X-Ray Crystal Structure Analyses of Unstable Triplet Carbenes and Nitrenes and Comparison with their Reactivities

不稳定三线态卡宾和氮烯的X射线晶体结构分析及其反应性比较

• 批准号: 13440174
• 负责人: OHASHI Yuji
• 金额: $ 9.6万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13440174/
• 关键词: Triplet Carbene; Triplet Nitrene; X-ray Analysis; Unstable Intermediates; Structure of Excites State; Excite state of Platinum Complex; Diazomethane Derivatives; Azido Compounds; 不定中間体の構造; カルベン; ナイトレン; 結晶構造; 光解離; 不安定構造; 反応中間体; 放射光

In order to understand the mechanism of chemical reactions, it is essential to obtain the reaction intermediates and to analyze their characteristics. Although the spectroscopic studies have been made clear the energy change of the excited molecules in the time scale of a few femtosecond, the structures of the excited molecule have been obscure till now, since it has been considered to be impossible to trap the excited molecules in a crystalline lattice and to analyze the structures by X-rays. In the present work, we intended to analyze the structures of unstable species such as triplet carbenes and nitrenes. The crystal of the reactant molecule, diazomethane or phenylazide, was cooled below 80 K on the diffractometer using the nitrogen-gas-flow method and was exposed to the high-pressure mercury lamp using a guide tube. The diffraction data were collected after the irradiation at low temperatures. In a difference Fourier map, the new peaks appeared, which were assigned the produced ca … More rbene or nitrene, although only 10% reactant molecules were converted to the unstable species. The structures are in good agreement with those obtained from the theoretical calculation. For the nitrene, it was difficult to obtain the precise structure, since the produced nitrene overlapped on the reactant molecule in the crystalline lattice. The host-guest complex was produced using dibenzylamine as a host. The irradiated crystal was analyzed by the vacuum camera set up at Spring-8. The precise structure of the nitrene was obtained from the host-guest complex. Moreover, the crystal of a platinum complex was exposed to a xenon lamp at 80K. The diffraction data before and during the irradiation were collected and both of the structures were analyzed. The lattice constant clearly changed during the irradiation. The structure during the irradiation clearly indicated that the Pt-Pt distance is shortened at the excited state in accordance with the molecular orbital theory. A11 the above results suggest that the X-ray crystallography will play an important role in analyzing the unstable species in near future. Less

为了了解化学反应的机理，必须获得反应中间体并分析其特性。虽然光谱学研究已经明确了激发态分子在几飞秒的时间尺度内的能量变化，但激发态分子的结构至今仍不清楚，因为人们认为不可能将激发态分子捕获在晶格中并用x射线分析其结构。在目前的工作中，我们打算分析不稳定的物种，如三重碳烯和亚胺的结构。将反应物分子（重氮甲烷或苯基肼）晶体在衍射仪上用氮气流法冷却至80k以下，并通过导管暴露在高压汞灯下。低温辐照后采集衍射数据。在差异傅里叶图中，出现了新的峰，这些峰被分配给产生的更多的rbene或nitrene，尽管只有10%的反应物分子转化为不稳定的物质。计算结果与理论计算结果吻合较好。对于硝基烯，由于生成的硝基烯在晶格中重叠在反应物分子上，因此难以获得精确的结构。以二苄胺为寄主制备主-客体复合物。利用设在Spring-8的真空照相机对辐照后的晶体进行分析。从主-客体络合物中得到了亚硝基的精确结构。此外，铂配合物的晶体在80K的氙灯下暴露。采集了辐照前后的衍射数据，并对两种结构进行了分析。在辐照过程中，晶格常数发生了明显变化。辐照过程中的结构清楚地表明，在激发态下，Pt-Pt距离缩短，符合分子轨道理论。以上结果表明，在不久的将来，x射线晶体学将在分析不稳定物质方面发挥重要作用。少

项目成果

大橋裕二: "励起分子のX線構造解析"未来材料. 2. 77-80 (2002)

Yuji Ohashi：“激发分子的 X 射线结构分析”Future Materials。2. 77-80 (2002)。

Yoshiki Ozawa, Madoka Terashima, Minoru Mitsumi, Koshiro Toriumi, Nobuhiro Yasuda, Hidehiro Uekusa, Yuji Ohashi: "Photoexcited Crystallography of Diplatinum Complex by Multi-exposure IP Method"Chem.Lett.. 2003. 62-63 (2003)

Yoshiki Ozawa、Madoka Terashima、Minoru Mitsumi、Koshiro Toriumi、Nobuhiro Yasuda、Hidehiro Uekusa、Yuji Ohashi：“通过多次曝光 IP 方法进行二铂配合物的光激发晶体学”Chem.Lett.. 2003. 62-63 (2003)

Nobuhiro Yasuda, Masaki Kanazawa, Hidehiro Uekusa, Yuji Ohashi: "Excited-state Structure of a Platinum Complex by X-ray Analysis"Chem.Lett.. 2002. 1132-1133 (2002)

Nobuhiro Yasuda、Masaki Kanazawa、Hidehiro Uekusa、Yuji Ohashi：“通过 X 射线分析确定铂络合物的激发态结构”Chem.Lett.. 2002. 1132-1133 (2002)

Masaki Kawano, Katsuyuki Hirai, Hideo Tomioka and Yuji Ohashi: "Structure Analysis of a Transient Triplet Carbene Trapped in a Crystal"J. Am. Chem. Soc.. 123. 6904-6908 (2001)

Masaki Kawano、Katsuyuki Hirai、Hideo Tomioka 和 Yuji Ohashi：“晶体中捕获的瞬态三线态卡宾的结构分析”J。

Masaki Kawano, Yoshiki Ozawa, Koutatsu Matsubara, Hidekazu Imabayashi, Minoru Mitsumi, Kshiro Toriumi, Yuji Ohashi: "Synchrotron Radiation Structure Analyses of the Light-induced Radical Pair of a Hexaarylbiimidazolyl Derivative. Origin of the Spin-Multip

Masaki Kawano、Yoshiki Ozawa、Koutatsu Matsubara、Hidekazu Imabayashi、Minoru Mitsumi、Kshiro Toriumi、Yuji Ohashi：“六芳基联咪唑基衍生物光致自由基对的同步辐射结构分析。自旋多重粒子的起源