Novel enrofloxacin imprinted polymer applied to the solid-phase extraction of fluorinated quinolones from urine and tissue samples

A new molecularly imprinted polymer, prepared following a non-covalent approach, was synthesised using enrofloxacin as a template molecule. The imprinting effect of the polymer was verified by chromatographic evaluation and, interestingly, this evaluation also revealed that the imprinted polymer showed a high degree of cross-reactivity for ciprofloxacin, the major metabolite of enrofloxacin. The molecularly imprinted polymer was then applied as a selective sorbent in a two-step solid-phase extraction method focussing upon complex biological matrices, specifically human urine and pig liver. This two-step solid-phase extraction protocol, in which a commercial Oasis HLB cartridge and a molecularly imprinted solid-phase extraction cartridge were combined, allowed enrofloxacin and ciprofloxacin to be determined by liquid chromatography coupled to a UV detector at levels below the maximum residue limits established by the European Union. The quantification and detection limits in tissue samples of enrofloxacin and ciprofloxacin were established at 50 μg kg⁻¹ and 30 μg kg⁻¹, respectively.     

氟代乙烯阳离子的理论研究

用B3LYP和MP2方法及6-31G(d, p)、6-31＋G(d, p)、6-311G(d, p)和6-311＋G(d, p) 基组，对六种氟代乙烯阳离子做了理论研究，优化了它们的基电子态的结构，计算了对应分子的垂直电离势（VIP）和绝热电离势(AIP).结果表明，与具有非平面结构的乙烯阳离子不同，六种氟代乙烯阳离子都只具有平面结构；与分子结构相比，离子结构的C－C键增长， C－F键缩短， CCF键角变小. 自然布居分析计算表明，这些离子的正电荷主要分布在与F原子相连的C原子和各H原子上. B3LYP/6-311＋G(d, p) 级别上计算的各分子的VIP和AIP值和实验值符合得很好. 使用含弥散基函数的基集可以明显提高这类分子的电离势的计算精度.     

N-Fluorinated phenyl-N＇-pyrimidyl urea derivatives： Synthesis,biological evaluation and 3D-QSAR study

With the increase of herbicide-resistant weeds, novel, more selective and even more potent herbicides to control weeds are needed. In this paper, a series of N-fluorinated phenyl-N＇-pyrimidyl urea derivatives were synthesized and screened for their herbicidal activities against Amaranthus retroflexus （AR） and Setaria viridis （ SV）. Compound 2S （N-（3-trifluoromethylphenyl）-N＇-（2-amino-4-chloro-6-methylpyr- imidyl） urea） exhibited marked herbicidal activity against SV（IC50 =11.67 mg/L） and is more potent than bensulfuron （IC50= 27.45 mg/L）, a commercially available herbicide. A statistically significant CoMFA model with high prediction abilities （q2 = 0.869, r2 = 0.989） was obtained.     

Synthesis and Bioactivity of Novel Fluorinated Heteroaromatic Ureas

In order to find new urea cytokinins, a series of novel fluorinated heteroaromatic ureas have been designed and synthesized. The crystal structure of 3g was further determined by single crystal X-ray diffraction to obtain the structural feature of this class of urea compounds. The preliminary bioassay showed that some title compounds have good cytokinin activity.     

Heat-resistant and soluble fluorinated poly(amide imide)s based on non-coplanar ortho-linked diimide-dicarboxylic acid

A series of novel fluorinated heat-resistant poly(amide imide)s (PAIS) based on non-coplanar diimide-diacid monomer (DIDA) were synthesized and characterized. The poly(amide imide)s were obtained in high yields and possessed inherent viscosities in the range of 0.47-0.91 dL g⁻¹. All of the polymers were amorphous in nature, showed outstanding solubility and could be readily soluble in common organic solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidinoned, dimethyl sulfoxide, N,N-dimethylformamide, pyridine and tetrahydrofuran. Glass transition temperatures were in the range of 221-263 °C, as determined by differential scanning calorimetry. Degradation temperatures for 10% weight loss occurred all above 520 °C and char yields was more than 50% at 700 °C in nitrogen atmosphere. Moreover, these PAIs possessed low refractive indexes (n = 1.58-1.59), birefringence (Δn = 0.008-0.013), and dielectric constants (? ≈ 2.5) due to the trifluoromethyl pendent groups and ortho-catenated aromatic rings that interrupt chain packing and increase free volume.     

预聚物复合助稳定剂条件下含氟丙烯酸酯共聚物的细乳液聚合

以甲基丙烯酸三氟乙酯(TFMA)、苯乙烯(St)和丙烯酸丁酯(BA)为共聚单体,在十二烷基硫酸钠(SDS)/磺酸盐型阴离子氟表面活性剂(S100)/辛基苯基聚氧乙烯醚(OP-10)组成的乳化体系中,采用预聚物和十六醇(HDL)共同组成的复合助稳定剂,对细乳液聚合制备St/BA/TFMA三元共聚物的过程进行了研究.通过F...     

Synthesis of dihydrofurans containing trifluoromethyl ketone and heterocycles by radical cyclization of fluorinated 1,3-dicarbonyl compounds with 2-thienyl and 2-furyl substituted alkenes

Manganese(III) acetate based radical cyclization of various fluorinated 1,3-dicarbonyl compounds with 2-thienyl and 2-furyl substituted alkenes produced 3-trifluoroacetyl and 2-trifluoromethyl-dihydrofurans in good yields. The radical cyclizations of 2-methyl-5-[(E)-2-phenylvinyl]furan 2b and 2-[(E)-2-phenylvinyl]thiophene 2c led to the formations of 5-(5-methyl-2-furyl)-4,5-dihydrofuran and 5-(2-thienyl)-4,5-dihydrofuran, respectively. In the reactions of 1,3-dicarbonyls with alkenes, 2-thienyl substituted alkenes formed 4,5-dihydrofurans in higher yields than 2-furyl substituted alkenes.     

Segregation phenomena in micelles from mixtures of fluorinated and hydrogenated surfactants

Mixtures of hydrogenated and fluorinated surfactants are known to form either mixed or segregated micelles: the conclusions are much dependant on the precision of the experimental measurements and on the model used for interpretation. Recently, mixed surfactant solutions were probed at the micellar or molecular level by SANS, fluorescence or NMR. It leads to an intermediate structure for the mixed micelles with an intramicellar segregation of the fluorinated and hydrogenated surfactant.This intramicellar segregation was also observed in a variety of more complex systems which are rapidly surveyed in the second part.     

Chloride ion promoted nucleophilic pentafluorophenylation of imines

Nucleophilic addition of the pentafluorophenyl group from (C₆F₅)₃SiF to non-activated imines affording α-C₆F₅-substituted secondary amines in high yield has been described. The reaction proceeds via simultaneous activation of imines and the silane reagent by means of a proton and chloride ion, respectively.     

Fluorination of alumino-silicate minerals: The example of lepidolite

The effect of fluorination on silicate and alumino-silicate minerals has been investigated, in particular on the lepidolite [K(Li,Al)₃ [Si₃AlO₁₀] (F,OH)₂] of the mica-type. The fluorination techniques included direct F₂-gas and cold radio-frequency-plasma involving c-C₄F₈ or O₂/CF₄ mixtures. The modifications of the surface properties have been followed mostly by XPS. Depending of the fluorination route used, either a reactive etching process involving M-F bonding occurs (direct F₂-gas; O₂-CF₄ rf-plasma), or a carbon fluoride deposition takes place (c-C₄F₈ rf-plasma).