Synthesis of dihydroxyoligophenylenes containing π-deficient or π-excess hetero-aromatic rings and their solvatochromic behavior
摘要:
Dihydroxyoligophenylenes (HO-ArPh(m)-OHs) with 9,9-dihexy1-2,7-fluorene (Ar=Flu), 2,5-dioctyloxy-1,4-benzene (Ar=Dob), pyridine (Ar=Py), or thiophene (Ar=Th) rings were synthesized by the Suzuki coupling reaction. Absorption maxima (lambda(max)) of HO-ArPh(m)-OHs shifted progressively toward long wavelengths due to the expansion of the it-conjugation system with an increase in the number of benzene rings. Deprotonation of the OH groups of HO-ArPh(m)-OHs by treatment with NaH caused a bathochromic shift of lambda(max). The bathochromic shift of the deprotonated species increased with the donor numbers (DNs) of the solvents. The emission peak positions of NaO-ArPh(m)-ONas depended on the DNs of the solvents; therefore, the emission color could be tuned by changing the solvent. (C) 2010 Elsevier Ltd. All rights reserved.
Synthesis of oligophenylenes containing hydroxyl group and their solvatochromic behavior
摘要:
Oligo(p-phenylene)s containing hydroxyl group(s), namely, OPP(n)-OH (n=3, 4, and 5; it denotes the number of benzene rings), HO-OPP(3)-OH, and 1,3,5-tri(4-biphenyl)phenol TBP-OH were synthesized in high yields by the Suzuki coupling reaction. Absorption maxima (lambda(max)s) of OPP(n)-OHs shifted progressively toward long wavelengths due to the expansion of the pi-conjugation system with an increase in the number of benzene rings. Deprotonation of the OH group of OPP(n)-OHs by treatment with NaH caused a bathochromic shift of lambda(max). The bathochromic shift of the deprotonated species increased with the donor numbers (DNs) of the solvents. The emission peak positions of OPP(n)-OH and OPP(n)-ONa depended on the DN of the solvents; that is, the emission color could be tuned by changing the solvent. (C) 2009 Elsevier Ltd. All rights reserved.