Acenes With a Click

Abstract

A protected pentacene precursor is functionalized in the 6‐ and 13‐positions with alkyne groups and subsequently derivatized by a copper‐catalyzed azide–alkyne Huisgen cycloaddition (CuAAC) reaction. Aromatization then gives the desired pentacene derivatives. This method offers an expedient route to a range of bench‐top stable, pentacene, and oligopentacene based chromophores, all derived from a single building block. These new pentacene derivatives are characterized by NMR, IR, and UV‐Vis spectroscopies. X‐ray crystallographic data for two derivatives is used to evaluate the prospect of electronic communication in the solid state via π‐stacking interactions.

Axial coordination of pyridyl-containing pentacenes to porphyrins

“…Compounds 1 [16], 2 [16], and 3 [18] were synthesized as reported. Chemicals were purchased in reagent grade from commercial suppliers and used without purification.…”

“…Furthermore, the meta-proton (7.63 ppm) and the para-proton (8.43 ppm) in 1 are shifted upfield upon coordination, and in dyad 5, they are found at 4.30 ppm (meta-proton) and 5.62 ppm (para-proton). Even the triazole proton, which is found somewhat downfield at 8.46 ppm in pentacene 1 (but still in the typical range [16,20], experiences the diamagnetic anisotropy from the porphyrin ring, and this proton is shifted upfield to 6.80 ppm in dyad 5.…”

“…We have recently shown that the Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC) [15] offers a possibility to easily alter the substitution pattern of 6,13-disubstituted pentacenes under mild reaction conditions [16]. In addition to allowing the incorporation of aryl and alkyl groups, the CuAAC allowed for the introduction of pyridyl moieties onto the pentacene framework, as in 1 and 2 (figure 1) [16].…”

“…In addition to allowing the incorporation of aryl and alkyl groups, the CuAAC allowed for the introduction of pyridyl moieties onto the pentacene framework, as in 1 and 2 (figure 1) [16]. It was hypothesized that a combination of pyridyl-containing pentacene derivatives 1 and 2 and a metalloporphyrin via axial coordination could lead to pentacene-porphyrin dyads with potentially interesting electronic and/or optical properties, based on the complementary chromophores of the two components of the dyad [17].…”

“…RutBuPP·H 2 O 3 (50 mg, 0.050 mmol) was dissolved in dry methylene chloride (10 mL). Dry pyridine (5 mL) was added and the reaction Pyridyl-containing pentacenes 1 and 2 formed by CuAAC[16].…”