Creation of persistent charge-transfer interactions in TCNQ polyester

Abstract

A 7,7,8,8-tetracyanoquinodimethane polyester was converted into a strongly colored polyester with low-energy charge-transfer (CT) bands by treatment with electron-rich alkyne molecules under mild conditions. The post-functionalization was monitored by its ultraviolet-visible-near infrared (IR) spectra, which suggested a quantitative addition reaction without any side reactions. This result was further supported by 1 H and 13 C nuclear magnetic resonance, IR and elemental analyses. The functionalized polymer retained a high thermal stability with a decomposition onset temperature of B200 1C and B63% residual soot at 500 1C. The CT chromophores in the polymer showed a clear positive solvatochromism and redox behaviors in both anodic and cathodic directions. The HOMO and LUMO levels estimated from the first oxidation potential (E ox,1 ) and the first reduction potential (E red,1 ), respectively, were markedly elevated by this post-functionalization. The extent of HOMO elevation (1.45 eV) was more significant than that of LUMO elevation (0.44 eV).

Postfunctionalization of aromatic polyamine by [2+2] cycloaddition of 7,7,8,8-tetracyanoquinodimethane with side chain alkynes

“…A similar result was observed for the postfunctionalization of polythiophene derivatives [25]. This study also suggested that the use of stronger acceptor molecules, such as 7,7,8,8-tetracyanoquinodimethane (TCNQ) and its derivatives [26][27][28][29][30][31][32][33][34], is effective for the dramatic lowering of the LUMO levels or the enhancement of the n-type characteristics.…”

The [2+2] Cycloaddition‐Retroelectrocyclization (CA‐RE) Click Reaction: Facile Access to Molecular and Polymeric Push‐Pull Chromophores

“…[35] However,t he F 4 TCNQ adducts gradually decomposed upon contact with glass surfaces to form green, insoluble products.T oa void this decomposition, the glassware was deactivated by silylation with dimethyldichlorosilane (DMDCS). [36] Thed icyanovinyl moiety was shown to be the minimal structural unit required for the CA-RE reactions.Aseries of dicyanovinyl (DCV) derivatives were prepared and their reactivities investigated under identical conditions (in DMF at 100 8 8C). [36] Thed icyanovinyl moiety was shown to be the minimal structural unit required for the CA-RE reactions.Aseries of dicyanovinyl (DCV) derivatives were prepared and their reactivities investigated under identical conditions (in DMF at 100 8 8C).…”

Polymeric Chemosensors: A Conventional Platform with New Click Chemistry

“…Since the TCNQ moieties were good acceptors for the click reactions, they were quantitatively converted into the D-A chromophore by the addition of the small alkyne molecule, 4,4¤-(ethyne-1,2-diyl)bis(N,N-dimethylaniline) (see Figure 20). 86 Although there were two possibilities of E-and Z-isomer products on the D-A chromophore unit, all the spectroscopic characterizations and computational calculations suggested that the Z-form is more stable than the corresponding E-form. The max of the precursor TCNQ polyester appeared at 412 nm in 1,2-dichlorobenzene, whereas the post-functionalized TCNQ polyester exhibited the red-shifted max at 623 nm due to the intramolecular CT interactions.…”