1028203-88-4Relevant articles and documents
Tetraarylcyclobutadienecyclopentadienylcobalt complexes: Synthesis, electronic spectra, magnetic circular dichroism, linear dichroism, and TD DFT calculations
Kottas, Gregg S.,Brotin, Thierry,Schwab, Peter F. H.,Gala, Kamal,Havlas, Zdenek,Kirby, James P.,Miller, John R.,Michl, Josef
, p. 3251 - 3264 (2014/08/05)
The known (tetraphenyl-η4-cyclobutadiene)- η5-cyclopentadienylcobalt (1) and a series of its new substituted derivatives have been prepared. The electronic states of a few representatives have been characterized by absorption and magnetic circular dichroism. Time-dependent density functional theory has been used to arrive at spectral assignments for several prominent low-energy bands. The absorption spectra of the radical ions of 1 have also been recorded.
Synthesis and photoluminescence properties of heterocycle-containing poly(disubstituted acetylene)s
Muroga, Tatsuoki,Sakaguchi, Toshikazu,Hashimoto, Tamotsu
, p. 4380 - 4387 (2012/11/13)
The metathesis polymerizations of disubstituted acetylenes containing heterocycles such as thiophene, furan, benzo[b]thiophene, and benzothiazole were examined using NbCl5, TaCl5, and WCl6. Thiophene-containing monomers polymerized to afford relatively high-molecular-weight polymers in moderate yields. Benzo[b]thiophene-containing monomers also polymerized to give polymers with relatively high molecular weights. On the other hand, furan- and benzothiazole-containing monomers exhibited low metathesis polymerizability, and the polymerizations did not provide high-molecular-weight polymers. Poly(1-hexyl-2-arylacetylene)s having heterocycles [poly(1a) and poly(3a), Scheme 1] emitted blue-colored lights, and the emission maxima were around 480 nm. Heterocycle-containing poly(1-phenyl-2-arylacetylene) [poly(1b)] and poly(1-fluorenyl-2-arylacetylene) [poly(3d)] showed green-colored and yellow-colored emissions, and the emission maxima were 520 and 540 nm, respectively. The emission wavelengths of poly(disubstituted acetylene)s having heterocycles were almost the same as those of the corresponding poly(disubstituted acetylene)s without heterocycles. However, heterocycle-containing polymers showed high fluorescence quantum yields compared to the corresponding polymers without heterocycles. Diarylacetylene polymers showed emission red-shifts between the solution and cast film, while the emission maximum of poly(1-hexyl-2-phenylacetylene) [poly(1a)] in the cast film was almost the same as that in the solution. Benzo[b]thiophene-containing poly(1-(4-trimethylsilylphenyl)-2-phenylacetylene) [poly(3b)] and poly(1-(9,9-dimethyl-2-fluorenyl)-2-phenylacetylene) [poly(3d)] afforded the free-standing membranes because of their high molecular weights. The oxygen permeability coefficient (PO2) of poly(3b) was as large as 1400 barrers. Poly(3d) showed higher gas permeability, and its PO2 was 5300 barrers.
Highly gas-permeable silanol-functionalized poly(diphenylacetylene)s: Synthesis, characterization, and gas permeation property
Sakaguchi, Toshikazu,Takeda, Aiko,Hashimoto, Tamotsu
scheme or table, p. 6810 - 6817 (2012/03/10)
Diphenylacetylenes having a diisopropylphenoxysilyl group [PhOSi(i-Pr) 2C6H4C≡CC6H4R; R = H (1a), SiMe3 (1b)] were synthesized and then polymerized with TaCl5/n-Bu4Sn to provide the corresponding poly(diphenylacetylene)s (2a and 2b). These siloxy group-containing polymers afforded tough free-standing membranes by casting from toluene solutions. Treatment of the membranes (2a and 2b) with n-Bu4N+F - gave the silanol-functionalized poly(diphenylacetylene)s (3a and 3b). FT-IR spectra of the silanol-functionalized polymers revealed that some their silanol groups were consumed and the polymers were cross-linked via siloxane bond. The oxygen permeability coefficients of membranes of 2a and 2b were 12 and 26 barrers, respectively. The deprotection of these membranes in DMF lowered membrane densities, and consequently their gas permeability significantly increased. The oxygen permeability coefficients of silanol group-containing membranes (3a and 3b) were 210 and 1300 barrers, respectively. These silanol-functionalized poly(diphenylacetylene) membranes were found to exhibit very high gas permeability irrespective of the presence of the polar silanol groups in the polymers. Membrane of 3a showed relatively high CO 2 permselectivity as well as high CO2 permeability.
