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21.
通过苯基甲基二乙氧基硅烷和苄基甲基二乙氧基硅烷的缩合反应制备了聚苯基甲基和聚苄基甲基硅氧烷。研究了它们与含氟酰基过氧化物间的反应。经酸碱滴定及IR、^1H NMR和^19F NMR光谱分析确证反应主要生成苯环上氟烷基取代产物。通过测定经氟烷基化后聚硅氧烷处理的玻璃表面的接触角,初步评价了氟烷基化率对其表现性能变化的影响。 相似文献
22.
C. André L. Ismaili M. Thomassin T. T. Truong B. Refouvelet Y. C. Guillaume 《Chromatographia》2003,58(3-4):165-170
Summary Lithium chloride (LiCl) effect on the retention process of a phenol derivative series was investigated on two types of fluorinated stationary phase (i.e. a silica grafted with fluorinated linear alkyl chain (L-FSP) and a silica grafted with fluorinated aromatic ring stationary phase (A-FSP)). The results showed that the solute retention is enhanced when the A-FSP was used instead of the L-FSP due to additional – interactions. For the two fluorinated stationary phases (FSPs), the phenol-FSP association process can be divided into two LiCl concentration domains demonstrated that it was important to take into account the adsorbtion of Cl– anion on the FSPs. As well, enthalpy-entropy compensation revealed that the solute retention mechanism was independent of the solute molecular structure and confirmed a change on the solute retention mechanism at a critical LiCl concentration value around 0.02M. 相似文献
23.
The reaction of α-halosubstituted β-ethoxyvinyl trifluoromethyl ketones with 2-aminopyridine gives 3-trifluoroacetyl imidazo[1,2-a]pyridine and 3-halo-1,1,1-trifluoro-4-(2-pyridinylamino)-3-buten-2-ones. The product ratio depends on the nature of the α-halogen atom and the solvent. 相似文献
24.
Xin ZhangDonald J. Burton 《Journal of fluorine chemistry》2002,116(1):15-18
The organometallic reagent, (EtO)2P(O)CF2ZnBr, reacts with 1-alkynyl halides (halide=Br, I) in the presence of Cu(I)Br to give good yields of α,α-difluoropropargylphosphonates via a one pot reaction. 相似文献
25.
Starting from trifluoromethyl β-dicarbonyl compounds, a rare loss of CF3CO was observed in the amination reactions performed under heterogeneous conditions using NsONHCO2Et as the aminating agent and CaO or NaH as the base, while corresponding nonfluorinated β-dicarbonyl compounds under analogous conditions give non deacylated aminated compounds. This reaction can facilitate a direct synthesis of N-substituted α-amino esters or α-amino ketones. 相似文献
26.
Pina Romaniello 《Journal of fluorine chemistry》2004,125(2):145-149
The effect of fluorine atoms on the second-order optical nonlinear response of 4-nitro-4′-methoxy-trans-stilbene and polyene derivatives containing up to three double bonds (n=1, 2, 3) has been investigated within a semiempirical context (PM3 Hamiltonian). Experimental data reported in literature indicate a βvec(SHG) value of 34, 47 and 76 (×10−30 esu) for n=1, 2, 3, respectively, at 0.65 eV in CHCl3 solutions. Our calculations show that fluorinating the nitrophenyl group the βvec(SHG) is doubled. Further increase in the second-order nonlinear response can be obtained fluorinating the CC bond linkers between the aromatic moieties.Besides, the effect of different donor-acceptor pairs has been studied and the results interpreted in the two-state model context.Some results concerning the third-harmonic generation (THG), γ (THG), are presented, and a possible interpretation proposed. 相似文献
27.
Rong Zhang Qiao Bai Ling Xu Yan Hui Wang Department of Life Science Technology Beijing University of Chemical Technology Beijing China Institute of Materia Medica Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China 《中国化学快报》2007,18(6):656-658
2-Substituted-2,3-dihydro-4(1H)-quinazolinones were obtained in high yields by condensation of anthranilamide with aryl, alkyl or heteroaryl aldehydes or ketones in the refluxing 2,2,2-trifluoroethanol without any catalyst. 相似文献
28.
Vitalij V. Levin Pavel A. Belyakov Vladimir A. Tartakovsky 《Tetrahedron letters》2006,47(50):8959-8963
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. 相似文献
29.
The aggregation behavior of fluorinated surfactant in aqueous solution was investigated using dissipative particle dynamics (DPD) simulation method. Simulation results show that fluorinated surfactants behave mainly as their hydrocarbon analogues, having similar sequences of phases and aggregate structures, which are capable of building micelle, hexagonal phase and lamellar phase. But fluorinated surfactants also show interesting differences from hydrocarbon analogues, which can easily form hexagonal and lamellar structures with comparative little curvature. They can also form ellipsoid or rod-like micelles even in very low concentrations instead of spheroid ones. The dynamic aggregation behavior of fluorinated surfactants, as well as the comparison with hydrogenated ones, was also investigated. 相似文献
30.
氟代乙烯阳离子的理论研究 总被引:1,自引:0,他引:1
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. 相似文献