Two new hydralazine hydrochloride-derived Schiff bases</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">:</span></span><span style="...Two new hydralazine hydrochloride-derived Schiff bases</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">:</span></span><span style="font-family:Verdana;"> (E)-1-(Phthalazin-</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">1-yl)-1-[(Pyridin-2-yl)Ethylidene]Hydralazine (PPEH), and 1-[2-(1-(pyridine-</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">3</span><span style="font-family:Verdana;">-yl)ethylidene)hydrazinyl]phthalazine (PEHP), were synthesized and partially characterized by spectroscopic and crystallographic methods including IR and X-ray. The single-crystal X-ray diffraction (SCXRD) analysis of PEHP indicate</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span><span style="font-family:Verdana;"> that the hydralazine moiety of both ligands possess</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">es</span></span><span style="font-family:Verdana;"> the exoc</span><span style="font-family:Verdana;">yclic C=N bond. Both, PPEH and PEHP were tested as antimicrobials and antiparasites. Just PEHP could be considered as slightly antiplasmodial and antibacterial agent. In effect, PPEH showed low antimicrobial activity against one bacterial strain with Minimum Inhibitory Concentration (MIC) value of 250 μg/ml while PEHP showed very interesting activity against 18 out of 19 bacterial strains with MIC of 31.25 </span><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span><span style="font-family:Verdana;"> 250 μg/ml compared to the standard drug, amoxicillin. PPEH and PEHP showed higher reducing activity on ferric ions compared to Vitamin C. On the other hand, both hidrazaline synthetized derivatives show</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">ed</span></span><span style="font-family:Verdana;"> as better reducing agents than Vitamin C on ferric ions, while again, only the PEHP show</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">ed</span></span><span style="font-family:Verdana;"> slightly high inhibition of lipid peroxidation using Vitamin C as standard. Regarding their catalase activity, both compounds show</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">ed</span></span><span style="font-family:Verdana;"> concentration dependent effect, but Vitamin C continued showing a higher stimulatory effect on the enzyme activity. Additionally, while PPEH showed less than 80% inhibition in the preliminary antiplasmodial assay and so was not considered for the dose-response studies, PEHP</span><span style="font-family:Verdana;"> displayed an inhibition percentage of 83.60% and 50% Inhibitory Concentration (IC</span><sub><span style="font-family:Verdana;vertical-align:sub;">50</span></sub><span style="font-family:Verdana;">) value of 44.13 μg/mL compared to the standard drug, artemisinin and was classified as slightly active</span><span style="font-family:Verdana;">.展开更多
This study examined the sanitary conditions of public boreholes and hand dug wells water in relation to pathogenic bacteria isolated in water samples. To assess the suitability of drinking water, sanitary inspection o...This study examined the sanitary conditions of public boreholes and hand dug wells water in relation to pathogenic bacteria isolated in water samples. To assess the suitability of drinking water, sanitary inspection of surroundings of the sources was conducted, membrane filtration technic was used to trap the microorganisms in the water sample and other standard microbiological technics were applied to check the heterotrophic plate counts, total coliforms, fecal coliforms and some pathogenic bacteria in the samples. It was observed that there were no delineated protection zones around many boreholes (61.19%) and in almost all hand dug wells;thus, hand dug wells were pruned to more contamination than boreholes. Heterotrophic plate counts of boreholes were significantly different between (p < 0.0001) zones in dry and rainy seasons. Total coliforms per 100 ml varied significantly (p < 0.001) between the two seasons both in boreholes and hand dug wells. Fecal coliforms were significantly absent in some boreholes, but significantly present in all hand dug wells with the presence of <i>E. coli</i> 157H in some. Risk assessment of factors contributing to water contamination showed that: pumps manipulation with feet, other sources of contamination such as wastewater dumps, within 10m were significantly associated to boreholes contamination with <i>Salmonella</i> spp, <i>Staphylococcus aureuse</i>, fecal coliform (p = 0.01);in hand dug wells, presence of latrine or septic tank soak-away within 10 m of the wells, poor depth and lack of internal lining, uncapped wells, presence of trees near the wells, animal and birds feces, were significant and associated to contamination with <i>Salmonela</i> spp., <i>B. cepaceae, S. aureus E. coli</i> 1 (p < 0.05). Generally water collection points are marked with very poor sanitary conditions and this situation may not change unless the contaminating risk factors are fixed and sanitary measures are taken.展开更多
A novel chiral Nickel (II) complex of N-(2-pyridylmethyl)-L-alanine (Hpyala) <b>1</b> has been prepared and structurally characterized by elemental analysis, FT-IR, UV-visible, TGA and single crystal X-ray...A novel chiral Nickel (II) complex of N-(2-pyridylmethyl)-L-alanine (Hpyala) <b>1</b> has been prepared and structurally characterized by elemental analysis, FT-IR, UV-visible, TGA and single crystal X-ray diffraction techniques. Complex <b>1</b> crystallizes in an orthorhombic P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub> space group. The nickel (II) centre in the complex adopts a distorted octahedral geometry. This compound has been seen to exhibit structural diversity resulting from the number of lattice water molecules. The photoluminescent properties of this compound which have also been investigated, indicates the potential application in luminescence.展开更多
The novel ligand, 1-(phthalazin-1(2H)-one)[(pyridin-2-yl)ethylidene]hydrazone,(APN), derived from the antihypertensive drug, hydralazine hydrochloride, was synthesized and characterized by spectroscopic methods (IR, 1...The novel ligand, 1-(phthalazin-1(2H)-one)[(pyridin-2-yl)ethylidene]hydrazone,(APN), derived from the antihypertensive drug, hydralazine hydrochloride, was synthesized and characterized by spectroscopic methods (IR, 1H NMR). The X-ray crystallographic data indicates that APN has an exocyclic C=N bond on the hydralazine moiety. APN revealed significant anti-onchocercal activity with IC50 values of 0.3125 μg/mL on microfilaria and 10 μg/mL on adult worms compared to the standard drug, ivermectin.展开更多
Uncontrolled uses of antibiotics have led to rapid evolution of antibiotic-resistance bacteria and antibiotic resistance gene transfer, especially in a pool of aquatic system where resistance, intermediate and suscept...Uncontrolled uses of antibiotics have led to rapid evolution of antibiotic-resistance bacteria and antibiotic resistance gene transfer, especially in a pool of aquatic system where resistance, intermediate and susceptible bacteria to some antibiotics strive together. Consequently, there is a transfer of resistance genes. In this study, bacteria of the Enterobacteriaceae family and some gram positive bacteria isolated from some boreholes and hand dug wells water of public use were tested on 19 antibiotics of different classes. This was achieved through a disk diffusion technique to determine the antimicrobial resistance profile of the said bacteria, microbial resistance index of the drugs used (and their ability to produce Beta-lactamase). These isolates were shown to demonstrate a very high resistance to the drugs used in the area. The resistance was highest in Escherichia coli 1 (73.68%) and lowest in Streptococcus pneumoniae (47.82%). These isolates also indicated very high levels of multi-drug resistance. The minimum resistance index was 0.47, indicating that bacteria isolates were of fecal origin. It is evident from the present study that multiple antibiotic-resistant bacteria can thrive in water as an environmental reservoir, and can therefore provide a route to multidrug-resistant pathogens to enter human and animal population.展开更多
A novel ligand N-4-hydroxyacetophenone isonicotinoyl hydrazone and its manganese(II) and nickel(II) metal complexes have been synthesized. The synthesized Schiff base and its metal complexes have been characterized by...A novel ligand N-4-hydroxyacetophenone isonicotinoyl hydrazone and its manganese(II) and nickel(II) metal complexes have been synthesized. The synthesized Schiff base and its metal complexes have been characterized by physical state determination, melting point and solubility measurements in different solvents, infrared, proton nuclear magnetic resonance, mass spectrometric and powder X-ray spectroscopic techniques. The thermal properties of the prepared compounds were obtained from TG/DTG measurements. On the basis of the analytical techniques, the ligand was found to be bidentate in nature coordinating to the metal ions through the azomethine nitrogen and carbonyl oxygen atoms leading to distorted octahedral geometries of the metal complexes which were modeled using MM2 force field. The ligand and its metal(II) complexes were evaluated for antifungal activity against <i>Aspergillus fumigatus, Aspergillus niger, Candida albicans and Rhizopus stolonifera.</i> The antifungal evaluation results revealed an enhanced activity upon coordination of the ligand with the metal(II) ions. The activity of the metal complex to the tested fungal strains was in the order Ni(II) > Mn(II).展开更多
A novel Schiff base, benzylmethyl-4-methyl-3-thiosemicarbazone (BMM) de-rived from benzylmethylketone and 4-methylthiosemicarbazide was synthe-sized and characterized by elemental analysis, spectroscopic methods (IR, ...A novel Schiff base, benzylmethyl-4-methyl-3-thiosemicarbazone (BMM) de-rived from benzylmethylketone and 4-methylthiosemicarbazide was synthe-sized and characterized by elemental analysis, spectroscopic methods (IR, 1H NMR, 13C NMR) and physical means. The single crystal structure analysis of the Schiff base reveals that it crystallizes in a monoclinic system in the P21/c space group. BMM revealed moderate antibacterial activity on three bacterial strains with diameter zone of inhibition of 16 mm (E. coli), 14 mm (K. pneumonia) and 13 mm (S. epider-midis) compared with the standard drug, ciprofloxacin.展开更多
Reaction of Ba0.50[Ag2Cr(C2O4)3]·5H2O with Ag2SO4 in an aqueous solution of sulfuric acid (pH ≈ 3) yielded the silver(I)/chromium(III) oxalate salt H0.50[Ag2.50Cr(C2O4)3]·5H2O (1). Compound 1 can be best de...Reaction of Ba0.50[Ag2Cr(C2O4)3]·5H2O with Ag2SO4 in an aqueous solution of sulfuric acid (pH ≈ 3) yielded the silver(I)/chromium(III) oxalate salt H0.50[Ag2.50Cr(C2O4)3]·5H2O (1). Compound 1 can be best described as an anionic silver-deficient oxalatochromate(III) complex [Ag2.50Cr(C2O4)3]0.5- with nanochannels containing hydrogen-bonded water molecules and protons. Thermal analyses show significant weight losses corresponding to the elimination of water molecules of crystallization followed by the decomposition of the network.展开更多
The inhibition performance of 1-hydralazinophthalazine (HPZ) (1), and synthesized1-(2-[(5-methylfuran-2-yl)methylene)] hydrazono) phthalazine (MFHPZ) (2), 1-(phthalazin-1(2H)-one) [(pyridin-2-yl) ethylidene] hydrazone...The inhibition performance of 1-hydralazinophthalazine (HPZ) (1), and synthesized1-(2-[(5-methylfuran-2-yl)methylene)] hydrazono) phthalazine (MFHPZ) (2), 1-(phthalazin-1(2H)-one) [(pyridin-2-yl) ethylidene] hydrazone (ACPHPZ) (3) and (2-acetylthiophene hydrazono) phthalazine (ACTHPZ) (4) has been investigated for mild steel in 1 M HCl. Compound 4 shows maximum inhibition efficiency of 93% at 5.0 × 10-3 M concentration. The evaluation of thermodynamics and activation parameters indicated spontaneous adsorption of the inhibitor molecules which takes place through chemisorption. The adsorption of 3 and 2 follows Langmuir adsorption isotherm and Temkin adsorption isotherm for 4 and 1. The inhibitor efficiency was of the order 4 > 3 > 1 > 2. Impedance study for the representative inhibitor compounds 4 and 3 showed that decrease in charge transfer resistance is responsible for effective protection of mild steel surface by the tested inhibitor.展开更多
Two novel dopamine hydrochloride Schiff bases (E)-4-(2-((4-hydroxy-2H-chromen-2-ylidene)amino)ethyl)benzene-1,2-diol (1) and (E)-3-((3,4-dihydroxyphenethyl)imino)indolin-2-one (2) have been synthesized using isatin an...Two novel dopamine hydrochloride Schiff bases (E)-4-(2-((4-hydroxy-2H-chromen-2-ylidene)amino)ethyl)benzene-1,2-diol (1) and (E)-3-((3,4-dihydroxyphenethyl)imino)indolin-2-one (2) have been synthesized using isatin and 4-hydroxycoumarin. The prepared compounds have been characterized by solubility in different solvents, melting point determination, elemental analysis, FT-IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR and powder X-ray diffraction spectroscopic techniques, with the structures of the Schiff bases proposed. The proposed structures of the compounds have been optimized using the Spartan program so as to get the most stable conformers. The synthesized Schiff bases have been tested for their biological activity against two Gram positive bacteria;Staphylococcus aureus, Bacillus subtilis, and two Gram negative bacteria;Klebsiella pneumoniae and Escherichia coli with their minimum inhibition concentration (MIC) values determined. The Schiff base 1 was found to inhibit E. coli and K. pneumonia with MIC values of 3.12 and 6.25 μg/mL, followed by K. pneumonia compared to the reference standards with MIC values of 3.12 μg/ml indicating that 1 could be a potential lead compound.展开更多
A new cobalt(II) complex, [Co(H2 oxado)3 ]C2 O4 H2 oxado·2H2 O (H2 oxado = oxamide dioxime), has been synthesized in aqueous solution and characterized by elemental analysis and single crystal X-ray structure det...A new cobalt(II) complex, [Co(H2 oxado)3 ]C2 O4 H2 oxado·2H2 O (H2 oxado = oxamide dioxime), has been synthesized in aqueous solution and characterized by elemental analysis and single crystal X-ray structure determination. The complex crystallizes in the triclinic space group P-1, with the parameters a = 9.46(4), b = 11.84(5), c = 12. 81(5)?Å, α = 104.94(6), β = 99.29(5), γ = 106.73(5), V = 1284(9) Å3, Z = 2. The central cobalt(II) cation is pseudo-octahedrally coordinated by six imino N atoms of the neutral oxamide dioxime ligand. In the solid state, each of the following bricks, namely the cationic complexes, the oxalate dianions as well as the oxamide dioxime crystallization molecules, pile up parallel to the a axis. The bulk structure is consolidated by an extended three-dimensional network of hydrogen bridgings—that link the ionic partners, oxamide dioxime and water molecules to one another—and by coulombic interactions.展开更多
A novel dinuclear complex [Co2(atr)3(mal)2(H2O)2]·4H2O(1) (atr = 4-amino-1,2,4-triazole and mal = malonic acid) containing mixed N and O-donor atoms has been prepared and structurally characterized. The structure...A novel dinuclear complex [Co2(atr)3(mal)2(H2O)2]·4H2O(1) (atr = 4-amino-1,2,4-triazole and mal = malonic acid) containing mixed N and O-donor atoms has been prepared and structurally characterized. The structure is made up of the symmetrically 1, 2, 4-triazole bridged [Co2(atr)3(mal)2(H2O)2] moiety and four lattice water molecules. The single crystal X-ray analysis reveals that the complex has a distorted octahedral structure. Magnetic susceptibility measurements reveals that antiferromagnetic interactions exists between the high spin Co(II) ions within the dinuclear unit.展开更多
文摘Two new hydralazine hydrochloride-derived Schiff bases</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">:</span></span><span style="font-family:Verdana;"> (E)-1-(Phthalazin-</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">1-yl)-1-[(Pyridin-2-yl)Ethylidene]Hydralazine (PPEH), and 1-[2-(1-(pyridine-</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">3</span><span style="font-family:Verdana;">-yl)ethylidene)hydrazinyl]phthalazine (PEHP), were synthesized and partially characterized by spectroscopic and crystallographic methods including IR and X-ray. The single-crystal X-ray diffraction (SCXRD) analysis of PEHP indicate</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span><span style="font-family:Verdana;"> that the hydralazine moiety of both ligands possess</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">es</span></span><span style="font-family:Verdana;"> the exoc</span><span style="font-family:Verdana;">yclic C=N bond. Both, PPEH and PEHP were tested as antimicrobials and antiparasites. Just PEHP could be considered as slightly antiplasmodial and antibacterial agent. In effect, PPEH showed low antimicrobial activity against one bacterial strain with Minimum Inhibitory Concentration (MIC) value of 250 μg/ml while PEHP showed very interesting activity against 18 out of 19 bacterial strains with MIC of 31.25 </span><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span><span style="font-family:Verdana;"> 250 μg/ml compared to the standard drug, amoxicillin. PPEH and PEHP showed higher reducing activity on ferric ions compared to Vitamin C. On the other hand, both hidrazaline synthetized derivatives show</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">ed</span></span><span style="font-family:Verdana;"> as better reducing agents than Vitamin C on ferric ions, while again, only the PEHP show</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">ed</span></span><span style="font-family:Verdana;"> slightly high inhibition of lipid peroxidation using Vitamin C as standard. Regarding their catalase activity, both compounds show</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">ed</span></span><span style="font-family:Verdana;"> concentration dependent effect, but Vitamin C continued showing a higher stimulatory effect on the enzyme activity. Additionally, while PPEH showed less than 80% inhibition in the preliminary antiplasmodial assay and so was not considered for the dose-response studies, PEHP</span><span style="font-family:Verdana;"> displayed an inhibition percentage of 83.60% and 50% Inhibitory Concentration (IC</span><sub><span style="font-family:Verdana;vertical-align:sub;">50</span></sub><span style="font-family:Verdana;">) value of 44.13 μg/mL compared to the standard drug, artemisinin and was classified as slightly active</span><span style="font-family:Verdana;">.
文摘This study examined the sanitary conditions of public boreholes and hand dug wells water in relation to pathogenic bacteria isolated in water samples. To assess the suitability of drinking water, sanitary inspection of surroundings of the sources was conducted, membrane filtration technic was used to trap the microorganisms in the water sample and other standard microbiological technics were applied to check the heterotrophic plate counts, total coliforms, fecal coliforms and some pathogenic bacteria in the samples. It was observed that there were no delineated protection zones around many boreholes (61.19%) and in almost all hand dug wells;thus, hand dug wells were pruned to more contamination than boreholes. Heterotrophic plate counts of boreholes were significantly different between (p < 0.0001) zones in dry and rainy seasons. Total coliforms per 100 ml varied significantly (p < 0.001) between the two seasons both in boreholes and hand dug wells. Fecal coliforms were significantly absent in some boreholes, but significantly present in all hand dug wells with the presence of <i>E. coli</i> 157H in some. Risk assessment of factors contributing to water contamination showed that: pumps manipulation with feet, other sources of contamination such as wastewater dumps, within 10m were significantly associated to boreholes contamination with <i>Salmonella</i> spp, <i>Staphylococcus aureuse</i>, fecal coliform (p = 0.01);in hand dug wells, presence of latrine or septic tank soak-away within 10 m of the wells, poor depth and lack of internal lining, uncapped wells, presence of trees near the wells, animal and birds feces, were significant and associated to contamination with <i>Salmonela</i> spp., <i>B. cepaceae, S. aureus E. coli</i> 1 (p < 0.05). Generally water collection points are marked with very poor sanitary conditions and this situation may not change unless the contaminating risk factors are fixed and sanitary measures are taken.
文摘A novel chiral Nickel (II) complex of N-(2-pyridylmethyl)-L-alanine (Hpyala) <b>1</b> has been prepared and structurally characterized by elemental analysis, FT-IR, UV-visible, TGA and single crystal X-ray diffraction techniques. Complex <b>1</b> crystallizes in an orthorhombic P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub> space group. The nickel (II) centre in the complex adopts a distorted octahedral geometry. This compound has been seen to exhibit structural diversity resulting from the number of lattice water molecules. The photoluminescent properties of this compound which have also been investigated, indicates the potential application in luminescence.
文摘The novel ligand, 1-(phthalazin-1(2H)-one)[(pyridin-2-yl)ethylidene]hydrazone,(APN), derived from the antihypertensive drug, hydralazine hydrochloride, was synthesized and characterized by spectroscopic methods (IR, 1H NMR). The X-ray crystallographic data indicates that APN has an exocyclic C=N bond on the hydralazine moiety. APN revealed significant anti-onchocercal activity with IC50 values of 0.3125 μg/mL on microfilaria and 10 μg/mL on adult worms compared to the standard drug, ivermectin.
文摘Uncontrolled uses of antibiotics have led to rapid evolution of antibiotic-resistance bacteria and antibiotic resistance gene transfer, especially in a pool of aquatic system where resistance, intermediate and susceptible bacteria to some antibiotics strive together. Consequently, there is a transfer of resistance genes. In this study, bacteria of the Enterobacteriaceae family and some gram positive bacteria isolated from some boreholes and hand dug wells water of public use were tested on 19 antibiotics of different classes. This was achieved through a disk diffusion technique to determine the antimicrobial resistance profile of the said bacteria, microbial resistance index of the drugs used (and their ability to produce Beta-lactamase). These isolates were shown to demonstrate a very high resistance to the drugs used in the area. The resistance was highest in Escherichia coli 1 (73.68%) and lowest in Streptococcus pneumoniae (47.82%). These isolates also indicated very high levels of multi-drug resistance. The minimum resistance index was 0.47, indicating that bacteria isolates were of fecal origin. It is evident from the present study that multiple antibiotic-resistant bacteria can thrive in water as an environmental reservoir, and can therefore provide a route to multidrug-resistant pathogens to enter human and animal population.
文摘A novel ligand N-4-hydroxyacetophenone isonicotinoyl hydrazone and its manganese(II) and nickel(II) metal complexes have been synthesized. The synthesized Schiff base and its metal complexes have been characterized by physical state determination, melting point and solubility measurements in different solvents, infrared, proton nuclear magnetic resonance, mass spectrometric and powder X-ray spectroscopic techniques. The thermal properties of the prepared compounds were obtained from TG/DTG measurements. On the basis of the analytical techniques, the ligand was found to be bidentate in nature coordinating to the metal ions through the azomethine nitrogen and carbonyl oxygen atoms leading to distorted octahedral geometries of the metal complexes which were modeled using MM2 force field. The ligand and its metal(II) complexes were evaluated for antifungal activity against <i>Aspergillus fumigatus, Aspergillus niger, Candida albicans and Rhizopus stolonifera.</i> The antifungal evaluation results revealed an enhanced activity upon coordination of the ligand with the metal(II) ions. The activity of the metal complex to the tested fungal strains was in the order Ni(II) > Mn(II).
文摘A novel Schiff base, benzylmethyl-4-methyl-3-thiosemicarbazone (BMM) de-rived from benzylmethylketone and 4-methylthiosemicarbazide was synthe-sized and characterized by elemental analysis, spectroscopic methods (IR, 1H NMR, 13C NMR) and physical means. The single crystal structure analysis of the Schiff base reveals that it crystallizes in a monoclinic system in the P21/c space group. BMM revealed moderate antibacterial activity on three bacterial strains with diameter zone of inhibition of 16 mm (E. coli), 14 mm (K. pneumonia) and 13 mm (S. epider-midis) compared with the standard drug, ciprofloxacin.
文摘Reaction of Ba0.50[Ag2Cr(C2O4)3]·5H2O with Ag2SO4 in an aqueous solution of sulfuric acid (pH ≈ 3) yielded the silver(I)/chromium(III) oxalate salt H0.50[Ag2.50Cr(C2O4)3]·5H2O (1). Compound 1 can be best described as an anionic silver-deficient oxalatochromate(III) complex [Ag2.50Cr(C2O4)3]0.5- with nanochannels containing hydrogen-bonded water molecules and protons. Thermal analyses show significant weight losses corresponding to the elimination of water molecules of crystallization followed by the decomposition of the network.
文摘The inhibition performance of 1-hydralazinophthalazine (HPZ) (1), and synthesized1-(2-[(5-methylfuran-2-yl)methylene)] hydrazono) phthalazine (MFHPZ) (2), 1-(phthalazin-1(2H)-one) [(pyridin-2-yl) ethylidene] hydrazone (ACPHPZ) (3) and (2-acetylthiophene hydrazono) phthalazine (ACTHPZ) (4) has been investigated for mild steel in 1 M HCl. Compound 4 shows maximum inhibition efficiency of 93% at 5.0 × 10-3 M concentration. The evaluation of thermodynamics and activation parameters indicated spontaneous adsorption of the inhibitor molecules which takes place through chemisorption. The adsorption of 3 and 2 follows Langmuir adsorption isotherm and Temkin adsorption isotherm for 4 and 1. The inhibitor efficiency was of the order 4 > 3 > 1 > 2. Impedance study for the representative inhibitor compounds 4 and 3 showed that decrease in charge transfer resistance is responsible for effective protection of mild steel surface by the tested inhibitor.
文摘Two novel dopamine hydrochloride Schiff bases (E)-4-(2-((4-hydroxy-2H-chromen-2-ylidene)amino)ethyl)benzene-1,2-diol (1) and (E)-3-((3,4-dihydroxyphenethyl)imino)indolin-2-one (2) have been synthesized using isatin and 4-hydroxycoumarin. The prepared compounds have been characterized by solubility in different solvents, melting point determination, elemental analysis, FT-IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR and powder X-ray diffraction spectroscopic techniques, with the structures of the Schiff bases proposed. The proposed structures of the compounds have been optimized using the Spartan program so as to get the most stable conformers. The synthesized Schiff bases have been tested for their biological activity against two Gram positive bacteria;Staphylococcus aureus, Bacillus subtilis, and two Gram negative bacteria;Klebsiella pneumoniae and Escherichia coli with their minimum inhibition concentration (MIC) values determined. The Schiff base 1 was found to inhibit E. coli and K. pneumonia with MIC values of 3.12 and 6.25 μg/mL, followed by K. pneumonia compared to the reference standards with MIC values of 3.12 μg/ml indicating that 1 could be a potential lead compound.
文摘A new cobalt(II) complex, [Co(H2 oxado)3 ]C2 O4 H2 oxado·2H2 O (H2 oxado = oxamide dioxime), has been synthesized in aqueous solution and characterized by elemental analysis and single crystal X-ray structure determination. The complex crystallizes in the triclinic space group P-1, with the parameters a = 9.46(4), b = 11.84(5), c = 12. 81(5)?Å, α = 104.94(6), β = 99.29(5), γ = 106.73(5), V = 1284(9) Å3, Z = 2. The central cobalt(II) cation is pseudo-octahedrally coordinated by six imino N atoms of the neutral oxamide dioxime ligand. In the solid state, each of the following bricks, namely the cationic complexes, the oxalate dianions as well as the oxamide dioxime crystallization molecules, pile up parallel to the a axis. The bulk structure is consolidated by an extended three-dimensional network of hydrogen bridgings—that link the ionic partners, oxamide dioxime and water molecules to one another—and by coulombic interactions.
文摘A novel dinuclear complex [Co2(atr)3(mal)2(H2O)2]·4H2O(1) (atr = 4-amino-1,2,4-triazole and mal = malonic acid) containing mixed N and O-donor atoms has been prepared and structurally characterized. The structure is made up of the symmetrically 1, 2, 4-triazole bridged [Co2(atr)3(mal)2(H2O)2] moiety and four lattice water molecules. The single crystal X-ray analysis reveals that the complex has a distorted octahedral structure. Magnetic susceptibility measurements reveals that antiferromagnetic interactions exists between the high spin Co(II) ions within the dinuclear unit.
