Now showing 1 - 3 of 3
  • Publication
    Cyano substituted acetylide-thiourea as d-Ï€-a semiconductor material for CO2 sensing
    ( 2017-09-26) ;
    Wan Mohd Khairul Wan Mohamed Zin
    ;
    Khairul Anuar Abd Wahid
    Hybrid molecular system of acetylide and thiourea generally provide a wide range of electronic properties as they exhibit electronic delocalization in extended like-rod rigid π-orbital molecular system in their designated molecular framework. In this occasion, a new member of 4-methylbenzoyl-3-(4-ethynylbenzonitrile-phenyl)-thiourea (MeCNTh) was successfully designed, synthesised, and characterised for semiconductor properties and interest. The preliminary response of MeCNTh towards CO2 gas was evaluated via density functional theory (DFT) at B3LYP/6-31G (d,p) TD-SCF level of theory. The unique properties of MeCNTh is attributed by the presence of two potential active site of -NH-C=O and acetylide C≡C for H-bonding interaction between molecule MeCNTh and CO2 analyte. The sensing behaviors of both active sites were evaluated in term of interaction and stabilisation energy that give an effective evidence for sensing ability between MeCNTh and CO2. In fact, the response of sensing properties was also obtained from the difference in Mulliken charge distribution of MeCNTh and MeCNTh-CO2 to provide mechanism response of MeCNTh and CO2. Results revealed that -NH-C=O site of MeCNTh is a good interaction site for MeCNTh-CO2 to occur.
  • Publication
    Structural study of a novel acetylide-thiourea derivative and its evaluation as a detector of benzene
    ( 2017-07-05)
    Wan Mohd Khairul Wan Mohamed Zin
    ;
    ;
    Noor Azura Mohd Hanifaah
    ;
    Suhana Arshad
    ;
    Ibrahim Abdul Razak
    ;
    Hafiza Mohamed Zuki
    ;
    Mauricio F. Erben
    The new derivative 1-hexanoyl-3-(4-p-tolylethynyl-phenyl)-thiourea (APHX) was synthesised by the addition reaction between 4[4-aminophenyl] ethynyltoluene and hexanoyl isothiocyanate in acetone. The acetylide group was incorporated by using Sonogashira cross-coupling reaction allowing for the preparation of acetylide-thiourea compound. APHX was then elucidated via single crystal X-ray crystallography analysis, spectroscopic and elemental analysis by Fourier Transform Infrared (FT-IR) spectroscopy, 1H and 13C Nuclear Magnetic Resonance (NMR), UV–visible analysis, CHNS-elemental analysis. APHX was also evaluated theoretically via density functional theory (DFT) approach. APHX was fabricated onto glass substrate via drop-cast technique prior to act as optical thin-film and its performance as volatile organic compounds (VOCs) sensor was investigated through the difference in UV–vis profile before and after exposure towards benzene. Preliminary findings revealed that APHX showed interaction towards benzene with about 48% sensitivity. According to thermogravimetric studies, APHX showed good thermal stability, without decomposition up to ca. 190 Â°C. Whilst, crystal structure of APHX consists in a nearly planar acylthiourea moiety with the C[dbnd]O and C[dbnd]S bonds utilizing trans position, favoring by an intramolecular N[sbnd]H⋯O[dbnd]C hydrogen bonds. The alkyl chain is oriented 90° with respect to acylthiourea group. The phenyls group in the 1-methyl-4-(phenylethynyl)benzene moieties are mutually planar and slightly twisted with respect to the acylthiourea plane. Centrosymmetric dimers generated by intermolecular N[sbnd]H⋯S[dbnd]C and C[sbnd]H⋯S[dbnd]C hydrogen bonds forming R22 (8) and R21(6) motifs are present in the crystals. The interaction between APHX with benzene has been modelled and calculated using density functional theory (DFT) via Gaussian 09 software package and the preferred sites of binding are located at the acylthiourea group.
  • Publication
    Cytotoxicity effects of alkoxy substituted thiourea derivatives towards Acanthamoeba sp.
    ( 2017-05-01)
    Wan Mohd Khairul Wan Mohamed Zin
    ;
    Yit Peng Goh
    ;
    ;
    Nakisah Mat Amin
    In this study, the effort was to design and synthesize five new members of alkoxy substituted thiourea derivatives (3a–3e) featuring general formula of A-ArC(O)NHC(S)NHAr-D in which A represents the methoxy group and D as –OCnH2n+1 (alkoxyl group, where n = 6,7,8,9, and 10) have been successfully designed, prepared, characterized, and evaluated for anti-amoebic activities. They were spectroscopically characterized by 1H and 13C Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FT-IR) spectroscopy, and Ultraviolet–visible (UV–vis) spectroscopy analysis. In turn, they were used to investigate the cytotoxicity effect on Acanthamoeba sp. at their IC50 values and membrane permeability. Compounds 3a and 3b revealed to have good activity towards Acanthamoeba sp. compared to other compounds of 3c, 3d, and 3e. The observation under fluorescence microscopy by AOPI (Acridine-orange/Propidium iodide) staining indicated that treated amoeba cells by 3a–3e show loss of their membrane permeability.
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