Synthesis of oligophenylenes containing hydroxyl group and their solvatochromic behavior

Synthesis of dihydroxyoligophenylenes containing π-deficient or π-excess hetero-aromatic rings and their solvatochromic behavior

“…Similar solvatochromic behavior was observed in the case of OPP(n)-OHs (n¼3, 4, and 5) and their deprotonated species reported earlier. 16 To prove that these observations were due to the deprotonation of the OH groups after treatment with NaH, we confirmed that there was no change in the absorption spectra of MeO-FluPh (8) OPP(n)-ONas (n¼4 and 5) reported earlier. 5 The l max and Dl values of NaO-FluPh(4)-ONa were larger than those of NaO-DobPh(5)-ONa despite the smaller number of benzene rings in NaO-FluPh (4)-ONa than in NaO-DobPh(5)-ONa.…”

“…OPP(5)-OH, which consisted of five benzene rings, showed considerably low solubility in polar organic solvents. 16 Despite the larger number of benzene rings in HO-FluPh(6)-OH and HO-DobPh(5)-OH than in OPP(5)-OH, HO-FluPh(6)-OH and HO-DobPh(5)-OH showed good solubility in organic solvents because of the presence of the long alkyl chains. They were soluble in polar organic solvents such as 1,4-dioxane, N,Ndimethylformamide (DMF), and dimethyl sulfoxide (DMSO) as well as in less polar organic solvents such as dichloromethane and toluene.…”

“…Br-OPP(3)-OH, Br-OPP(3)-OMe, and 2 were synthesized according to the literatures. 16,20 Other reagents were purchased and used without further purification. Reactions were carried out with standard Schlenk techniques under nitrogen.…”

“…Recently, we have reported OPPs with an OH group located at one end and at both ends, namely, OPP(n)-OHs (where n is the number of benzene rings) and HO-OPP(3)-OH, respectively. 16 The OPPs exhibited significant solvatochromism; the deprotonation of the OH groups of OPP(n)-OHs and HO-OPP(3)-OH, when treated with NaH, caused a bathochromic shift of l max that increased with the donor numbers (DNs) of the solvents. Furthermore, the emission peak positions of OPP(n)-ONas and NaO-OPP(3)-ONa depended on the DNs of the solvents; therefore, the emission color could be tuned by changing the solvent.…”

Suzuki–Miyaura monocouplings of p-dibromobiphenyl and substituted p-dibromo(penta-p-phenylenes)

“…-methoxy-p-terphenyl (5a) 24 . The reaction was carried out by following the rt-18 h procedure, using p-dibromobiphenyl (1, 0.62 g, 1.98 mmol), 4-methoxyphenyl boronic acid (3a, 0.20 g, 1.32 mmol), cesium carbonate (0.86 g, 2.64 mmol), Pd (PPh 3 ) 4 (0.12 g, 0.11 mmol), toluene (20 mL), and methanol (20 mL).…”