Electrosyntheses of high‐quality polyphenanthrene in the electrolyte of boron trifluoride diethyl etherate containing trifluoroacetic acid

Abstract

A novel inherently conducting polymer, high‐quality polyphenanthrene (PPh) films were synthesized electrochemically by direct anodic oxidation of phenanthrene (Ph) in boron trifluoride diethyl etherate (BFEE) containing a certain amount of trifluoroacetic acid (TFA). The oxidation potential of Ph in this medium was measured to be only 0.63 V versus SCE, which was greatly lower than that determined in acetonitrile + 0.1 mol L−1 Bu4NBF4 (1.55 V vs. SCE). The electrolytes of BFEE containing TFA enable facile anodic oxidation of Ph monomer; however, similar oxidation using acetonitrile never produces such a polymeric material. PPh films obtained from this medium showed good redox activity and stability even in concentrated sulfuric acid. Dedoped PPh films were partly soluble in polar solvent such as CH2Cl2, acetone, tetrahydrofuran, and dimethyl sulfoxide. Fluorescent spectral studies indicate that PPh is a good blue‐light emitter. The structure and morphology of the polymer were studied by UV–vis spectroscopy, FTIR spectroscopy, 1H NMR spectroscopy, and scanning electron microscopy, respectively. The results of quantum chemistry calculations of Ph monomer and the spectroscopies of dedoped PPh indicated the polymerization mainly occurred at C(9) and C(10) positions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3929–3940, 2007

Simple Efficient Synthesis of Strongly Luminescent Polypyrene with Intrinsic Conductivity and High Carbon Yield by Chemical Oxidative Polymerization of Pyrene

“…This may imply an ordered graph-A C H T U N G T R E N N U N G itization of the residual char. In particular, the char yields of 73.5 % at 1000 8C and 70.6 % at 1300 8C are much higher than those of some carbon precursors like polyfluoranthene (24 % at 855 8C), [30] viscose rayon (28.5 % at 950 8C), [31] polyacrylonitrile (50 % at 900 8C), [32] polyphenanthrene (65 % at 907 8C), [29] poly (9,10-anthracenediylidene) (70 % at 900 8C), [33] and modified pitch (72 % at 1000 8C), [34] and are even very close to that of typically high char-yield mesophase pitch (75 % at 1000 8C). [34] Moreover, the char formed at 1000 8C consists of fine carbon microparticles with an average particle size of 118 mm (Figure 10 c), a size-polydispersity index of 1.08, and high conductivity of 2.1 S cm…”

“…Compared to the spectrum of pyrene monomer, the resonance peaks of the polypyrene significantly extend over a wider range of chemical shifts and also become broad because of the establishment of the long pconjugated structure in polypyrene chains. [29] All the proton resonance peaks in the COSY and HSQC spectra are indicated in the high-resolution 1 H NMR spectrum in Figure 5. Note that two pairs of cross-peaks [(e8.33, 126.2) and (g8.36, 128.9)] in Figure 7 a are stronger than the others, that is, the 2,7-pyrenylene units in the polypyrene are more numerous than the others, which is basically verified by Figure 5; in other words, the polypyrene chains may consist of more 2,7-pyrenylene units and fewer 1,6-/1,3-pyrenylene units.…”

Direct low‐potential electropolymerization of 9,10‐dihydrophenanthrene in boron trifluoride diethyl etherate

“…Some new peaks appeared after polymerization, and most of the peaks moved to a lower field, which was mainly because of the introduction of a higher conjugation length in the PPh main chain. As shown in Figure 6(B), the proton chemical shift from about 8.85 to 9.17 was ascribed to the protons at C (4) and C (5) , and the proton chemical shift from about 7.80 to 8.00 was ascribed to the protons at C (1) , C (3) , C (6) , and C (8) (Scheme 1). The origin of the peak at about 7.20 was attributed to the terminal proton in the polymer because of its small shift in field relative to those of the peaks of monomer [C (2) and C (7) ].…”

“…3 Polyphenanthrene, representing the simplest tricyclic aromatic hydrocarbons, has been studied theoretically because of its great technological importance as an electrode material for lithium-ion rechargeable batteries. 4,5 However, to date, there have only been a few publications 8,9 concerned with polymers prepared from 9,10-dihydrophenanthrene (Ph; Scheme 1) with an ethylene-type bridge in the poly(para-phenylene). At the very start, Saito et al 8 reported the preparation of poly(9,10-dihydrophenanthrene) (PPh) obtained from 2,7-dibromo-9,10-dihydrophenanthene with an isolated zero-valent nickel complex and an electrochemically generated zero-valent nickel complex.…”

“…Recently, polycyclic aromatic hydrocarbons such as poly(para-phenylene), 1 polyfluorene, 2,3 and polyphenanthrene 4,5 have been investigated. Poly(para-phenylene) obtained from benzene 6 or with dissolved biphenyl 7 as the starting material under mild conditions is one of the simplest conjugated polymers with a high stability and moderate electrical conductivity.…”