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461.
Crystal structures are reported for four related diethyl [(arylamino)(4‐ethynylphenyl)lmethyl]phosphonate derivatives, namely diethyl [(4‐bromoanilino)(4‐ethynylphenyl)methyl]phosphonate, C19H21BrNO3P, (I), diethyl ((4‐chloro‐2‐methylanilino){4‐[2‐(trimethylsilyl)ethynyl]phenyl}methyl)phosphonate, C23H31ClNO3PSi, (II), diethyl ((4‐fluoroanilino){4‐[2‐(trimethylsilyl)ethynyl]phenyl}methyl)phosphonate, C22H29FNO3PSi, (III), and diethyl [(4‐ethynylphenyl)(naphthalen‐2‐ylamino)methyl]phosphonate, C23H24NO3P, (IV). The conformation of the anilinobenzyl group is very similar in all four compounds. The P—C bond has an approximately staggered conformation, with the aniline and ethynylphenyl groups in gauche positions with respect to the P=O double bond. The two six‐membered rings are almost perpendicular. The sums of the valence angles about the N atoms vary from 344 (2) to 351 (2)°. In the crystal structures, molecules of (I), (III) and (IV) are arranged as centrosymmetric or pseudocentrosymmetric dimers connected by two N—H...O=P hydrogen bonds. The molecules of (II) are arranged as centrosymmetric dimers connected by Cmethyl—H...O=P hydrogen bonds. The N—H bond of (II) is not involved in hydrogen bonding.  相似文献   
462.
Abstract

2-(5-Methyl-2-phenyl-2Н-1,2,3-diazaphosphol-4-yl)-4H-benzo[d]-1,3,2-dioxaphosphorin-4-one 1 readily reacts with hexafluoroacetone, mesoxalic acid diethyl ester, trifluoropyruvic acid ethyl ester and chloral to give 2-(5-methyl-2-phenyl-2H-1,2,3-dizaphosphole-4-yl)-derivatives of 1,3,2- and 1,4,2-dioxaphosphepines.  相似文献   
463.
Abstract

Peracid oxidation of triester and related phosphorothionates and diester phosphorothioic acids with excess magnesium monoperoxyphthalate in water gives, among other products, dialkyl hydrogenphos-phonates in yields of up to 70%. Hydrogenphosphonate formation is facilitated by the presence of a good leaving group in the starting material.  相似文献   
464.
荧光及ESI质谱法研究溶菌酶与磷酰化黄酮的相互作用   总被引:10,自引:0,他引:10  
分别用荧光法和ESI质谱法研究了磷酰化黄酮和溶菌酶的相互作用 .结果均显示磷酰化黄酮能够和溶菌酶发生弱相互作用 ,与黄酮相比它对溶菌酶更具亲和力 .根据荧光猝灭双倒数图计算了磷酰化黄酮与溶菌酶之间的结合常数为k2 0℃ =1.68× 10 4L/mol,k3 7℃ =1.0 6× 10 4L/mol,实验证明随着温度的升高 ,磷酰化黄酮与溶菌酶的结合常数逐渐降低 ,说明了两者之间形成了复合物 ,此荧光猝灭过程为静态猝灭 .根据F ster能量传递原理计算出磷酰化黄酮在溶菌酶上的结合距离 ,并根据热力学参数确定了磷酰化黄酮与溶菌酶之间的作用力类型为电荷作用力  相似文献   
465.
High‐quality poly(9,9‐dichlorofluorene) (PDCF), a new part soluble polyfluorene derivative, was easily synthesized electrochemically by direct anodic oxidation of 9,9‐dichlorofluorene (DCF) in boron trifluoride diethyl etherate (BFEE) containing 15% (by volume) trifluoroacetic acid (TFA). It was hard for DCF to deposit on the electrode in neutral solvents such as CH3CN system. This methodology may help promotion of researches to reveal unknown properties and applications of polyfluorene materials. PDCF films with conductivity of 3.3 × 10?2 S cm?1 obtained from this media show good redox activity and thermal stability. The structure and morphology of the polymer were studied by UV–vis, FTIR, 1H NMR spectra, and scanning electron microscopy, respectively. The results of quantum chemistry calculations and the spectroscopies of dedoped PDCF indicate that the polymerization of DCF mainly occurs via C(2) and C(7) position. Fluorescent spectral studies indicate that PDCF film with high fluorescence quantum yields and photochemical stability is a novel green light emitter. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1791–1799, 2010  相似文献   
466.
High quality free-standing polyfluorene (PFe) films were synthesized electrochemically by direct anodic oxidation of fluorene in pure boron trifluoride diethyl etherate (BFEE) on stainless steel sheet. The oxidation potential of fluorene in this medium was measured to be only 1.1 V versus SCE, which was much lower than that determined in acetonitrile + 0.1 mol L−1 TBATFB. PFe films obtained from this medium showed good electrochemical behavior, good thermal stability with conductivity of 0.25 S cm−1, indicating that BFEE is a better medium than acetonitrile for the electrosyntheses of PFe films. FTIR and 1H NMR spectral investigations indicated that the polymerization of fluorene occurred mainly at 2, 7 position. As-formed PFe films can be partly dissolved in acetone, acetonitrile, tetrahydrofuran, etc.  相似文献   
467.
High quality poly(5-methylindole) (P5MeI) films, especially with good fluorescence properties, were synthesized electrochemically by direct anodic oxidation of 5-methylindole in boron trifluoride diethyl etherate (BFEE) containing additional 50% diethyl ether (EE) (by volume). The oxidation potential onset of 5-methylindole in this medium was measured to be only 0.84 V vs. SCE, which was much lower than that determined in acetonitrile + 0.1 mol L−1 TBATFB (1.08 V vs. SCE). P5MeI films obtained from this medium showed good electrochemical behavior and good thermal stability with conductivity of 10−2 S cm−1, indicating that BFEE was a better medium than acetonitrile for the electrosyntheses of P5MeI films. Dedoped P5MeI films were thoroughly soluble in strong polar solvent such as dimethyl sulfoxide (DMSO). 1H NMR spectroscopy and FT infrared spectrum of dedoped P5MeI films strongly suggested that the monomers were linked via the positions 2 and 3. Fluorescent spectral studies indicated that P5MeI was a good violet-blue light emitter with the excitation and emission wavelength of 310 nm and 418 nm, respectively. To the best of our knowledge, this is the first case that 5-methyl group substituted polyindole films with good fluorescence properties can be electrodeposited.  相似文献   
468.
在高钙及不同浓度枸橼酸二乙酯(Et2Cit)、枸橼酸钠(Na3Cit)和膦甲酸钠(PFA)存在下培养小鼠血管平滑肌细胞(MOVAS)14 d,分别通过茜素红染色、免疫荧光和annexin V染色检测细胞的分化、凋亡和细胞钙沉积量,研究了Et2Cit、Na3Cit和PFA对高钙诱导MOVAS细胞钙化的抑制效果及可能的作用机制。结果表明,Et2Cit、Na3Cit和PFA均能减少高钙诱导的MOVAS钙化,减少细胞外钙化斑块和钙沉积量。这些抑制剂均能抑制平滑肌细胞向成骨样细胞表型转化,导致向成骨细胞转化的标记物碱性磷酸酶(ALP)活性降低。抑制效果均存在浓度依赖性。当抑制剂浓度相同时,其抑制效果从大到小为:PFA > Na3Cit > Et2Cit。低浓度的Et2Cit和Na3Cit可通过减少细胞凋亡来抑制钙化,但高浓度的Et2Cit、Na3Cit和PFA自身具有毒性,这增加了细胞的凋亡。作为血液抗凝剂的Et2Cit和Na3Cit可以有效地抑制MOVAS的钙化。  相似文献   
469.
(C4N2H12)[Ga2F3(HPO3)2(H2PO3)] 1 is a new open-framework fluorinated gallium phosphite obtained by mild hydrothermal synthesis using piperazine as template agent and characterized by single crystal X-ray diffraction (XRD), powder XRD, infra-red spectroscopy, inductively coupled plasma, thermogravimetric and elemental analyses. The three-dimensional (3D) anionic framework of compound 1 is constructed from two distinct motifs, a 1D tancoite chain and a single 4-ring (S4R) unit, which contains four intersecting channels running throughout the structure as 8, 12-member rings channels along to the a-axis and 12-member ring channels along the b- and c-axis, respectively. The well-ordered, diprotonated piperazine cations occupy all the channels, and interact with the fluorinated gallium-phosphite framework by strong hydrogen bonds.  相似文献   
470.
A new open-framework iron (III) phosphite |C4N3H14|[Fe3(HPO3)4F2(H2O)2] has been solvothermally synthesized by using diethylenetriamine (DETA) as the structure-directing agent. Single-crystal X-ray diffraction analysis reveals that the compound crystallizes in the monoclinic space group C2/c having unit cell parameters a=12.877(3) Å, b=12.170(2) Å, c=12.159(2) Å, β=93.99(3)°, V=1900.9(7) Å3, and Z=4 with R1=0.0447, wR2=0.0958. The complex structure consists of HPO3 pseudo-tetrahedra and {Fe3O14F2} trimer building units. The assembly of these building units generates 3D inorganic framework with intersecting 6-, 8-, and 10-ring channels. The DETA cations are located in the 10-ring channels linked by hydrogen bonds. The Mössbauer spectrum shows that there exhibit two crystallographically independent iron (III) atoms. And the magnetic investigation shows the presence of antiferromagnetic interactions. Further characterization of the title compound was performed using X-ray powder diffraction (XRD), infrared (IR) spectra, thermal gravimetric analyses (TGA), inductively coupled plasma (ICP) and elemental analyses.  相似文献   
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