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Xueqin Song - One of the best experts on this subject based on the ideXlab platform.
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a cationic tetrahedral zn ii cluster based on a new Salicylamide imine multidentate ligand synthesis structure and fluorescence sensing study
Dalton Transactions, 2019Co-Authors: Huanhuan Meng, Xueqin Song, Caiyun Wang, Li WangAbstract:A monocationic ZnII tetrahedral cluster, [Zn4L3(μ3-OH)]·NO3·1.25H2O (Zn4L3) based on a new Salicylamide imine ligand H2L, H2L = 1-(2-hydroxy-3-methoxy-benzamido)-3-(2-hydroxy-3-methoxy-benzylideneamino)-propane, has been prepared. Single crystal X-ray analysis reveals that three deprotonated ligands L2– chelate three Zn(II) centres with their Salicylamide moiety in such a way that the three salicylimine groups attached to the other side of the three chelates are converged to bind another Zn(II) centre to provide a tetrahedral cluster with two phenyl groups of the same ligand L2– being close enough to present a strong intramolecular π⋯π stacking effect. Fluorescence studies indicate that Zn4L3 is stable in water and exhibits highly sensitive and selective recognition of phosphates against other common anions including CO32–, HCO3–, NO3–, F−, Cl−, Br−, I−, HSO4–, SO42–, OAc−, BF4–, ClO4– and CF3SO3– in HEPES buffer solution (pH = 7.4) + DMSO (V : V = 1 : 9). The excellent sensing capability of Zn4L3 for phosphate against other common anions with a low detection limit of 0.15 μM renders it a candidate probe for phosphate detection. Furthermore, the observed fluorescence quenching responses of Zn4L3 towards phosphates were highly reversible. The possible sensing mechanisms for phosphate detection by Zn4L3 was investigated by means of 1H NMR, UV-Vis spectra and high-resolution ESI-MS spectra and the results indicate that phosphates could exclusively decompose Zn4L3 to release H2L in HEPES buffer solution (pH = 7.4) + DMSO (V : V = 1 : 9).
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pentanuclear sandwich type zn ii ln iii clusters based on a new salen like Salicylamide ligand structure near infrared emission and magnetic properties
Polyhedron, 2017Co-Authors: Caiyun Wang, Mo Zhang, Xueqin SongAbstract:Abstract Two new sandwich-type heterometallic ZnII-LnIII clusters based on a methoxy substituted Salicylamide Salen-like ligand, [Zn2Er3(HL)2(H2L)2(OH)2(NO3)3](NO3)2·2CH3OH (Zn2Er3), [Zn2Yb3(HL)2(H2L)2(OH)2 (NO3)3](NO3)2·2CH3OH (Zn2Yb3), H3L = 1-(2-hydroxy-4-methoxy-benzamido)-2-(2-hydroxy-3-methoxy-benzylideneamino)-ethane, were prepared and structurally characterized. Single-crystal structure analyses reveal that both compounds are pentanuclear clusters with a hydroxyl bridged trinuclear LnIII3 core swaddled by two ZnII ions, two singly deprotoned H2L− ligands, two doubly deprotoned HL− ligands and three nitrate anions. Photophysical determination indicates that the two ZnII-LnIII compounds display both ligand-centered and near-infrared emission. The magnetic susceptibility measurements reveal that Zn2Er3 displays antiferromagnetic interactions with zero field slow magnetization relaxation diagnostic of single-molecule-magnet (SMM).
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two dodecanuclear heterometallic zn6ln6 clusters constructed by a multidentate Salicylamide salen like ligand synthesis structure luminescence and magnetic properties
Dalton Transactions, 2016Co-Authors: Xueqin Song, Jingjing Zhou, Xiaolong WangAbstract:The employment of a multidentate Salicylamide salen-like ligand, 2-hydroxy-N-(2-(2-hydroxybenzylidene)amino)ethyl)benzamide (H3L), in aid of NO3− anions under weak basic conditions in ZnII–LnIII chemistry (Ln = Eu, 1 and Dy, 2) led to the isolation of two novel butterfly heterometallic dodecanuclear clusters with six LnIII ions occupying the body position and six ZnII ions the outer wing-tip sites. All of them are fully characterized by elemental analysis, FT-IR spectroscopy, TG analysis, single-crystal X-ray diffraction, and X-ray powder diffraction (XRPD) techniques. Luminescence studies indicate that 1 exhibits dual emission, while 2 exhibits a bright blue emission under visible light excitation. Furthermore, magnetic susceptibility studies carried out for 2 indicate that the magnetic exchange between DyIII ions revealed ferromagnetic interactions with interesting slow relaxation of magnetization of the SMM behavior.
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structure variation and luminescence properties of lanthanide complexes incorporating a naphthalene derived chromophore featuring Salicylamide pendant arms
European Journal of Inorganic Chemistry, 2008Co-Authors: Wei Dou, Weisheng Liu, Xueqin Song, Yawen Wang, Jiangrong Zheng, Zhipeng ZangAbstract:A new potentially bridging ligand containing two Salicylamide pendant arms separated by a 2,3-dimethoxynaphthalene spacer has been prepared and its coordination chemistry with Ln(III) ions has been investigated. An analysis of the presented crystal structures indicates that the diversity of these supramolecular structures is mainly dictated by the nature of the metal ions. These compounds represent good examples of tuning crystal structures arising from the flexibility of the ligands and the Ln contraction effect. Luminescence studies showed that the introduction of the methoxyl substituents on the naphthalene backbone lowers the triplet energy and considerably changes the luminescent behaviors of the Eual and Tb(III) complexes, which is very different from the literature data on similar compounds. In the emission spectra of the Tb complex the ligand fluorescence remains relatively important because of the back-energy transfer from the Tb(III) ion to the ligand, which to the best of our knowledge, may be the first example of Salicylamide lanthanide complexes. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).
Robert A Batey - One of the best experts on this subject based on the ideXlab platform.
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total synthesis of prunustatin a utility of organotrifluoroborate mediated prenylation and shiina mnba esterification and macrolactonization to avoid a competing thorpe ingold effect accelerated transesterification
Organic Letters, 2018Co-Authors: Maja W Chojnacka, Robert A BateyAbstract:A convergent total synthesis of (+)-prunustatin A is described through the assembly of two key fragments and a macrolactonization. Shiina MNBA couplings were used for the formation of each of the four ester bonds in the tetralactone ring, including the key macrocyclization which was essential to minimize competing Thorpe–Ingold accelerated transesterification. Other key steps included an organoboron-based prenylation using potassium prenyltrifluoroborate and a carbonyldiimidazole-mediated coupling to form the Salicylamide.
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Total Synthesis of (+)-Prunustatin A: Utility of Organotrifluoroborate-Mediated Prenylation and Shiina MNBA Esterification and Macrolactonization To Avoid a Competing Thorpe–Ingold Effect Accelerated Transesterification
2018Co-Authors: Maja W Chojnacka, Robert A BateyAbstract:A convergent total synthesis of (+)-prunustatin A is described through the assembly of two key fragments and a macrolactonization. Shiina MNBA couplings were used for the formation of each of the four ester bonds in the tetralactone ring, including the key macrocyclization which was essential to minimize competing Thorpe–Ingold accelerated transesterification. Other key steps included an organoboron-based prenylation using potassium prenyltrifluoroborate and a carbonyldiimidazole-mediated coupling to form the Salicylamide
Maja W Chojnacka - One of the best experts on this subject based on the ideXlab platform.
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total synthesis of prunustatin a utility of organotrifluoroborate mediated prenylation and shiina mnba esterification and macrolactonization to avoid a competing thorpe ingold effect accelerated transesterification
Organic Letters, 2018Co-Authors: Maja W Chojnacka, Robert A BateyAbstract:A convergent total synthesis of (+)-prunustatin A is described through the assembly of two key fragments and a macrolactonization. Shiina MNBA couplings were used for the formation of each of the four ester bonds in the tetralactone ring, including the key macrocyclization which was essential to minimize competing Thorpe–Ingold accelerated transesterification. Other key steps included an organoboron-based prenylation using potassium prenyltrifluoroborate and a carbonyldiimidazole-mediated coupling to form the Salicylamide.
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Total Synthesis of (+)-Prunustatin A: Utility of Organotrifluoroborate-Mediated Prenylation and Shiina MNBA Esterification and Macrolactonization To Avoid a Competing Thorpe–Ingold Effect Accelerated Transesterification
2018Co-Authors: Maja W Chojnacka, Robert A BateyAbstract:A convergent total synthesis of (+)-prunustatin A is described through the assembly of two key fragments and a macrolactonization. Shiina MNBA couplings were used for the formation of each of the four ester bonds in the tetralactone ring, including the key macrocyclization which was essential to minimize competing Thorpe–Ingold accelerated transesterification. Other key steps included an organoboron-based prenylation using potassium prenyltrifluoroborate and a carbonyldiimidazole-mediated coupling to form the Salicylamide
Luisa Garcia F Bermejo - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of Salicylamide and salsalate in serum and urine by first derivative variable angle synchronous fluorescence spectrometry
Analytical Biochemistry, 1998Co-Authors: J Murillo A Pulgarin, Luisa Garcia F BermejoAbstract:Abstract The determination of Salicylamide and salsalate in human serum and urine is performed using a simple, rapid, sensitive, and selective method. The broad-band overlapping conventional spectra of both compounds are resolved by means of first derivative variable-angle synchronous fluorescence spectrometry. The method is based on the intrinsic fluorescence of both drugs in chloroformic solution. The measurements are performed in an alkaline medium, which is adjusted by adding 0.40 M pyrrolidine chloroformic solution to the organic phase. The method was applied for the simultaneous determination of Salicylamide and salsalate, at concentrations between 0.100 and 1.000 μg mL−1for both components, by means of absolute values of a first derivative variable-angle synchronous scan at the emission/excitation wavelengths of 410/299 nm for Salicylamide and 440/307 nm for salsalate. Serum and urine are extracted with chloroform, by adding acetate buffer solution to provide pH 4.8 in the aqueous phase. Finally, pyrrolidine chloroformic solution is added to organic phase, where both components are determined, without the need for a reextraction step to an aqueous phase.
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first derivative non linear variable angle synchronous fluorescence spectroscopy for the simultaneous determination of Salicylamide salsalate and naproxen in serum and urine
Analytica Chimica Acta, 1998Co-Authors: J Murillo A Pulgarin, Luisa Garcia F BermejoAbstract:Abstract Derivative variable-angle synchronous fluorescence spectrometry is developed to improve the selectivity of fluorescence measurements without loss of sensitivity. The first derivative non-linear variable-angle synchronous scanning permits the rapid simultaneous determination of Salicylamide, salsalate and naproxen in a mixture from a single spectrum based on a single scan. The method is based on the intrinsic fluorescence of Salicylamide, salsalate and naproxen in chloroform. The analyses are performed in the organic phase, using an alkaline medium provided by the addition of 0.40 M pyrrolidine chloroformic solution. The range of application is 0.100–1.000 μg/ml for all of them. A systematic examination of the experimental data by applying an exhaustive statistical analysis is reported. The method is applied in urine and serum samples spiked with all the drugs. Serum and urine samples are extracted into chloroform–1% acetic acid solution, using in the aqueous medium a pH of 4.8 obtained by the addition of acetate buffer solution, and a basic medium is provided with pyrrolidine prior to instrumental measurement. The simultaneous determination of Salicylamide, salsalate and naproxen in human serum and urine samples is performed with this technique in the extracted chloroform phase, without necessity of any re-extraction step. The validity, applicability and simplicity of the method are demonstrated.
J Murillo A Pulgarin - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of salicylic acid and Salicylamide in biological fluids
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2011Co-Authors: J Murillo A Pulgarin, Alanon A Molina, Sanchezferrer I RoblesAbstract:Abstract A new methodology for the simultaneous determination of salicylic acid and Salicylamide in biological fluids is proposed. The strong overlapping of the fluorescence spectra of both analytes makes impossible the conventional fluorimetric determination. For that reason, the use of fluorescence decay curves to resolve mixtures of analytes is proposed; this is a novel technique that provides the benefits in selectivity and sensitivity of the fluorescence decay curves. In order to assess the goodness of the proposed method, a prediction set of synthetic samples were analyzed obtaining recuperation percentages between 98.2 and 104.6%. Finally, a study of the detection limits was done using a new criterion resulting in values for the detection limits of 8.2 and 11.6 μg L −1 for salicylic acid and Salicylamide respectively. The validity of the method was tested in human serum and human urine spiked with aliquots of the analytes. Recoveries obtained were 96.2 and 94.5% for salicylic acid and Salicylamide respectively.
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simultaneous determination of Salicylamide and salsalate in serum and urine by first derivative variable angle synchronous fluorescence spectrometry
Analytical Biochemistry, 1998Co-Authors: J Murillo A Pulgarin, Luisa Garcia F BermejoAbstract:Abstract The determination of Salicylamide and salsalate in human serum and urine is performed using a simple, rapid, sensitive, and selective method. The broad-band overlapping conventional spectra of both compounds are resolved by means of first derivative variable-angle synchronous fluorescence spectrometry. The method is based on the intrinsic fluorescence of both drugs in chloroformic solution. The measurements are performed in an alkaline medium, which is adjusted by adding 0.40 M pyrrolidine chloroformic solution to the organic phase. The method was applied for the simultaneous determination of Salicylamide and salsalate, at concentrations between 0.100 and 1.000 μg mL−1for both components, by means of absolute values of a first derivative variable-angle synchronous scan at the emission/excitation wavelengths of 410/299 nm for Salicylamide and 440/307 nm for salsalate. Serum and urine are extracted with chloroform, by adding acetate buffer solution to provide pH 4.8 in the aqueous phase. Finally, pyrrolidine chloroformic solution is added to organic phase, where both components are determined, without the need for a reextraction step to an aqueous phase.
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first derivative non linear variable angle synchronous fluorescence spectroscopy for the simultaneous determination of Salicylamide salsalate and naproxen in serum and urine
Analytica Chimica Acta, 1998Co-Authors: J Murillo A Pulgarin, Luisa Garcia F BermejoAbstract:Abstract Derivative variable-angle synchronous fluorescence spectrometry is developed to improve the selectivity of fluorescence measurements without loss of sensitivity. The first derivative non-linear variable-angle synchronous scanning permits the rapid simultaneous determination of Salicylamide, salsalate and naproxen in a mixture from a single spectrum based on a single scan. The method is based on the intrinsic fluorescence of Salicylamide, salsalate and naproxen in chloroform. The analyses are performed in the organic phase, using an alkaline medium provided by the addition of 0.40 M pyrrolidine chloroformic solution. The range of application is 0.100–1.000 μg/ml for all of them. A systematic examination of the experimental data by applying an exhaustive statistical analysis is reported. The method is applied in urine and serum samples spiked with all the drugs. Serum and urine samples are extracted into chloroform–1% acetic acid solution, using in the aqueous medium a pH of 4.8 obtained by the addition of acetate buffer solution, and a basic medium is provided with pyrrolidine prior to instrumental measurement. The simultaneous determination of Salicylamide, salsalate and naproxen in human serum and urine samples is performed with this technique in the extracted chloroform phase, without necessity of any re-extraction step. The validity, applicability and simplicity of the method are demonstrated.
