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31.
John G. Stuart Michael J. Quast Gary E. Martin Vincent M. Lynch Stanley H. Simonsen Milton L. Lee Raymond N. Castle Jerry L. Dallas Boban K. John LeRoy F. Johnson 《Journal of heterocyclic chemistry》1986,23(4):1215-1234
Syntheses of benzo[3,4]phenanthro[1,2-b]thiophene, benzo[3,4]phenanthro[2,1-b]thiophene and their 1-methyl analogs are reported as potential constituents of solvent refined coal liquids and for mutagenicity testing. The attempted synthesis of the 13-methyl analogs which gave the 11-methyl isomers is also described. Total assignments of the 1H- and 13C-nmr spectra based on long range optimized heteronuclear protoncarbon two-dimensional chemical shift correlation are reported. Carbon assignments obtained for benzo[3,4]-phenanthro[1,2-b]thiophene using this approach were confirmed with a 125 MHz 13C–13C INADEQUATE spectrum. X-Ray crystal structures were determined for benzo[3,4]phenanthro[1,2-b]thiophene and 1-methyl-benzo[3,4]phenanthro[2,1-b]thiophene. Both molecules were helically distorted from planarity. Close intramolecular contacts between the bay region H1–H13 and ClMe-H13 of 2.03 and 2.28 Å, respectively, were responsible for the distortions. There were no close intermolecular contacts of <3.5Å. both molecules refined to an R value of <0.05. 相似文献
32.
Yoshinori Tominaga Jiann-Kuan Luo Lyle W. Castle Raymond N. Castle 《Journal of heterocyclic chemistry》1993,30(1):267-273
The synthesis of the novel pyrazolo[4′,3′:5,6]pyrido[2,3-d]pyridazine ring system and some of its derivatives has been accomplished such as 4-amino-1-phenyl-5,8-dioxo-, 4-amino-5,8-dioxo-, 1-phenyl-5,8-dioxo-, 5,8-dioxo-, 5,8-dichloro-1-phenyl-, 5-ethoxy-1-phenyl- and 8-ethoxy-1-phenylpyrazolo[4′,3′:5,6]pyrido[2,3-d]pyrid-azines. 相似文献
33.
M. J. Musmar Andrew S. Zektzer Raymond N. Castle N. Kent Dalley 《Journal of heterocyclic chemistry》1993,30(2):487-492
Naphtho[1′,2′:4,5]thieno[3,2-a]-4,7-phenanthroline, a novel hexacyclic ring system has been synthesized in four steps. The 1H and 13C nmr assignments have been made using two-dimensional nmr techniques. The tertiary helical structure was determined by X-ray crystallographic analysis. 相似文献
34.
M. J. Musmar M. Robert Willcott Gary E. Martin Robert T. Gampe Masatomo Iwao Milton L. Lee Ralph E. Hurd Leroy F. Johnson Raymond N. Castle 《Journal of heterocyclic chemistry》1983,20(6):1661-1669
Development of successively higher field nmr spectrometers has facilitated the study of increasingly more complex molecules, although smaller molecules such as phenanthro[3,4-b]thiophene still offer very substantial assignment problems because of the highly congested nature of their 1H- and 13C-nmr spectra. Assignments of such spectra, if they are to be unequivocal, frequently require the utilization of two-dimensional nmr spectroscopic techniques. Total assignments of the 1H- and 13C-nmr spectra of phenanthro[3,4-b]thiophene are reported. Assignments were based on a conventional high resolution 500 MHz 1H-nmr spectrum, autocorrelated two-dimensional 1H-nmr spectra (COSY), two-dimensional 1H-13C chemical shift correlation spectra and a modified version of autocorrelated 13C-13C double quantum coherence two-dimensional nmr spectroscopy. From NOE measurements, a separation of 1.99 Å between H1 and H11 was computed, suggesting that phenanthro[3,4-b]thiophene has a pronounced helical conformation in solution. 相似文献
35.
Abusaidi R Akerib DS Barnes PD Bauer DA Bolozdynya A Brink PL Bunker R Cabrera B Caldwell DO Castle JP Clarke RM Colling P Crisler MB Cummings A Da Silva A Davies AK Dixon R Dougherty BL Driscoll D Eichblatt S Emes J Gaitskell RJ Golwala SR Hale D Haller EE Hellmig J Huber ME Irwin KD Jochum J Lipschultz FP Lu A Mandic V Martinis JM Nam SW Nelson H Neuhauser B Penn MJ Perera TA Perillo Isaac MC Pritychenko B Ross RR Saab T Sadoulet B Schnee RW Seitz DN Shestople P Shutt T Smith A Smith GW 《Physical review letters》2000,84(25):5699-5703
The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data, accounting for the neutron background, give limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV/c2 WIMP mass and, at >75% C.L., the entire 3sigma allowed region for the WIMP signal reported by the DAMA experiment. 相似文献
36.
Yoshinori Tominaga Lyle W. Castle Raymond N. Castle 《Journal of heterocyclic chemistry》1993,30(3):845-847
6-Aminobenzo[b]naphtho[2,1-d]thiophene has been prepared by two different routes, one, a one-pot synthesis. 相似文献
37.
8-Amino-s-triazolo[4, 3-b]pyridazine (I), an adenine analog has been prepared by two different routes. Likewise 8-amino-3-phenyl-s-triazolo[4,3-b]pyridazine (V) has been prepared. Both of these compounds have been prepared utilizing 3,4,5-trichloropyridazine and 3,4,6-trichloropyridazine as the starting materials thus interrelating the 3,4,5-and the 3,4,6-series. A variety of other transformations have been carried out. 相似文献
38.
Yovchev I.G. Lawson W.G. Nusinovich G.S. Granatstein V.L. Castle M. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2000,28(3):523-528
A design of a Ku-band 17.1-GHz four-cavity coaxial gyroklystron amplifier for driving future linear colliders is presented. The X-band input cavity operates in the TE0.11 mode, whereas the remaining three cavities (buncher, penultimate, and output) operate in the TE021 mode, doubling the frequency of the input signal. The electron beam parameters are the following: current of 540 A, voltage of 460 kV, perpendicular-to-parallel velocity ratio of 1.5, and a parallel velocity spread of 6.4%. The output cavity has been simulated as (1) zero-drive unstable with Q-factor of 320 and (2) zero-drive stable with Q-factor of 250. The simulations show that the maximum efficiency in the first case is 37.4%, and in the second one is 34.4%. In both cases, a high gain of 60 dB at a 100-MW output power level can be realized 相似文献
39.
Michael J. Quast Gary E. Martin Vincent M. Lynch Stanley H. Simonsen John G. Stuart Marvin L. Tedjamulia Raymond N. Castle Milton L. Lee 《Journal of heterocyclic chemistry》1986,23(4):1115-1118
The crystal structure of 9-methylphenanthro[4,3-a]dibenzothiophene, C25H16S, Mr = 348.47, has been determined. Monoclinic, P21/c, a = 11.364(3), b, = 14.257(3), c = 11.575(2)Å, β = 116.26(2)°, V = 1681.9(7)Å3, Z = 4, Dx = 1.38 g/cc, MoKα radiation λ = .71069 Å, F(000) = 728, T = 163K, R = .0458 for 2330 reflections. The structure compares favorably with that of hexahelicene and methylated derivatives. The thiophene moiety increases the helical core radius and decreases the pitch with respect to hexahelicene and its derivatives. 相似文献
40.
John P. Shockcor Ronald C. Crouch Gary E. Martin Abdallah Cherif Jiann-Kuan Luo Raymond N. Castle 《Journal of heterocyclic chemistry》1990,27(2):455-458
One-dimensional ( 1D ) variants of two-dimensional ( 2D ) nmr techniques can frequently provide the required information in a much shorter period of time than the 2D experiment from which they were derived. Application of the 1D homonuclear Hartmann-Hahn (1D-HOHAHA) experiment to establish proton-proton connectivity networks in highly overlapped four-spin systems in the proton nmr spectra of polynuclear aromatics is described. Selective subspectra are contrasted to the data obtained in a COSY experiment on the same molecule, benzo[f][l]benzothieno [2,3 -c]quinoline. Results from the 1D-HOHAHA technique are especially useful when component resonances from several spin systems are heavily overlapped. Relayed 1D-HOHAHA provides the means of exploiting small, long range coupling pathways of polynuclear aromatics. 相似文献