A 3D porous Cu(II)-MOF (1), having Lewis acid−base dual-functional sites, has been utilized, whose frameworks have two types of 1D channels decorated with both axially water-bound metal sites and weak base, i.e., tertiary amine groups in the crystallographic c-axis. Upon activation under a high vacuum at 120 °C, the axial water molecule is removed and affords a solvent-free and unsaturated Lewis acidic Cu(II) containing framework (1′). The piperazine functionalities from the linkers enhance the selective adsorption of CO₂ which, in turn, facilitate the further interaction with the open Cu(II) metal centres, leading to catalytic chemical fixation of CO₂ into five-membered cyclic carbonates, in the presence of epoxides and co-catalyst TBAB, under mild and solvent-free reaction conditions. The significance of dual functionalization and the synergy with TBAB on adeptly catalyzed CO₂ fixation are explored using several epoxides, and substantial conversion is achieved. Moreover, the catalyst 1′ displays satisfactory stability and easy recyclability for five consecutive cycles without any appreciable loss in its catalytic activity. The results are compared with various MOFs based catalysts at the closest reaction conditions and, based on literature and experimental inferences, a possible mechanism of chemical fixation of CO₂ with epoxide catalyzed by 1′ has been proposed.

已利用具有路易斯酸-碱双功能位点的3D多孔Cu（II）-MOF（1），其骨架具有两种类型的一维通道，均用轴向水结合的金属位点和弱碱修饰，即结晶c轴上的叔胺基。在120°C的高真空下活化后，轴向水分子被除去，得到不含溶剂且不饱和的路易斯酸性Cu（II）含骨架（1'）。来自接头的哌嗪官能团可增强CO ₂的选择性吸附，进而促进与开放的Cu（II）金属中心的进一步相互作用，从而导致CO _2的催化化学固定在环氧化物和助催化剂TBAB存在下，在温和且无溶剂的反应条件下，生成五元环状碳酸酯。使用几种环氧化物探索了双重功能化的重要性以及与TBAB协同作用对CO ₂固定催化的重要性，并实现了实质性转化。此外，催化剂1'在五个连续的循环中表现出令人满意的稳定性和容易的再循环性，而其催化活性没有任何明显的损失。将结果与各种基于MOF的催化剂在最接近的反应条件下进行了比较，并根据文献和实验推论，提出了用1'催化环氧化物将CO ₂化学固定的可能机理。