摘要:
A series of oligomers, the hetero-coupled mono-terminated di-tert-butyl-substituted phenylene ethynylene dimer, trimer, tetramer, and pentamer have been successfully synthesized in a stepwise process and characterized. Their electronic properties have been studied by UV-vis and fluorescence spectroscopy. Both UV absorption and FL emission maxima have red shift trends with increasing conjugation length of the oligomers. In addition, homo-coupling products inevitably complicate the hetero-coupling reaction. With increasing substituent group size on the terminal alkyne, the amount of homo-coupling product is increased. (C) 2012 Elsevier Ltd. All rights reserved.