Chloro Phenyl Research Articles

DEVELOPMENT OF A MODIFIER FOR GIVING MATERIALS FROM EFFICIENTLY PROCESSED WOOD BIOMASS SPECIAL PROPERTIES

Background. Wood is a unique material in its structure. However, materials made from wood raw materials have such negative properties as insufficient bio- and fire-resistance. In turn, when organizing and improving the efficiency of logging activity, large amounts of practically unused cutting residues is produced. Their modification for the purposes of the forest industry is an effective tool for creating many valuable and demanded products. In particular, arilazo-β-dicarbonyl compounds are widely used as syntons for the production of heterocyclic compounds. Among heterocycles, a large number of compounds have found application in the form of biologically active substances that have been successfully and for a long time used as pesticides for the wood processing industry.
 Purpose. Synthesis of p-nitrophenyl hydrobutanons, cyclocondensation to form pyrazoles and study of their chemical properties of the substances first obtained. Proof of structure by modern spectral analysis methods.
 Materials and Methods. Research methods include: organic synthesis; UV spectrometry, 1H NMR, 13H NMR.
 Results. Four new compounds were synthesized: 4-methoxy-1-(p-chloro(bromo)phenyl)-2-(p-nitrophenylhydrazo)-1,2,3-butantrions and 3(5)-methoxy-5(3)-(p-chloro(bromo)phenyl)-4-(p-nitrophenylhydrazo)-1H-pyrazoles. Amines were prepared by the reduction of the related nitrosopyrazoles. The acylation reaction was demonstrated for the obtained amine. The structures of all synthesized compounds were proved by modern methods of analysis.
 Conclusion. Thus, we synthesized p-nitrophenylhydrazobutanetriones with a chloro(bromo)phenyl substituent, their cyclization products with hydrazine, and N-(5-(4-chloro(bromo)phenyl)-3-(methoxymethyl)-1H-pyrazole-4-yl)acetamides based on them. The structure of the obtained substances was determined by spectral methods of analysis.

Synthesis and Spectral Characterization of New Azo Imidazole Ligand 2-[ 2' - (4 - Chloro Phenyl)azo [- 1 - Methyl Imidazole and its Complexes with Ag(I) and Ni(II) ions

Synthesis and Spectral Characterization of New Azo Imidazole Ligand 2-[ 2' - (4 - Chloro Phenyl)azo [- 1 - Methyl Imidazole and its Complexes with Ag(I) and Ni(II) ions

Synthesis and spectral characterization of some metal complexes with new heterocyclic azo imidazole dye ligand and study biological activity as anticancer

The complexation of Cu(II), Ag(I)and Au(III) ions studied with new synthesized azo imidazole ligand (ClPA1-MeI) which prepared by coupling reaction between 2-] 2′ - (4 - Chloro Phenyl)azo [- 1 - Methyl imidazole, whereas these compounds characterized by 1H and 13C- NMR, UV-Vis, Mass, Infrared spectrum, SEM, X-ray diffraction studies and molar conductance. The studies show that the azo dye ligand has a tridentate structure and coordinates to the metal ion through the nitrogen atom of the azo group, which is the furthest away from the imidazole molecule, the nitrogen atom of the azomethine group of the heterocyclic imidazole ring, and the phenolic oxygen. Furthermore, MTT assays were used to test the anticancer properties of synthesized azo dye ligand and Au (III) complexes against brain cancer (A172) cell lines, and the results revealed that the prepared compounds exhibited good anticancer properties and are very promising candidates for future applications in anti-tumor drugs.

Biological Evaluation of Synthesized Naringenin Derivatives as Antimicrobial Agents

Background: Flavonoids are among the most abundant plant secondary metabolites and have been shown to have natural abilities as microbial deterrents and anti-infection agents in plants. Naringenin as one of the flavonoids and its derivatives have been reported to exhibit antimicrobial activity. Aims: The aim of the study was to evaluate synthesized novel naringenin derivatives (ND-1 to ND- 12) substituted at 3-position with bulky substituent by using the grinding technique (Claisen- Schmidt reaction) as antimicrobial agents. Methods: Synthesized naringenin derivatives were evaluated for in-vitro antimicrobial activity by “Agar disc diffusion method”. Results: Novel naringenin derivatives showed mild to moderate antimicrobial activity with respect to standard drugs against two gram-positive, two gram-negative bacteria and two fungal strains. The substitution of naringenin derivatives at position 3 with substituted phenyl rings showed variation in activity as chloro, nitro and hydroxyl-substituted phenyl ring showed potent activity while methoxy substituted phenyl ring impede the activity. Conclusion: In conclusion, on the basis of the above findings, the substituted naringenin scaffolds may be selected as a skeleton for the development of flavonoid structurally-related compounds having antimicrobial activity.

Synthesis and Properties of N,N′-Disubstituted Ureas and Their Isosteric Analogs Containing Polycyclic Fragments: VI. N-[Fluoro(chloro)phenyl]-N′-(4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptan-1-yl)ureas

The reaction of (S)-(–)-1-isocyanato-4,7,7-trimethyl-2-oxabicyclo[2.2.1]heptan-3-one with fluoro- and chloro-substituted anilines afforded a series of N,N′-disubstituted ureas containing a natural lipophilic camphanic acid moiety in 42–75% yield. The synthesized compounds are promising as inhibitors of human soluble epoxide hydrolase.

Copper (II) phthalocyanines: Electrode modification and sensing studies

Metal phthalocyanine complexes have been used as electro catalysts in various reactions. Chemically inert and thermally stable Para chloro phenyl [1,3,4] oxadiazole substituted copper phthalocyanine was used for the determination of dopamine and ascorbic acid. Experiments revealed that the compound possesses strong electro catalytic activity towards the oxidation of dopamine and ascorbic acid. The modified carbon paste electrode (MCPE) has talented features such as simplicity of electrode preparation, high stability and distinct advantage of simple polishing. Also there was no leaching or discharge of electrode because of insoluble nature of phthalocyanine in aqueous solution and hence a single electrode surface can be used for multiple analytical determinations.

Synthesis and Properties of N,N′-Disubstituted Ureas and Their Isosteric Analogs Containing Polycyclic Fragments: II. N-(4-Oxoadamantan-1-yl)-N′-[fluoro(chloro)phenyl]ureas

A series of N-(4-oxoadamantan-1-yl)-N′-[fluoro(chloro)phenyl]ureas have been synthesized in 27–73% yields by reaction of 1-isocyanatoadamantan-4-one with fluoro- and chlorosubstituted anilines. The products are promising as human soluble epoxide hydrolase inhibitors.

Experimental and theoretical spectroscopic studies in relation to molecular structure investigation of para chloro, para fluoro and para nitro maleanilinic acids

In the present work novel para chloro, para fluoro and para nitro maleanilic acid derivatives were prepared and investigated using FT-IR, thermal analyses (TA) measurements (TGA/DTG and DTA) in comparison with mass spectral (MS) fragmentation at 70 eV. The crystallographic structures of studied compounds were investigated by X-ray diffraction (XRD). The vibrational frequencies and the corresponding normal modes were evaluated at the optimized geometry. Vibrational modes were analyzed using GAUSSVIEW software. Experimental FT-IR and Raman spectra of the three newly prepared derivatives, namely, (E) – oxo -4- ((4- nitro phenyl) amino)-4- oxobut-2-enoic acid (p-NMA), (E) -4- ((4- chloro phenyl)amino)-4- oxobut -2- enoic acid (p-ClMA), (E) -4- ((4- fluoro phenyl) amino)- 4- oxobut -2- enoic acid (p-FMA) were compared with the theoretically calculated one. FT-IR and the observed vibrational frequencies were assigned; thermal analysis and mass spectrum measurements of the maleanilic acid derivatives were recorded and discussed. The computational calculations were carried out by DFT - B3LYP method with 6-311++G(d,p) basis sets and the corresponding results were tabulated. The alternations of structures of p-FMA, p-ClMA and p-NMA due to the subsequent substitutions were investigated. This correlation between experimental and theoretical calculations provided a good confirmation of the proposed structures of the newly prepared compounds. The derivatives were found to be highly effective against Hepatocellular carcinoma cells > Breast carcinoma cells > colon carcinoma cells. It was recognized, that cancer cells over expression promotes tumorigenic functions; can be suppressed by p-NMA > p-FMA > p-ClMA inhibitors.

Synthesis of 1,2,4-triaza-3,5-diphospholidines

1,2,4-Triaza-3,5-diphospholidines were synthesized by highly selective cyclization reactions between N,N-bis[chloro(phenyl)phosphino]methylamine and 1,2-disubstituted hydrazines. Three examples of molecular structures are discussed against the background of configurational isomers and the potential of the title compounds as versatile cyclic ligands with chelating P–N–P motif.

Reaction of transsilylation of N-methyl-N-trimethylsilylacetamide with silanes ClCH2SiR1R2Cl

The reaction of N-methyl-N-trimethylsilylacetamide with silanes ClCH2SiR1R2Cl (R1, R2 = H, Me; H, Ph; Ph2) leads to the formation of (O→Si) chelate compounds with pentacoordinate silicon: N-[chloro(methyl)-silyl]methyl-, N-[chloro(phenyl)silyl]methyl-, and N-[chloro(diphenyl)silyl]methyl-N-methylacetamides. From the data of multinuclear NMR spectroscopy, the intermediates of the reaction of N-methyl-N-trimethylsilylacetamide with ClCH2SiPhHCl and ClCH2SiPh2Cl are stable in CDCl3 solution at room temperature during several days and slowly rearrange to the final (O–Si) chelate compounds.

Preparation and identification of some metal complexes with new heterocyclic azo dye ligand 2-[2−- (1- Hydroxy -4- Chloro phenyl) azo ]- imidazole and their spectral and thermal studies

The preparation and spectral identification of metal complexes for Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) ions with new heterocyclic azo dye as ligand 2-[2−- (1- Hydroxy - 4- Chloro phenyl) azo ]- imidazole (HClPAI) were prepared by reacting adizonium chloride salt solution of 2-amino -4- chloro phenol with imidazole in alkaline ethanolic solution. Azo dye ligand and their metal complexes have been characterized by analytical data, 1H NMR, Mass spectrum, Infrared, Electronic spectral data, XRD, SEM, thermal analysis (TG-DSC-DTG), magnetic susceptibility and molar conductance. The elemental analysis of the metal complexes confirm the stoichiometry of the type [M(L)2] Cl where M = Cr(III), Fe(III), Co(II) and [M(L)2] where M = Mn(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and L = azo dye ligand. Molar conductance measurements for prepared metal complexes showed 1:1 electrolyte for Cr(III), Fe(III) and Co(III) ions and non-electrolyte the rest metal complexes. The data show that the azo dye ligand behaves a tridentate and coordinates to the metal ion via nitrogen atom of azo group which is the farthest of imidazole molecule, nitrogen atom of azomethine group of heterocyclic imidazole ring and phenolic oxygen. Octahedral environment is suggested for all metal complexes.

High-resolution Imaging of pH in Alkaline Sediments and Water Based on a New Rapid Response Fluorescent Planar Optode.

A new dual-lumophore optical sensor combined with a robust RGB referencing method was developed for two-dimensional (2D) pH imaging in alkaline sediments and water. The pH sensor film consisted of a proton-permeable polymer (PVC) in which two dyes with different pH sensitivities and emission colors: (1) chloro phenyl imino propenyl aniline (CPIPA) and (2) the coumarin dye Macrolex® fluorescence yellow 10 GN (MFY-10 GN) were entrapped. Calibration experiments revealed the typical sigmoid function and temperature dependencies. This sensor featured high sensitivity and fast response over the alkaline working ranges from pH 7.5 to pH 10.5. Cross-sensitivity towards ionic strength (IS) was found to be negligible for freshwater when IS <0.1 M. The sensor had a spatial resolution of approximately 22 μm and aresponse time of <120 s when going from pH 7.0 to 9.0. The feasibility of the sensor was demonstrated using the pH microelectrode. An example of pH image obtained in the natrual freshwater sediment and water associated with the photosynthesis of Vallisneria spiral species was also presented, suggesting that the sensor held great promise for the field applications.

Metabolism, Excretion and Pharmacokinetics of MLN3897, a CCR1 Antagonist, in Humans.

MLN3897 is a small molecule antagonist of the C-C chemokine receptor-1. Since preclinical studies showed that the molecule was metabolized into two halves, the metabolism, excretion, and pharmacokinetics of MLN3897 were investigated in humans using MLN3897 14C-radiolabeled either on the chlorophenyl (CP) or the tricyclic (TC) half of MLN3897 after an oral dose. To evaluate the mass balance, metabolism and pharmacokinetics of MLN3897 in two cohorts of six randomized healthy subjects. After receiving informed consent, subjects were dosed after an overnight fast of 10-hours followed by at least 4- hours after dosing on day-1. Each cohort received a single 29 mg oral dose of either the CP or the TC as an oral solution in water. Serial blood samples, urine and feces were collected over a 10-day period post-dose. For both radiolabeled moieties, 55-59% of the dose was recovered in feces and 32% recovered in urine. MLN3897 was metabolized extensively in humans, with minor amounts of intact MLN3897 detected in the urine and feces. N-oxidation of the tricyclic moiety (M28) and N-dealkylation of the piperidinyl moiety were the primary metabolic pathways leading to further formation of the carboxylic acid metabolite (M19) and the (4-(4-chlorophenyl)-3,3- dimethylpiperidin-4-ol) metabolite (M40). Oxidative metabolites M11, M19, M28, M44 were present at >10% of the total circulating radioactivity and also at >25% of MLN3897 exposure. Metabolites resulting from the chlorophenyl-labeled moiety (M40) had significantly more systemic exposure compared to the tricyclic-labeled moiety (M19).

Nitroxide-Mediated Radical Polymerization of Styrene Initiated from the Surface of Titanium Oxide Nanoparticles

Titanium dioxide (TiO 2 ) nanoparticles, with an average size of about 45 nm, were encapsulated by polystyrene using in situ nitroxide mediated radical polymerization in the presence of 3-aminopropyl triethoxy silane as a coupling agent and 2, 2, 6, 6-tetramethylpiperidinyl-1-oxy as a initiator. First, the initiator for nitroxide mediated radical polymerization was covalently bonded onto the surface of Titanium dioxide nanoparticles through our novel method. For this purpose, the surface of TiO 2 nanoparticle was treated with 3-aminopropyl triethoxy silane, a silane coupling agent, and then these functionalized nanoparticles was reacted with ± -chloro phenyl acetyl chloride. The chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2, 2, 6, 6-tetramethyl piperidine. These modified TiO 2 nanoparticles were then dispersed in styrene monomers to carry out the in situ free radical polymerization.

Reaction of chloro(ethyl)silanes with chloro(phenyl)silanes in the presence of aluminum chloride. Synthesis of chloro(ethyl)(phenyl)silanes

Substituent exchange at the silicon atom between chloro(phenyl)silanes (PhSiCl3, MePhSiCl2, Ph2SiCl2) and chloro(ethyl)silanes (EtSiCl3, Et2SiCl2, Et3SiCl, Et4Si) in the presence of aluminum chloride has been studied. The examined compounds, except for PhSiCl3 and Et4Si, react fairly readily to give chloro(ethyl)-(phenyl)silanes in up to 48–52% yield. A probable mechanism has been proposed.

SYNTHESIS AND EVALUATION OF SOME NEWLY TRIAZOLYLINDOLE DERIVATIVES FOR ANTIFUNGAL ACTIVITY

A series of novel 2 - ((2 - (phenyl/4 - chl orophenyl) - 1 - ((4 - ((Z) - 1 - (substitutedphenyl)ethylideneamino) - 5 - mercapto - 4H - 1,2,4 - triazol - 3 - yl)methyl) - 1H - indol - 3 - yl)methyleneamino)benzoic acid (9 - 16) were synthesized by treating 2 - ((1 - ((4 - amino - 5 - mercapto - 4H - 1,2,4 - triazol - 3 - yl)methyl) - 2 - (phenyl/4 - chloroph enyl) - 1H - indol - 3 - yl)methyleneamino)benzoic acid (7 - 8) with various substituted acetophenone. The structure of the compounds was characterized by IR and 1 General procedure for preparation of 2 - ((2 - phenyl/4 - chlorophenyl - 1H - indol - 3 - yl)methyleneamino)benzoic acid (1 - 2) A mixture of 2 - phenyl/4 - chlorophenyl - 1H - indole - 3 - carbaldehydes (0.1 mol) and anthranilic acid (0.1 mol) in absolute ethanol (90 ml) cont aining few drops of glacial acetic acid was refluxed for 28 h and excess of solvent was distilled off. The solids thus obtained were filtered, dried and re crystallized from ethyl acetate to yield compounds 1 - 2 2 - ((1 - (2 - ethoxy - 2 - oxoethyl) - 2 - (phenyl/4 - chlo rophenyl) - 1H - indol - 3 - yl)methyleneamino)benzoic acid (3 - 4) A mixture of compounds 1 - 2 (0.1 mol), ethyl chloroacetate (0.1 mol), anhydrous acetone (90 ml) and NaOH (16 g) was heated under reflux of 22 h. The reaction mixtures were cooled, wash with excess of water, filtered and dried, again washed with ethanol and re c r ystallized from appropriate solvent to yield compounds 3 - 4. 2 - ((1 - (2 - hydrazinyl - 2 - oxoethyl) - 2 - phenyl - 1H - indol - 3 - yl)methyleneamino)benzoic acid (5 - 6) A mixture of compounds 3 - 4 (0.1 mol) and hy drazine hydrate (0.2 mol) in absolute ethanol (80 ml) was refluxed for 18 h then cooled and poured on crushed ice and separated. The solids were filtered, washed with cold water, dried and re c r ystallized from appropriate solvent to yield compounds 5 - 6. 2 - ((1 - ((4 - amino - 5 - mercapto - 4H - 1,2,4 - triazol - 3 - yl)methyl) - 2 - (phenyl/4 - chlorophenyl) - 1H - indol - 3 - yl)methylene amino)benzoic acid (7 - 8) To the ice cold mixture of compounds 5 - 6 (0.1 mol) and KOH (0.4 mol) in dry ethanol (90 ml), carbon disulphide (0.1 mol) was a dded with magnetic stirring. The reaction mixtures were stirred further at room temperature for 24 h. The separated solids were filtered washed with dry ether and dried. These were further magnetically stirred with hydrazine hydrate (0.15 mol) on boiling w ater bath for 4 h till the evolution of H 2 S ceased. The reaction mixtures were poured into ice - cold water then filtered, washed with water, dried and re crystallized from acetic acid to yield compounds 7 - 8.

Construction of Novel PVC-Based Membrane Electrodes for the Selective Determination of Fe3+ Ion

Iron is fourth most abundant elements of the earth crust and is widely and uniformly distributed. It generally present in surface waters as salts containing Fe3+ion. Most of those salts are insoluble and settle out , thus, the concentration of iron in well-aerated waters is seldom high. Siderite, haematite, limonite ad magnetite are the most important commercial iron ores. It finds many applications both in support of animal life and industrial processes. At trace concentration, iron promotes many important biological processes of human life. However, at higher concentration, it is toxic and causes liver and kidney damages. Tissue damage has also been reported from prolonged consumption of acidic foodstuffs cooked in iron kitchenware. Thus it is important to monitor the concentration of iron in various environmental samples.There are number instrumental technique such as X-ray fluorescence, neutron activation analysis, isotope dilution multiple collector inductively coupled plasma mass spectrometry, flame atomic absorption spectrometry, cathodic stripping voltammetry and spectrophotometry for the determination of Fe3+ ion. Although these methods provide accurate determination of Fe3+ion content but require large infrastructure backup, highly expensive and support of expertise. These requirements make difficult for such a technique to be used in routine manner for the analysis of large number of samples. Thus in the search of analytical technique which is portable, fast and low cost is the obvious choice. Such requirements are generally met by ion selective electrodes. But, a good ion-selective electrode need a good ionophore.Schiff bases N-(4-(dimethylamino)benzylidene)-thiazol-2-amine [L1], 5-((3-methylthiophene-2yl) methyleneamino)-1,3,4-thiadiazole-2-thiol [L2] and N-((3-methylthiophene-2yl)methylene)thiazol-2-amine [L3] were synthesized and explored as Fe3+ ion-selective electrodes. The effect of various plasticizers (o-nitrophenyloctyl ether (o-NPOE), dibutylphthalate (DBP), 1-Chloronapthalene (1-CN), Dioctylphthalate (DOP) and acetophenone (AP)) and anionic excluders (sodium tetraphenylborate (NaTPB)/ Potassium tetrakis p-(chloro phenyl)borate (KTpClPB)) were also examined and observed that the membrane electrode having a composition of L2: PVC: o-NPOE: NaTPB as 3: 38.5: 56: 2.5 (w/w; mg) was showing the best performance characteristics. A coated graphite electrode (CGE) was also fabricated with the same composition and their potentiometric studies were compared. CGE is found to perform better as it shows wider working concentration range 8.3 × 10-8 ‒ 1.0 × 10-1 mol L-1, lower detection limit 2.3 × 10-8 mol L-1, Nernstian slope 19.5± 0.4 mV decade-1 of activity with response time 10 s. The CGE shows a shelf life of 6 weeks and in view of high selectivity, it can be used to quantify Fe3+ ion in water, soil, vegetable and medicinal plants. It can also be used as an indicator electrode in potentiometric titration of EDTA with Fe3+ion.Fig. 1. Calibration characteristics of the electrodes (PME and CGE) based on L2.Table 1. Response characteristics of Fe (III) ion selective PME and CGE.PropertiesElectrode ResponsePMECGEWorking concentration range (mol L-1)6.7 × 10-7 - 1.0 × 10-1 8.3 × 10-8 - 1.0 × 10-1 Detection limit (mol L-1)1.4 × 10-7 2.3 × 10-8 Slope (mV decade-1 of activity)19.6± 0.519.5± 0.4Response time (s)1310Life span5 weeks6 weekspH range2.0-5.01.5-6.5

Acyl hydrazides and triazoles as novel inhibitors of mammalian cathepsin B and cathepsin H

In the past decade, the work on the identification of small molecular weight compounds as inhibitors of cysteine proteases has been in focus. In this direction, we here present the facile microwave assisted synthesis of some acyl hydrazides and triazoles, followed by their evaluation as protease inhibitors and inhibitory studies on cathepsin B and cathepsin H, two significant lysosomal cysteine proteases. The compounds were characterized by 1H NMR, 13C NMR, Mass and IR spectral data. The compounds which were found inhibitory to endogenous proteolysis in liver homogenate at pH 5.0 were further studied for determination of inhibition type and Ki values on purified cathepsin B and cathepsin H. The maximum inhibitory effect was exerted by 3-(3′-nitrophenyl)-5-(3′-nitrophenyl)-4-amino-1,2,4-triazoles (2c), 3-(4′-chlorophenyl)-5-(4′-chloro phenyl)-4-amino-1,2,4-triazoles (2h), 3-(3′-aminophenyl)-5-(3′-aminophenyl)-4-amino-1,2,4-triazoles (2i) and 4-methoxybenzohydrazide (1b).

Synthesis and Liquid Crystalline Properties of Novel Ethylene Derivatives

A novel homologous series of liquid crystals, viz., α-4-[4′-n-alkoxy cinnamoyloxy] benzoyl -β-4″-chloro phenyl ethylenes, has been synthesized. The series consists of twelve homologs. The methyl to butyl derivatives are not liquid crystalline and the rest of the homologs are enantiotropic liquid crystals. The octyl to dodecyl derivatives of the series are enantiotropically smectogenic in addition to nematogenic in character, but the pentyl, hexyl, heptyl tetradecyl, and hexadecyl homolog derivatives of the series are only nematogenic without the exhibition of a smectic phase. The transition temperatures of the novel substances were determined by optical polarizing microscopy equipped with a heating stage. A plot of transition temperatures versus the number of carbon atoms present in the n-alkoxy terminal chain represents the phase behavior of the series. An odd-even effect is observed for the nematic-isotropic transition curve. The textures of the nematic phase are of a threaded or Schlieren type and those of the smectic A and smectic C phases are typical. Analytical and spectral data agree with the molecular structures. The smectic and nematic thermal stabilities are 132.6°C and 156.7°C, respectively. The smectic phase commences from the octyloxy homolog. Smectogenic phase lengths vary from 26°C to 33°C and the nematogenic phase lengths vary from 6°C to 70°C. The series is predominantly nematogenic and partly smectogenic with considerable mesophase length and a middle-ordered melting type. The liquid crystal properties of the present series are compared with structurally similar homologous series.

Biologically active Schiff bases as potentiometric sensor for the selective determination of Nd3+ ion

Novel multidentate Schiff bases 5-((1-(3-(3-((5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl)-1H-indol-1-yl)propyl)-1H-indol-3-yl)methyleneamino)-1,3,4-thiadiazole-2-thiol (S1) and N-((1-(3-(3-((thiazol-2-ylimino)methyl)-1H-indol-1-yl)propyl)-1H-indol-3-yl)methylene)thiazol-2-amine (S2) were synthesized for the construction of Nd3+ ion-selective electrode. The polymeric membrane electrodes (PME) were fabricated along with various plasticizers and additive. It is found that the PME based on S1 having the composition (S1: (potassium tetrakis p-(chloro phenyl)borate) KTpClPB: (o-nitrophenyloctyl ether) o-NPOE: PVC≡4:2:58:36, w/w, mg) is found to be better. Thus, the coated graphite electrode (CGE) was constructed with the same composition and the results were compared with PME. The CGE is found to be better in comparison to PME with respect to all the potentiometric characteristics such as low detection limit (1.1×10−8molL−1), wide working concentration range (3.1×10−8–1.0×10−1molL−1), near Nernstian slope (19.8±0.3mVdecade−1 of activity), low response time (10s), shelf life time (105 days) and wide pH range (3.5–8.0). Both the PME and CGE were used for the quantifying the Nd3+ ion in various samples such as water, soil samples, binary mixtures and as an indicator electrode using EDTA. PME and CGE were also used for the determination of F− ion in mouth wash solution and tooth paste sample. Further the antibacterial activity of Schiff bases were examined by broth micro-dilution method and found that these are antibiotics against Staphylococcus aureus (Gram positive) and Escherichia coli (ATCC25922) (Gram negative).