Selective Implantation of Diamines for Cooperative Catalysis in Isoreticular Heterometallic Titanium–Organic Frameworks

다국어 초록 (Multilingual Abstract)

We introduce the first example of isoreticular titanium–organic frameworks, MUV‐10 and MUV‐12, to show how the different affinity of hard Ti(IV) and soft Ca(II) metal sites can be used to direct selective grafting of amines. This enables the combination of Lewis acid titanium centers and available ‐NH2 sites in two sizeable pores for cooperative cycloaddition of CO2 to epoxides at room temperature and atmospheric pressure. The selective grafting of molecules to heterometallic clusters adds up to the pool of methodologies available for controlling the positioning and distribution of chemical functions in precise positions of the framework required for definitive control of pore chemistry.
The different affinity of Ti(IV) and Ca(II) sites was used to direct selective coordination of amines. This enables the combination of Lewis acid and available ‐NH2 sites in sizeable pores for cooperative cycloaddition of CO2 to epoxides. MUV‐12 displays full conversion of propylene oxide at room temperature and atmospheric pressure in absence of additional co‐catalysts and with excellent cyclability.