Syntheses, Characterizations, Luminescent Properties, and Controlling Interpenetration of Five Metal–Organic Frameworks Based on Bis(4-(pyridine-4-yl)phenyl)amine

Five new metal–organic frameworks (MOFs), {[Zn₂(BPPA)₂­(BDC)₂]­·6H₂O}_<i>n</i> (<b>1</b>), {[Cd₃(BPPA)­(BDC)₂­(DMF)₂]­·DMF­·3H₂O}_<i>n</i> (<b>2</b>), {[Zn­(BPPA)­(NDC)_1/2­(HCO₂)]}_<i>n</i> (<b>3</b>), {[Zn₃(BPPA)₃­(TFBDC)₃]­·H₂O}_<i>n</i> (<b>4</b>), and {[Cd₂(BPPA)₂­(TFBDC)₂]}_<i>n</i> (<b>5</b>), have been synthesized from the self-assembly of the “V-shape” BPPA ligand with Zn/Cd metal salts, incorporating coligands (H₂BDC = 1,4-benzenedicarboxylic acid, H₂NDC = 2,6-naphthalenedicarboxylic acid, TFBDC = 2,3,5,6-tetrafluoroterephthalic acid, BPPA = bis­(4-(pyridine-4-yl)­phenyl)­amine, DMF = <i>N</i>,<i>N</i>-dimethylformamide). Compound <b>1</b> is a 4-fold interpenetrated three-dimensional (3D) network with <b>sra</b> topology. Compound <b>2</b> is the first 2-fold interpenetrated <b>sxa</b> topology, which is reported only non-interpenetration before. Compound <b>3</b> is a one-dimensional chain by utilizing a “longer” rigid H₂NDC coligand. Via a “fatter” rigid TFBDC ligand, we control interpenetration by one-pot synthesis. Both compounds <b>4</b> and <b>5</b> are non-interpenetrated 3D <b>6T8</b> frameworks, and the <b>6T8</b> topology has rarely been reported in MOFs before. Interestingly, carboxyl groups in <b>1</b>–<b>5</b> adopt various coordinate modes. Luminescent properties of <b>1</b>–<b>5</b> have also been explored, and the emission decay lifetimes of <b>4</b> and <b>5</b> are longer than compounds <b>1</b>–<b>3</b> and free ligands because of a fluorescent synergistic effect. This may provide an feasible way to exploit materials with long emission decay lifetimes