A solvent-responsive terbium-organic framework for photocatalytic CO 2 reduction.

A Tb-MOF with a 5,5,6-c 3-nodal net, {[Tb(DTDA) 1.5 ·2H 2 O]·DMF·8H 2 O} n (AQNU-4), has been synthesized (DTDA = 2',5'-diethoxy-[1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid). AQNU-4 contains a 1-periodic secondary building unit (rod SBU) and has an unusual topological type with the point symbol {3 2 ·4 4 ·6 2 ·7·8}{3 2 ·4 6 ·5·6}{3 2 ·4 6 ·5 2 ·6 5 }. Efficient light harvesting and electron-hole separation make AQNU-4 an effective photocatalyst for use in the CO 2 reduction reaction (CO 2 RR). Interestingly, as a photocatalyst, AQNU-4 shows an obvious solvent dependence during the catalytic process. In cyclohexanone in particular, it shows the highest CO 2 to CO conversion, reaching 138.65 μmol g -1 h -1 , making AQNU-4 a good solvent-responsive MOF material.