TIME-RESOLVED IR SPECTROMETRIC DETECTION SYSTEM FOR KINETIC AND STRUCTURAL STUDIES OF REACTIVE INTERMEDIATES AT AMBIENT TEMPERATURE

本研究的目的是建立激光闪光光解（LFP）的时间分辨红外检测系统。它的设计是紧凑的，适合动力学和结构的研究，以获得高性价比。我们的LFP系统的操作软件也进行了修改，使其能够与红外探测系统同步。到目前为止，能够很容易地检测到具有足够消光系数和几百秒寿命的中间体。另一方面，反应中间体的时间分辨光谱研究也进行了紫外可见检测。我们对这种特殊的碳感兴趣，并试图从前体生成苯并环丁烯，以研究其反应性。苯并环丁烯酮的N-（2-苯基苄基）亚胺的LFP （XeCl, 308 nm）产生瞬时物质，其吸收最大值约为450 nm。这些瞬态消失后，寿命为1 μs，在510 nm处观察到一个较长寿命的弱吸收，寿命为660 μs。根据所观察到的对烯烃和醇的反应性，我们把前一种瞬变归为苯并环丁烯二烯引起的。后一个510 nm的瞬态可以被指定为重氮苯环丁烯，因为该物质可以被双极性试剂如富马腈猝灭。相同前驱体的相似LFP与红外检测允许我们观察到2042 cm^<-1>的吸收，这可以归因于重氮苯并环丁烯。寿命为1 ms，与UV-VIS检测结果吻合较好。仪器灵敏度和时间分辨率方面的进一步进展正在进行中，以便可以观察到苯并环丁烯二烯和吡啶二烯。

The goal of this study is to build a time-resolved IR detection system for laser flash photolysis (LFP). It is designed to be compact and suited for kinetic and structural studies of gain high cost-performance. The operational software for our LFP system is also modified so that it can be synchronized with the IR detection system. So far, intermediates with sufficient extinction coefficients and the lifetime of some hundred seconds can be readily detected.On the other hand, time-resolved spectroscopic studies of reactive intermediates are also carried out with UV-VIS detection. We are interested in this particular carbene and have attempted to generate benzocyclobutenylidene from precursors in order to investigate its reactivity. LFP (XeCl, 308 nm) of N-(2-phenylazyridyl)imine of benzocyclobutenone results in transient species with its absorption maximum around 450 nm. After these transients disappeared with the lifetime of 1 μs, a longer-lived species was observed as a weak absorption at 510 nm with the lifetime of 660 μs. We assign the former transient as being due to benzocyclobutenylidene based on the observed reactivity toward alkenes and alcohols. The latter 510 nm transient can be assigned as diazobenzocyclobutene because this species can be quenched by dipolarophiles such as fumaronitrile.Similar LFP of the same precursor with IR detection allowed us to observe absorption at 2042 cm^<-1>, which can be assigned as being due to diazobenzocyclobutene. The lifetime is 1 ms, which is in good agreement with the observation by UV-VIS detection. Further progress in the instrumental sensitivity and time-resolution is underway so that benzocyclobutenylidene and the pyridine ylide can be observed.