The amidine formed by tacrine and saccharin revisited: An ab initio Investigation of Structural, Electronic and Spectroscopic Properties

Authors : Nursel ACAR

Pages : 25-37

Doi:10.33435/tcandtc.486573

View : 39 | Download : 13

Publication Date : 2019-06-15

Article Type : Research Paper

Abstract :Computational study of tacrine and saccharin and their amidine complex insert ignore into journalissuearticles values(TacSac); was peformed by ab initio calculations including electron correlation. Structure, UV-Vis spectra and charge distribution of the amidine insert ignore into journalissuearticles values(TacSac); were investigated using ground state geometries optimized at MP2/6-311++Ginsert ignore into journalissuearticles values(d,p); level. The effects of solvent was investigated using polarizable continuum model insert ignore into journalissuearticles values(PCM); in conjunction with the solvation model based on density insert ignore into journalissuearticles values(SMD); approach. TacSac geometry remained same in gas phase and in H 2 O both with PCM and SMD models in contrast to former DFT results. The amidine is calculated to be stable indicating that former DFT calculations underestimated the stability of the investigated amidine. UV-Vis spectra and electronic transitions were calculated at CIS/6-311++Ginsert ignore into journalissuearticles values(d,p);, B3LYP/6-311++Ginsert ignore into journalissuearticles values(d,p); and CAM-B3LYP/6-311++Ginsert ignore into journalissuearticles values(d,p); levels of theory and B3LYP gave the best results. TacSac has a peak at a higher wavelength enabling S 0 →S 1 transition with a lower energy. S 0 →S 1 transition corresponds to full charge transfer between HOMO and LUMO orbitals of TacSac in H 2 O. The ab initio results indicate that the TacSac system can be synthesized with an easy condensation reaction, and that the amidine product is a potential candidate for photochemical charge-transfer systems.
Keywords : Amidine, Møller Plesset, Density Functional Theory, Tacrine, Saccharin

ORIGINAL ARTICLE URL