Omer Yasin Thayee Al-Janabi

A tetrahedral Hg(II) diethyl dithiocarbamate (Et₂Dt) complex containing triphenylphosphine (PPh₃) of the composition [HgCl(κ²‐Et₂Dt)₂(PPh₃)] (1) is prepared. Furthermore, complex (1) is used as a synthone to prepare a novel series of complexes of the following composition [Hg(Et₂Dt)L(PPh₃)] {L = saccharinate (2), thiosaccharinate (3), benzisothiazolinate (4), benzothiozole‐2‐thiolate (5), and benzooxazole‐2‐thiolate (6) anions}. The resulted complexes (1)–(6) are characterized by elemental analysis, molar conductivity, powder X‐ray diffraction, fourier transform Infrared, and NMR (¹H and ³¹P) spectroscopic techniques. The Et₂Dt ligand is coordinated as bidentate chelate through the sulfur atoms, whereas the L ligands are bonded as monodentate ligands to afford a tetrahedral geometry around the Hg(II) ion. Nitrogen adsorption–desorption isotherm for two of as‐prepared complexes (2) and (3) are measured first to get their Brunauer–Emmett–Teller surface area. Moreover, the mentioned two complexes are evaluated for their ability to store hydrogen gas at 77 K. However, the results of the hydrogen storage tests proved that the selected complexes are all capable of storing hydrogen, but in varying degrees, where complex (2) exhibited a storage capacity of 4.22 wt% under 88 bar.

Water (W) and oil (O) normally mix during production and while passing through valves and pumps to form a persistent water-in-oil (W/O) emulsion, which is a serious restriction in oil production and transporting and refining processes. The objective of this work is to treat emulsions of two crude oil samples labeled KD1 and DGH2 using commercial polymers and surfactants which are also known as demulsifiers. Hydrophile–lipophile balance (HLB) in the demulsifier structure has demonstrated a great effect on breaking W/O emulsion. Emulsion breakers with low HLB value showed better reduction in the dynamic IFT, high diffusivity at the W/O interface, and accelerated coalescence of water droplets. Concomitantly, high emulsion temperatures were found to reduce the interfacial film viscosity and accelerate water droplets coalescence. A maximum water separation efficiency (WSE) of 97% was achieved in the case of KD1 and 88% for DGH2, and using a (1:1) polymer blend demulsifier further increased WSE to 99% after 100 min.

New liquid crystalline thiadiazole dibenzaldehyde monomers labeled as THDB1–THDB3 were successfully synthesized by alkylation of thiadiazole’s potassium salt with 4-(bromomethyl) benzaldehyde. A number of polymers consisting of thiadiazole and azomethine coded PTDAZ1–PTDAZ5 were synthesized via condensation reaction of the presynthesized monomers THDB1–THDB3 with aromatic diamines. The chemical structures of the prepared materials were confirmed using Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance techniques. The liquid crystalline behavior of the studied monomers and polymers was examined by differential scanning calorimetry and hot stage polarized optical microscopy (POM) techniques. All these compounds were found to demonstrate mesomorphic transitions belonging to smectic and nematic liquid crystals. The studied monomers exhibited fan-like texture of smectic mesophase under POM cooling investigation. Fan-like texture of smectic and nematic mesophases was observed under POM for PTDAZ1 and PTDAZ2, while PTDAZ3 and PTDAZ4 revealed clay and schlieren textures of the smectic and nematic mesophases, respectively, and nematic texture has been found for the polymer PTDAZ5.