Porphyrin metal–organic frameworks with bilayer and pillar-layered frameworks and third-order nonlinear optical properties
Ziyi Zhu, Zirui Wang, Qiaohong Li, Zhi‐Zhou Ma, Fei Wang, Jian Zhang
Abstract
paddlewheel units are connected by TCPP-Zn ligands to form a 2D layer. Interestingly, these layers are linked by BIE ligands to form a bilayer in PMOF-1 and a 3D pillar-layered framework in PMOF-2, which serve as structural models to evaluate the influence of dimensions on third-order NLO properties. It is speculated that the 3D pillar-layered framework in PMOF-2 with BIE conjugated pillars is more conducive to interlayer charge transfer than the two-dimensional bilayer in PMOF-1, thus achieving a better third-order NLO performance. The third-order NLO test results of PMOFs in a polydimethylsiloxane (PDMS) matrix showed that PMOF-2 displayed a higher nonlinear absorption coefficient, large third-order susceptibility and lower limiting threshold than PMOF-1/PDMS, which may be mainly attributed to the fact that the 3D pillar-layered framework is more conducive to interlayer charge transfer than the two-dimensional bilayer. This work reveals the influence of dimensions on third-order nonlinear properties which will help to explore new MOF materials with excellent third-order NLO properties.