The effect of 2-butyne-1, 4-diol on silver electrodeposition process from 5, 5-dimethyl hydantoin solutions was investigated by means of cyclic voltammetric measurement, scanning electron microscopy (SEM) and X-ray di...The effect of 2-butyne-1, 4-diol on silver electrodeposition process from 5, 5-dimethyl hydantoin solutions was investigated by means of cyclic voltammetric measurement, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Cyclic voltammetric studies indicate that the reduction process of silver electrodeposition is influenced by adding 2-butyne-1, 4-diol. Owing to its adsorption on the electrode surface, 2-butyne-1, 4-diol moderately hinders the mass transfer of the silver complexed ions from the bulk solution to the outer limit of the electrode double layer and affects the electrocrystallization step. Scanning electron microscopy analysis reveals that the presence of 2-butyne-1, 4-diol in the electrolyte is beneficial and the silver deposits obtained are smoother, more compact and more leveled. X-ray diffraction analysis of the silver deposits obtained at 0.5 g·L-1 2-butyne-1, 4-diol indicated that the (110) plane is the most preferred plane and is not affected by the presence of 2-butyne-1, 4-diol in the electrolyte.展开更多
Based on the strength and microstructure tests,the effects of the hydantoin epoxy resin content and curing time on the mechanical properties and microstructure of copper tailings specimens were studied.The results sho...Based on the strength and microstructure tests,the effects of the hydantoin epoxy resin content and curing time on the mechanical properties and microstructure of copper tailings specimens were studied.The results showed that the strength of the solidified specimens was increased to 20.84 MPa with 30 wt.%addition of hydantoin epoxy resin.When the specimens with 10%hydantoin epoxy resin were cured for 7 and 14 d,the strengths were 6.33 and 6.67 MPa respectively,which met the requirements as foundation filler and building materials.The microscopic tests showed that the agglomeration was enhanced and the porosities of the solidified specimens were reduced with increase in the hydantoin epoxy resin content,which could greatly enhance the strength of solidified specimens.展开更多
Eight novel poly(amide-imide)s were synthesized under microwave irradiation by using a domestic microwaveoven from the polycondensation reactions of N.N'-(pyromellitoyl)-bis-L-alanine diacid chloride(1)with eight ...Eight novel poly(amide-imide)s were synthesized under microwave irradiation by using a domestic microwaveoven from the polycondensation reactions of N.N'-(pyromellitoyl)-bis-L-alanine diacid chloride(1)with eight differentderivatives of hydantoin compounds(2a-h)in the presence of a small amount of a polar organic medium such as o-cresol.The polycondensation proceeded rapidly,compared with the conventional solution polycondensation and was completedwithin 8-10 min,producing a series of new poly(amide-imide)s(3a-h)with inherent viscosities about 0.35-0.68 dL/g inhigh yields.The obtained PAIs(3a-h)were fully characterized by means of FT-IR spectroscopy,elemental analyses,inherentviscosity(ηinh),solubility and specific rotation measurements.All of the resulting polymers show optical rotation and areoptically active.Thermal properties of the poly(amide-imide)s were investigated by using thermal gravimetric analysis(TGA).展开更多
Six new optically active poly（amide-imide）s （5a-f） were synthesized through the direct polycondensation reaction of N,N′-（4,4′- diphthaloyl）-bis-L-leucine （3） with six hydantoin derivatives （4a-f）. Tripben...Six new optically active poly（amide-imide）s （5a-f） were synthesized through the direct polycondensation reaction of N,N′-（4,4′- diphthaloyl）-bis-L-leucine （3） with six hydantoin derivatives （4a-f）. Tripbenyl phosphite （TPP）/pyridine in the presence of calcium chloride （CaCl2） and N-methyl-2-pyrrolidone （NMP） were successfully applied for direct polycondensation. The polycondensation reactions produce a series of new poly（amide-imide）s （5a-f） in high yields, and inherent viscosity between 0.42 and 0,55 dL/g. The resulting poly（amide-imide）s （5a-f） were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis （TGA and DTG）, solubility test and FT-IR spectroscopy.展开更多
Diastereoselective conjugate addition of 1-enoyl-5-substituted hydantoins with allyltrimethylsilane in the presence of Ti(IV) chloride proceeded to give the corresponding allyl adducts in high yield and high diastereo...Diastereoselective conjugate addition of 1-enoyl-5-substituted hydantoins with allyltrimethylsilane in the presence of Ti(IV) chloride proceeded to give the corresponding allyl adducts in high yield and high diastereoselectivity. In order to determine the absolute configuration on the β-position of the acyl group, the hydantoin was removed by hydrolysis of the allyl adducts with a base to give the corresponding carboxylic acid. It was found that the absolute configuration was S on the basis of specific rotation.展开更多
Facile and rapid polycondensation reactions of N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride 1 with eight different derivatives of hydantoin compounds 2a-h were developed by using a domestic microwave oven in...Facile and rapid polycondensation reactions of N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride 1 with eight different derivatives of hydantoin compounds 2a-h were developed by using a domestic microwave oven in the presence of a small amount of polar organic medium such as o-cresol. The polycondensation reactions proceeded rapidly, compared with the conventional solution polycondensation, and was completed within 7-10 min, producing a series of novel optically active poly(amide-imide)s 3a-h with high yield and inherent viscosity of 0.35-0.65 dL/g. All of the above polymers were fully characterized by FT-IR, elemental analyses, inherent viscosity (η inh ), solubility test and specific rotation. Some structural characterization and physical properties of these optically active poly(amide-imide)s are reported.展开更多
The reduction of various hydantoins with sodium borohydride gave the corresponding 4-hydroxy- 2-imidazolidinones in high yields. In contrast, reduction employing a boron trifluoride etherate-sodium borohydride system ...The reduction of various hydantoins with sodium borohydride gave the corresponding 4-hydroxy- 2-imidazolidinones in high yields. In contrast, reduction employing a boron trifluoride etherate-sodium borohydride system generated 2-imidazolidinones. In both reductions, the reactivity of the hydantoin was dependent on its substituents. The Lewis acid-promoted reactions of a 4-hydroxy-2-imidazolidinone with nucleophiles were also investigated.展开更多
A [ReO(Imz)(Hyd)(H2O)2OH] complex was successfully synthesized by the ligand exchange method using oxorhenuim citrate and an imidazole /Hydanton mixed ligand system. Geometry optimization of complex has been carried o...A [ReO(Imz)(Hyd)(H2O)2OH] complex was successfully synthesized by the ligand exchange method using oxorhenuim citrate and an imidazole /Hydanton mixed ligand system. Geometry optimization of complex has been carried out using DFT at the B3LYP/LANL2DZ functional in singlet state. B3LYP predicated infrared spectrum of the geometrically optimized structure using the same level of the theory and the same base set showed good agreement with experimentally observed values. The spin allowed singlet-singlet electronic transition of the [ReO(Imz)(Hyd) (H2O)2OH] complex was calculated with time dependent density function theory (TD-DFT) and the UV-Vis spectra has been discussed on this basis. The complex was characterized using microanalysis and IR, UV-Vis, NMR and mass spectroscopic. The technetium tracer [99mTcO(Imz)(Hyd) (H2O)2OH] has also been synthesized by two methods using 99mTc-gluconate as a precursor or;by direct reduction. The radiochemical purity of the complex was over 95% as measured by thin layer chromatography. In vitro studies showed that the complex possessed good stability under physiological conditions. The partition coefficient indicated that the complex hydrophilic and the electrophoresis results showed that the complex cationic. Biodistrbution in mice showed that the complex accumulated in heart uptake of 9.53±3.87 % ID/gm at 5 min and good retention (6.37±1.21) % ID/gm at 60 min. One hour after the injection, the heart/liver, heart/lung and heart/blood radioactivity ratios were 0.46, 1.04 and 0.56, respectively. These findings indicate that the complex might be suitable for myocardial imaging.展开更多
文摘The effect of 2-butyne-1, 4-diol on silver electrodeposition process from 5, 5-dimethyl hydantoin solutions was investigated by means of cyclic voltammetric measurement, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Cyclic voltammetric studies indicate that the reduction process of silver electrodeposition is influenced by adding 2-butyne-1, 4-diol. Owing to its adsorption on the electrode surface, 2-butyne-1, 4-diol moderately hinders the mass transfer of the silver complexed ions from the bulk solution to the outer limit of the electrode double layer and affects the electrocrystallization step. Scanning electron microscopy analysis reveals that the presence of 2-butyne-1, 4-diol in the electrolyte is beneficial and the silver deposits obtained are smoother, more compact and more leveled. X-ray diffraction analysis of the silver deposits obtained at 0.5 g·L-1 2-butyne-1, 4-diol indicated that the (110) plane is the most preferred plane and is not affected by the presence of 2-butyne-1, 4-diol in the electrolyte.
基金financial support from the National Natural Science Foundation of China (Nos. 41972282, 41807253)the Natural Science Foundation of Hunan Province, China (No. 2021JJ30804)the Research Fund Program from Yunnan Diqing Nonferrous Metal Co., Ltd., China (No. DQYS-ZYB-09-(2021)001)
文摘Based on the strength and microstructure tests,the effects of the hydantoin epoxy resin content and curing time on the mechanical properties and microstructure of copper tailings specimens were studied.The results showed that the strength of the solidified specimens was increased to 20.84 MPa with 30 wt.%addition of hydantoin epoxy resin.When the specimens with 10%hydantoin epoxy resin were cured for 7 and 14 d,the strengths were 6.33 and 6.67 MPa respectively,which met the requirements as foundation filler and building materials.The microscopic tests showed that the agglomeration was enhanced and the porosities of the solidified specimens were reduced with increase in the hydantoin epoxy resin content,which could greatly enhance the strength of solidified specimens.
基金This work was supported by the Research Affairs Division of Arak University.
文摘Eight novel poly(amide-imide)s were synthesized under microwave irradiation by using a domestic microwaveoven from the polycondensation reactions of N.N'-(pyromellitoyl)-bis-L-alanine diacid chloride(1)with eight differentderivatives of hydantoin compounds(2a-h)in the presence of a small amount of a polar organic medium such as o-cresol.The polycondensation proceeded rapidly,compared with the conventional solution polycondensation and was completedwithin 8-10 min,producing a series of new poly(amide-imide)s(3a-h)with inherent viscosities about 0.35-0.68 dL/g inhigh yields.The obtained PAIs(3a-h)were fully characterized by means of FT-IR spectroscopy,elemental analyses,inherentviscosity(ηinh),solubility and specific rotation measurements.All of the resulting polymers show optical rotation and areoptically active.Thermal properties of the poly(amide-imide)s were investigated by using thermal gravimetric analysis(TGA).
文摘Six new optically active poly（amide-imide）s （5a-f） were synthesized through the direct polycondensation reaction of N,N′-（4,4′- diphthaloyl）-bis-L-leucine （3） with six hydantoin derivatives （4a-f）. Tripbenyl phosphite （TPP）/pyridine in the presence of calcium chloride （CaCl2） and N-methyl-2-pyrrolidone （NMP） were successfully applied for direct polycondensation. The polycondensation reactions produce a series of new poly（amide-imide）s （5a-f） in high yields, and inherent viscosity between 0.42 and 0,55 dL/g. The resulting poly（amide-imide）s （5a-f） were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis （TGA and DTG）, solubility test and FT-IR spectroscopy.
文摘Diastereoselective conjugate addition of 1-enoyl-5-substituted hydantoins with allyltrimethylsilane in the presence of Ti(IV) chloride proceeded to give the corresponding allyl adducts in high yield and high diastereoselectivity. In order to determine the absolute configuration on the β-position of the acyl group, the hydantoin was removed by hydrolysis of the allyl adducts with a base to give the corresponding carboxylic acid. It was found that the absolute configuration was S on the basis of specific rotation.
基金This project was supported by the Research Affairs Division of Arak University.
文摘Facile and rapid polycondensation reactions of N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride 1 with eight different derivatives of hydantoin compounds 2a-h were developed by using a domestic microwave oven in the presence of a small amount of polar organic medium such as o-cresol. The polycondensation reactions proceeded rapidly, compared with the conventional solution polycondensation, and was completed within 7-10 min, producing a series of novel optically active poly(amide-imide)s 3a-h with high yield and inherent viscosity of 0.35-0.65 dL/g. All of the above polymers were fully characterized by FT-IR, elemental analyses, inherent viscosity (η inh ), solubility test and specific rotation. Some structural characterization and physical properties of these optically active poly(amide-imide)s are reported.
文摘The reduction of various hydantoins with sodium borohydride gave the corresponding 4-hydroxy- 2-imidazolidinones in high yields. In contrast, reduction employing a boron trifluoride etherate-sodium borohydride system generated 2-imidazolidinones. In both reductions, the reactivity of the hydantoin was dependent on its substituents. The Lewis acid-promoted reactions of a 4-hydroxy-2-imidazolidinone with nucleophiles were also investigated.
文摘A [ReO(Imz)(Hyd)(H2O)2OH] complex was successfully synthesized by the ligand exchange method using oxorhenuim citrate and an imidazole /Hydanton mixed ligand system. Geometry optimization of complex has been carried out using DFT at the B3LYP/LANL2DZ functional in singlet state. B3LYP predicated infrared spectrum of the geometrically optimized structure using the same level of the theory and the same base set showed good agreement with experimentally observed values. The spin allowed singlet-singlet electronic transition of the [ReO(Imz)(Hyd) (H2O)2OH] complex was calculated with time dependent density function theory (TD-DFT) and the UV-Vis spectra has been discussed on this basis. The complex was characterized using microanalysis and IR, UV-Vis, NMR and mass spectroscopic. The technetium tracer [99mTcO(Imz)(Hyd) (H2O)2OH] has also been synthesized by two methods using 99mTc-gluconate as a precursor or;by direct reduction. The radiochemical purity of the complex was over 95% as measured by thin layer chromatography. In vitro studies showed that the complex possessed good stability under physiological conditions. The partition coefficient indicated that the complex hydrophilic and the electrophoresis results showed that the complex cationic. Biodistrbution in mice showed that the complex accumulated in heart uptake of 9.53±3.87 % ID/gm at 5 min and good retention (6.37±1.21) % ID/gm at 60 min. One hour after the injection, the heart/liver, heart/lung and heart/blood radioactivity ratios were 0.46, 1.04 and 0.56, respectively. These findings indicate that the complex might be suitable for myocardial imaging.
