Oligo(3,6-phenanthrene ethynylenes): Synthesis, Characterization, and Photoluminescence

Abstract

A series of highly fluorescent, oligo(3,6-phenanthrene ethynylenes) (F1-F7) were synthesized, and their photophysical behavior was systematically investigated. They emitted light with highly emissive quantum yields, up to 0.92. Emissive wavelengths of these compounds relied on the number of phenanthrene blocks existing in the oligomers. Red-shifted emissions were observed as the number of phenanthrenes increased. On the basis of theoretical calculations, helical structures could be formed for F4-F7, indicating that the excimer emissions might be observed for F4-F7 due to the intramolecular π-π stackings of phenanthrenes in the helical structures. However, excimer emissions were only observed for F5-F7 in dilute cyclohexane and for F6 and F7 in dilute methylene chloride, respectively. No excimer emission was observed for F4-F7 in dilute tetrahydrofuran due to the degree of solvation.

Highly Efficient Red–Orange Delayed Fluorescence Emitters Based on Strong π‐Accepting Dibenzophenazine and Dibenzoquinoxaline Cores: toward a Rational Pure‐Red OLED Design

“…Free radical bromination of phenanthrene‐9,10‐dione with Br 2 (1 equiv.) in the presence of benzoyl peroxide (BPO) proceeded regioselectively to yield monobromide 5 . Under palladium‐catalyzed Suzuki–Miyaura cross‐coupling conditions, 5 was subsequently coupled with the corresponding donor‐containing boronic acid or ester ( 6 or 7 ), affording key diketone intermediates 8 and 9 in high yields (85% and 82%, respectively).…”

Study of the controlled chain‐growth polymerization of poly(3,6‐phenanthrene)

“…The synthesis of the precursor monomer used in the Kumada and Negishi mechanisms, 3,6‐dibromo‐9,10‐di(octyloxy)phenanthrene 1 , was performed as described before . Of course, the actual monomer formation is the in situ conversion of the precursor monomer to the 3‐bromo‐6‐bromomagnesio derivative 2 using a GRIM reaction.…”

“…1 H and 13 C nuclear magnetic resonance (NMR) measurements were carried out with a Bruker Avance 300 MHz. 3,6‐Dibromo‐9,10‐di(octyloxy)phenanthrene 1 was prepared as described in the literature …”

Matrix‐assisted laser desorption/ionisation quadrupole ion trap time‐of‐flight mass spectrometry of novel shape‐persistent macrocycles

“…The SPMs were synthesised starting from the commercially available phenanthrene‐9,10‐dione, which was brominated to obtain 3,6‐dibromophenanthrene‐9,10‐dione . Reduction of the dione and subsequent alkylation were performed according to reported procedures with various alkylating agents . The Pd‐catalyzed Sonogashira cross‐coupling reaction between an alkylated compound and 2‐methylbut‐3‐yn‐2‐ol followed by deprotection under basic condition gave 9,10‐bis(alkoxy)‐3,6‐diethynylphenanthrenes .…”

“…[16] Reduction of the dione and subsequent alkylation were performed according to reported procedures with various alkylating agents. [17][18][19][20] The Pd-catalyzed Sonogashira cross-coupling reaction between an alkylated compound and 2-methylbut-3yn-2-ol followed by deprotection under basic condition gave 9,10-bis(alkoxy)-3,6-diethynylphenanthrenes. [15] Those diyne precursors were either used in further Sonogashira coupling reactions with 9,10-bis(alkoxy)-3,6-diiodophenanthrenes yielding phenanthrylene-acetylene SPMs 1, 3, and 4 or underwent a one-pot cyclisation under palladium-mediated oxidative coupling reaction [21] yielding arylene-butadiyne macrocycles 2 and 7, which were separated by column chromatography on silica gel using a mixture of hexane and dichloromethane as eluent.…”