A Dual Approach on Experimental, Theoretical Insight of Structural Elucidation, Hirshfeld Surface Analysis, Optical and Electrochemical Properties of Acyl Thiourea-Ethynyl Hybrid Derivatives

Hybrid moieties of ethynylated-thiourea, Th1 and Th2 have been synthesised via the addition reaction between ethynyl derivatives and 4-tert-butylbenzoyl isothiocyanate in acetone, and were characterised by selected spectroscopic methods (i.e., 1H and 13C NMR, UV–visible, FT-IR) and elemental analysis. Thermogravimetric analysis indicated that Th1 and Th2 were relatively stable up to ca. 210 °C. Single-crystal X-ray diffraction was used to identify the crystal structure of Th2 in which the centre of 1-acyl thiourea moiety (-C(O)NHC(S)NH) exhibits S conformation. The Hirshfeld surface analysis has allowed visualizing the crystal packing, which is characterised by the prolonged intermolecular N–H⋯O = C and N–H⋯S = C hydrogen-bonding interactions within Th2 molecule. Electrochemical data of both compounds correspondingly exhibit irreversible redox potential processes. Besides, frontier molecular orbitals and Natural Bond Orbital population analysis were computed at the B3LYP/6-31G (d, p) level of approximation, suggesting strong delocalization of the electronic density through a conjugated π-system involving the ethynyl-phenyl and thiourea groups. Graphical Abstract: Figure of molecular structure for acyl thiourea-ethynyl derivative. Two derivatives of acyl thiourea-ethynyl were synthesised and characterised by selected spectroscopic methods such as 1H and 13C NMR, UV-visible, FT-IR, elemental, thermal, electrochemical, X-ray diffraction, and density functional theory (DFT) calculation for molecular orbitals and natural bond orbital population analysis.Fil: Daud, Adibah Izzati. Universiti Malaysia Perlis; Malasia. Universiti Malaysia Terengganu; MalasiaFil: Khairul, Wan M.. Universiti Malaysia Terengganu; MalasiaFil: Arshad, Suhana. Universiti Sains Malaysia; MalasiaFil: Razak, Ibrahim Abdul. Universiti Sains Malaysia; MalasiaFil: Nossa González, Diana Lisseth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Erben, Mauricio Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin

Study on Semiconductor Properties of Acetylide-Thiourea Fabricated onto Interdigitated Electrodes (Ides) Platform Towards Application In Gas Sensing Technology

In the past few decades, the unique properties of acetylide and thiourea moieties individually have attracted great attention from researchers in various fields to be developed in numerous applications in advanced materials technology, especially as active layer in gas sensing devices. Acetylide and thiourea molecular system provides a wide range of electronic properties as they possess rigid π-systems in their designated structures. In this study, a derivative of acetylide-thiourea featuring N-(4[4-aminophenyl] ethynyl benzonitrile)-N’-(4-ethyl benzoyl)thiourea (TCN) has been synthesised having general formula of ArC(O)NHC(S)NHC≡C)Ar adopting the system of D-π-A for significant development of conductive materials. The derivative consists of donating substituent which has been characterised by typical spectroscopic techniques namely infrared spectroscopy, UV-visible spectroscopy, and 1H and 13C Nuclear Magnetic Resonance. In turn, TCN was deposited onto interdigitated electrode (IDE) for the measurement of thin-film resistance. The resistance values of synthesised compound is due to the effect of donating substituent attached to the acetylide-thiourea, which indeed altered the conductivity performances of fabricated IDE substrate. In fact, the theoretical calculation also was carried out using Gaussian 09 to evaluate the relationship between experimental and theoretical analyses of acetylide-thiourea semiconductor properties in term of energy band gap and sensing response towards selected analyte

An Efficient Palladium-Thiourea Catalysed Heck Cross-Coupling Reaction for Molecular Electronic Interest

The synthesis and utilization of C-C bonds formation are concerned about the key steps for the building of several conducting molecular electronics involving many asymmetric catalysts approached, which is an essential task that most researchers would ignore in preparing these materials to enhance the production yield of cross-coupling materials. Despite the enormous progress, there still remains a great demand for economic and practicable cross-coupling processes involving ultra-low catalyst loadings with high turnover numbers due to the employment of conventional metal catalyst. Thus, there has been an excessive interest to cultivate non-phosphine palladium catalysts for excellent achievement of activity, stability, and substrate tolerance which permit the coupling reactions to be conducted under mild reaction condition at ambient atmosphere. In this contribution, N-(4-nitrophenylcarbamothioyl)-N’-(4-methylbenzoyl) thiourea (LT1) and its metal complex of MLT1 featuring Pd (II) have been successfully characterisedvia typical spectroscopic methods namely; Infrared (IR) spectroscopy, Ultraviolet-visible (UV-Vis) spectroscopy, CHNS elemental analysis, and Nuclear Magnetic Resonance (1H and 13C NMR). In turn, catalytic studies of palladium catalyst (MLT1) were tested for its homogenous catalytic activity in Heck cross-coupling reaction. The reaction wasmonitored by Gas Chromatography-Flame Ionisation Detector (GC-FID). Results reveal that MLT1 exhibits 100% of conversion starting material into a cross-coupling product, which was alkene-based compound

Single molecule thin film featuring disubstituted thiourea (TU) doped with chlorophyll as potential active layer in photovoltaic cell

The versatility of conjugated thiourea compound enhances the development of molecular wire architectures due to the overlapping of π-electrons which can be applied as potential organic solar cell (OSC). Hence, new innovational and breakthrough are needed for OSC molecules to become competitive in the future since they represent lower cost and more flexible devices, tunable electronic properties and easier processing compared to other organic molecules. Due to this interest, a study on the performance of essentially linear conjugated organic compound based on Donor (D)-π-Acceptor (A) system which featuring D-ArNHC=SNH-A-NHC=SNHAr-D to act as potential active layer in OSC was carried out. The synthesized compound was successfully designed, prepared, and characterized prior to form thin film. The compound was then spectroscopically and analytically characterized via ¹H and 13C Multi-Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FT-IR), UV-Visible Analysis (UV-Vis), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), CHNS Elemental Microanalysis as well as Cyclic Voltammetry (CV) analysis. In turn, it was fabricated on Indium Tin Oxide (ITO) substrate before its conductivity behaviour, efficiency and OSC parameter were evaluated by Four Point Probe. From the electrical conductivity study, it revealed that it performed better and higher conductivity with the presence of chlorophyll (CHLO) under maximum light intensity of 100 Wm-2. The result shows the electrical conductivity increases with the increasing of the light intensity. The electrical conductivity of the thin films shows the conductivity of 0.2040 Scm-1 (with CHLO) compares to 0.1472 Scm-1 (without CHLO) under maximum light intensity. From the result obtained, it clearly shows the synthesized compound has great potential to act as an active layer in photovoltaic cell. Therefore, further investigation on photovoltaic studies on the similar molecular system should be seriously considered for further development in molecular electronics application

Synthesis, characterization, molecular structure and computational study of tetrahedral pentamethylcyclopentadienyl iridacycle complexes with α,β-conjugated Schiff base ligands

Due to the excellent catalytic activities and phosphorescent properties that iridium complexes display, iridium chemistry has been of great interest for scientific investigation over the past 30 years. Iridium metallacycle analogues (also known as an iridacycles) bearing phenylpyridine (ppy) ligands have been well reported on, whilst complexes with R-phenyl-(3-R-phenylallylidene)amine, which is an α,β-conjugated Schiff base ligand, have not had the same attention, despite the fact that both ligands share a similar coordination mode. In this research, four pentamethylcyclopentadienyl iridacycle complexes, Ir1a-Ir1d, with different α,β-conjugated Schiff base ligands were synthesized from a di-μ-chloro-dichloro-bis-(η5-pentamethylcyclopentadienyl)diiridium(III) precursor. The iridacycle complexes were characterized using spectroscopic techniques and the molecular structures of Ir1ab-Ir1d were determined using X-ray crystallography. The X-ray results revealed that the iridacycle complexes have a tetrahedral geometry, the iridium centre being coordinated through the Ndouble bondCsingle bondCαdouble bondCβ moiety of the α,β-conjugated Schiff base ligand. Computational calculations with the B3LYP method and with LanL2DZ basis sets indicated that the HOMO-LUMO energy gaps Ir1b-Ir1d were in the range 3.31–3.36 eV. The OMe substituent at the C terminal has a greater impact on the HOMO energy level than the one at the N terminal

Synthesis and characterization of <i>N</i>-(4-Aminophenylethynylbenzonitrile)-<i>N</i>′ -(1-naphthoyl)thiourea as single molecular chemosensor for carbon monoxide sensing

<div><p>This contribution reports on the design, preparation, and characterization of a novel acetylide-thiourea presenting <i>N</i>-(4-Aminophenylethynylbenzonitrile)-<i>N</i>′-(1-naphthoyl)thiourea (AETU) obtained from continuous reaction of intermediate compound 4[(4aminophenyl)ethynyl benzonitrile] (AMEB) with 1-naphthoyl chloride prior to form an active substrate for the detection of carbon monoxide (CO). These compounds were then characterized via several spectroscopic and analytical methods, namely Fourier transform infrared spectroscopy, UV–visible spectroscopy, nuclear magnetic resonance (¹H and ¹³C NMR), carbon, hydrogen, nitrogen, and sulfur elemental analysis, and Thermogravimetric analysis. The performance of sensor response toward CO was measured using difference response in spectral features of UV–VIS spectrophotometry in thin-film studies with and without the presence of CO. The findings revealed that AETU possibly has an interaction with CO of concentrations 10, 20 and 30 ppm. In addition, quantum chemical calculations also proved that AETU exhibits potential sense interaction toward CO with stabilization energy−6.30 kJ/mol and interaction distance is about 3.14 Ǻ. This proposed material sensor gives an ideal indication for application in the aspect of direct detection of CO in real sample and for development of single molecule gas sensor devices.</p></div

<i>In vitro</i> antimicrobial activities, molecular docking and density functional theory (DFT) evaluation of natural product-based vanillin derivatives featuring halogenated azo dyes

Chemical modification of active scaffolds from natural products has gained interest in pharmaceutical industries. Nevertheless, the metabolites extraction is time-consuming while the lead is frequently mismatched with the receptor. Here, the diazo coupling approach was introduced to generate a series of vanillin derivatives featuring halogenated azo dyes (1a-h). The vanillin derivatives showed effective inhibition of S. aureus (7-9 mm) and E. coli (7-8 mm) compared to the parent vanillin, while 1b had the highest inhibition zone (9 mm) against S. aureus comparable to the reference ampicillin. The presence of N = N, C = O, -OH, -OCH3 and halogens established strategic binding interactions with the receptor. The potential vanillin-azo as an antimicrobial drug was supported by in silico docking with penicillin-binding proteins and DFT (using Gaussian 09) with binding affinity −7.5 kcal/mol and energy gap (Egap) 3.77 eV, respectively. This study represents a significant advancement in drug discovery for effective antibiotics with excellent properties.</p

Structural study of a novel acetylide-thiourea derivative and its evaluation as a detector of benzene

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 °C. Whilst, crystal structure of APHX consists in a nearly planar acylthiourea moiety with the CO and CS bonds utilizing trans position, favoring by an intramolecular NH⋯OC 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 NH⋯SC and CH⋯SC 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.Fil: Khairul, Wan M.. Universiti Malaysia Terengganu; MalasiaFil: Daud, Adibah Izzati. Universiti Malaysia Terengganu; Malasia. Universiti Malaysia Perlis; MalasiaFil: Mohd Hanifaah, Noor Azura. Universiti Malaysia Terengganu; MalasiaFil: Arshad, Suhana. Universiti Sains Malaysia; MalasiaFil: Razak, Ibrahim Abdul. Universiti Sains Malaysia; MalasiaFil: Zuki, Hafiza Mohamed. Universiti Malaysia Terengganu; MalasiaFil: Erben, Mauricio Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin

Elucidating mesomorphic and electrical properties of conjugated acetylide-imine as electrochemically deposited electron transporting materials in organic conductive film

A new class of liquid crystalline acetylide-imine system was successfully synthesized, characterized and deposited on indium tin oxide (ITO) coated substrate via electrochemical deposition method for potential organic film application. The relationship between liquid crystal molecular structure, phase transition temperature and electrical performance was evaluated. The mesomorphic properties were identified via polarized optic microscopy (POM) which displayed fan-shaped texture of smectic A phase and their corresponding transition enthalpies are in concurrence with DSC and TGA studies. The findings from the conductivity analysis revealed that the fabricated film exhibits good electrical performance where it displayed linear current-voltage relationship of I-V curve. Therefore, this proposed type of molecular framework has given an ideal indication to act as transporting material for application in optoelectronic devices