Advanced Journal of Chemistry, Section A
Volume:2 Issue: 3, Summer 2019

The synthesis of some new cobalt (III) complexes: [Co (5-Xsalen) (PEt3)] ClO4.H2O (where X= H, NO2, Br, OMe) were synthesized and characterized using elemental analysis, 1HNMR, IR and UV-vis spectroscopy. The summarized results of these spectral evidences are in conformity with the structure of the synthesized complexes. In this study, we synthesized four novel complexes of Co (III) by the reaction of the metal ions with the salen ligands. The ligands coordinated with the metal ions through N- and O-donors. The complexes exhibited a geometry based on the coordination number 5. The results showed 1HNMR spectra of these complexes are consistent with the suggest formulation and show that the cobalt in these complexes is low spin. Its structure was established by 1HNMR, IR, and UV-visible spectroscopy.

Some thermophysical parameters of CBD and THC such as free energy, entropy, dipole moment, binding energy, nuclear energy, electronics energy, heat of formation, and chemical reactivity like HOMO (Occupied Molecular Orbital Highest) and LUMO (Lowest Unoccupied Molecular Orbital, HUMO-LUMO gap, ionization potential and electron affinity were calculated via semi-empirical and molecular mechanic method. For the characterization, the IR vibration spectroscopy, NMR in case of coupling and shielding constant were calculated. The Quantitative Structure Activity Relation (QSAR) properties of molecules like charge density, surface area grid, volume, LogP, polarizability, refractivity, molecular mass were determined using the HyperChem 8.0.10 program. Using the thermophysical and QSAR data, the IC50 and pHIC50 (–logIC50) was developed which is referred as biological activity parameter.

A new method for estimation of adsorption properties of a solid phase microextraction fiber by artificial neural network (ANN) has been studied for the first time ever. An etched steel fiber which is simple prepared and durable was selected and adsorption of 12 analytes that were in four different chemical categories, was studied. 9 of them were selected as the training and 3 as the test. The amount of adsorptions were obtained through the direct extraction from aqueous and then GC analysis. The adsorption were analyzed by ANN. The results are quite satisfactory and the mean absolute percentage error of tests was 18.0 %. The method was simple, practical, straightforward, economical, and accurate. The method did not require many analytes.

Tomato leafminers, Tuta absoluta pose a control challenge against dozens of chemical pesticides including abamectin as a result of increase in resistance with time. This study aimed at improving the field performance of abamectin using crude neem oil. The oil was obtained from the healthy neem seeds by cold pressing method. A total of 10 larvae were used in each bioassay experiment. Abamectin at 1000 ppm caused corrected mortality of 79% and its concentration that kills half of the experimental larvae (LC50) was 363 ppm. The crude neem oil at concentration of 2500 ppm caused corrected mortality of 61% with LC50 at 1089 ppm. The 1:1 mixture of abamectin and crude neem oil (without heating) at concentration of 1000 ppm gave 83% as highest corrected mortality and LC50 at 251 ppm. The findings from bioassay experiments revealed that, both neem oil and abamectin are potential pesticides; however their performance was even high after mixing. It was the synergism effect that gave the mixture high performance.

The oxidation of propane-1,3-diol by potassium permanganate in aqueous solution was investigated at λmax 525 nm. The rate of the reaction was found to increase with increase in [KMnO4] and [Propane-1,3-diol]. The reaction showed first order dependence each in [KMnO4] and [Propane-1,3-diol] and independent in the ionic strength of the solution. The values of 〖∆H〗^#(kJ mol-1), 〖∆S〗^# (kJK-1mol-1) and〖 ∆G〗^#(kJ mol-1) were 24.98, -0.22 and 90.50 respectively. Negative activation of entropy revealed an ordered transition state for the reaction. Spectroscopic studies and FTIR analysis revealed the product of the reaction to be 3-hydroxy-propanone. A suitable reaction mechanism is proposed for the reaction investigated.

Three isostructural metal-organic framework materials (MOFs) formulated as M[(HBTC)(H2O)]ˑH2O(M = Cu for 1, Zn for 2 and Ca for 3) constructed with 1, 3, 5-benzenetricarboxylate (BTC) were synthesised under hydro/solvothermal conditions. The three compounds were characterised on the basis of infrared and UV-Vis spectroscopy and the structure of 3 elucidated with the help of single-crystal x-ray crystallography. The UV-Vis spectrum of 1 exhibited a unique band at 511 nm. In the region 520 – 534 nm, the band splits into two moderately intense peaks at 527 and 531 nm. These absorption peaks along with other bands at 629 and 638 nm were assigned to d-d transitions of the copper (II) ion with distorted square planar geometry. The infrared spectra of the three compounds revealed that the ligand, BTC anion coordinated in a chelating and / or bridging mode to the metal center. The presence of absorption bands at 1699 cm-1 in 1 and 2, (1681 cm-1 in 3) can be attributed to protonated HBTC for 1-3. Single-crystal X-ray crystallographic studies of compound 3 revealed well-ordered structure with BTC ligand linking the individual chains to form a network structure. On heating Cu(HBTC)(H2O)ˑH2O up to 400oC, a copper-oxide embedded in carbon matrix was obtained with uniform particles of 10 -100 nm size.

A new, simple, accurate and sensitive UV ‐ Spectrophotometric absorbance correction method has been developed for simultaneous determination of Pyridoxine Hydrochloride and Doxylamine Succinate in bulk and in combined tablet dosage form using distilled water as a solvent. The wavelengths selected for the analysis were 260 nm and 324 nm. Both Pyridoxine hydrochloride and Doxylamine Succinate were linear over the concentration range of 5 - 40 µg/ ml and 10 - 60 µg/ ml of Doxylamine Succinate and Pyridoxine hydrochloride, respectively. The percentage recovery was found to be in the range of 99.15 ‐ 100.71% for Pyridoxine Hydrochloride and 99.30 ‐ 101.99% for Doxylamine Succinate. The %RSD for recovery studies was found to be 0.5484 and 0.9071 for Pyridoxine hydrochloride and Doxylamine Succinate, respectively for. The low %RSD of recovery studies indicated that there is no interference due to excipients used in formulation. The amount of PYRI and DOXY was found to be 100.92% ± 0.6961 and 101.05% ± 0.7965. Optical characteristics like slope, intercept, molar absorptivity, correlation coefficient, LOD and LOQ were calculated. The developed method was validated statistically by recovery studies as per ICH guidelines. The % RSD value was found to be less than 2. Thus the proposed method was simple, precise, rapid and accurate and can be successfully applied for routine quality control analysis of simultaneous determination of Pyridoxine Hydrochloride and Doxylamine Succinate in bulk and in combined tablet dosage form.

Synthesis of some novel indole derivatives has been undertaken by the reaction of poly(maleic anhydride-co-styrene), P(MA-co-St), poly(maleic anhydride-co-chloromethyl styrene), P(MA-co-CMS), poly (maleic anhydride-co-methyl methacrylate), P(MA-co-MMAc) and poly(maleic anhydride-co-methacrylate) P(MA–co–MAc), copolymers with indole in the presence of NaH at -5ºC. Compositions of the copolymers were obtained using related 1H NMR spectra and the polydispersity indices of the copolymers determined using gel permeation chromatography (GPC). The anhydride group possesses a higher reactivity with the indole group. The ring opening reaction between the anhydride group and the indole is simple and fast. All the resulted polymers were characterized by FT-IR and 1H NMR spectroscopic techniques. The glass transition temperature (Tg) of all the copolymers was determined by dynamic mechanical thermal analysis (DMTA). All the polymers containing indole groups showed a high glass transition temperature in comparison with the unmodified copolymers (I-IV). It was found that these polymers with indole moieties have high thermal stability and the presence of bulky indole groups in polymer side chains leads to an increase in the rigidity of polymers.