Dinitrogen Cleavage and Functionalization with Carbon Dioxide in a Dititanium Dihydride Framework
Dinitrogen Cleavage and Functionalization with Carbon Dioxide in a Dititanium Dihydride Framework
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二氢化二钛框架中的二氮裂解和二氧化碳官能化
DOI：
10.1021/jacs.2c01851
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发表时间：
2022
影响因子：
15
通讯作者：
Hou Zhaomin
中科院分区：
文献类型：
--
作者：
Zhuo Qingde;Yang Jimin;Mo Zhenbo;Zhou Xiaoxi;Shima Takanori;Luo Yi;Hou Zhaomin
用二氧化碳（CO2）活化和官能化二氮（N2）具有极大的兴趣和重要性，但极具挑战性。本文首次报道了N_2与CO_2在二氢化二钛骨架中的反应，该反应导致N-C键的形成以及N-N和C-O键的断裂。将二氮二钛氢化物络合物{[（acriPNP）Ti]2（μ2-n1：n2-N2）（μ2-H）2}（1）（acriPNP = 4，5-双（二异丙基膦基）-2，7，9，9-四甲基-9H-吖啶-10-化物）在室温下暴露于CO2气氛中快速产生腈基/N，N-二羧酰氨基络合物{[（acriPNP）Ti]2（μ2-N）[μ2-N（CO2）2]}（2.28%）和二异氰酸酯基/二氧代络合物{[（acriPNP）Ti]2（NCO）2（μ2-O）2}（3.52%），并释放H2。当1与CO2（1大气压）在-50 °C下反应时，在5 min内选择性地形成络合物2，产率为82%。在1大气压CO2下在80 °C下加热2 30 min得到3，产率为67%。当使1与1.5当量的CO2在室温下反应时，在5 min内，只生成异氰酸根/硝基/氧代配合物{[（acriPNP）Ti]2（NCO）（μ2-N）（μ2-O）}（4），产率为89%.在室温下，4与CO2反应，在5 min内几乎定量生成二氧代/二异氰酸酯配合物3标记的实验和密度泛函理论（DFT）计算，提供了前所未有的洞察N2与CO2的反应。还建立了以H2为还原剂，由N2、CO2和Me 3SiCl合成三甲基硅基异氰酸酯Me 3SiNCO的钛介导循环。
The activation and functionalization of dinitrogen (N2) with carbon dioxide (CO2) are of great interest and importance but highly challenging. We report here for the first time the reaction of N2with CO2in a dititanium dihydride framework, which leads to N–C bond formation and N–N and C–O bond cleavage. Exposure of a dinitrogen dititanium hydride complex {[(acriPNP)Ti]2(μ2-η1:η2-N2)(μ2-H)2} (1) (acriPNP = 4,5-bis(diisopropylphosphino)-2,7,9,9-tetramethyl-9H-acridin-10-ide) to a CO2atmosphere at room temperature rapidly yielded a nitrido/N,N-dicarboxylamido complex {[(acriPNP)Ti]2(μ2-N)[μ2-N(CO2)2]} (2, 28%) and a diisocyanato/dioxo complex {[(acriPNP)Ti]2(NCO)2(μ2-O)2} (3, 52%) with release of H2. When the reaction of1with CO2(1 atm) was carried out at −50 °C, complex2was selectively formed in 82% yield within 5 min. Heating2at 80 °C under 1 atm CO2for 30 min afforded3in 67% yield. When1was allowed to react with 1.5 equiv of CO2at room temperature, an isocyanato/nitrido/oxo complex {[(acriPNP)Ti]2(NCO)(μ2-N)(μ2-O)} (4) was exclusively formed in 89% yield within 5 min. The reaction of4with CO2at room temperature almost quantitatively yielded the dioxo/diisocyanato complex3within 5 min. The mechanistic details were clarified by the15N- and13C-labeled experiments and density functional theory (DFT) calculations, providing unprecedented insights into the reaction of N2with CO2. A titanium-mediated cycle for the synthesis of trimethylsilyl isocyanate Me3SiNCO from N2, CO2, and Me3SiCl using H2as a reducing agent was also established.