Dual emissions and thermochromic luminescences of isomorphic chiral twofold interpenetrated 3-D nets built from I1O2 type hybrid inorganic–organic frameworks of [NH2(CH3)2]3[Pb2X3(BDC)2] (X = Br, I)

摘要: Two pairs of MOF-based hybrid enantiomorphs, [NH2(CH3)2]3[Pb2X3(BDC)2] (H2BDC = 1,4-benzenedicarboxylic acid, X Br or I), have been synthesized using the solvothermal reaction and then manually separated, which are labeled as 1a/1b (X Br) 2a/2b I). The isomorphic 1a 2a crystallize in tetragonal space group P43212, 1b 2b enantiomorphic P41212. Twofold interpenetrated three-dimensional (3-D) networks were built from two sets equivalent I1O2 type inorganic–organic frameworks 2a/2b. Each framework constructs by inorganic pentagonal bipyramid-shape PbX3O4 I) polyhedral chains along c-axis, further connected though bridged BDC2− ligands directions perpendicular to c-axis. Hybrids characterized elemental analysis (C, H N elements), thermogravimetric powder X-ray diffraction techniques, UV-visible absorption spectroscopy solid state. These hybrids show dual emissions at ambient conditions, arise π–π* electron transition within aromatic rings semiconducting chains, well thermochromic luminescence behavior 10 300 K owing emission bands displaying different responses temperature change.