Photophysical and Electrochemical Properties of 1,7-Diaryl-Substituted Perylene Diimides

Abstract

Substituent effects on the photophysical and electrochemical properties of 1,7-diaryl-substituted perylene diimides (1,7-Ar(2)PDIs) have been carefully explored. Progressive red-shifts of the absorption and emission maxima were observed when the electron-donating ability of these substituents was increased. Linear Hammett correlations of 1/lambda(max) versus sigma(+) were observed in both spectral analyses. The positive slopes of the Hammett plots suggested that the electronic transitions carry certain amounts of photoinduced intramolecular charge-transfer (PICT) character from the aryl substituents to the perylene diimide core which leads to the reduction of the electron density on the substituents. The substituent electronic effects originated mainly from the perturbation of the core PDI HOMO energy level by the substituents. This conclusion was supported by PM3 analyses and confirmed by cyclic voltammetry experiments. More interestingly, the Ph(2)NC(6)H(4)-substituted PDI, 4i, showed an unusual dual-band absorption that spans from 450 to 750 nm. We tentatively assigned these two bands as the charge-transfer band and the PDI core absorption, respectively.

Functionalized Supramolecular Nanoporous Arrays for Surface Templating

“…[26] The preparation of Br 2 -PTCDA yields a mixture of both 1,7-and 1,6-isomers in an estimated 4:1 ratio that it has not proven possible to separate.…”

“…[26] All reactions were carried out under an atmosphere of nitrogen. Column chromatography was performed on silica gel (Merck silica gel 60, 0.2-0.5 mm, 50-130 mesh).…”

“…N,N'-DiA C H T U N G T R E N N U N G (n-butyl)dipropylthioperylene-3,4:9,10-tetracarboxylic acid di-A C H T U N G T R E N N U N G imide (mixture of 1,7-and 1,6-isomers) (1): N,N'-DiA C H T U N G T R E N N U N G (n-butyl)-1,7-dibromoperylene-3,4:9,10-tetracarboxylic acid diimide [26] (660 mg, 1 mmol), NaOH (100 mg, 2.5 mmol) and propanethiol (0.19 mL, 3 mmol) were suspended in pyridine (30 mL) and heated under reflux for 3 h. The progress of the reaction was followed by thin-layer chromatography with CH 2 Cl 2 as eluent. After cooling to room temperature, the mixture was poured into 10 % HCl and extracted with CH 2 Cl 2 .…”

Introduction of Two Anthracene Moieties into Perylenebis(dicarboximide) Core by Suzuki–Miyaura Coupling toward Construction of Donor–Acceptor–Donor Arrays

“…Meanwhile, the absorption spectrum of parent PBI 6 gave structured bands with a maximum at 523 nm, whereas the corresponding bands were shifted to the longwavelength region in the order of monosubstituted analog 7, 12 1a and 2a, accompanied with broadened bands. This means that the ³ system is extended as more AEP units are introduced, 13 even though the perylene and phenyl moieties are nonplanar, as mentioned above. As for the disubstituted compounds, the bathochromic effect was slightly larger in the absorption spectrum of 1,7-substitution than in that of 1,6-substitution.…”

Synthesis and Characterization of Pentafluorophenyl‐Substituted Perylenebis(dicarboximides)

“…The synthesis of core-phenyl-substituted PDI was up to now only accomplished by Pd-catalyzed Suzuki coupling of phenylboronic acids with 1,7-dibromo-PDIs [21] [22]. The disadvantage of this route lies in the use of potentially difficult to synthesize molecules (i.e., boronic acids or esters) and expensive Pd catalysts.…”