Photocatalytic dehydrogenative C-C coupling of acetonitrile to succinonitrile

• Published in: Nature communications 2022-07, Vol.13 (1), p.4379-4379, Article 4379
• Main Authors: Zhou, Xian, Gao, Xiaofeng, Liu, Mingjie, Gao, Zirui, Qin, Xuetao, Xu, Wenhao, Ye, Shitong, Zhou, Wenhua, Fan, Haoan, Li, Jing, Fan, Shurui, Yang, Lei, Fu, Jie, Xiao, Dequan, Lin, Lili, Ma, Ding, Yao, Siyu
• Format: Article
• Language: English
• Subjects: 147/28; 639/638/549/933; 639/638/77/887; 639/638/77/890; Acetonitrile; Anatase; Aqueous solutions; Catalysts; Chemical synthesis; Clean energy; Coupling (molecular); Dehydrogenation; Green hydrogen; Humanities and Social Sciences; Hydrogen bonds; Hydrogen-based energy; Hydroxyl radicals; multidisciplinary; Oxidation; Photocatalysis; Reagents; Renewable energy; Science; Science (multidisciplinary); Selectivity; Succinonitrile; Titanium dioxide
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-32137-y

The coupling of acetonitrile into succinonitrile, an important terminal dinitrile for value-added nylon production, via a dehydrogenative route is highly attractive, as it combines the valuable chemical synthesis with the production of green hydrogen energy. Here, we demonstrate that it is possible to achieve a highly selective light driven dehydrogenative coupling of acetonitrile molecules to synthesize succinonitrile using anatase TiO 2 based photocatalysts in aqueous medium under mild conditions. Under optimized conditions, the formation rate of succinonitrile reaches 6.55 mmol/(g cat *h), with over 97.5% selectivity to target product. Mechanism studies reveal that water acts as cocatalyst in the reaction. The excited hole of anatase semiconductor oxidizes water forming hydroxyl radical, which subsequently assists the cleavage of sp 3 C-H bond of acetonitrile to generate ·CH 2 CN radical for further C-C coupling. The synergy between TiO 2 and Pt cocatalyst is important to enhance the succinonitrile selectivity and prevent undesirable over-oxidation and hydrolysis. This work offers an alternative route to prepare succinonitrile based on renewable energy under mild conditions and avoid the use of toxic reagents and stoichiometric oxidative radical initiators. The coupling of acetonitrile into succinonitrile via a dehydrogenative route is highly attractive in terms of valuable chemical synthesis and green hydrogen energy production. Here, the authors report succinonitrile synthesis with high selectivity and rate via a light driven dehydrogenative coupling reaction of CH 3 CN over the anatase TiO 2 supported Pt catalyst.