An unusual Pb8 clusters based coordination polymer with room-temperature orange phosphorescence

A new 2D phosphorescence lead metal cluster-based coordination polymer (CP) [Pb4(μ2-OH) (μ3-OH) (μ4-O) (3-qlc)4]n (1; 3-qlc ​= ​3-quinolinecarboxylate) has been successfully synthesized by solvothermal reaction. CP 1 is a robust Pb(II) CP constructed by a rare [Pb8(μ2-OH)2 (μ3-OH)2 (μ4-O)2(COO)8] cluster units and 3-qlc ligands. The bulky clusters provide architectural stability to the framework of 1. Interestingly, CP 1 exhibited almost pure room-temperature orange phosphorescence with absolute phosphorescence quantum yields of 3.3% and a phosphorescence lifetime of 1.52 ​ms benefiting from the restriction of molecular vibrations/rotations of organic luminogens (3-qlc) and the heavy-atom effect of Pb(II).