Synthesis of Vinylene-Linked Two-Dimensional Conjugated Polymers via the Horner-Wadsworth-Emmons Reaction.

ABSTRACT: In this work, we demonstrate the first synthesis of vinylene-linked 2D CPs, namely, 2D poly(phenylenequinoxalinevinylene)s 2D-PPQV1 and 2D-PPQV2, via the Horner-Wadsworth-Emmons (HWE) reaction of C₂ -symmetric 1,4-bis(diethylphosphonomethyl)benzene or 4,4'-bis(diethylphosphonomethyl)biphenyl with C₃ -symmetric 2,3,8,9,14,15-hexa(4-formylphenyl)diquinoxalino[2,3-a:2',3'-c]phenazine as monomers. Density functional theory (DFT) simulations unveil the crucial role of the initial reversible C-C single bond formation for the synthesis of crystalline 2D CPs. Powder X-ray diffraction (PXRD) studies and nitrogen adsorption-desorption measurements demonstrate the formation of proclaimed crystalline, dual-pore structures with surface areas of up to 440?m² ?g^-1 . More importantly, the optoelectronic properties of the obtained 2D-PPQV1 (E_g =2.2?eV) and 2D-PPQV2 (E_g =2.2?eV) are compared with those of cyano-vinylene-linked 2D-CN-PPQV1 (E_g =2.4?eV) produced by the Knoevenagel reaction and imine-linked 2D COF analog (2D-C=N-PPQV1, E_g =2.3?eV), unambiguously proving the superior conjugation of the vinylene-linked 2D CPs using the HWE reaction.

SUBMITTER: Pastoetter DL 

PROVIDER: S-EPMC7814668 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature