Controlling polymorphism of metal-organic frameworks

Nonlinear optical (NLO) materials have attracted considerable attention due to their potential applications for wavelength converters and electro-optical modulators. One way to fabricate SHG materials is to align asymmetric organic dyes with high second-order hyperpolarizability constants. Here, we demonstrate one-dimensional alignment of asymmetric organic dyes in pores of metal-organic framework (MOF). MOF with Kagome-type lattice was synthesized to encapsulate the organic dyes in its one-dimensional pores. The organic dyes were oriented along with the onedimensional pores, which was confirmed by fluorescence under linearly-polarized excitation light.