End-capping of poly-9,9'-dihexylfluorenes

POLY 190

Nadezda Fomina, fomina@usc.edu, M. E. Thompson, met@usc.edu, and Thieo E. Hogen-Esch, hogenesc@usc.edu. Department of Chemistry, University of Southern California, Los Angeles, CA 90089
Poly-9,9'-dihexylfluorenes were synthesized through the nickel – mediated Yamamoto reaction in the presence of 2-bromo-9,9'-dimethylfluorene, 2-bromotoluene, 2-bromo-N,N'-dimethylaniline and 4-bromo-N,N'-dimethylaniline end-capping agents. MALDI-TOF and NMR analyses shown that 2-bromotoluene and 4-bromo-N,N'-dimethylaniline were the most efficient end-cappers giving 83% and 86% of chains end-capped at both ends, respectively. MALDI analysis shown that the distributions of non-endcapped, mono-endcapped and bi-endcapped chains remained molecular weight independent within the examined range of molecular weights. The resedual protonation, presumably due to the work-up, is being studied.