Search

Reaction of di- n-butyltin oxide with 4,5-dimethoxy-2-nitrobenzoic acid yields the title compound which crystallizes as the usual dicarboxylatotetraorganodistannoxane dimer. Experimental details for the preparation and the structural characterization (by FTIR, NMR and single crystal XRD) are provided. The IR data shows that ligand acts in the bidentate manner. The crystal structure analysis of the compound reveals the presence of a centrosymmetric planar SnO unit connected to exocyclic Sn atom via two bidentate bridging carboxylate ligands. The remaining two carboxylate ligands are coordinated to the exocyclic Sn atom in the monodentate manner. Graphical Abstract: The crystal structure analysis of the title compound reveals the presence of a centrosymmetric planar Sn2O2 unit connected to exocyclic Sn atom via two bidentate bridging carboxylate ligands. The remaining two carboxylate ligands are coordinated to the exocyclic Sn atom in the monodentate manner. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A series of bimetallic organotin(IV) complexes with ferrocene-based azomethines (Schiff bases) were synthesized by reacting sodium salt of tranexamic acid, 4-amino butanoic acid, and phenyl alanine with trimethyltin and tributyltin chloride in 1 : 1 molar ratio under inert atmosphere. The synthesized trialkyl organotin complexes condense with formyl ferrocene under inert atmosphere to yield organotin(IV) ferrocenyl Schiff bases. Composition of the organotin(IV) complexes, bonding behavior of donor groups, and structural assignments were studied by elemental analysis, FT-IR, 1H, 13C, 119Sn NMR, and mass spectrometry. The spectral data suggest that the ligand is bidentate, coordinating through oxygens. Spectroscopic techniques reveal distorted tetrahedral geometry in solution for the complexes. As solids, the complexes are trigonal bipyramidal, confirmed by semi-empirical study. Mass spectrometric and elemental analysis data support the solid and solution spectroscopic results. Bioactivity screenings show in vitro biological potential. [ABSTRACT FROM AUTHOR]

Organotin complexes with the general formulae R2SnL2, R2Sn(Cl)L, and R3SnL have been synthesized where R = CH3, n-C4H6, C6H5, C6H11, and L = 4-(hydroxy methyl)piperidine-1-carbodithioic acid. The newly synthesized complexes have been characterized by elemental analysis, IR, NMR (1H, 13C and 119Sn), and, for one example, a single crystal x-ray structure. The FT-IR data shows the bidentate nature of the ligand. This coordination behavior is also confirmed by semi-empirical study. In the solid state, diorganotin complexes exhibit the penta/hexacoordinated geometry, whereas the triorganotin(IV) complexes show the five coordinated geometry. 119Sn NMR data reveal that triorganotin(IV) complexes exhibit the four coordinated geometry in solution, whereas the diorganotin(IV) compounds show the higher coordination, probably five or six. X-ray diffraction analysis of complex (2) shows a square pyramidal geometry around the tin atom on the basis of τ value. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT[image omitted] [ABSTRACT FROM AUTHOR]

Abstract: Biodiesel was synthesized from rocket seed oil by base-catalyzed transesterification with methanol. The synthesis of biodiesel was confirmed by FT-IR and NMR (1H and 13C) spectroscopy. Various fuel properties of the synthesized biodiesel were determined using ASTM methods and discussed accordingly. A total of eleven fatty acid methyl esters (FAMEs) were identified in rocket seed oil biodiesel (RSOB) by the retention time and the fragmentation pattern data of GC/MS analysis. The identified FAMEs were, methyl 9-hexadecenoate (C16:1), 14-methyl pentadecanoate (C16:0), methyl 9,12-octadecadienoate (C18:2), methyl 9-octadecenoate (C18:1), methyl octadecanoate (C18:0), methyl 11-eicosenoate (C20:1), methyl eicosanoate (C20:0), methyl 13-docosenoate (C22:1), methyl docosanoate (C22:0), methyl 15-tetracosenoate (24:1) and methyl tetracosanoate (C24:0). The percentage conversion of triglycerides to corresponding methyl esters determined by 1H NMR was 88.49%. [ABSTRACT FROM AUTHOR]

Eight organotin carboxylates have been synthesized in quantitative yield by reaction of NaL (L = 2-aminobenzoate) with the di- and triorganotin chlorides and triphenylphosphine. All the complexes have been characterized by elemental analysis, IR, multinuclear NMR (1H, 13C, and 119Sn), and mass spectrometry. The spectroscopic data indicate 1 : 2/1 : 1 M : L stoichiometry in 1, 3, 5, and 7 and 1 : 2 : 1/1 : 1 : 1 M : L : PPh3 stoichiometry in 2, 4, 6, and 8. FT-IR spectra clearly demonstrate metal attachment with both oxygens of the ligand and bidentate coordination in 1, 3, 5, and 7 while monodentate ligand for 2, 4, 6, and 8. In solid state, 1, 2, 5, and 6 exhibit six coordination whereas 3, 4, 7, and 8 show five coordination. The structural behavior is confirmed by semi-empirical study. NMR data reveal four-coordinate geometry in solution. These complexes were screened for antimicrobial activity in vitro. The screening tests show that tributyltin carboxylates are more potent antibacterial and fungicidal agents than corresponding methyl derivatives, and triphenylphosphine enhances the antibacterial and fungicidal activities of these complexes. [ABSTRACT FROM AUTHOR]

A new series of organotin(IV) complexes of aniline derivatives, R2SnL2 and R3SnL [where R = Me, n-Bu, n-Oct, and Ph], have been synthesized by the reaction of ligand acid with respective organotin halides in the presence of triethylamine as base or dioctyltin oxide using a Dean-Stark trap for the removal of water under reflux conditions. Experimental details for the preparation and characterization, including elemental analysis, IR, semi-empirical study, multinuclear NMR (1H, 13C, and 119Sn spectra and EI mass spectral studies) of all reported complexes are provided. The IR data indicate that in both di- and triorganotin(IV) carboxylates, the ligand moiety -COO acts as a bidentate group in the solid state. Multinuclear NMR data show that triorganotin complexes exhibits a four-coordinated geometry, while diorganotin(IV) complexes show a coordination number greater than four, probably five or six, in solution state. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. [ABSTRACT FROM AUTHOR]

This paper investigates the multiple emitting multiple receiving points diversity technique as one of the ways of meeting the tripartite conditions of high data rate, less transmit power, and low unwanted electromagnetic radiations of the frequency-selective power-line channels. To be resilient to the intersymbol interference present in frequency-selective fading, the diversity technique must be used in conjunction with wideband multicarrier modulation. We propose an efficient space-frequency and space-time-frequency (STF)-coded multitone M-ary multilevel frequency-shift keying (M3FSK) for high-rate indoor communications over the multiwire power-line channels. We show that coding by using three dimensions of space, frequency, and time, the STF system is capable of achieving up to 8-dB diversity gain. Simulation results are provided to demonstrate the performance improvement of the STF over other diversity schemes as well as over single-wire M3FSK systems in a highly impulsive power line. [ABSTRACT FROM AUTHOR]

2-(N-naphthylamido)benzoic acid was synthesized by the reaction of phthalic anhydride with naphthylamine in glacial acetic acid at room temperature. Complexes 1-9 were synthesized under reflux in good yield with general formula R4-nSnLn (R = Me, n-Bu, Ph, n-Oct, Bz and n = 2, 3), which were studied by microanalysis, IR, NMR (1H, 13C, 119Sn), and mass spectrometry. Cytotoxicity of the synthesized compounds was checked against Brine-shrimp larvae. In vitro activities against some Gram-positive and Gram-negative bacteria and fungi were also determined. Antimicrobial activities show that species with tetrahedral geometry in solution are more toxic. [ABSTRACT FROM AUTHOR]

Potassium methyl xanthate and its complex [Pd(Me-Xanthate)2 ] were synthesized at room temperature under stirring conditions. The ligand and the complex were characterized by elemental analysis, IR, NMR (1H, 13C) and XRD. NMR data revealed that potassium methyl xanthate acts as a bidentate specie and the complex exhibits 4-coordinated geometry in solution. In solid state, the palladium atom is coordinated to the 2 sulfur atoms of the xanthate ligand and the complex exhibits distorted square planar geometry. [ABSTRACT FROM AUTHOR]

Coverage is a fundamental issue in wireless sensor networks (WSNs). It plays a important role in network efficiency and performance. When sensor nodes are randomly scattered in the network environment, an ON/OFF scheduling mechanism can be designed for these nodes to ensure network coverage and increase the network lifetime. In this paper, we propose an appropriate and optimal area coverage method. The proposed area coverage scheme includes four phases: (1) Calculating the overlap between the sensing ranges of sensor nodes in the network. In this phase, we present a novel, distributed, and efficient method based on the digital matrix so that each sensor node can estimate the overlap between its sensing range and other neighboring nodes. (2) Designing a fuzzy scheduling mechanism. In this phase, an ON/OFF scheduling mechanism is designed using fuzzy logic. In this fuzzy system, if a sensor node has a high energy level, a low distance to the base station, and a low overlap between its sensing range and other neighboring nodes, then this node will be in the ON state for more time. (3) Predicting the node replacement time. In this phase, we seek to provide a suitable method to estimate the death time of sensor nodes and prevent possible holes in the network, and thus the data transmission process is not disturbed. (4) Reconstructing and covering the holes created in the network. In this phase, the goal is to find the best replacement strategy of mobile nodes to maximize the coverage rate and minimize the number of mobile sensor nodes used for covering the hole. For this purpose, we apply the shuffled frog-leaping algorithm (SFLA) and propose an appropriate multi-objective fitness function. To evaluate the performance of the proposed scheme, we simulate it using NS2 simulator and compare our scheme with three methods, including CCM-RL, CCA, and PCLA. The simulation results show that our proposed scheme outperformed the other methods in terms of the average number of active sensor nodes, coverage rate, energy consumption, and network lifetime. [ABSTRACT FROM AUTHOR]

Di-(1, 3, 8) and triorganotin(IV) complexes (2, 5, 7) with the general formula RnSnL4-n, where R = Me, Et, n-Bu, n-Oct, Ph, and Bz, and L = the n-C4H9OCOC6H4COO- monoanionic ligand have been synthesized by the reaction of the silver salt of the n-butylhydrogen phthalate with di- and triorganotin chloride in dry chloroform. However, di-n-butyl- and di-n-octyltin(IV) derivatives (4 and 6, respectively) were synthesized by the reaction of the corresponding organotin(IV) oxide with n-butylhydrogen phthalate in dry toluene. All the synthesized complexes were characterized by elemental analysis, FT-IR, multinuclear (¹H, 13C, 119Sn) NMR, and mass spectrometric techniques to assess the binding mode of the n-butylphthalate (n-C4H9OCOC6H4COO-) anion. The diorganotin(IV) derivatives were found to adopt distorted octahedral and triorganotin(IV) n-butylphthalates and to have linear, polymeric trigonal bipyramidal structures in which n-butylphthalate is a monoanionic bidentate coordinating through the C(O)O group. The biocidal activity and LD50 values of the synthesized compounds are also reported. Some complexes exhibited good activity comparable to that of standard drugs. Furthermore, triorganotin(IV) derivatives exhibited significantly better activity than the diorganotin(IV) derivatives. [ABSTRACT FROM AUTHOR]

The decontamination of lead ions from aqueous media has been investigated using styrene-divinylbenzene copolymer beads (St-DVB) as an adsorbent. Various physico-chemical parameters such as selection of appropriate electrolyte, contact time, amount of adsorbent, concentration of adsorbate, effect of foreign ions, and temperature were optimized to simulate the best conditions which can be used to decontaminate lead from aqueous media using St-DVB beads as an adsorbent. The atomic absorption spectrometric technique was used to determine the distribution of lead. Maximum adsorption was observed at 0.001 mol L-1 acid solutions (HNO3, HCl, H2SO4 and HClO4) using 0.2 g of adsorbent for 4.83×10-5 mol L-1 lead concentration in two minutes equilibration time. The adsorption data followed the Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) isotherms over the lead concentration range of 1.207×10-3 to 2.413×10-2 mol L-1. The characteristic Freundlich constants i.e. 1/n=0.164±0.012 and A=2.345×10-3±4.480×10-5 mol g-1 have been computed for the sorption system. Langmuir isotherm gave a saturated capacity of 0.971±0.011 mmol g-1, which suggests monolayer coverage of the surface. The sorption mean free energy from D-R isotherm was found to be 18.26±0.75 kJ mol-1 indicating chemisorption involving chemical bonding for the adsorption process. The uptake of lead increases with the rise in temperature. Thermodynamic parameters i.e. ΔG, ΔH, and ΔS have also been calculated for the system. The sorption process was found to be exothermic. The developed procedure was successfully applied for the removal of lead ions from real battery wastewater samples. [ABSTRACT FROM AUTHOR]

Acetal of warfarin acid has been synthesized via a hemi acetal intermediate and structurally characterized by X-ray diffraction. The crystal structure shows that the title compound was formed by the hydrolysis of warfarin acid in methanol at pH 3, with space group P21/n and unit cell parameters a = 5.859 (17), b =16.745 (5), c = 16.402 (5) Å, α = 90.00; β = 94.853 (4), and γ = 90.00°. [ABSTRACT FROM AUTHOR]

Abstract: Chloro-diorganotin(IV) complexes of 4-methyl-1-piperidine carbodithioic acid (4-MePCDTA) have been synthesized by the reaction with diorganotin dichloride in 1:1 molar ratio in anhydrous toluene. These newly synthesized complexes have been characterized by elemental, IR, multinuclear NMR (1H and 13C) and mass spectrometric studies. The crystal structures of complex 1 [Me2SnCl(4-MePCDT)] and 3 [Ph2SnCl(4-MePCDT)] have been determined by X-ray single crystal analysis, which show trigonal bipyramid geometry. These complexes were tested for their antimicrobial activity against six different plant and human pathogens. The screening results show that the complexes exhibit higher antibacterial and antifungal activity than the free ligand. [Copyright &y& Elsevier]

Organotin carboxylates of general formula R3SnL (1), (2) (4) and (6), R2SnL2 (5) and {[(R2SnL)2O]2} (3), where L = N-maleoylglycinate, N-maleoyl-b-alaninate and N-maleoylmethioninate were prepared. The synthesis of these compounds was achieved by either reaction of organotin halides, R3SnCl, with triethylammonium salt of N-maleoylamino acids or/and organotin oxides, (R3Sn)2O and R2SnO, with maleamic acid in the presence of triethyl amine. These compounds were characterized by FT-IR, multinuclear NMR (1H, 13C and 119Sn), mass and 119mSn Mössbauer spectroscopy. The geometry around the tin atom is compared both in solution and in solid state. Different literature methods were employed to calculate the C-Sn-C angle in non-coordinating solvents. The mass fragmentation pattern demonstrated the McLafferty rearrangement in compound (6). Salient features of the X-ray structures for (1), (4) and (6) are also given. [ABSTRACT FROM AUTHOR]

Organotin(IV) complexes of 2-(N-maleoylamino)-2-methylpropanoate were prepared by treating the ligand acid with diorganotin dichloride and triorganotin chloride in 1:2 and 1:1 molar ratios, respectively. These reactions proceeded smoothly to completion and the complexes formed were characterized by elemental analysis, infrared multinuclear NMR (1H, 13C, 119Sn) and mass spectrometry. The biological activities of the tin complexes were studied by screening the compounds against various animal and plant pathogens. These results show that triorganotin(IV) carboxylates are more active against the animal and plant pathogens tested as compared to diorganotin dicarboxylates. [ABSTRACT FROM AUTHOR]

In an effort to develop new organotin(IV) compounds of industrial and biological importance, a series of di- and triorganotin(IV) complexes of(E)-3-(4-chlorophenyl)-2-phenylpropenoic acid with the general formula R4-nSnLn have been synthesized by the reaction of the corresponding organotin chlorides with the sodium salt of(E)-3-(4-chlorophenyl)-2-phenylpropenoic acid(C15H10ClO2Na) where, R = CH3, C2H5, n-C4H9, C6H5, C6H5 · CH2, n = 1 or 2 and L = acid anion(C15H10ClO2−). The dimeric tetraorganodicarboxylatodistannoxanes[(Me2SnL)2O]2 compound(2) and[(Bu2SnL)2O]2 compound(4), L = C15H10ClO2−, were synthesized by the reaction of R2SnO with the ligand acid(HL) in 1:1 molar ratio with azeotropic removal of water. The structures of the complexes are discussed on the basis of IR, multinuclear(1H, 13C, 119Sn) NMR, 119mSn Mössbauer spectroscopies and mass spectrometry. The spectroscopic results substantiate that all the diorganotin(IV) derivatives possess trigonal-bipyramidal structures in solution and octahedral geometry in the solid state. A linear polymeric trigonal-bipyramidal structure in the solid state and a tetrahedral environment around the tin atom in non-coordinating solvents has been proposed for the triorganotin(IV) derivatives. TheΔν[Δν = νasym(COO) − νsym(COO)] values obtained from the IR data, in comparison to the ligand acid and its sodium salt, fall in the range which shows that the ligand may act as a bidentate coordinating group through the carboxyl(COO) oxygen atoms. The biological activity and LD50 data of the synthesized compounds are also reported. The triorganotin(IV) complexes exhibit significantly better activities than the diorganotin(IV) derivatives. The LD50 data show that most of the investigated compounds are cytotoxic. [ABSTRACT FROM AUTHOR]

Di- and triorganotin(IV) compounds of the type R2SnR2′ and R3SnR′ (R = CH3, n-C4H9, C6H5, C6H5CH2 and R′=n-C7H15) have been prepared by the reaction of R2SnCl2 and R3SnCl with a stoichiometric amount of n-heptylmagnesium bromide, prepared in situ in dry diethyl ether. The products obtained were vacuum distilled. The structural assignments were made on the basis of spectral studies such as FT-IR, 1H, 13C, 119Sn NMR, and mass spectrometry which ascertain the tetrahedral environment around the tin atom. [ABSTRACT FROM AUTHOR]

The reaction of 2-[(2,3-dimethylphenyl)amino]benzoic acid (HL) with tri- and diorganotin(IV) chlorides yielded complexes of the type R3SnL and R2SnL2 (R = n-C4H9, C6H5, C6H5CH2, n-C8H17). The compounds R2SnClL were obtained by a redistribution reaction between R2SnL2 and R2SnC12. All the compounds were characterized by CHN analysis, infrared, multinuclear NMR, mass and Mössbauer spectroscopy. The possible mode of carboxylate group bonding in solid as well as in solution is proposed on the basis of infrared, Mössbauer and NMR (¹H, 13C, 119Sn) spectroscopy. [ABSTRACT FROM AUTHOR]

A series of tri- and diorganotin(IV) compounds with the general formulae R3SnL and R2SnL2 (where R = Me, n-Bu, Ph and L = 2-[N-(2,6-dichloro-3-methylphenyl)-amino]benzoate) were synthesized. These compounds were characterized by different instrumental methods such as infrared, multinuclear NMR (¹H, 13C, 119Sn) and mass spectrometry. The spectroscopic investigation illustrates that the carboxylate group acts as a bidentate in solid state and as a monodentate in solution. Biological screening tests reveal that the investigated compounds have potential as antibacterial agents. [ABSTRACT FROM AUTHOR]

A series of organotin(IV) derivatives with the general formula R[sub4-n]SnL[subn] (where n = 1 or 2, R = Me, Et, n-Bu, Ph and L = 2-(2-fluoro-4-biphenyl)propanoate) have been synthesized and characterized by infrared, multinuclear NMR (¹H, [sup13]C, [sup119]Sn), [sup119m]Sn Mössbauer spectroscopy and mass spectrometry. Screening tests of these compounds showed that they are highly active against various bacteria and fungi. [ABSTRACT FROM AUTHOR]

Organotin(IV) derivatives of the general formulae R2SnL2 and R3SnL where R = Me, n-Bu, n-Oct, Ph and Bz and HL = 4-bromomaleanilic acid have been synthesised. These compounds were characterized by elemental analyses, infrared, multinuclear (1H, 13C, 119Sn) NMR and mass spectrometry. Biological screenings were performed in order to establish their biological activity. [ABSTRACT FROM AUTHOR]

Deals with a study which synthesized and characterized a series of organotin complexes with the general formula R[sub2]SnL[sub2] and R[sub3]SnL, where R=CH[sub3], C[sub2]H[sub5], n-C[sub4]H[sub9], C[sub6]H[sub5], C[sub6]H[sub5]CH[sub2] and L=2-[(4-bromoanilino)carboxyl]benzoate by infrared, mass and multinuclear nuclear magnetic resonance spectroscopies. Experimental details; Results and discussion; Conclusion.

Presents a study that examined the synthesis of unsymmetric tetraorganotin (IV) compounds by the reaction of n-hexylmagnesium bromide with corresponding organotin (IV) chlorides. Characteristics of organometallic compounds; Uses of unsymmetric organotin (IV); Techniques in predicting the structures of compounds.

A series of di- and triorganotin(IV) carboxylates of 4-p-(chlorophenyl)-2-phenyl-5-thiazoleacetic acid has been synthesized and characterized by various instrumental techniques such as infrared, 1H, 13C, 119Sn NMR, mass spectrometry and thermal analysis. These compounds were also tested for their antibacterial and antifungal activities to study their biological significance. [ABSTRACT FROM AUTHOR]

In an effort to develop new organotin materials for investigation and biocidal evaluation, a series of compounds with the general formula R4-nSnLn (where R=CH3, n-C4H9, C6H5, C6H5CH2 and L=2-(N-maleoyl)-3-phenylpropanoic acid anion) have been synthesized, and characterized by elemental analyses, IR, multinuclear (1H, 13C and 119Sn) NMR and mass spectrometry. The biological activity of these compounds against various bacteria and fungi has been investigated. All of the compounds were found to be active against the tested fungi with a few exceptions. These compounds also showed significant antibacterial activity. LD50 data show that the investigated compounds also have significant toxicity. [ABSTRACT FROM AUTHOR]

Complexes of the composition R4-nSnLn (R=Me, Et, Bu, Ph, Bz, n=1 and 2, and L=2-(6-methoxynaphthyl)propionic acid anion have been synthesized by the reaction of tri- and diorganotin halides with the silver salt of 2-(6-methoxynaphthyl)propionic acid in dry chloroform. Conductance data show that the complexes are non-electrolytes. Structural assignments were made on the basis of spectral studies (FTIR, 1H, 13C, 119Sn NMR, mass and UV-Vis spectroscopy). [ABSTRACT FROM AUTHOR]

Various organotin derivatives of 3-benzoyl-α-methylphenylacetic acid (HL1) and 3-(2-thienyl)acrylic acid (HL2) of the general formulae R3SnL, R2SnL2 and R2Sn(Cl)L where R=Me, Et, n-Bu and Ph, L=L1 or L2, have been synthesized. These compounds were characterized by elemental analyses, infrared, mass, 1H, 13C and 119Sn NMR spectra and the geometry around the tin atom has been discussed. [ABSTRACT FROM AUTHOR]

Dentin adhesives (DAs) play a critical role in the clinical success of dental resin composite (DRC) restorations. A strong bond between the adhesive and dentin improves the longevity of the restoration, but it is strongly dependent on the various properties of DAs. The current review was aimed at summarizing the information present in the literature regarding the improvement of the properties of DAs noticed after the addition of bioactive inorganic fillers. From our search, we were able to find evidence of multiple bioactive inorganic fillers (bioactive glass, hydroxyapatite, amorphous calcium phosphate, graphene oxide, calcium chloride, zinc chloride, silica, and niobium pentoxide) in the literature that have been used to improve the different properties of DAs. These improvements can be seen in the form of improved hardness, higher modulus of elasticity, enhanced bond, flexural, and ultimate tensile strength, improved fracture toughness, reduced nanoleakage, remineralization of the adhesive–dentin interface, improved resin tag formation, greater radiopacity, antibacterial effect, and improved DC (observed for some fillers). Most of the studies dealing with the subject area are in vitro. Future in situ and in vivo studies are recommended to positively attest to the results of laboratory findings. [ABSTRACT FROM AUTHOR]

In a panel session on "Data, Platforms, and Policies," participants examined the state of artificial intelligence (AI) in the Arab states and discussed the responsible use of AI in data-driven systems in government, health care, education, and industry. [ABSTRACT FROM AUTHOR]

• Synthesis of novel organotin(IV) carboxylates • Spectroscopic characterizations and structural elucidation • Interaction with SS-DNA via intercalative mode of interaction • In vitro antibacterial, anticancer, and antileishmanial activity A series of ten organotin(IV) carboxylate derivatives of 2-((2-methoxyphenyl)carbamoyl)benzoic acid were prepared and confirmed by FTIR, CHN analysis and single crystal XRD (SCXRD) as well as by NMR and mass spectrometry. The microelemental CHN analysis results give a close matching with those of the theoretical values of CHN atoms. The results of the solid state SCXRD for the complex 3 reveals a trigonal bipyramidal geometry (TBG) with slight distortion for the R 3 SnL derivatives. Further confirmation about the 5-coordinated TBG may also be achieved from the τ value which is 0.87 for the complex 3. It is obvious from the crystal structure of the complex 3 that the involvement of the O1 of the carboxylate moiety and O3 of the amide moiety with Sn atom are responsible for formation of the polymeric structure having 5-coordinated TBG. The comparison of SCXRD value (124.8°) and that of 13C NMR value (123°) for C-Sn-C angle in complex 3 is the best confirmation of 5-coordinated TBG for the R 3 SnL derivatives. The evaluated compounds interact with DNA by an intercalative type of binding as displayed by the results obtained from UV-vis. and viscosity measurements. The results of the antimicrobial activity of the evaluated compounds in comparison to the standard drugs demonstrate that the tested compounds possess good antimicrobial potentials. The cytotoxicity results obtained against H-157 and BHK-21 cell lines using Sulforhodamine B based method show that compound 1 has the maximum activity among the studied compounds and its activity is comparable to that of the vincristine. The small IC 50 value for the compound 1 as compared to the standard antileishmanial drug, Amphotericin B, proves the efficiency of the tested compounds for the treatment of leishmania disease. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Salivary biomarkers are indicators of many biological and pathological conditions and provide further information regarding the early detection of diseases. This bibliometric analysis aims to identify and evaluate the scientific literature addressing salivary biomarkers from a dental perspective, to identify the most prolific organizations, authors, journals, countries, and keywords used within this research domain. An electronic search was performed using Elsevier's Scopus database. From a total of 587 retrieved papers (published between 1997 and 2021), 399 were selected. For the data analysis and its visualization, the title of the articles, year of publication, countries, authors, journals, articles, and keywords were analyzed using Microsoft Excel and VOSviewer (a bibliometric software program). An increase in the number of publications was identified from 1997 to 2021. The United States (U.S.) published the most papers (84) and received the highest citations (3778), followed by India and Brazil. The Journal of Periodontology published the highest number of articles (39) that received the highest citations. The University of Kentucky from the U.S. published most of the papers related to salivary biomarkers that received the highest citations. Timo Sorsa published the most papers (14 papers), while Craig Miller was the highest cited author (754 citations). Concerning the highly cited papers, a paper by Micheal et al., published in 2010, received the highest citations (487 citations). "Saliva", followed by "human", were the most common keywords used by the authors in the papers related to salivary biomarkers. The findings of this analysis revealed an increase in salivary biomarker-related publications that positively influenced the number of citations each paper received. The U.S. produced the most publications that received the highest citations, and the University of Kentucky, U.S., was the most prominent. The articles were mostly published in the Journal of Periodontology and received the highest number of citations. [ABSTRACT FROM AUTHOR]

Optical character recognition is gaining immense importance in the domain of deep learning. With each passing day, handwritten digits (0–9) data are increasing rapidly, and plenty of research has been conducted thus far. However, there is still a need to develop a robust model that can fetch useful information and investigate self-build handwritten digit data efficiently and effectively. The convolutional neural network (CNN) models incorporating a sigmoid activation function with a large number of derivatives have low efficiency in terms of feature extraction. Here, we designed a novel CNN model integrated with the extreme learning machine (ELM) algorithm. In this model, the sigmoid activation function is upgraded as the rectified linear unit (ReLU) activation function, and the CNN unit along with the ReLU activation function are used as a feature extractor. The ELM unit works as the image classifier, which makes the perfect symmetry for handwritten digit recognition. A deeplearning4j (DL4J) framework-based CNN-ELM model was developed and trained using the Modified National Institute of Standards and Technology (MNIST) database. Validation of the model was performed through self-build handwritten digits and USPS test datasets. Furthermore, we observed the variation of accuracies by adding various hidden layers in the architecture. Results reveal that the CNN-ELM-DL4J approach outperforms the conventional CNN models in terms of accuracy and computational time. [ABSTRACT FROM AUTHOR]

Taking cognizance of the medicinal significance and diverse functions of synthetic Morita-Baylis-Hillman adducts (MBHA), the title ligand was synthesized and purified through column chromatography. Cr+3, Mn+2, Co+3, Ni+2, Cu+2 complexes of the ligand were synthesized under basic conditions, subjected to characterization through spectral analyses and verified with the IR spectrum that was generated computationally by the DFT B3LYP method, with 6-311++ G (d,p) basis set and Hartree Fock (HF) B3LYP method in conjunction with 3-21G(d,p) basis set. Powder XRD helped to testify crystals of the complexes. Moreover, the antibacterial, and antioxidant characteristics of MBHA and its complexes were also established. All of them were found to be active antioxidants. The antibacterial activities, examined against S. aureus, E. coli, B. pumilis and S. typhi have revealed that its Cobalt complex has an excellent potential to act against all of them. Hence, these compounds maybe having potentialities for the discovery of new, cheaper and efficient drugs against various infectious diseases. The study also uncovers the first example of utilization of MBHA towards metal complex formation. [ABSTRACT FROM AUTHOR]

In this study, Raman spectroscopy has been employed for the characterization of two structurally different monodentate N-heterocyclic carbene ligands (ligand-1 and ligand-2) and their respective complexes (complex-1 and complex-2). The Raman spectral features are found helpful for the confirmation of formation of complexes. The significant Raman spectral features are identified for benzimidazole ring with higher intensities in carbene complexes having more polarizability as compared to their ligands, providing the evidence for the formation of coordinate covalent bond. The successful complexation is further supported by using multivariate data analysis technique, Principal Component Analysis (PCA), which is found very helpful to highlight the variability of Raman spectral data of both ligands and their respective metal complexes from each other. Moreover, the coordination of carbene with Ag(I) is confirmed from the dominant spectral markers of higher intensities at 359 cm−1 in complex-1 and 338 cm−1 in complex-2. The effective and reliable characterization and confirmation of metal complexes indicates the potential of Raman spectroscopy for its use for the characterization of the organometallic complexes and other chemical products. Unlabelled Image • Raman spectroscopy employed for the characterization of two different ligands and their respective co-ordinate complexes. • Raman spectral signatures observed for both Ag(I)-(NHCs) complexes were associated with their respective ligands. • Principal Component Analysis (PCA) is found very helpful to differentiate two ligands and complexes from each other. • Raman peaks with higher intensities in complexes are due to enhanced polarizability of benzimidazolium on complex formation. [ABSTRACT FROM AUTHOR]

The carboxylic acid functional group plays a fundamental role in the biochemistry of living systems as well as in drug design by enhancing the hydrophilicity of drugs as well as their polarity which in turn affect their bioavailability. Two new carboxylic acid derivatives with molecular formula C 15 H 12 N 2 O 6 , (1) and C 11 H 12 N 2 O 6 (2) were successfully confirmed by different instrumental techniques. Confirmation by FT-IR and 1H NMR techniques was proved by the presence of the OH peak (3289 cm−1 & 3264 cm−1 and 12.20 ppm & 12.12 ppm, respectively). Biological potency of the compounds was explored in term of bacterial, cancer and leishmania treatment. Furthermore the interaction with Salmon sperm DNA (SS-DNA) was also explored resulting in an intercalative binding mode. From the preliminary in vitro antibacterial activity, it is found that the synthesized compounds have higer effect against some tested pathogens as compared to the recommended standard antibiotics. The anticancer potency against H-157 (lung carcinoma) and BHK-21 (kidney fibroblast) cell lines of the both compounds is relatively smaller compared to that of the vincristine while a significant antileishmanial potency against leishmania major was observed. The intercalative binding mode was further confirmed by Molecular docking study. The interaction of the designed compounds with SS-DNA was assigned an intercalative mode of binding that was confirmed both by experimental and theoretical studies. The compounds also show good antibacterial, anticancer and antileishmanial activities. Image 1 • Synthesis of potentially bioactive peptide linkage carboxylic acid derivatives. • Structural and spectroscopic characterizations. • Antibacterial activity. • Interaction with SS-DNA via intercalative mode of interaction. • In vitro anticancer and antileishmanial activity. [ABSTRACT FROM AUTHOR]

This article focus on the synthesis of three 5-coordinated Sn(IV) complexes based on carboxylate ligand: 4-((4-methoxy-2-nitrophenyl)amino)-4-oxobutanoic acid. The complexes were characterized both in solid state (FT-IR, single crystal XRD and micro elemental analysis) as well as in solution state (1H, 13C and 119Sn NMR) and their results demonstrate that the carboxylate moiety of the ligand is linked with Sn atom. A 5-coordinated trigonal bipyramidal structure was obtained from crystallographic data for the reported complexes with little bit distortion from the ideal structure. Preliminary antifungal screening showed that the tested compounds have 100% fungal inhibition capability as shown by the well known antifungal drug, Terbinafine. Bacterial inhibition results showed that these compounds have outstanding inhibition capability against various pathogens as compared to the market available standard antibacterial drugs, Cefixime and Roxithromicine. The antiproliferative/anticancer result against H157 cancer cell line revealed that compounds 1 and 2 have shown the maximum activity (49–69% cytotoxicity even at 2 μg/mL final concentration). The tested compounds were found active against human corneal epithelial cells (HCEC). The synthesized compounds were almost non-toxic towards HCEC. Compounds 1 and 2 have shown 6.9% and 7.9% antiproliferative activity, respectively when used at the 2.0 μg/mL final concentration while compound 3 is totally non-toxic towards HCEC like the standard drug, Methotrexate. The antileishmanial results of these compounds are good though their activity is lower than that of the Amphotericin B. An intercalative mode of interaction was observed during the interaction of the titled compounds with DNA. • Synthesis of new triorganotin(IV) carboxylates. • Interaction with SS-DNA via intercalative mode of interaction. • In vitro antimicrobial against various strains. • Anticancer Activity against H157, BHK21 ad HCEC cell lines. • Antileishmanial activity against leishmanial major strain kwh 23. [ABSTRACT FROM AUTHOR]

In this study Raman spectroscopy is employed for the characterization of two different ligands called as S1 and S2 and their respective co-ordinate complexes called C1 and C2. Specific Raman spectral signatures are observed for each of these Silver(I)- N -heterocyclic carbene complexes Ag(I)-(NHCs), which can be associated with the imidazolium ring, part of both of the ligands, indicating the formation of new coordinate covalent bond. For the detailed analysis, Raman spectral data of these ligands and complexes is analyzed by multivariate data analysis technique, Principal Component Analysis (PCA) which is found very helpful to differentiate two ligands and complexes from each other. The significant Raman peaks with higher intensities in the complexes as compared to the respective ligands are associated with imidazole ring which can be attributed to the enhanced polarizability of this ring on complex formation. Moreover, the spectral features associated with (Ag C) bond are observed with higher intensity at 360 in (C1) and 383 in (C2). This study indicates the potential of Raman spectroscopy for the characterization and confirmation of formation of organometallic complexes and other chemical products. Unlabelled Image • Raman spectroscopy employed for the characterization of two different ligands and their respective co-ordinate complexes. • Specific Raman spectral signatures observed for each of the Silver(I)- N -heterocyclic carbene complexes Ag(I)-(NHCs), associated with the imidazolium ring, part of both of the ligands. • Principal Component Analysis (PCA) is found very helpful to differentiate two ligands and complexes from each other. • Raman peaks with higher intensities in the complexes as compared to the respective ligands are associated with enhanced polarizability of imidazole ring on complex formation. [ABSTRACT FROM AUTHOR]

The title compound, C15H19NO3, a Schiff base, crystallizes as a zwitterion with the hydroxyl H atom transfered to the imine N atom. This leads to the formation of an intra­molecular N—H⋯O hydrogen bond. In the crystal structure, symmetry-related mol­ecules are linked by an inter­molecular O—H⋯O hydrogen bond, forming chains extended in the a-axis direction. The mol­ecules are also connected via C—H⋯O hydrogen bonds, forming a two-dimensional network. [ABSTRACT FROM AUTHOR]

The title compound, C8H5NO5, consists of a cyclic diether (1,3-dioxalene) fused to 3-nitro­benzaldehyde. In the crystal structure, symmetry-related mol­ecules are linked by C—H⋯O hydrogen bonds, forming a sheet-like structure parallel to the ab plane. These sheets are further linked by C—H⋯O hydrogen bonds, forming a three-dimensional network. [ABSTRACT FROM AUTHOR]

• Synthesis of mononuclear and poly-nuclear copper(II) complexes. • Characterization through FT–IR, UV–Visible, ESR, electrochemical and powder and single crystal XRD techniques. • Structural description. • DNA-binding, antibacterial studies and DFT studies. Polynuclear copper(II) complexes [Cu(para -fluorophenyl acetate) 2 n (1) and [Cu(para -nitrophenyl acetate) 2 n (2) were converted in-situ to mono-nuclear complexes [Cu(para -fluorophenyl acetate) 2 (1,10-Phenanthroline)(H 2 O)] (3) and [Cu(para -nitrophenyl acetate) 2 (2,2́-Bipyridine)(H 2 O)].3H 2 O (4). The complexes were isolated in quantitative yield, purified and characterized using FT-IR, absorption, electrochemical, electron paramagnetic resonance and powder XRD techniques yielding results in accordance with structural data. Structures of 1 and 2 consist of directly interlinked paddlewheel units with square pyramidal geometry while those of 3 and 4 are mononuclear with octahedral and square pyramidal geometry around Cu. Fluorinated complexes 1 and 3 were found to consist of extensive intermolecular interactions while 2 and 4 contained no such interactions. Their optical band gap was around 1.4 eV which indicates semiconducting property of the complexes. Moreover, the flourous complex 3 was found to possess significant activity against Bacillus subtilis and Escherichia coli and good activity against Micrococcus luteus. A similar trend was observed in their DNA-binding potency studied through absorption as well as electrochemical solution studies yielding K b values 1.494 × 104, 1.342 × 104 and 1.411 × 104 M−1 and 7.547 × 104, 2.457 × 104 and 3.667 × 104 M−1 for 1–3, respectively. The electronic structures of the complexes elucidated using density functional theory ab -initio calculations confirmed the Intermediate states which play important role in the enhancement of the optoelectronic properties. The structure and properties of the flourous complexes were found different than their non-flourous analogues which was attributable to fluorine. [ABSTRACT FROM AUTHOR]

In the search for new therapeutic agents we have synthesized 13 new organotin(IV) carboxylate derivatives of (E)-4-((4-methoxy-2-nitrophenyl)amino)-4-oxobut-2-enoic acid. The synthesized complexes were characterized by several spectroscopic techniques. A chelating or bridging bidentate nature of the carboxylate ligand was suggested from the solid state FT-IR results. Solution state multinuclear NMR (1H, 13C and 119Sn) results reveal that the geometry around the Sn atom in triorganotin(IV) complexes is trigonal bipyramidal and in diorganotin(IV) complexes is octahedral. The ligand, (E)-4-((4-methoxy-2-nitrophenyl)amino)-4-oxobut-2-enoic acid, complex 1 and complex 2 were also analyzed by single crystal X-ray technique and the results fully supports the spectroscopic data. For 1 and 2 the geometry optimized by the single crystal X-ray analyses is distorted trigonal bipyramidal. The interaction of the studied compounds with SS-DNA was investigated by UV–Vis. Spectroscopy and Molecular docking showing an intercalative mode of binding. The evaluation of the screened compounds for cancer treatment displays even higher than that of the vincristine used as a standard drug. Similarly the performance of the tested compounds as an antileishmanial agent considers them very close in activity to the standard drug, amphotericin B. The antibacterial results show that the most of the compounds have a moderate sensitivity against the studied bacterial pathogens. Unlabelled Image • Synthesis of novel organotin(IV) carboxylates • Spectroscopic characterizations and Structural elucidation • Interaction with SS-DNA via intercalative mode of interaction. • In vitro antibacterial, anticancer and antileishmanial activity • Molecular docking [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, [Sn(CH3)3(C15H10ClO2)] n, contains polymeric chains along the b axis. The geometry around the Sn atom is distorted trigonal bipyramidal, wherein three methyl groups are bonded to the Sn atom at equatorial positions with essentially identical bond distances [mean Sn—C = 2.119 (6) Å] and two O atoms of the carboxylate ligand are bonded asymmetrically with significantly different Sn—O distances of 2.159 (2) and 2.351 (2) Å. [ABSTRACT FROM AUTHOR]

Chemical screening on ethyl acetate fraction (Fr. C) obtained from the roots of Berberis brevissima Jafri. resulted in three compounds. Their structures were elucidated as β-Sitosterol-3-O-β-ᴅ-glucopyranoside (1), Berberine (2), and Pakistanine (3) using spectroscopic analysis, including mass, 1D, and 2D NMR data techniques. The antibacterial assays of the obtained six oil sub-fractions (H-1 to H-6) were accomplished against S. epidermis, E. coli, and S. aureus bacterial strains and the results ranged from 10-18 mm zone of inhibition. The GC-MS analysis of the six oil sub-fractions (H-1 to H-6) confirmed the existence of linoleic acid, palmitic acid, and oleic acid in the highest amount. [ABSTRACT FROM AUTHOR]

Eight new amide‐based carboxylate derivatives were synthesized and evaluated for anti‐inflammatory potentials using in‐vitro, in‐vivo and in silico studies. In cyclooxygenase‐2 assay, maximum percent antagonist potential was exhibited by sodium 4‐((4‐fluorophenyl) amino)‐4‐oxobutanoate (93.91 %), bis ((4‐((4‐methoxy‐2‐nitrophenyl)amino)‐4‐oxobutanoyl)oxy) zinc (93.04 %), and bis ((4‐((4‐bromo‐2‐fluorophenyl) amino)‐4‐oxobutanoyl)oxy)zincio (2‐bromopyridine) (92.64 %) with IC50 values of 1.65, 2.08, and 0.288 μM/ml respectively. Celecoxib demonstrated 98.60 % effect with an IC50 value of 0.041 μM/ml. In LOX assay, 4‐((4‐methoxy‐2‐nitrophenyl)amino)‐4‐oxobutanoic acid (97.03 %), bis ((4‐((4‐methoxy‐2‐nitrophenyl)amino)‐4‐oxobutanoyl)oxy)zinc (95.45 %), and (92.53 %) demonstrated maximum percent effect with IC50 values 3.48, 0.45, and 0.83 μM/ml respectively. The standard 5‐lipoxygenase inhibitor (montelukast) resulted from a 98.39 % inhibitory effect with an IC50 value of 0.194 μM/ml. In in‐vivo analysis, the potent tested compounds (5, 10, and, 20 mg/kg) significantly (p<0.001) reversed the induced edema by carrageenan. The standard drug aspirin displayed significant results (74–83 %). The standard drugs in these phlogestic agents displayed excellent results like cetirizine (67.9 %), celecoxib (81.61 %), icatibant (82.22 %) and nemesulide (87.17 %) at 5th h. The compounds displayed the inhibitory potential against targeted proteins. 4‐((4‐methoxy‐2‐nitrophenyl)amino)‐4‐oxobutanoic acid, 4‐((4‐fluorophenyl)amino)‐4‐oxobutanoic acid and sodium 4‐((4‐bromo‐2‐fluorophenyl)amino)‐4‐oxobutanoate shown excellent behavior by giving negative binding energies close of standard drugs montelukast (5F1A: −7.9 kcal/mol) and diclofenac (3O8Y: −8.5 Kcal/mol). The tested compounds were proven significant anti‐inflammatory potentials. [ABSTRACT FROM AUTHOR]

Two copper(II) paddlewheel carboxylate complexes 1 and 2 of the general formula ACuL4CuA, where A is DMSO (1) and meta-bromopyridine (2) and L is meta-chlorophenyl acetate, have been synthesised, isolated quantitatively, crystallised and characterised using FTIR, UV-Visible spectroscopy, electrochemistry and XRD. FTIR spectra contained all the required peaks with the most prominent peaks those of carboxylate moiety indicating the bridging bidentate carboxylate binding mode. Electrochemistry yielded results typical of complexes containing Cu2+ centres. The structures were completely solved by XRD technique assigning square pyramidal geometry to each copper ion of the dinuclear complexes. The square base is formed by four oxygen atoms of the carboxylate moiety while the apical position is occupied by the fifth oxygen (of the DMSO molecule in 1) or nitrogen of the meta-bromopyridine in complex 2. The DNA-binding potency of the complexes was explored by viscometry, cyclic voltammetry, UV-Visible spectrophotometry and spectrofluorimetry. All these techniques provided coincident results and showed that the complexes bonded with DNA via an intercalative-binding mode. Additionally, these complexes were found to scavenge the free radical DPPH effectively. The complexes add interesting and valuable addition to the existing treasury on the copper paddlewheel complexes and their biological relevance. [ABSTRACT FROM AUTHOR]

Objective: To determine the association between pseudoexfoliation and glaucoma. Study Design: Cross-sectional analytical study. Place and Duration of Study: Eye Outpatient department of Combined Military Hospital, Multan from Jan to Dec 2019. Methodology: A total of 170 patients reporting to the eye outpatient department were examined for the presence of Pseudoexfoliation and glaucoma based on raised intraocular pressure >21mm Hg, increased cup disc ratio and visual field defects. Therefore, a total of 340 eyes were examined. Results: Out of a total of 252 eyes with pseudoexfoliation, 40 (15.9%) had glaucoma. This frequency of glaucoma was significantly higher in eyes with pseudoexfoliation 87 (98.9%), in comparison to eyes without pseudoexfoliation 1 (1.1%); p<0.01). Conclusion: Pseudoexfoliation was found to be strongly associated with glaucoma. [ABSTRACT FROM AUTHOR]

Our commentaries from the Primary Care Neurology Society (P‐CNS) provide a primary care perspective on the neurology articles in Progress. Here Dr Bindemann and Dr Ali consider ‘Psychobiotics: bacterial hope for depression’ (see page 9). [ABSTRACT FROM AUTHOR]

Environmental problems caused by the influence of organic dyes have devoted researchers to build the system for the degradation of dyes. Photocatalysis has gained a remarkable interest to degrade organic dyes for wastewater treatments. In this work Polyaniline@NiO with different wt.% the composition was synthesized with rich catalytic sites by in‐situ polymerization to degrade the organic dye Rhodamine‐B from water. The synthesized materials were characterized by XRD, RAMAN spectroscopy, SEM, UV/Vis spectroscopy and Photocatalytic degradation. Polyaniline (PANI) showed a high absorption coefficient in visible light and NiO absorbs light in the ultraviolet range. The charge mobility was enhanced by making a composite of PANI and NiO. The photocatalytic performance of PANI in visible light was improved by making its composite with NiO, which provides the easing path to flow photoelectron from LUMO of PANI to the surface of the water and further dye degradation mechanism was performed [ABSTRACT FROM AUTHOR]

Four mononuclear copper(II) and zinc(II) complexes were synthesized by the reaction of copper and zinc salts with 3,4‐dichlorophenylactic acid, 2‐bromophenylactic acid, biphenylacetic acid (O‐donor ligand) and bipyridine (N‐donor ligands) having the general formulae [(L)2Cu(bp)(H2O)] (1), [(BpA)2Cu(bp)] (2), [(L)2Zn(bp)(H2O)] (3) and [(L*)2Zn(bp)] (4) (L = 3,4‐dichlorophenylacetate, L* = 2‐bromophenylacetate bp = bipyridine, and BpA = biphenylacetate). Structures of all compounds were characterized through FT‐IR spectroscopy and X‐ray diffraction analysis. FT‐IR spectra of all complexes confirmed the binding mode of Cu‐O and Zn‐O. XRD data revealed that complexes 1–3 exhibited distorted octahedral arrangement, whereas complex 4 has a distorted tetrahedral environment. Micellization behavior was examined with anionic surfactant (SDS) by conductance measurement as well as absorption spectral analysis. DNA binding study was assessed through viscosity measurement and UV/Vis spectrophotometry. DPPH free radical scavenging assay was measured by UV/Vis spectrophotometry. The results showed nice biological potential of all the complexes. [ABSTRACT FROM AUTHOR]