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101.
Dr. Sumanta Banerjee Peter A. Macdonald Dr. Samantha A. Orr Dr. Alan R. Kennedy Alexander van Teijlingen Dr. Stuart D. Robertson Prof. Tell Tuttle Prof. Robert E. Mulvey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(55):e202201085
A series of group 1 hydrocarbon-soluble donor free aluminates [AM(tBuDHP)(TMP)Al(iBu)2] (AM=Li, Na, K, Rb) have been synthesised by combining an alkali metal dihydropyridyl unit [(2-tBuC5H5N)AM)] containing a surrogate hydride (sp3 C−H) with [(iBu)2Al(TMP)]. These aluminates have been characterised by X-ray crystallography and NMR spectroscopy. While the lithium aluminate forms a monomer, the heavier alkali metal aluminates exist as polymeric chains propagated by non-covalent interactions between the alkali metal cations and the alkyldihydropyridyl units. Solvates [(THF)Li(tBuDHP)(TMP)Al(iBu)2] and [(TMEDA)Na(tBuDHP)(TMP)Al(iBu)2] have also been crystallographically characterised. Theoretical calculations show how the dispersion forces tend to increase on moving from Li to Rb, as opposed to the electrostatic forces of stabilization, which are orders of magnitude more significant. Having unique structural features, these bimetallic compounds can be considered as starting points for exploring unique reactivity trends as alkali-metal-aluminium hydride surrog[ATES]. 相似文献
102.
Hieu T. Nguyen Di Yan Fan Wang Peiting Zheng Young Han Daniel Macdonald 《固体物理学:研究快报》2015,9(4):230-235
We report and explain the photoluminescence spectra emitted from silicon solar cells with heavily‐doped layers at the surface. A micro‐photoluminescence spectroscopy system is employed to investigate the total spectrum emitted from both the heavily‐doped layer and the silicon substrate with micron‐scale spatial resolution. The two regions of the device give rise to separate photoluminescence peaks, due to band‐gap narrowing effects in the highly‐doped layer. Two key parameters, the absorption depth of the excitation wavelength, and the sample temperature, are shown to be critical to reveal the separate signatures from the two regions. Finally, this technique is applied to locally diffused and laser‐doped regions on silicon solar cell pre‐cursors, demonstrating the potential value of this micron‐scale technique in studying and optimizing locally doped regions. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
103.
Dr. Malte Brasholz Dr. James M. Macdonald Dr. Simon Saubern Dr. John H. Ryan Prof. Dr. Andrew B. Holmes 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(37):11471-11480
The total synthesis of the spiropiperidine alkaloid (?)‐perhydrohistrionicotoxin (perhydro‐HTX) 2 has been accomplished on a gram scale by employing both conventional batch chemistry as well as microreactor techniques. (S)‐(?)‐6‐Pentyltetrahydro‐pyran‐2‐one 8 underwent nucleophilic ring opening to afford the alcohol 10 , which was elaborated to the nitrone 13 . Protection of the nitrone as the 1,3‐adduct of styrene and side‐chain extension to the unsaturated nitrile afforded a precursor 17 , which underwent dipolar cycloreversion and 1,3‐dipolar cycloaddition to give the core spirocyclic precursor 18 that was converted into perhydro‐HTX 2 . The principal steps to the spirocycle 18 have successfully been transferred into flow mode by using different types of microreactors and in a telescoped fashion, allowing for a more rapid access to the histrionicotoxins and their analogues by continuous processing. 相似文献
104.
Tony W. J. Cooper Ian B. Campbell Dr. Simon J. F. Macdonald 《Angewandte Chemie (International ed. in English)》2010,49(44):8082-8091
Synthetic organic reactions are a fundamental enabler of small‐molecule drug discovery, and the vast majority of medicinal chemists are initially trained—either at universities or within industry—as synthetic organic chemists. The sheer breadth of synthetic methodology available to the medicinal chemist represents an almost endless source of innovation. But what reactions do medicinal chemists use in drug discovery? And what criteria do they use in selecting synthetic methodology? Why are arrays (small focused libraries) so powerful in the lead‐optimization process? In this Minireview, we suggest some answers to these questions and also describe how we have tried to expand the number of robust reactions available to the medicinal chemist. 相似文献
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106.
Yang J Cyr PW Wang Y Soong R Macdonald PM Chen L Manners I Winnik MA 《Photochemistry and photobiology》2006,82(1):262-267
We describe experiments that determine the quenching kinetics by poly(ferrocenylsilane) (PFS) for platinum octaethylporphine (PtOEP) phosphorescence in toluene solution. The phosphorescence quenching process was interpreted in terms of diffusion-controlled kinetics. Pulsed-gradient spin-echo nuclear magnetic resonance (PGSE NMR) and dynamic light scattering (DLS) were used to characterize the diffusion behavior of PFS and PtOEP in toluene solution. We found that the ferrocene group present in the repeat unit of polymer backbone is a good quencher for PtOEP phosphorescence. Quenching by the polymer involves the entire PFS polymer chain instead of individual ferrocene groups. The intrinsic quenching ability of PFS was found to be higher than that of a model compound, Bu-FS, that contains a single ferrocene group. 相似文献
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109.
Varrot A Macdonald J Stick RV Pell G Gilbert HJ Davies GJ 《Chemical communications (Cambridge, England)》2003,(8):946-947
A cellobio-derived isofagomine glycosidase inhibitor (Ki approximately 400 nM) displays an unusual distorted 2,5B (boat) conformation upon binding to cellobiohydrolase Cel6A from Humicola insolens, highlighting the different conformational itineraries used by various glycosidases, with consequences for the design of therapeutic agents. 相似文献
110.