Preparation and evaluation of uniform-sized molecularly imprinted polymer beads used for the separation of sulfamethazine

Uniform-sized molecularly imprinted polymer (MIP) beads were prepared using a one-step swelling and polymerization method. The obtained sulfamethazine (SMZ)-imprinted polymer showed high affinity and selectivity toward SMZ and other structurally related sulfonamides in acetonitrile or water-acetonitrile mobile phases, particularly in high aqueous systems. The column performance of the MIPs for SMZ and its analogues could be improved by elevating the column temperature and optimizing the flow rate. The hydrogen-bonding effect plays a significant role in the recognition process of SMZ-imprinted polymer systems in organic media, while the ion-exchange effect, as well as hydrophobic effect, dominates the retention mechanism in aqueous-rich media, in addition to shape recognition.     

含水杨酸的缩聚物对P-硝基苯酚乙酸酯水解反应的催化作用(Ⅱ)

水杨酸、甲醛和烷基伯胺(烷基:甲基,正-丙基,正-己基或正-十二烷基)通过Mannich缩合反应制得了主链上既含有水杨酸基又含有叔胺基的线型缩聚物。用这些缩聚物催化P-硝基苯酚乙酸酯(PNPA)水解反应的动力学研究结果表明,缩聚物的催化活性随N-烷基侧链的链长增加而增加。在催化剂过量的条件下,带有十二碳烷基侧链的缩聚物催化PNPA水解反应时符合简单的Michaelis-Menten动力学历程。     

一氧化碳的双共振多光子电离研究

用两束脉冲染料激光进行了CO的光学双共振四光子电离, 获得了转动分辩的CO A~(1Π)←X~(1Σ~+)和B~(1Σ~+)←A~(1Π)跃迁的光谱。观察到了在此2+1光子相继吸收中特有的选择定则。动力学研究表明CO基态到A~(1Π)态的双光子吸收是速率决定步骤, 其吸收截面约为1×10~(-49) cm~4 s。还测定了A~(1Π)态的单态转动传能截面。对于宇称指数e守恒、△J×±1的过程的截面约为0.05 nm; 随△J值增大而减小。对相同的△J, e正负变号的过程的截面总是小于e不变过程的截面。     

超导体Y-Ba-Cu-O复合氧化物催化苯酚羟化反应的研究

利用HZOZ和苹酚联产对苯二醋和邻苯二酚是目前二酚生产领域中比较活跃的课题．长久以来，人们曾利用酸、金属盐、金属配合物等作为催化剂，在均相体系中来研究其对苯酸羟化反应的催化活性．由平均相反应存在着明显的缺点，后来又转向了多相催化剂的开发，先后出现了TSull］TS42     

Green-synthesized,low-cost tetracyanodiazafluorene (TCAF) as electron injection material for organic light-emitting diodes

As facile,green,low-cost as possible:One more electron-deficient azaacene (TCAF) with deep LUMO (-4.52 eV), strong electronic affinity,excellent yield,and simple purification procedure was successfully created and explored as good electron injection material.It is believed TCAF would be a promising and pervasive acceptor material and bring in more significant achievements to green and sustainable organic electronics including OLEDs,OFETs,OPVs, and perovskite solar cells,etc.     

Studies on the substrate specificity of Escherichia coli galactokinase

In vitro glycorandomization (IVG) technology is dependent upon the ability to rapidly synthesize sugar phosphates. Compared with chemical synthesis, enzymatic (kinase) routes to sugar phosphates would be attractive for this application. This work focuses upon the development of a high-throughput colorimetric galactokinase (GalK) assay and its application toward probing the substrate specificity and kinetic parameters of Escherichia coli GalK. The demonstrated dinitrosalicylic assay should also be generally applicable to a variety of sugar-processing enzymes. [reaction: see text]     

ＳRN 1 反应及某些SET引发的链式反应的新进展

本文综述了近几年来 S_(RN)1反应及某些 SET 引发的链式反应的研宄进展。包括四方面,即有机杂环化合物的 S_(RN)1反应;在 S_(RN)1反应中作为亲核试剂的各种有机负离子;金属离子对 S_(RN)1反应的催化作用以及 S_(RN)1在合成应用方面的进展。     

Reverse of regioselectivity in intramolecular nucleophilic substitution of pi-allyl palladium species. Highly selective formation of vinylic cyclopropanes via the Pd(0)-catalyzed coupling-cyclization reaction of organic iodides with 2-(2', 3'-Dienyl)malonates

Vinylic cyclopropanes were formed highly selectively via the Pd(PPh(3))(4)-catalyzed insertion-intramolecular nucleophilic substitution reaction of aryl or 1-alkenyl iodides with 2-(2', 3'-dienyl)malonates. The regioselectivity observed here is different from what was reported by Cazes et al.     

Unusual frequency dispersion effects of the nonlinear optical response in highly conjugated (polypyridyl)metal-(porphinato)zinc(II) chromophores

The syntheses and electrooptic properties of a new family of nonlinear optical chromophores are reported. These species feature an ethyne-elaborated, highly polarizable porphyrinic component and metal polypyridyl complexes that serve as integral donor and acceptor elements. Examples of this structural motif include ruthenium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)(2+) bis-hexafluorophosphate (Ru-PZn); osmium(II) [5-(4'-ethynyl-(2,2';6',2'-terpyridinyl))-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2'-terpyridine)(2+) bis-hexafluorophosphate (Os-PZn); ruthenium(II) [5-(4'-ethynyl-(2,2';6',2'-terpyridinyl))-15-(4'-nitrophenyl)ethynyl-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phen-yl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)(2+) bis-hexafluorophosphate (Ru-PZn-A); osmium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-15-(4'-nitrophenyl)ethynyl-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)(2+) bis-hexafluorophosphate (Os-PZn-A); and ruthenium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))osmium(II)-15-(4'-ethynyl-(2,2';6',2'-terpyridinyl))-10,20-bis (2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-bis(2,2';6',2'-terpyridine)(4+) tetrakis-hexafluorophosphate (Ru-PZn-Os). The frequency dependence of the dynamic hyperpolarizability of these compounds was determined from hyperRayleigh light scattering (HRS) measurements carried out at fundamental incident irradiation wavelengths (lambda(inc)) of 800, 1064, and 1300 nm. These data show that (i) coupled oscillator photophysics and metal-mediated cross-coupling can be exploited to elaborate high beta(0) supermolecules that exhibit significant excited-state electronic communication between their respective pigment building blocks; (ii) high-stability metal polypyridyl compounds constitute an attractive alternative to electron releasing dialkyl- and diarylamino groups, the most commonly used donor moieties in a wide range of established nonlinear optical dyes; (iii) this design strategy enables ready elaboration of chromophores having extraordinarily large dynamic hyperpolarizabilities (beta(lambda) values) at telecommunication relevant wavelengths; and (iv) porphyrin B- and Q-state-derived static hyperpolarizabilities (beta(0) values) can be designed to have the same or opposite sign in these species, thus providing a new means to regulate the magnitude of lambda(inc)-specific dynamic hyperpolarizabilities.     

The first metal (Nd3+, Mn2+, and Pb2+) coordination compounds of 3,5-dinitrotyrosine and their nonlinear optical properties

The reactions of 3,5-dinitrotyrosine (H2DNTY) with Nd(NO3)3.6H2O, Mn(ClO4)2.6H2O, and Pb(OAc)2 afforded three homochiral compounds: discrete [Nd(Hdnty)2(NO3)(H2O)5].3H2O (1) and two- and three-dimensional coordination polymers, [Mn(Hdnty)2] (2) and [Pb(dnty)(0.5 H2O)] (3), respectively. The Nd atom in 1 displays a tricapped trigonal prism and supramolecular weak interactions, such as pi-pi stacking and H-bonds, between amino and nitro groups result in the formation of a three-dimensional network through these interactions. 2 has a two-dimensional square-grid topological net while 3 has the first three-dimensional homochiral ThSi2 net. To the best of our knowledge, these are the first metal coordination compounds with 3,5-dinitrotyrosine. Preliminary second harmonic generation (SHG) investigations indicated that 1 and 2 are SHG active with estimated responses 5 and 6 times larger than that of urea, respectively, while 3 is SHG non-active (obeying the Klainman symmetry requirement). Strong enhancement of their SHG efficiency, compared with H2DNTY, may be due to 1) the addition of a good donor-pi-acceptor organic chromophore into the compound resulting in superior qualities of both inorganic and organic materials and 2) the H-bonds that persist in them. Crystal data: 1: C18H32N7O25Nd, Mr = 890.75 g mol(-1), monoclinic, P2(1), a=7.0179(7), b=27.060(3), c=8.3097(8) A, alpha=gamma=90.00, beta=95.646(2) degrees , V=1570.4(3) A(3), Z=2, rho(calcd)=1.884 Mg m(-3), R(1)=0.0489, wR(2)=0.1223, mu=17.67 mm(-1), S=0.811, Flack value=0.003(13); 2: C(18)H(16)N(6)O(14)Mn, M(r)=595.31 g mol(-1), orthorhombic, P2(1)2(1)2, a=8.4381(14), b=13.639(2), c=19.697(3) A, alpha=beta=gamma=90.00 degrees , V=2266.9(6) A(3), Z=4, rho(calcd)=1.744 Mg m(-3), R(1)=0.0866, wR(2)=0.2030, mu=6.72 mm(-1), S=1.095, Flack value=0.02(6); 3: C(9)H(8)N(3)O(7.5)Pb, M(r)=485.37 g mol(-1), tetragonal, P4(1)2(1)2, a=12.8136(12), b=12.8136(12), c=14.931(2), alpha=beta=gamma=90.00 degrees , V=2451.5(5) A(3), Z=8, rho(calcd)=1.885 Mg m(-3), R(1)=0.0564, wR(2)=0.1323, mu=6.942 mm(-1), S=0.878, Flack value=0.03(2). For space group P4(3)2(1)2: R(1)=0.0672, wR(2)=0.1656, S=1.034, Flack value=1.02(3); this suggests the chosen space group P4(1)2(1)2 is correct.