Piperazine-Linked\nCovalent Organic Frameworks with\nHigh Electrical Conductivity

Abstract

A new kind of piperazine-linked covalent\norganic framework (COF)\nwas synthesized through the nucleophilic substitution reaction between\noctaminophthalocyanines and hexadecafluorophthalocyanines. The two-dimensional\n(2D) frameworks are in tetragonally shaped polygon sheets, which stack\nin an AA stacking mode to constitute periodically ordered metallophthalocyanine\ncolumns and one-dimensional (1D) microporous channels. The piperazine-linked\nCOFs exhibit excellent chemical stability and permanent porosity.\nBy virtue of the neatly arrayed phthalocyanine columns and inbuilt\ncationic radicals, the piperazine-linked frameworks are highly conductive.\nThe conductivity values of NiPc-NH-CoPcF₈ COF reached up\nto 2.72 and 12.7 S m^–1 for pellet and film samples,\nrespectively. Moreover, this <i>p</i>-type conductive COF\nexhibited a high carrier mobility of 35.4 cm² V^–1 s^–1. Both the electric conductivity and carrier\nmobility set new records for conductive COFs.