Structure Function Relationships in Ruthenium Carbon Dioxide Reduction Catalysts with CNC Pincers Containing Donor Groups
Structure Function Relationships in Ruthenium Carbon Dioxide Reduction Catalysts with CNC Pincers Containing Donor Groups
复制标题
DOI：
10.1002/ejic.202000444
复制
发表时间：
2020-07
影响因子：
2.3
通讯作者：
Sanjita Das;Dinesh Nugegoda;Fengrui Qu;Chance M. Boudreaux;Phillip E. Burrow;Matthew T. Figgins;R. W. Lamb;C. E. Webster;J. Delcamp;Elizabeth T. Papish
中科院分区：
文献类型：
--
作者：
Sanjita Das;Dinesh Nugegoda;Fengrui Qu;Chance M. Boudreaux;Phillip E. Burrow;Matthew T. Figgins;R. W. Lamb;C. E. Webster;J. Delcamp;Elizabeth T. Papish
用7种通式为[（CNC）Ru（CH 3CN）2Cl]OTf的钌催化剂研究了敏化光催化CO2还原反应中的结构-功能关系。在本文中，CNC是一种钳形配体，其含有与中心吡啶基环连接的咪唑基N-杂环卡宾（NHC），其中R基团位于3-或4-位。两个新的配合物（R = 3-OMe，4-NPh 2）已通过分析和光谱方法以及单晶X射线衍射进行了充分表征。此外，三个先前合成的配合物（R = 4-Me，4-NMe 2和4-OH）首次用于双金属化。4位的甲氧基和甲基供体基团导致具有高TOF（高达174 h-1）的用于CO生产的耐用催化剂（TON高达1000）。相比之下，R = 4-NPh 2、3-OMe和4-H取代基导致适度的TOF值（高达32 h-1），但这些系统仍然稳健，并达到高达565 TON。相比之下，用4-NMe 2和4-OH取代基观察到低活性，其类似于牺牲供体并且可能导致副反应。因此，发现远程取代基极大地影响催化剂活性和寿命。
Seven ruthenium catalysts with the general formula [(CNC)Ru(CH3CN)2Cl]OTf have been used to understand structure function relationships in the sensitized photocatalytic CO2reduction reaction. Herein, CNC is a pincer ligand containing imidazole‐based N‐heterocyclic carbenes (NHCs) attached to a central pyridyl ring with R groups at the 3‐ or 4‐position. Two new complexes (R = 3‐OMe, 4‐NPh2) have been fully characterized by analytical and spectroscopic methods and single‐crystal X‐ray diffraction. Furthermore, three previously synthesized complexes (R = 4‐Me, 4‐NMe2, and 4‐OH) are used for photocatalysis for the first time. Methoxy and methyl donor groups in the 4‐position lead to durable catalysts (TON up to 1000) with high TOFs (up to 174 h–1) for CO production. In contrast, R = 4‐NPh2, 3‐OMe, and 4‐H substituents lead to modest TOF values (up to 32 h–1), yet these systems are still robust and achieve up to 565 TON. In contrast, low activity is observed with 4‐NMe2and 4‐OH substituents, which resemble sacrificial donors and may be leading to side reactions. Thus, remote substituents were found to greatly influence catalyst activity and longevity.