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61.
A convenient procedure for the preparation of various substituted (thio)hydantoins is described. The method is based on Wittig and aza-Wittig reactions of parabanic acids with phosphonium ylides. The reactions occurred both regio- and stereo-selectively. 相似文献
62.
Hakan Durmaz Muge Butun Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2012,50(15):3116-3125
We demonstrated the successful postfunctionalization of poly(oxanorbornene imide) (PONB) with two types of double bonds using sequential orthogonal reactions, nucleophilic thiol‐ene coupling via Michael addition and radical thiol‐ene click reactions. First, the synthesis of PONB with side chain acrylate groups is carried out via ring‐opening metathesis polymerization and nitroxide radical coupling reaction, respectively. Subsequently, the resulting polymer having two different orthogonal functionalities, main chain vinyl and side chain acrylate, is selectively modified via two sequential thiol‐ene click reactions, nucleophilic thiol‐ene coupling via Michael addition and photoinduced radical thiol‐ene. The orthogonal reactivity of two diverse double bonds, vinyl and acrylate functionalities, for the abovementioned consecutive thiol‐ene click reactions was first demonstrated on the model compound. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
63.
Hakan Durmaz Aydan Dag Duygu Gursoy A. Levent Demirel Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2010,48(7):1557-1564
Multiarm star triblock terpolymers were obtained by using two different click reactions sequentially: Cu(I) catalyzed azide–alkyne and Diels–Alder. The synthetic strategy is described as follows: (poly(methyl methacrylate))n‐(polystyrene)m‐poly(divinyl benzene)) ((PMMA)n‐(PS)m‐polyDVB) multiarm star diblock copolymer was first obtained from an azide–alkyne click reaction of (alkyne‐PS)m‐polyDVB multiarm star polymer with α‐anthracene‐ω‐azide PMMA (anth‐PMMA‐N3), followed by a Diels–Alder click reaction of the anthracene groups at the star periphery with α‐maleimide poly (tert‐butyl acrylate) (PtBA‐MI) or α‐maleimide poly(ethylene glycol) (PEG‐MI) leading to target (PtBA)k‐(PMMA)n‐(PS)m‐polyDVB and (PEG)p‐(PMMA)n‐(PS)m‐polyDVB multiarm star triblock terpolymers. The hydrodynamic diameter of individual multiarm star triblock terpolymers were measured by dynamic light scattering (DLS) to be ~24–27 nm in consistent with the atomic force microscopy (AFM) images on silicon substrates. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1557–1564, 2010 相似文献
64.
Multilayer structures form a particular class of samples employed in nuclear resonant scattering of synchrotron radiation. Their specific properties lead to unusual energy and time characteristics of nuclear resonant scattering, which differ much from those of single crystals. The analysis of these distinctions is presented. Several approaches to achieve pure nuclear reflections with multilayers are discussed. Finally, we review the studies of multilayer structures with nuclear resonant scattering of synchrotron radiation.
相似文献65.
Perturbation theory in a framework of iteration methods 总被引:1,自引:0,他引:1
In a previous paper [J. Phys. A 36 (2003) 11807], we introduced the ‘asymptotic iteration method’ for solving second-order homogeneous linear differential equations. In this Letter, we study perturbed problems in quantum mechanics and we use the method to find the coefficients in the perturbation series for the eigenvalues and eigenfunctions directly, without first solving the unperturbed problem. 相似文献
66.
The principal and engineering aspects of a dedicated synchrotron radiation beamline under construction at the Advanced Photon Source for nuclear resonant scattering purposes are explained. The expected performance in terms of isotopes to be studied, flux, and timing properties is discussed.This work is supported by the US-DOE-BES Materials Sciences, under Contract No. W-31-109-ENG-38. 相似文献
67.
Ruckert T. Keune W. Sahoo B. Sturhahn W. Toellner T. S. Alp E. E. Röhlsberger R. 《Hyperfine Interactions》2002,144(1-4):65-76
Hyperfine Interactions - Nuclear resonant inelastic X-ray scattering (NRIXS) of 14.4125 keV synchrotron radiation was used to measure directly the partial vibrational density of states (VDOS),... 相似文献
68.
69.
Ertuğrul Gazi Sağlam Sevcan Erden Özgür Tutsak Dilek Eskiköy Bayraktepe Zehra Yazan Durmuş Hakan Dal 《Phosphorus, sulfur, and silicon and the related elements》2017,192(3):322-329
Some 1,3-dithiadiphosphetane 2,4-disulfides (X2P2S4, X: Fc, FcLR; X: CH3O?C6H4?, LR) were allowed to react with alcohols to obtain dithiophosphonic acids (X(OR)PS2H). These were converted to the corresponding ammonium salts. The salts were of the structures [Fc(OR)PS2]?[NH4]+, R: 3-methyl-1-butyl- for I; 1-phenyl-1-propyl- for II; 3-pentyl- for III; 3-phenyl-1-propyl- for IV and [CH3O?C6H4(OR)PS2]?[NH4]+, R: 3-methyl-1-butyl- for V and 1-phenyl-1-propyl- for VI. To the best of our knowledge, all the compounds except V were prepared for the first time.The compounds synthesized were characterized by elemental analysis, NMR (1H, 13C, 31P), MS, FTIR, and Raman spectroscopies. Electrochemical behaviors of I–VI at disposable pencil graphite electrode (PGE) were investigated by using cyclic voltammetry (CV) and square-wave voltammetry (SWV). Adsorption and diffusion patterns of all the compounds on the PGE were also studied.Two electroactive groups were identified in the compounds I–IV and only one in V and VI. The ferrocenyl groups of I-IV were oxidized at around 0.4 V. The same compounds display a second, more intense CV band at 0.8 V. The corresponding band for the compounds V–VI appears at around 0.6 V with a much weaker intensity. It is suggested that the ferrocenyl group introduced into the structures stabilizes the radical species formed as the product of the oxidation of the dithiophosphonato group. 相似文献
70.
A gas chromatographic-mass spectrometric method was developed, validated and demonstrated by measuring the levels of nitrogen mustard hydrolysis products in the urine collected from dosed rats. The recovery values for trimethylsilyl derivatives of EDEA and MDEA are between 82-95% and 88-112%, respectively. In vivo studies performed by using three different doses (0.5 mg/kg, 1.0 mg/kg, and 2.0 mg/kg) of HN2 base of nitrogen mustard. MDEA concentrations were between 43.1-232.2 ng/mL. The limit of detection (S/N = 3) values are 2.5 ng/mL and 1.6 ng/mL for EDEA and MDEA, respectively, and the precision of the method in terms of RSD is between 5-8%. 相似文献