistry methods were used to aid the rational design of 1,3,5-triazines ultraviolet rays absorber compounds.For this purpose,a series of 1,3,5-triazines were synthesized and their UV absorption properties were tested.The experimental UV absorption data are in good agreement with those predicted using the Time-Dependent Density Functional Theory?TD-DFT?[B3LYP/6-311+G?d,p?].It revealed a suitable forecasting model which the ^maximum absorption wavelength from observed and prediction calculated by TDDFT have certain linear relationship with high correlation coefficient with R=0.9098,P<0.0001 and the ^maximum molar absorption coefficient has results with R=0.8136,P<0.0001.Predictive 3D-QSPR model was established using SYBYL multifit molecular alignment rule.The optimum models were statistically significant with cross-validated coefficients?Q2 =0.501?>0.5 and conventional coefficients?R2 =0.918?>0.9,indicating they were reliable enough for the ^maximum absorption wavelength prediction,and their conclusion is consistent with the TD-DFT calculation.The CoMFA contour maps revealed electrostatic field is the main factor influencing the ^maximum absorption.Since the exceptional photostability of such ultraviolet rays absorber compounds is principally banked upon their ability to undergo excited-state deactivation via an ultrafast excited-state proton transfer?ESIPT?mechanism.And intramolecular hydrogen bond?IMBH?is the basis for the realization of excited state proton transfer.The IMHB of 1,3,5-triazines compounds was explored by IR spectroscopy,UV spectra,structural and energetic aspects of different conformers and frontier molecular orbitals analysis.