Synthesis, X-ray, NMR, FT-IR, UV/vis, DFT and TD-DFT studies of N-(4-chlorobutanoyl)-N'-(2-, 3- and 4-methylphenyl)thiourea derivatives.
A new isomers of thiourea derivatives, namely N-(4-chlorobutanoyl)-N'-(2-methylphenyl)-thiourea (1a), N-(4-chlorobutanoyl)-N'-(3-methylphenyl)thiourea (1b) and N-(4-chlorobutanoyl)-N'-(4-methylphenyl)thiourea (1c) have been synthesized by refluxing mixture of equimolar amounts of 4-chlorobutanoylisothiocyanate with 2, 3 or 4-toluidine, respectively. The three isomers were characterized by spectroscopic (UV/vis, FT-IR and NMR) and X-ray crystallography techniques. To investigate the isomerization effect on spectroscopic data, DFT and TD-DFT calculations have been carried out using five hybrid functionals (B3LYP, B3P86, CAM-B3LYP, M06-2X and PBE0) to predict UV/vis absorption bands (n→π∗ and π→π∗), (1)H and (13)C NMR chemical shifts, FT-IR vibration modes and X-ray parameters (bonds, bond angles and torsion angles) for 1a, 1b and 1c isomers. The results showed that the isomerization effect is significant on λ(MAX) absorption bands, while for IR and NMR the effect is negligible. In accordance with previous studies, B3LYP, B3P86 and PBE0 gave the most reliable to predict the excitation energies of thiourea derivatives.
School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43650 Bangi, Selangor, Malaysia.
Hamza M
HM
Abosadiya
Atta-ur-Rahman Institute for Natural Product Discovery, Universiti Teknologi MARA Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor D.E., Malaysia; Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia. Electronic address: anouarelhassane@yahoo.fr.
El Hassane
el H
Anouar
School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43650 Bangi, Selangor, Malaysia.
Siti Aishah
SA
Hasbullah
School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43650 Bangi, Selangor, Malaysia. Electronic address: bohari@ukm.edu.my.
Bohari M
BM
Yamin
D066241:Carbon-13 Magnetic Resonance Spectroscopy; D018360:Crystallography, X-Ray; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D010670:Phenylthiourea / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D066244:Proton Magnetic Resonance Spectroscopy; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013890:Thiourea / Q000138:chemical synthesis* / Q000737:chemistry*; D014732:Vibration; D014965:X-Rays
D010670:Phenylthiourea; D013890:Thiourea
DFT; N-(4-chlorobutanoyl)-N′-(2-methylphenyl)-thiourea; NMR; TD-DFT; Thiourea derivatives; X-ray