① 低温合成 （Low-temperature synthesis）

对于低温基质隔离研究而言，首先面对的挑战即需要对不稳定的前体物进行低温微量分离提纯，并加以完整结构表征。本课题组依托独具特色的低温微量样品预处理平台，实现对同位素取代分子、产生高能物质的前体、以及在室温下本身不稳定分子的微量分离、提纯和表征。以 HCCNCO的前体叠氮化合物 HCCC(O)N3为例，我们通过HCCC(O)Cl和NaN3反应得到HCCC(O)N3，利用配备J. Young阀的多级冷阱真空和在线红外光谱检测对其进行表征，得到气相红外光谱信息。此外，采用X射线单晶衍射、核磁共振波谱、拉曼光谱和紫外-可见吸收光谱等检测手段对气、固、液等不同相态下的前体化合物进行完整表征。

(1) Lu, B.; Shao, X.; Jiang, X.; Xue, J. F.; Rauhut, G.; Tan, G. W.; Fang, W.; Zeng, X. Q. Diazophosphane HPN2. J. Am. Chem. Soc. 2022, 144, 21853−21857.

(2) Qin, Y. Y.; Lu, B.; Rauhut, G.; Song, C.; Chu, X. X.; Wang, L. N.; Zeng, X. Q. The Simplest, Isolable, Alkynyl Isocyanate HCCNCO: Synthesis and Characterization. Angew. Chem. Int. Ed. 2019, 58, 17277–17281.

(3) Zhao, X. F.; Chu, X. X.; Rauhut, G.; Chen, C. Y.; Song, C.; Lu, B.; Zeng, X. Q. Phosphorus Analogues of Methyl Nitrite and Nitromethane: CH3OPO and CH3PO2. Angew. Chem. Int. Ed. 2019, 58, 12164–12169.

(4) Chu, X. X.; Yang, Y.; Lu, B.; Wu, Z.; Qian, W. Y.; Song, C.; Xu, X. F.; Abe, M.; Zeng, X. Q. Methoxyphosphinidene and Isomeric Methylphosphinidene Oxide. J. Am. Chem. Soc. 2018, 140, 13604–13608.

(5) Chen, C. Y.; Wang, L. N.; Zhao, X. F.; Wu, Z.; Bernhardt, E.; Eckhardt, A. K.; Schreiner, P. R.; Zeng, X. Q. Photochemistry of HNSO2 in cryogenic matrices: spectroscopic identification of the intermediates and mechanism. Phys. Chem. Chem. Phys. 2020, 22, 7975-7983.

(6) Qian, W.; Chu, X.; Wu, W.; Jiao, M.; Liu, H.; Zou, B.; Rauhut, G.; Tew, D. P.; Grützmacher, H.; Wang, L.; Zeng, X. Q. Hydrogen-Atom Tunneling in Metaphosphorous Acid. Chem. Eur. J. 2020, 26, 8205-8209.

② 活性中间体的光谱探测和反应 （Spectroscopic detection and reactivity of  reactive intermediates)

活性中间体普遍存在于有机合成反应、大气光氧化、燃烧化学、星际物质转化等过程，在合成化学、生物转化、材料科学、工业催化等方面具有非常重要的应用价值。证实中间体的存在并揭示其分子结构与反应机制对于认识化学反应本质、设计并优化反应路径、精准调控中间体的化学反应活性具有十分重要的意义。作为一类亚稳态产物，中间体在室温条件下具有反应活性高、寿命短、极易转化等特点，其直接光谱探测存在巨大的技术挑战。基于我们新构建的超低温（2.8 K）基质隔离仪器和专门设计的光解热解仪器，实现对新颖瞬态中间体的首次实验研究；采用控温手段和特定波长的光诱导，对极低温度惰性基质中的中间体的结构与构象转化开展精准调控；通过基质掺杂，探索高活性物种如自由基或原子团簇与原始大气小分子如CO、CO2、O2和H2O的基元反应过程，直观揭示极端条件下物质转化的动力学机制。

(1) Li, X. L.; Lu, B.; Jiang, J. J.; Wang, L. N.; Trabelsi, T.; Francisco, J. S.; Fang, W.; Zhou, M. F.; Zeng, X. Q. Water Complex of Imidogen. J. Am. Chem. Soc. 2023, doi.org/10.1021/jacs.2c12808

(2)  Chen, C. Y.; Lu, B.; Zhao, X. F.; Qian, W. Y.; Liu, J.; Trabelsi, T.; Francisco, J. S.; Qin, J.; Li, J.; Wang, L. N.; Zeng, X. Q. J. Am. Chem. Soc. 2020, 142, 2175-2179.

(3) Wu, Z.; Chen, C. Y.; Liu, J.; Lu, Y.; Xu, J.; Liu, X. Y.; Cui, G. L.; Trabelsi, T.; Francisco, J. S.; Mardyukov, A.; Eckhardt, A. K.; Schreiner, P. R.; Zeng, X. Q. Caged Nitric Oxide−Thiyl Radical Pairs. J. Am. Chem. Soc. 2019, 141, 3361−3365.

(4) Dong, X. L.; Deng, G. H.; Wu, Z.; Xu, J.; Lu, B.; Trabelsi, T.; Francisco, J. S.; Zeng, X. Q.  Spectroscopic Identification of H2NSO and syn- and anti-HNSOH Radicals. Angew. Chem. Int. Ed. 2018, 57, 7513–7517.

(5) Wu, Z.; Feng, R. J.; Li, H. M.; Xu, J.; Deng, G. H.;Abe, M.;Bégué, D.; Liu, K.; Zeng, X. Q. Fast Heavy-Atom:Tunneling in TrifluoroacetylNitrene.Angew.Chem.Int. Ed. 2017, 56, 15672–15676.

(6) Xu, J.; Wu, Z.; Wan, H. B.; Deng, G. H.; Lu, B.; Eckhardt, A. K.; Schreiner, P. R.; Trabelsi, T.; Francisco, J. S.; Zeng, X. Q. Phenylsulfinyl Radical: Gas-Phase Generation, Photoisomerization, and Oxidation. J. Am. Chem. Soc. 2018,140,9972-9978.

③ 星际化学 （Interstellar chemistry）

星际分子为行星、卫星以及彗星等天体提供了基本成分，星际分子的研究是天体演化，生命起源与物质结构三大基础理论学科的重要交叉点。硫、磷、氮是生态化学的基本元素，与生命起源息息相关，其二元或多元分子作为星际物种是星际化学的重要课题。我们的目标是实验室获得这些星际物种的指纹光谱，为宇宙探测提供理论基础。

(1) Lu, B.; Wang, L. N.; Jiang, X.; Rauhut, G.; Zeng, X. Q. Spectroscopic Identification of Diphosphene HPPH and Isomeric Diphosphinyldene PPH2. Angew. Chem. Int. Ed. 2023, doi.org/10.1002/anie.202217353.

(2) Li, X. X.; Lu, B.; Wang, L. N.; Xue, J. F.; Zhu, B. F.; Trabelsi, T.; Francisco, J. S.; Zeng, X. Q. Unraveling Sulfur Chemistry in Interstellar Carbon Oxide Ices. Nat. Commun. 2022, 12, 7150.

(3) Chu, X. X.; Qian, W. Y.; Lu, B.; Wang, L. N.; Qin, L.; Li, J.; Rauhut, G.; Trabelsi, T.; Francisco, J. S.; Zeng, X. Q. The Triplet Hydroxyl Radical Complex of Phosphorus Monoxide. Angew. Chem. Int. Ed. 2020, 59, 21949-21953.

(4) Wu, Z.; Feng, R. J.; Xu, J.; Lu, Y.; Lu, B.; Yang, T.; Frenking, G.; Trabelsi, T.; Francisco, J. S.; Zeng, X. Q. Photoinduced Sulfur−Nitrogen Bond Rotation and Thermal Nitrogen Inversion in Heterocumulene OSNSO. J. Am. Chem. Soc.2018,140, 1231–1234.

(5) Wu, Z.; Song, C.; Liu, J.; Lu, B.; Lu, Y.; Trabelsi, T.; Francisco, J. S.; Zeng, X. Q. Photochemistry of OPN: Formation of Cyclic PON and Reversible Combination with CarbonMonoxide.  Chem. Eur.J .2018, 24,14627-14630.

(6) Wu, Z.; Li, D. Q.; Li, H. M.; Zhu, B. F.; Sun, H. L.; Francisco, J. S.; Zeng, X. Q. Gas-Phase Generation and Decomposition of a Sulfinylnitrene into the Iminyl Radical OSN. Angew. Chem. Int. Ed.2016, 55, 1507–1510.

(7) Wu, Z.; Liu, Q. F.; Xu, J.; Sun, H. L.; Li, D. Q.; Song, C.;Andrada, D. M. A.; Frenking, G.; Trabelsi, T.;Francisco,J.S.; Zeng, X. Q. Heterocumulene Sulfinyl Radical OCNSO. Angew.Chem. Int. Ed.2017, 56, 2140–2144.

(8) Wu, Z.; Wan, H. B.; Xu, J.; Lu, B.; Lu, Y.; Eckhardt, A. K.; Schreiner, P. R.; Xie, C. J.; Guo, H.; Zeng, X. Q. The Near-UV Absorber OSSO and Its Isomers. Chem. Commun. 2018, 54, 4517-4520.

(9) Wu, Z.; Lu, B.; Feng, R. J.; Xu, J.; Lu, Y.; Wan, H. B.; Eckhardt, A. K.; Schreiner, P. R.; Xie, C. J; Guo, H.; Zeng, X. Q. Capture of SO3 isomers in the oxidation of sulfur monoxide with molecular oxygen. Chem. Comm. 2018, 54, 1690-1693.

(10) Lu, B.; Song, C.; Liu, J.; Trabelsi, T.; Francisco, J. S., Wang, L. N.; Zeng, X. Q. Dihalogenated Methylperoxy Radicals: Spectroscopic Characterization and Photodecomposition by Release of HO. Chem. Eur. J. 2020, 26, 2817–2820.

(11) Lu, B.; Song, C.; Qian, W. Y.; Wu, Z.; Csaszar. A. G.; Zeng, X. Q. Heterocumulenic carbene nitric oxide radical OCCNO. Chem. Commun., 2019,55, 13510-13513.