Halogenations of Anthracenes and Dibenz[<i>a,c</i>]anthracene with <i>N</i>-Bromosuccinimide and <i>N</i>-Chlorosuccinimide<sup>1</sup>
作者:Shaoming Duan、Jeff Turk、Joseph Speigle、Jean Corbin、John Masnovi、Ronald J. Baker
DOI:10.1021/jo991495h
日期:2000.5.1
exclusively 9-(bromomethyl)anthracene with NBS in the absence of iodine, but mainly (67%) 9-bromo-10-methylanthracene in the presence of iodine. Chlorination of 3 with NCS in the presence of HCl also affords mostly (65%) nuclear halogenation. Nuclear bromination of anthracene, 9-methylanthracene, and dibenz[a, c]anthracene by NBS in the absence of added HBr is accelerated by iodine. This effect is
bibenzyls and related ethane derivatives in high yields. Other diselenides were easily caused to cleave to give various aromatic and aliphatic olefins in good yields together with elemental selenium. Lepidopterene, [2.2]paracyclophane, and benzocyclobutene were prepared by thermal cleavage of their corresponding phenylselenomethyl-substituted compounds as an application of the pyrolysis concerned.
communication reports a novel and efficient synthesis of lepidopterene from 9-(chloromethyl)anthracene. Furthermore, the radical nature of the process is unambiguously established through the obtention of several 9-anthracenemethyl derivatives, which are formed via a common 9-anthracenemethyl radical intermediate, derived from 9-(iodomethyl)anthracene.
Multiple-Photon Chemistry of 9-(Phenoxymethyl)- and 9,10-Bis(phenoxymethyl)anthracenes in the Laser-Jet: Generation, Photochemistry, and Time-Resolved Laser-Flash Spectroscopy of Anthracenylmethyl Radicals and Pulse Radiolysis of 9-(Bromomethyl)anthracene
photons are required, the resulting arylmethyl radical 2a dimerizes in benzene, in methylene chloride it engages in photoinduced electron transfer, while in methanol it undergoes photoionization. With the help of time-resolved laser-flash photolysis of the monoether 1a it was confirmed that the homolysis of the C−O bond leads to the 9-anthracenylmethyl radical 2a. The authentic radi...
Mono- and biphotonic photochemistry in glass matrices
作者:Gerd Kaupp
DOI:10.1016/j.molstruc.2005.10.030
日期:2006.4
Inter- and intramolecular donor acceptor systems provide stable charge separation at 15 or 77 K upon pulsed laser irradiation and radicalanion spectra are recorded. Biphotonic photochemistry at ≥10 K allows for the formation of new ring systems such as dioxathiirane ( cyclo -SO 2 ), several aryldioxaziridines, and an electron rich triaziridine, compounds that revert upon thawing and could not be obtained
摘要 硬质玻璃溶剂基质中的光化学结果与气体基质中的结果不同。它是在 83、77 和 ≥10 K 下通过连续照射和脉冲多 MW cm -2 峰值强度激发对那些不进行单光子反应的系统进行的。高度结构化的矩阵谱应作为解释瞬态谱的基础以避免歧义。许多 [2.2] 对环芳烷被光解。除了荧光和磷光外,它们中的大多数还提供稳定的双自由基和醌二甲烷光谱。一些苄基双自由基在其光化学生成后会发生化学发光。基质分离光谱与鳞翅目案例中的常见解释不同。取代的环己烯在 83 K 下的 [2+4]-光环逆转导致二烯立体异构体/旋转异构体在进一步照射时发生异构化。E/Z-光平衡在 MTHF 基质中从两侧与 ω-硝基苯乙烯和 α-亚苄基-γ-丁内酯在 83 K 下获得,后者的立体异构化也在 10 K 下成功研究。 技术光稳定剂在 10 K 下的脉冲照射导致通过连续激发无法看到的质子迁移形成稳定的两性离子。分子间和分子内供体受体系统在