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521.
522.
Prof. Jamie L. Manson Michelle L. Warter Dr. John A. Schlueter Dr. Tom Lancaster Andrew J. Steele Prof. Stephen J. Blundell Dr. Francis L. Pratt Dr. John Singleton Dr. Ross D. McDonald Dr. Changhoon Lee Prof. Myung‐Hwan Whangbo Alex Plonczak 《Angewandte Chemie (International ed. in English)》2011,50(7):1726-1726
523.
Bird RG Neill JL Alstadt VJ Young JW Pate BH Pratt DW 《The journal of physical chemistry. A》2011,115(34):9392-9398
Microwave spectra of N,N'-dimethylaniline and 4,4'-dimethylaminobenzonitrile have been recorded in a pulsed supersonic jet using chirped pulse techniques. Experimental substitution structures have been determined for both molecules by detection of the spectra of all (13)C and (15)N isotopomers in natural abundance using a broadband spectrometer. Additionally, a narrowband spectrometer has been used to reveal the (14)N quadrupole splittings at high resolution, from which the orbital occupancy numbers of the amino- and cyano-nitrogen atoms have been determined. An apparent direct relationship between these values and the barriers to inversion of the amino groups is discussed. 相似文献
524.
Lancaster T Blundell SJ Baker PJ Brooks ML Hayes W Pratt FL Coldea R Sörgel T Jansen M 《Physical review letters》2008,100(1):017206
Zero-field muon-spin relaxation measurements of the frustrated triangular quantum magnet AgNiO2 are consistent with a model of charge disproportionation that has been advanced to explain the structural and magnetic properties of this compound. Below an ordering temperature of TN=19.9(2) K we observe six distinct muon precession frequencies, due to the magnetic order, which can be accounted for with a model describing the probable muon sites. The precession frequencies show an unusual temperature evolution which is suggestive of the separate evolution of two opposing magnetic sublattices. 相似文献
525.
Carol A. Parish Martel Zeldin Sean Hilson Jennifer Pratt 《Macromolecular Symposia》2003,196(1):327-336
The conformational flexibility of six hybrid organodisiloxane oligomers were studied using the Low Mode-Monte Carlo conformational search method with the MM2* force field and the Generalized Born/Surface Area continuum solvent model for water. These systems have enzyme-like properties as synthetic acyltransferases and contain aminopyridine groups in various states of protonation. An ensemble of low energy structures was generated and used to investigate the dependence of molecular shape and flexibility on protonation, which plays an important role in catalyst solubility and self-association. The results as measured by the number of unique conformations, end-to-end or longest intramolecular distance and radius of gyration of the conformational point cloud indicate that the number of protonated pyridines plays a significant role in the overall molecular shape. A similar study was also carried out on various POSS-substitutive organodisiloxane oligomers. 相似文献
526.
Bec J. Roldan Travis A. Hammerstad Matthew S. Galliher Mitchell H. Keylor Prof. Dr. Derek A. Pratt Prof. Dr. Corey R. J. Stephenson 《Angewandte Chemie (International ed. in English)》2023,62(34):e202305801
A simple method for accessing trans-2,3-diaryl dihydrobenzofurans is reported. This approach leverages the equilibrium between quinone methide dimers and their persistent radicals. This equilibrium is disrupted by phenols that yield comparatively transient phenoxyl radicals, leading to cross-coupling between the persistent and transient radicals. The resultant quinone methides with pendant phenols rapidly cyclize to form dihydrobenzofurans (DHBs). This putative biomimetic access to dihydrobenzofurans provides superb functional group tolerance and a unified approach for the synthesis of resveratrol-based natural products. 相似文献