Journal of Polymer Science Part A: Polymer Chemistry, Vol.54, No.20, 3257-3266, 2016
Synthesis, characterization, and preceramic properties of pi-conjugated polymers based on Ni(II) complexes of goedken's macrocycle
Nickel(II) complexes of Goedken's macrocycle bearing alkyne substituents were copolymerized with 2,7-dibromo-9,9-dihexylfluorene, 2,5-dibromo-3-hexylthiophene, and 1,4-dibromo-2,5-bis(hexyloxy)benzene via microwave-induced Sonogashira cross-coupling reactions to produce copolymers 6F, 6T, and 6B. The spectroscopic and electrochemical properties of the copolymers were examined and compared to model compounds. Specifically, each polymer exhibited a nickel-based absorption centered at about 589 nm and two * transitions between 272 and 387 nm. While the copolymers did not exhibit extended conjugation, the nature of the organic spacer did affect the high energy transitions. Furthermore, each copolymer underwent two ligand-based one-electron oxidations at potentials of about 0.24 V and about 0.75 V relative to the ferrocene/ferrocenium redox couple. Postpolymerization functionalization of the alkyne group in 6F with Co-2(CO)(8) afforded a novel heterobimetallic copolymer that yielded amorphous nanomaterials containing Ni/Co when pyrolyzed at 800 degrees C for 3 h under an atmosphere of N-2/H-2 (95:5). (c) 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3257-3266