title: One pot synthesis, molecular structure and spectroscopic studies (X-ray, IR, NMR, UV-Vis) of novel 2-(4,6-dimethoxy-1,3,5-triazin-2-yl) amino acid ester derivatives.
abstract: Novel series of 2-(4,6-dimethoxy,1,3,5-triazin-2-yl) amino acid ester derivatives were synthesized using simple one pot method in methanol. The products were obtained in high yields and purities as observed from their spectral data, elemental analyses, GC-MS and X-ray crystallographic analysis. The B3LYP/6-311G(d,p) calculated molecular structures are well correlated with the geometrical parameters obtained from the X-ray analyses. The spectroscopic properties such as IR vibrational modes, NMR chemical shifts and UV-Vis electronic transitions were discussed both experimentally and theoretically. The IR vibrational frequencies showed good correlations with the experimental data (R(2)=0.9961-0.9995). The electronic spectra were assigned based on the TD-DFT results. Intense electronic transition band is calculated at 198.1 nm (f=0.1389), 204.2 nm (f=0.2053), 205.0 (f=0.1704) and 205.7 (0.2971) for compounds 6a-i, respectively. The molecular orbital energy levels contributed in the longest wavelength transition band were explained. For all compounds, the experimental wavelengths showed red shifts compared to the calculations due to the solvent effect. The NMR chemical shifts were calculated using GIAO method. The NBO analyses were performed to predict the stabilization energies due to the electron delocalization processes occur in the studied systems.
authors: Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321, Egypt. Electronic address: aelfaham@ksu.edu.sa.
authors: Ayman
authors: A
authors: El-Faham
authors: Department of Chemistry, Rabigh College of Science and Art, King Abdulaziz University, P.O. Box 344, Rabigh 21911, Saudi Arabia; Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321, Egypt. Electronic address: saied1soliman@yahoo.com.
authors: Saied M
authors: SM
authors: Soliman
authors: Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; Advanced Materials Research Chair, Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
authors: Sameh M
authors: SM
authors: Osman
authors: Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box. 2457, 11451, Riyadh, Saudi Arabia.
authors: Hazem A
authors: HA
authors: Ghabbour
authors: Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
authors: Mohammed R H
authors: MR
authors: Siddiqui
authors: Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box. 2457, 11451, Riyadh, Saudi Arabia; X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
authors: Hoong-Kun
authors: HK
authors: Fun
authors: Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa; Institute for Research in Biomedicine (IRB Barcelona), BaldiriReixac 10, Barcelona 08028, Spain; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Barcelona 08028, Spain; Department of Organic Chemistry, University of Barcelona,Barcelona 08028, Spain.
authors: Fernando
authors: F
authors: Albericio
keywords: Amino acid esters; B3LYP; Dimethoxy-1,3,5-triazine derivatives; NBO; TD-DFT; X-ray crystallographic analysis