Vol 11, No 4 (2020)

December 2020

Table of Contents


Hakan Arslan
DOI 10.5155/eurjchem.11.4.i-ii.2052
Editorial Board
Hakan Arslan
DOI 10.5155/eurjchem.11.4.iii-vii.2053
Graphical Contents

Research Article

Arkalgud Satyanarayana Jeevan Chakravart, Suresh Hari Prasad
DOI 10.5155/eurjchem.11.4.261-275.2020

2-Chloro-3-tosyl-5,5-dimethyl-2-cyclohexenone was subjected to a series of regiospecific Suzuki-Miyaura cross-coupling reactions in suspensions of nine different substituted boronic acids, Pd(OAc)2, P(Ph3)3, K3PO4 and 1,4-dioxane solvent, under sealed tube conditions. The regiospecific substitution of the tosyl-group by the aryl group in preference over the chloride- group was observed. A comparison between the bromo- and tosylate group’s reactivities is highlighted. Using the methodology, the products: 2-chloro-3-aryl-5,5-dimethyl-2-cyclohexenones were isolated in greater than 85% yields. Good quality crystals of three representative compounds were obtained by slow evaporation technique and subjected to single crystal XRD studies, Hirshfeld surface analysis, 3-D energy framework, and molecular docking studies. Crystal data for compound 3; C15H17ClO4S: monoclinic, space group P21/c (no. 14), a = 8.8687(3) Å, b = 10.5537(4) Å, c = 16.6862(7) Å, β = 89.807(3)°, V = 1561.78(10) Å3, Z = 4, T = 290 K, μ(MoKα) = 0.390 mm-1, Dcalc = 1.398 g/cm3, 13623 reflections measured (6.716° ≤ 2Θ ≤ 54.962°), 3570 unique (Rint = 0.0467, Rsigma = 0.0512) which were used in all calculations. The final R1 was 0.0452 (I > 2σ(I)) and wR2 was 0.1019 (all data). Crystal data for compound 5e; C20H18O2FCl: monoclinic, space group P21/c (no. 14), a = 6.4900(5) Å, b = 18.6070(13) Å, c = 14.2146(11) Å, β = 102.324(2)°, V = 1677.0(2) Å3, Z = 4, T = 296(2) K, μ(MoKα) = 0.239 mm-1, Dcalc = 1.309 g/cm3, 25575 reflections measured (6.262° ≤ 2Θ ≤ 52.224°), 3283 unique (Rint = 0.0494, Rsigma = 0.0307) which were used in all calculations. The final R1 was 0.0875 (I > 2σ(I)) and wR2 was 0.2056 (all data). Crystal data for compound 5h; C12H13OSCl: triclinic, space group P-1 (no. 2), a = 6.7517(6) Å, b = 8.8376(9) Å, c = 12.6049(12) Å, α = 109.538(3)°, β = 98.597(3)°, γ = 90.417(3)°, V = 699.52(12) Å3, Z = 2, T = 290 K, μ(MoKα) = 0.410 mm-1, Dcalc = 1.376 g/cm3, 28754 reflections measured (6.114° ≤ 2Θ ≤ 59.288°), 3898 unique (Rint = 0.0544, Rsigma = 0.0349) which were used in all calculations. The final R1 was 0.1101 (I > 2σ(I)) and wR2 was 0.2481 (all data).

Gajanan Gopinath Mandawad, Baseer Mubeen Shaikh, Santosh Subhash Chobe, Shankaraiah Guruvaiah Konda
DOI 10.5155/eurjchem.11.4.276-279.2009

A simple and eloquent procedure for the synthesis of a new series of thienyl benzo[b]1,4-diazepines is reported. They were synthesized by the condensation of o-phenylenediamine (o-PDA) with distinct hetero chalcones using NaOH in polyethylene glycol (PEG-400) as green and alternative reaction solvent. The significances of this present method are shorter reaction time, easy work-up, high yields, and mild reaction conditions. Furthermore, this method is environment friendly and without use of an expensive catalyst. The all newly synthesized compounds are characterized by the spectroscopic methods.

Vaishali Yogesh Londhe, Sreevidya Ramesh Krishnan
DOI 10.5155/eurjchem.11.4.280-284.2010

Ziprasidone (ZPR) is an antipsychotic agent having less solubility. It is used for the treatment of schizophrenia. Complexation of hydrophobic drugs with cyclodextrins leads to enhanced solubility and dissolution. In this study, inclusion complexes were prepared by different methods, using ZPR, β-cyclodextrin (β-CD), and different auxiliary agents like hydrophilic polymer and hydroxy acid (1:1:0.5) to improve the aqueous solubility. The characterization of the ternary complexes was carried out using solubility study, Differential scanning calorimetry (DSC), Powder X-ray diffraction (PXRD), Fourier transformation infrared spectroscopy (FT-IR) and in vitro dissolution studies. DSC, XRD, and FT-IR studies showed interaction in drug, cyclodextrin, and auxiliary agents which are confirmed by enhancement of solubility and dissolution. Spray-dried dispersion showed less crystallinity and higher solubility as compared to the kneading method for both citric acid and Lutrol® F-68. Thus, the investigation concludes that the presence of the auxiliary agent has a synergistic action on complexation with cyclodextrin, which helps to modify the physicochemical properties of the drug.

Thierno Moussa Seck, Fatou Dieng Faye, Aissatou Alioune Gaye, Ibrahima Elhadji Thiam, Ousmane Diouf, Mohamed Gaye, Pascal Retailleau
DOI 10.5155/eurjchem.11.4.285-290.2023

Carbonohydrazide was used for synthetizing a new dissymmetrical bis-substituted Schiff base 1-(2'-hydroxybenzylidene)-5-(1'-pyridylethylidene)carbonohydrazone (2). A mono substituted compound (1-(pyridin-2-yl)ethylidene)carbonohydrazide (1) was firstly prepared by condensation reaction of carbonohydrazide and 2-acetylpyridine in 1:1 ratio. Secondly, compound 2 was obtained by condensation reaction of compound 1 and salicylaldehyde in 1:1 ratio. The prepared compounds were characterized by elemental analysis, infrared and 1H and 13C NMR spectroscopy techniques, and the structure of compound 2 was determined by single-crystal X-ray diffraction study. The compound 2 (C15H15N5O2) crystallises in the monoclinic space group P21/c with the following unit cell parameters: a = 8.3683(3) Å, b = 13.9986(4) Å, c = 12.1610(4) Å, β = 97.512(3)°, V = 1412.37(8) Å3, Z = 4, T = 100(2) K, μ(MoKα) = 0.098 mm-1, Dcalc = 1.398 g/cm3, 6057 reflections measured (5.708° ≤ 2Θ ≤ 54.962°), 6057 unique (Rsigma = 0.0395) which were used in all calculations. The final R1 was 0.0474 (I > 2σ(I)) and wR2 was 0.1971 (all data). The oxygen atom O1 and the azomethine nitrogen atom N5 adopt cis-configuration relative to the C8-N4 bond, while O1 adopts trans-configuration with the azomethine nitrogen atom N2 relative to C8-N3 bond. The crystal packing of compound 2 is stabilized by intramolecular O(phenol)–H···N(carbohydrazide) and intermolecular N (carbohydrazide)–H···O (carbo-hydrazide) hydrogen bonds which form layers parallel to [010] axis. Additional C–H···O hydrogen bond consolidate the structure. The carbonohydrazide moiety C=N–N–C(O)–N–N=C fragment and the phenyl ring are almost coplanar; with an angle of 1.73(1)° between their means plans. The dihedral angle between the mean planes of the phenyl and the pyridine rings is 22.267(2)°.

Hutaf Mustafa Baker, Hussam Ahmad Alsaoud, Hamzeh Mohamad Abdel-Halim
DOI 10.5155/eurjchem.11.4.291-297.2002

A simple, sensitive and reproducible method for the determination of ranitidine hydrochloride in pharmaceutical preparations was investigated. This spectrophotometric method was based on the formation of a deep red color product with ninhydrin in basic media and the absorbance measured at λmax = 480 nm. The reaction occurs at 45 °C with pH = 10 having a contact time of 38 minutes. Under the optimum conditions, Beer’s Law is obeyed in the concentration range of 8.98×103 - 9.90×104 µg/L. The coefficient of correlation was found to be 0.999 for the obtained method with molar absorptivity of 3.05×103 L/mol.cm. The calculated Sandell’s sensitivity is 0.108 μg/cm2. The limit of detection and limit of quantification are 0.0997 and 0.3023 µg/mL, respectively. The low values of the percentage relative standard deviation and percentage relative error indicate the high precision and the good accuracy of the proposed method. The stoichiometry of the reaction is determined and found to be 1:4 (Ranitidine hydrochloride:Ninhydrin). The initial rate method confirmed that this reaction is first order one.

Alina Madalina Darabut, Olha Hennadiivna Purikova, Yevheniia Volodymyrivna Lobko
DOI 10.5155/eurjchem.11.4.298-303.2032

In this work, two types of azobenzene derivatives based on Disperse Yellow 7 (DY7, 4-[4-(phenylazo)phenylazo]-o-cresol) were synthesized, which are bis-azobenzenes bearing flexible functional 6-bromohexyl chain or carboxylic acid moiety. The first one was synthesized by alkylation of DY7 with an excess of 1,6-dibromohexane in the presence of a mild base (K2CO3). The second one (azo dye with carboxylic acid functionality) was obtained by the alkaline hydrolysis of the ester bond of the newly obtained DY7 derivative with the ethoxycarbonyl group. The synthesized compounds were characterized by different spectral analytical techniques such as 1H NMR, 13C NMR, FT-IR, and UV-Vis. They can be employed for the synthesis of a wide variety of azo-based materials, which may be suitable for photochromic systems and molecular electronics applications.

Susma Das, Shilpika Khanikar, Shunan Kaping, Jayanti Datta Roy, Arnab Sen, Philippe Helissey, Jai Narain Vishwakarma
DOI 10.5155/eurjchem.11.4.304-313.2033

A green synthetic route leading to the discovery of a series of diversely substituted pyrazolo[1,5-a]pyrimidines, having CO2Et group embedded at position-2 has been unraveled in this article. A series of formylated active proton compounds that were chosen to react with a carboxylate substituted-3-aminopyrazole under ultrasonic irradiation in the presence of a mild acid as a catalyst and aqueous ethanol medium afforded the desired products. The molecular structures of all these synthesized compounds were established by their spectral and analytical data. A model molecule 3d, subjected to single-crystal X-ray crystallography analysis further confirms their molecular structure. The crystal crystallized to a monoclinic cell with P21/c space group, a = 7.468 (5) Å, b = 27.908 (17) Å, c = 7.232 (4) Å, β = 104.291 (7)o, V =1460.7(15) Å3, Z = 4, μ(MoKα) = 0.096 mm-1, Dcalc = 1.352 Mg/m3 16667 measured reflection (5.63 ≤ 2Θ ≤ 57.57°), 3720 unique (Rint = 0.0965, Rsigma = 0.0945) which were used in all calculations. The final R1 was 0.0750 (I > 2σ(I)) and wR2 was 0.2226 (all data). These compounds were further explored for their antibacterial potential, and a few of them have exhibited encouraging results.

Mina Mikhael, Mary Hanna, Evana Halaka, Ivan Bernal, Roger Lalancette
DOI 10.5155/eurjchem.11.4.314-318.2022

We are evaluating the proposition that compounds with pronounced tendencies to crystallize as kryptoracemates contain molecular fragments responsible for such a property. Why Sohncke space groups display such a tendency is not currently known, but one such fragment is the [tris(2-aminoethyl)amine-N,N',N'',N'''] ligand when attached to cobalt(III). Therefore, proceeding to test the concept further, we examined the title compound and found a previously unknown kryptoracemic species, described in what follows. It seems then that the prescription has some merit and should be examined further inasmuch as guidelines for the occurrence of kryptoracemic crystallization are scant, if any exist. Crystal data for C6H20Cl3CoN4O: monoclinic, space group P21 (no. 4), a = 7.6672(3) Å, b = 15.7153(5) Å, c = 10.7170(4) Å, β = 92.964(2)°, V = 1289.59(8) Å3, Z = 4, T = 100(2) K, μ(CuKα) = 16.026 mm-1, Dcalc = 1.697 g/cm3, 13406 reflections measured (8.26° ≤ 2Θ ≤ 133.402°), 3976 unique (Rint = 0.0300, Rsigma = 0.0519) which were used in all calculations. The final R1 was 0.0220 (I > 2σ(I)) and wR2 was 0.0459 (all data).

Cemal Koray Ozer, Gun Binzet, Hakan Arslan
DOI 10.5155/eurjchem.11.4.319-323.2047

Herein, we describe the synthesis and characterization of bis(N-(diethylcarbamothioyl)cyclohexane carboxamido)copper(II) complex, cis-[Cu(L-κ2S,O)2], has been prepared by the reaction of N-(diethyl carbamothioyl)cyclohexanecarboxamide ligand with copper(II) acetate. The green colored crystals of the complex were obtained by slow evaporation of their dichloromethane:ethanol solution (2:1, v:v). The crystal structure of cis-[Cu(L-κ2S,O)2] was obtained by single-crystal X-ray diffraction. The crystal structure reveals an monoclinic C2 (no. 5) space group with cell parameters a = 14.848(3) Å, b = 10.543(2) Å, c = 10.511(2) Å, β = 123.84(3)°, = 1366.7(7) Å3, Z = 2, T = 153(2) K, μ(MoKα) = 0.979 mm-1, Dcalc = 1.327 g/cm3, 4979 reflections measured (6.6° ≤ 2Θ ≤ 50.68°), 2243 unique (Rint = 0.0223, Rsigma = 0.0444) which were used in all calculations. The final R1 was 0.0225 (>2sigma(I)) and wR2 was 0.0490 (all data). The angular structural index parameter, τ4, is equal to 0.40, which confirms the distorted square planar geometry for the title compound. The puckering parameters (q2 = 0.015(3) Å, q3 = 0.576(3) Å, QT = 0.577(3) Å, θ = 1.6(3)° and φ = 20(11)°) of the title complex show that the cyclohexane ring adopts a chair conformation. The two ethyl groups of the diethyl amine group have anti-orientation with respect to one another. The crystal packing shows the molecules stacked in parallel sheets along [010], accompanied by C3-H3A···O1ⁱ (i -x, +y, 1-z) intermolecular contact.

Gopal Sharma, Anshul Uppal, Sumati Anthal, Madhukar Baburao Deshmukh, Priyanka Pandharinath Mohire, Tanaji Ramchandra Bhosale, Chellappanpillai Sudarsanakumar, Rajni Kant
DOI 10.5155/eurjchem.11.4.324-333.2028

A combined theoretical and experimental investigation on a pharmaceutically important binary complex 3,3'-[(3-benzimidazolyl)methylene]bis(4-hydroxy-2H-1-benzopyran-2-one): 5-methyl-1,3-thiazol-2(3H)-imine is presented in this manuscript. The compound crystallizes in the monoclinic crystal system with space group Cc with unit cell parameters: a = 19.8151(8) Å, b = 15.2804(6) Å, c = 8.3950(4) Å, β = 94.0990(10)°, = 2535.36(19) Å3, Z = 4, T = 296(2) K, μ(MoKα) = 0.184 mm-1, Dcalc = 1.490 g/cm3, 35833 reflections measured (5.332° ≤ 2Θ ≤ 56.678°), 6168 unique (Rint = 0.0467, Rsigma = 0.0388) which were used in all calculations. The final R1 was 0.0435 (I > 2σ(I)) and wR2 was 0.1073 (all data). The crystal structure has been determined by the conventional X-ray diffraction method, solved by direct methods and refined by the full matrix least squares procedure. Intramolecular hydrogen bonding of the type C–H⋅⋅⋅O and O–H⋅⋅⋅O is present and the crystal structure stabilizes via N–H…O, C–H…N and O–H…N intermolecular interactions. The optimized structural parameters have been compared and the parameters like ionization potential, electron affinity, global hardness, electron chemical potential, electronegativity, and global electrophilicity based on HOMO and LUMO energy values were calculated at B3LYP/6-311G(d,p) level of theory for a better understanding of the structural properties of the binary complex.

Jahangir Mondal, Amit Kumar Manna, Goutam Kumar Patra
DOI 10.5155/eurjchem.11.4.334-341.2037

Three new halide bridged copper(I)complexes [Cu2(µ-L)(µ-X)2)(PPh3)2]n {X: I (1), Br (2) and Cl (3)} have been synthesized by the reaction of Cu(I)X (X: I, Br and Cl) with PPh3 and the polydentate imino-pyridyl ligand L. Interestingly, copper(I) forms coordination polymers with the ligand L and the co-ligand PPh3. These complexes 1, 2 and 3 have been characterized by elemental analysis, IR, UV-Vis, and NMR spectroscopy. The crystal structure of the complex 2 has been determined by single-crystal X-ray analysis. Crystal data for complex 2: triclinic, space group P-1 (no. 2), a = 9.471(10) Å, b = 11.043(11) Å, c = 13.215(18) Å, α = 65.853(18)°, β = 69.94(2)°, γ = 67.350(14)°, = 1135(2) Å3, Z = 2, T = 296.15 K, μ(MoKα) = 2.806 mm-1, Dcalc = 1.535 g/cm3, 4059 reflections measured (3.462° ≤ 2Θ ≤ 44.818°), 2639 unique (Rint = 0.0637, Rsigma = 0.1621) which were used in all calculations. The final R1 was 0.0700 (I > 2σ(I)) and wR2 was 0.2207 (all data). Hirshfeld surface analysis of the complex 2 showed H···H, N···H and Br···H interactions of 55.9, 14.4 and 4.1%, respectively. MEP of ligand L reflects the whole molecule is reddish yellow in color because of equally distributed electron density over the molecule. For this reason, the ligand is supramolecularly arranged via -{CuI2-µ-X2} rhomboid core in the complex 2. The ligand L is non-emissive at room temperature in dichloromethane, whereas the complexes 1, 2 and 3 are photoluminescent. DFT and Hirshfeld surface studies have also been performed for complex 2.

Toyese Oyegoke, Fadimatu Nyako Dabai, Adamu Uzairu, Baba El-Yakubu Jibril
DOI 10.5155/eurjchem.11.4.342-350.2045

A preliminary study to provides insight into the kinetic and thermodynamic assessment of the reaction mechanism involved in the non-oxidative dehydrogenation (NOD) of propane to propylene over Cr2O3, using a density functional theory (DFT) approach, has been undertaken. The result obtained from the study presents the number of steps involved in the reaction and their thermodynamic conditions across different routes. The rate-determining step (RDS) and a feasible reaction pathway to promote propylene production were also identified. The results obtained from the study of the 6-steps reaction mechanism for dehydrogenation of propane into propylene identified the first hydrogen abstraction and hydrogen desorption to be endothermic. In contrast, other steps that include propane’s adsorption, hydrogen diffusion, and the second stage of hydrogen abstraction were identified as exothermic. The study of different reaction routes presented in the energy profiles confirms the Cr-O (S1, that is, the reaction pathway that activates the propane across the Cr-O site at the alpha or the terminal carbon of the propane) pathway to be the thermodynamically feasible pathway for the production of propylene. The first hydrogen abstraction step was identified as the potential rate-determining step for defining the rate of the propane dehydrogenation process. This study also unveils that the significant participation of Cr sites in the propane dehydrogenation process and how the Cr high surface concentration would hinder the desorption of propylene and thereby promote the production of undesired products due to the stronger affinity that exists between the propylene and Cr-Cr site, which makes it more stable on the surface. These findings thereby result in Cr-site substitution suggestion to prevent deep dehydrogenation in propane conversion to propylene. This insight would aid in improving the catalyst performance.

Harindu Rajapaksha, Bingun Tharusha Perera, Jeewani Meepage, Ruwan Tharanga Perera, Chithramala Dissanayake
DOI 10.5155/eurjchem.11.4.351-363.2043

The novel corona virus 2019 (COVID 19) is growing at an increasing rate with high mortality. Meanwhile, the cytokine storm is the most dangerous and potentially life-threatening event related to COVID 19. Phyto-compounds found in existing Ayurveda drugs have the ability to inhibit the Interleukin 6 (IL-6R) and Interleukin 1 (IL-1R) receptors. IL-6R and IL-1R receptors involve in cytokine storm and recognition of phytochemicals with proven safety profiles could open a pathway to the development of the most effective drugs against cytokine storm. In this study, we intend to perform an in silico investigation of effective phyto compounds, which can be isolated from selected medicinal herbs to avoid cytokine storm, inhibiting the IL-6 and IL-1 receptor binding process. An extensive literature survey followed by virtual screening was carried out to identify phytochemicals with potential anti-hyper-inflammatory action. Flexible docking was conducted for validated models of IL-1R and IL-6R-α with the most promising phytochemicals at possible allosteric sites using AutoDock Vina. Molecular dynamics (MD) studies were conducted for selected protein-ligand complexes using LARMD server and conformational changes were evaluated. According to the results, taepeenin J had Gibbs energy (ΔG) of -10.85 kcal/mol towards IL-1R but had limited oral bioavailability. MD analysis revealed that taepeenin J can cause significant conformational movements in IL-1R. Nortaepeenin B showed a ΔG of -8.5 kcal/mol towards IL-6R-α with an excellent oral bioavailability. MD analysis predicted that it can cause significant conformational movements in IL-6R-α. Hence, the evaluated phytochemicals are potential candidates for further in vitro studies for the development of medicine against cytokine storm on behalf of SARS-COV-2 infected patients.

Amadou Diop, Serigne Omar Sarr, Awa Boubou Sall, Ousmane Niass, Bara Ndiaye, Yerim Mbagnick Diop
DOI 10.5155/eurjchem.11.4.364-369.2046

Cucurbits are largely grown in tropical and subtropical areas for nutritional and medicinal purposes. In Senegal, two species, watermelon (Citrullus lanatus) and pumpkin (Cucurbita pepo), are cultivated and their use include consumption of flesh or the whole fruit. In general, people don’t give importance to seeds which can have nutritional properties of great interest. Hence, the relevance of this study whose objective is to assess the nutritional and therapeutic properties of seeds. For that purpose, the seeds of watermelon and pumpkin were air-dried, manually shelled, ground, and subjected to assays including physicochemical determination, characterization of oils, phytochemical screening and antioxidant analysis. Proteins (28.46 - 32.85 %), fat (36.3 - 39.7 %) and carbohydrates (23.6 - 13.9 %) were the main chemical components found in watermelon and pumpkin seeds. Micro-elements such as potassium, magnesium, phosphorous, calcium, and iron were also found with potassium showing the highest levels as 1026.07 and 635.00 mg/100 g for watermelon and pumpkin, respectively. Magnesium and phosphorous were the following minerals in terms of level content. The unsaturated fatty acids (UFAs) were predominant in seed oils with the linoleic acid most representative as 73.01 and 35.90% for watermelon and pumpkin, respectively. From the saturated fatty acids (SFAs), the palmitic acid was the most important. Phytochemical components in seeds include the presence of alkaloids, cardiac glycosides, flavonoids, and tannins in the ethanolic extracts of pumpkin and watermelon seeds. Regarding to the radical scavenging activity, relatively close values have been obtained for fractions from the ethanolic watermelon extract, the aqueous fraction showing the highest antioxidant activity (26.82%). For pumpkin, the highest values were registered for ethyl acetate and aqueous fractions as 36.17 and 35.36%, respectively. Therefore, seeds from watermelons and pumpkin cultivated in Senegal exhibited interesting nutritional and antioxidant properties which argue in favor of their use to overcome malnutrition issues.

Gun Binzet, Riza Binzet, Hakan Arslan
DOI 10.5155/eurjchem.11.4.370-376.2048

This study reports on the chemical compositions of the essential oil of Rosmarinus officinalis L. (Rosemary) grown in Mersin, Turkey. The essential oil of rosemary was obtained by hydrodistillation method, and the yield of rosemary oil was found to be about 1.2 % (v:w). The hydrodistilled volatile oil was analyzed by gas chromatography and mass spectrometry techniques. Forty-five components were identified in the essential oil of R. officinalis, which represented 100% of the total essential oils. The oxygenated monoterpenes content possessed the highest value, 64.78% of the oil, among which eucalyptol (33.15%) and camphor (10.31%) were the most abundant components. In addition, the oil contained mainly monoterpene hydrocarbons, sesquiterpene hydrocarbons, oxygenated sesquiterpenes, and diterpenes. The least amount of diterpenes were found in the content of the oil. Isopimara-9 (11),15-diene (0.14%) and α-springene (0.06%) were two compounds determined as diterpene compounds.

Samina Karimkha Tadavi, Ratnamala Subhash Bendre, Satish Vittal Patil, Shubha Gaguna, Jamatsing Darbarsing Rajput
DOI 10.5155/eurjchem.11.4.377-384.2040

Palladium complexes of sulfonyl hydrazone based ligands have been prepared by refluxing with the corresponding ligands and Pd(II) salt in 2:1 ratio. The compounds have been characterized by FT-IR and UV-Vis spectroscopic methods. The crystal structure of the prepared palladium complexes has been determined by single-crystal X-ray crystallographic technique. Crystal data for C40H50N4O6PdS2 (PMHT-Pd(II) complex): triclinic, space group P-1 (no. 2), a = 7.1561(6) Å, b = 12.1300(11) Å, c = 12.6117(17) Å, α = 63.498(11)°, β = 86.694(9)°, γ = 81.451(7)° and Z = 1. The final R1 was 0.0699 (I > 2σ(I)) and wR2 was 0.1834 (all data). Crystal data for C36H42N4O6PdS2 (PTHC-Pd(II) complex): monoclinic, space group P21/n (no. 14), a = 8.6726(2) Å, b = 20.8824(4) Å, c = 10.3351(2) Å, β = 104.429(2)° and Z = 2. The final R1 was 0.0344 (I > 2σ(I)) and wR2 was 0.0840 (all data). Crystal data for C36H42N4O6PdS2 (PTHT-Pd(II) complex): monoclinic, space group P21/n (no. 14), a = 9.7658(2) Å, b = 10.0488(3) Å, c = 18.7714(4) Å, β = 99.602(2)° and Z = 2. The final R1 was 0.0334 (I > 2σ(I)) and wR2 was 0.0832 (all data). Crystal data for C40H50N4O6PdS2 (PMHC-Pd(II) complex): triclinic, space group P-1 (no. 2), a = 10.2070(9) Å, b = 12.1841(13) Å, c = 16.8879(19) Å, α = 109.005(6)°, β = 90.061(5)°, γ = 99.032(5)° and Z = 2. The final R1 was 0.0822 (I > 2σ(I)) and wR2 was 0.2293 (all data). The single-crystal structure data showed a good agreement with the experimental results. The synthesized complexes were screened for their in vitro antibacterial activity against one Gram-negative (Escherichia coli) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and for in vitro antifungal activity against Aspergillus niger, Aspergillus flavus and Aspergillus fumigatus. The PTHC-Pd(II) complex possesses the nearby significant antifungal activity analogous to the standard drug fluconazole against selected fungal strains Aspergillus niger, Aspergillus Flavus and Aspergillus fumigatus as well as the same complex showed the antibacterial activity for Staphylococcus aureus as comparable to standard ofloxacin drug.

Shaifa Abrarin, Mohammed Jamaluddin Ahmed
DOI 10.5155/eurjchem.11.4.385-395.2030

A very simple, non-extractive and new spectrophotometric method for the swift determination of trace amount of vanadium using salicylaldehyde-benzoylhydrazone (Sal-BH) has been developed. Sal-BH undergoes a reaction in a slightly acidic solution (0.0016-0.0032 M H2S04) with vanadium to give a light greenish-yellow chelate, which has an absorption maximum at 392 nm. The reaction is instantaneous and absorbance remains stable for over 24 hrs. The average molar absorption co-efficient and Sandell’s sensitivity were found to be 2.5039×105 L/mol.cm and 1.0 ng/cm2 V, respectively. Beer’s law was obeyed for 0.001-30 mg/L of V, providing a detection limit of 0.1 µg/L of V and RSD 0-2 %. The stoichiometric composition of the chelate is 1:1 (V:Sal-BH). Interference study shows that a large excess of over 60 cations, anions, and some common complexing agents (such as chloride, azide, tartrate, EDTA and SCN, etc.) satisfy the tolerance limit. The developed method was successfully used in the determination of vanadium in several standard reference materials as well as in some environmental waters, biological fluids, soil, food and pharmaceutical samples and solutions containing both vanadium (IV) and vanadium (V). The results of the proposed method for assessing biological, food and vegetable samples were comparable with ICP-OES and AAS were found to be in excellent agreement. The method has high precision and accuracy (s = ±0.01 for 0.5 mg/L).