Quinoidal diindenothienoacenes: synthesis and properties of new functional organic materials

Abstract

The synthesis and characterization of a series of quinoidal diindeno(thieno)thiophenes (DI[n]Ts) are reported. NIR absorption, deep LUMO energy levels and progressively tighter solid-state packing allude to organic materials applications.

Indacenodibenzothiophenes: synthesis, optoelectronic properties and materials applications of molecules with strong antiaromatic character

“…Despite the indenofluorene naming convention (i.e., an indene fused to a fluorene), analysis of the 1 H NMR spectrum, 16i NICS values and x-ray crystal structure data 16a, 16b of indeno[1,2- b ]fluorene ( 1 ) reveal that this compound is more accurately described as a benzo-fused para -xylylene derivative ( 1′ , Fig. 2).…”

“…Our initial report on the assembly of diones 10 and 11 utilized a Stille cross-coupling to construct key precursors 12 and 13 , respectively. 16l We have improved the preparation of diesters 12 and 13 by employing a Suzuki-Miyaura cross-coupling (Scheme 1), allowing us to selectively synthesize diones 10 or 11 on gram scale from commercially available starting materials without the use of column chromatography. Concurrent work on a separate project suggested that performing the final SnCl 2 -mediated reduction under rigorous anhydrous and anaerobic conditions could induce a significant increase in product yield.…”

“…13a,16 The inclusion of two carbonaceous five-membered rings imparts an intrinsic ability to accept electrons reversibly, 16i which in turn has led to the examination of IFs and their derivatives as potential ambipolar and n-type materials. Recently, we explored thieno-fusion on the IF skeleton and published initial reports on the synthesis and characterization of indacenodithiophene and indaceno-dibenzothiophene ( anti -IDT 3a and syn- IDT 4 , anti -IDBT 6a and syn -IDBT 7a ), 16l diindenothienoacenes (DI[n]T 5a ), 16k and their selenophene analogues (IDS 3b and DIS 5b ) 16f (Fig. 1).…”

An Unusually Small Singlet–Triplet Gap in a Quinoidal 1,6‐Methano[10]annulene Resulting from Baird’s 4n π‐Electron Triplet Stabilization

“…[3] Two common motifs for these molecules are extended polycyclic aromatic frameworks [4][5][6][7] and conjugated oligomers with terminal dicyanomethylene groups (e.g. QnTCN, Scheme 1).…”

Origins of the Indenofluorene Project: Serendipity and Other Surprises

“…[15] We can dearomatize expanded central cores such as naphthalene (e.g., 11) [16] and thienoacenes (e.g., 12). [17] We have studied their redox chemistry [11] and photophysics [8] as well as made forays into materials applications. [13] Even the IF-diones are good electron acceptors; thus we have explored their optoelectronic properties [18] and solidstate packing.…”