ELECTRIC AND MOLECULAR STRUCTURAL INVESTIGATIONS

电和分子结构研究

• 批准号: 3776277
• 负责人: R MCDIARMID
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3776277
• 关键词: bridged cyclic compound; chemical bond resonance; chemical structure; diene; electronic spectra; molecular energy level; optical polarization; photochemistry; photon absorptiometry; saturated /unsaturated bonds; stereoisomer; terpenes

Optical absorption and 2 photon resonant multiphoton ionization (REMPI) and photoacoustic (PA) spectroscopic measurements on static samples and REMPI measurements on jet cooled samples of norbornadiene have been carried out to both interpret the spectrum of this molecule and to compare the results obtained by the different techniques. All three methods detected the structured 3s Rydberg <-X transition of norbornadiene but only the optical measurement could detect either of two diffuse valence transitions in this molecule. Comparisons of the REMPI and PA results indicated that the failure of these techniques to detect valence transitions is probably due to their small 2 photon cross sections. The 3s Rydberg <- X transition of norbornadiene was also analyzed. Polarization-selected, 2- and 3-photon REMPI measurements were carried out on the 3p Rydberg <- X transitions of acetone. The results were interpreted to indicate a significant reduction in the CCC angle deformation force constant on excitation and a coupling of one of these Rydberg states to the Pi-Pi* excited state of acetone. From the latter, the Pi-Pi* excited state was estimated to lie approximately 8 eV above the ground state of the molecule.

光吸收和双光子共振多光子电离(REMPI)和 静态样品和REMPI的光声光谱测量 对喷射冷却的降冰片二烯样品进行了测量。 为了解释这种分子的光谱并比较结果 通过不同的技术获得。这三种方法都检测到 降冰片二烯的结构3S里德堡-X跃迁 测量可以检测到这两个弥散价态转变中的任何一个 分子。REMPI和PA结果的比较表明， 这些技术检测价态转变的失败可能是由于 它们的小的双光子横截面。3S里德堡-X跃迁 并对降冰片二烯进行了分析。 进行了偏振选择、2光子和3光子REMPI测量 丙酮的3p里德堡-X跃迁。结果是 解释为表示CCC角显著减小 激励时的变形力常数和其中之一的联轴器 Rydberg态转变为丙酮的PI-PI*激发态。从后者来看， PI-PI*激发态估计位于大约8 eV的上方 分子的基态。