The DFT Study Of N-fused-ring Organic Compounds

Nitrogen-containing heterocyclic compounds are a large class of extremely important organic compounds,which usually have a very broad application prospect in the field of medicine due to their activity.This paper mainly studies the density functional theory of nitrogen-containing heterocyclic compounds 1,2,3-triazole,pyrrole-2-one,porphyrin and anthraquinone diamine compounds.This paper uses the DFT / B3 LYP / 6-31 G * or CAM-B3LYP/ 6-31+G** method to fully optimize the geometric structures of 1,2,3-triazole,pyrrole-2-one,porphyrin,and anthraquinone diamine compounds,and the configuration obtained through frequency calculation confirms that they are optimal structures.For 1,2,3-triazole compounds,based on the optimized ground-state stable configurations,the front-line orbital energy levels and energy gaps of the series of compounds were analyzed separately;the ADCH charges were calculated.The theoretical absorption spectrums,fluorescence emission wavelengths and IR spectrums were simulated.Through the analysis of the hydrogen bond interaction with HIV-1 protease,the results shows that this series of derivatives are expected to be an imaging anti-protein inhibitor.In addition,the reaction mechanism of ?-lactam carbene with 3,6-dipyrazine-1,2,4,5-tetrazine synthesis product C was studied.The mechanism of synthesis was further clarified,which provided a certain theoretical basis for the subsequent synthesis of this series of compounds.For pyrrol-2-one compounds,based on the optimized structures,the TD-DFT method was used to discuss the electron excitation and emission.The energy behavior of A,B,and C have been examined in a THF solvent using a polarizable continuum(PCM)model.The molecular orbital energy levels,UV-Vis spectra,heat maps,and fluorescence properties were studied in detail.In addition,based on the analysis of the hydrogen bonding interaction between the HIV-1 protease and compound C,it can be concluded that C and ILE 50 are expected to form stable hydrogen bonds.This is an important factor to stabilize the complex.The theoretical study of the D-A conjugate system constructed by porphyrin / tetrabenzoporphyrin with anthraquinone and thiophene.Based on the optimizational geometric structures,the calculation of the orbital energy levels of the four porphyrin derivatives,the theoretical absorption spectrums,and the simulation of the phosphorescence wavelengths revealed that thiophene is an effective fragment that redshifts and broadens the absorption spectrums of this system;The tetrabenzoporphyrin parent ring has a saddle-shaped structures,so that the entire conjugated system no longer presents a large planar structures;this D-A conjugated systems have a mild charge transfer process;In addition,by simulating the triplet state,the theoretical phosphorescence wavelength of this series of derivatives were between 1000 and 1200 nm.For anthraquinone diamines,the orbital energy levels,UV-Vis spectra,heat maps,and fluorescence properties of the compounds were also analyzed on the basis of geometrically optimized structures.It is found that A2,B2,C2,and D2 are strong fluorescent substances(?600 nm),which are expected to be used for fluorescent labeling(tracking drugs and action sites)in biological systems.