Nanochannel-based heterometallic {Zn II Ho III }-organic framework with high catalytic activity for the chemical fixation of CO 2 .

The exquisite combination of Zn II and Ho III generated the highly robust [ZnHo(CO 2 ) 6 (OH 2 )]-based heterometallic framework of {[ZnHo(TDP)(H 2 O)]·5H 2 O·3DMF} n (NUC-30, H 6 TDP = 2,4,6-tri(2',4'-dicarboxyphenyl)pyridine), which featured outstanding physicochemical properties, including honeycomb nanochannels, high porosity, large specific surface area, the coexistence of highly open Lewis acid-base sites, good thermal and chemical stability, and resistance to most organic solvents. Due to its extremely unsaturated metal tetra-coordinated Zn(ii) ions, hepta-coordinated Ho(iii) and high faveolate void volume (61.3%), the conversion rate of styrene oxide and CO 2 into cyclic carbonates in the presence of 2 mol% activated NUC-30 and 5 mol% n -Bu 4 NBr reached 99% under the mild conditions of 1.0 MPa and 60 °C. Furthermore, the luminescence sensing experiments proved that NUC-30 could be used as a fast, sensitive and highly efficiency sensor for the detection of Fe 3+ in aqueous solution. Therefore, these results prove that nanoporous MOFs assembled from pyridine-containing polycarboxylate ligands have wide applications, such as catalysis and as luminescent materials.