Co-reporter:Kazutoshi Imai;Takumi Sasaki;Jiro Abe
Polymer Bulletin 2012 Volume 68( Issue 6) pp:1589-1601
Publication Date(Web):2012 April
DOI:10.1007/s00289-011-0639-0
Poly(tetramethyl-1,6-silpyrenylenesiloxane) derivative with phenyl groups on pyrenylene moieties (P1) was prepared via polycondensation of disilanol monomer, i.e. 1,6-bis(dimethylhydroxysilyl)-3,8-diphenylpyrene (M1). P1 exhibited the very high glass transition temperature (Tg) of 191 °C. The temperature at 5% weight loss (Td5) of P1 was 482 °C, indicating the relatively good thermostability of P1. P1 exhibited the bathochromic effect in the absorption and fluorescence spectra, indicating the expansion of π-conjugation by introducing phenyl groups onto pyrene skeleton as well as the σ–π and σ*–π* conjugation between pyrene and silyl moieties. In addition, P1 exhibited relatively weak excimer emission because of the inhibition of the excimer formation of pyrene skeleton by introduction of bulky phenyl groups onto pyrene skeleton. The fluorescence quantum yields (ΦFs) of M1 and P1 in chloroform were determined to be 0.46 and 0.37, respectively. It was revealed that M1 and P1 exhibited the higher fluorescence intensity than 1,6-diphenylpyrene, owing to the effect of the introduction of silyl moieties onto pyrene skeleton.
Co-reporter:Hitoshi Hanamura, Ryoko Haneishi, Nobukatsu Nemoto
Tetrahedron Letters 2011 Volume 52(Issue 31) pp:4039-4041
Publication Date(Web):3 August 2011
DOI:10.1016/j.tetlet.2011.05.128
4,4-Dimethylcyclopenta[2,1-b:3,4-b′]dithiophene derivatives bearing trimethyl-, dimethylphenyl-, diphenylmethyl-, or triphenyl-silyl moieties were synthesized. The introduction of the silyl moieties onto cyclopenta[2,1-b:3,4-b′]dithiophene induced fluorescent emission as well as the bathochromic shift of wavelength at the maximum absorption and fluorescence. It was found that the larger number of phenyl group on silyl moiety resulted in the higher fluorescence quantum yield.
Co-reporter:Kazutoshi Imai, Yoshihiko Kihara, Atsushi Kimoto, Jiro Abe, Yasufumi Tamai and Nobukatsu Nemoto
Polymer Journal 2011 43(1) pp:58-65
Publication Date(Web):November 3, 2010
DOI:10.1038/pj.2010.104
Poly(tetramethylsilarylenesiloxane) derivatives having diphenylfluorene (P1) or diphenyldibenzosilole (P2) moieties were prepared via polycondensation of the corresponding disilanol monomers, that is, 2,7-bis(dimethylhydroxysilyl)-9,9-diphenylfluorene (M1) and 2,7-bis(dimethylhydroxysilyl)-9,9-diphenyldibenzosilole (M2), respectively. P1 and P2 exhibited good solubility in common organic solvents. The glass transition temperatures (Tgs) of P1 and P2 were determined by differential scanning calorimetry to be 125 and 119 °C, respectively. The melting temperature (Tm) of P1 was observed at 276 °C; however, the Tm of P2 was not observed, indicating that the introduction of a dibenzosilole moiety decreased the crystallization tendency. The temperatures at 5% weight loss (Td5s) of P1 and P2 were 539 and 520 °C, respectively, suggesting good thermostability of P1 and P2. Bathochromic and hyperchromic effects were observed in the absorption and fluorescence spectra by introducing a dimethylsilyl substituent onto diphenylfluorene and diphenyldibenzosilole skeletons. The replacement of diphenylfluorene by the corresponding diphenyldibenzosilole also led to bathochromic shifts. The fluorescence quantum yield (ΦF) of P1 was lower than that of M1, probably because of the formation of aggregates; however, the ΦF of P2 was higher than that of M2, indicating a decrease in the tendency toward aggregation using a dibenzosilole skeleton.
Co-reporter:Hitoshi Hanamura, Nobukatsu Nemoto
Polymer 2011 Volume 52(Issue 23) pp:5282-5289
Publication Date(Web):27 October 2011
DOI:10.1016/j.polymer.2011.09.031
Poly(silarylenesiloxane) derivatives with 4,4-dimethylcyclopenta[2,1-b:3,4-b′]dithiophene moiety, bearing dimethyl- (P1), methylphenyl- (P2) and diphenyl- (P3) substituents on silyl moieties, were prepared via polycondensation of the corresponding disilanol monomers, that is, 2,6-bis(dimethylhydroxysilyl)-4,4-dimethylcyclopenta[2,1-b:3,4-b′]dithiophene (M1), 2,6-bis(methylphenylhydroxysilyl)-4,4-dimethylcyclopenta[2,1-b:3,4-b′]dithiophene (M2), and 2,6-bis(diphenylhydroxysilyl)-4,4-dimethylcyclopenta[2,1-b:3,4-b′]dithiophene (M3), respectively. P1–P3 exhibited the good solubility in common organic solvents, such as benzene, toluene, chloroform, dichloromethane, THF, and so on. The glass transition temperatures (Tgs) of P1, P2 and P3 were determined by differential scanning calorimetry to be 56, 97 and 137 °C, respectively, depending on the substituent on the silyl moieties. No melting temperatures (Tms) of P1, P2 and P3 were observed, suggesting the obtained P1–P3 are amorphous polymers. The temperatures at 5% weight loss (Td5s) of P1, P2 and P3 were 460, 459 and 479 °C, respectively, indicating that the larger number of phenyl group on the silyl moieties resulted in the better thermostability. Bathochromic and hyperchromic effects were observed in the absorption and fluorescence spectra by introducing silyl substituents onto 4,4-dimethylcyclopenta[2,1-b:3,4-b′]dithiophene moiety. In addition, the bathochromic shift of the maximum absorption (λabs) and the increase in the fluorescence quantum yield (ΦF) were observed by the introduction of phenyl group onto the silyl moieties.
Co-reporter:Kazutoshi Imai, Sayaka Hatano, Atsushi Kimoto, Jiro Abe, Yasufumi Tamai, Nobukatsu Nemoto
Tetrahedron 2010 66(40) pp: 8012-8017
Publication Date(Web):
DOI:10.1016/j.tet.2010.08.010
Co-reporter:Yusuke Hattori
Polymer Bulletin 2009 Volume 63( Issue 4) pp:497-507
Publication Date(Web):2009 October
DOI:10.1007/s00289-009-0110-7
A novel poly(tetramethyl-1,3-silphenylenesiloxane) derivative having adamantyl moiety, i.e., poly(tetramethyl-5-adamantyl-1,3-silphenylenesiloxane) (P1) was synthesized by solution polycondensation of a novel disilanol monomer, i.e., 1-[3,5-(dimethylhydroxysilyl)phenyl]adamantane (M1). M1 was prepared by the Grignard reaction using chlorodimethylsilane and 1-(3,5-dibromophenyl)adamantane, followed by the hydrolysis catalyzed by 5% palladium on charcoal. P1 exhibited the good solubility in common organic solvents, such as tetrahydrofuran (THF), chloroform, dichloromethane, benzene, and toluene at ambient temperature. P1 was also soluble in hot hexane, diethyl ether, and ethyl acetate. The glass transition temperature (Tg) and temperature at 5% weight loss (Td5) of P1 were 85 and 517 °C, respectively, and much higher than those of poly(tetramethyl-1,3-silphenylenesiloxane), indicating that P1 is a new polysiloxane derivative with good solubility as well as good thermostability.
Co-reporter:Yuki Yanai, Takahiro Sasaki, Yumiko Otomo, Shizuka Ota, Yu Nagase and Nobukatsu Nemoto
Polymer Journal 2008 40(9) pp:875-881
Publication Date(Web):July 30, 2008
DOI:10.1295/polymj.PJ2008134
Novel functionalized poly(tetramethyl-1,4-silphenylenesiloxane) with pendant hydroxyl groups, i.e., poly[2,5-bis(2-hydroxyethoxy)-tetramethyl-1,4-silphenylenesiloxane] (P1), was synthesized and characterized by differential scanning calorimetry (DSC), thermogravimetry (TG), and X-ray diffraction analysis. P1 was obtained via catalytic deprotective-hydrogenation of poly[2,5-bis(2-benzyloxyethoxy)-tetramethyl-1,4-silphenylenesiloxane] (PreP1), which had been obtained by catalytic polycondensation of 2,5-bis(2-benzyloxyethoxy)-1,4-bis(dimethylhydroxysilyl)benzene (M1) in benzene. P1 was revealed to be an amorphous polymer as deduced from DSC as well as X-ray diffraction measurement, and soluble in highly polar solvents as ethanol and methanol in which poly(tetramethyl-1,4-silphenylenesiloxane) (1,4-PTMPS) is insoluble. The glass transition temperature (Tg) of P1 was determined to be 73 °C from DSC, which was much higher than that of 1,4-PTMPS (−20 °C), indicating that the intermolecular and/or intramolecular hydrogen bondings based on hydroxyl groups restricted the mobility of the main chain. The temperature at 5% weight loss (Td5) of P1 (290 °C) determined by TG was lower than that of 1,4-PTMPS, indicating that the oxyethylene and/or alcoholic-hydroxyl moieties decline the thermostability; however, the obtained P1 would promise to be a new reactive-polymer with hydroxyl moieties to develop new functional materials.
Co-reporter:Nobukatsu Nemoto;Tomoko Yamaguchi;Yuichiro Ozawa;Masaki Nigorikawa
Polymer Bulletin 2008 Volume 61( Issue 2) pp:165-175
Publication Date(Web):2008 August
DOI:10.1007/s00289-008-0944-4
Three novel poly(tetramethylsilfluorenylenesiloxane) derivatives having different substituent at 9-position
of fluorenylene moiety, i.e. dimethyl (P1), spirocyclohexyl (P2), and spirofluorenyl (P3) substituents, were
obtained by polycondensation of novel three disilanol monomers, i.e. 2,7-bis(dimethylhydroxysilyl)-9,9-dimethyl-
fluorene (M1), 2’,7’-bis(dimethylhydroxysilyl)-spiro(cyclohexane-1,9’-fluorene)
(M2), 2,7-bis(dimethylhydroxysilyl)-9,9’-spirobifluorene (M3),
respectively. P1–P3 exhibited the
good solubility in common organic solvents, such as tetrahydrofuran (THF), chloroform, dichloromethane,
and toluene. It was suggested from the differential scanning calorimetry (DSC) and the X-ray diffraction
analysis that P1 exhibited the crystallinity whereas P2
and P3 were amorphous polymers. The glass transition temperature (Tg) determined by DSC and the temperature at 5% weight loss
(Td5) determined by thermogravimetry (TG) were
dependent on the substituent at 9-position on fluorene; both orders of Tg
and Td5 were P3
> P2 > P1, indicating the bulkiness
of substituent at 9-position of fluorene resulted in the good thermal stability. It is noteworthy that
amorphous P3 exhibiting very high Tg
of 156 °C and Td5 of 535 °C
is a new heat-resistant polysiloxane derivative as well as a promising candidate for blue-light-emitting
materials.
Co-reporter:Yoshinori Niwa;Shigeki Kouno;Wakako Sayama
Journal of Polymer Science Part A: Polymer Chemistry 2008 Volume 46( Issue 2) pp:692-701
Publication Date(Web):
DOI:10.1002/pola.22417
Abstract
Novel poly(tetramethyl-1,3-silphenylenesiloxane) derivative with phenol moiety in the main chain, that is, poly(tetramethyl-5-hydroxy-1,3-silphenylenesiloxane) (P1), was synthesized and the thermal properties were investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG). P1 was obtained via deprotective hydrogenation of poly(tetramethyl-5-benzyloxy-1,3-silphenylenesiloxane) (Pre-P1) catalyzed by 10% palladium on charcoal as well as via direct polycondensation of 3,5-bis(dimethylhydroxysilyl)phenol (M2). Pre-P1 was obtained by polycondensation of 1,3-bis(dimethylhydroxysilyl)-5-benzyloxybenzene (M1), catalyzed by 1,1,3,3-tetramethylguanidinium 2-ethylhexoate. M1 was prepared by the Grignard reaction using chlorodimethylsilane and 1,3-dibromo-5-benzyloxybenzene followed by the hydrolysis catalyzed by 5% palladium on charcoal. M2 was prepared by deprotective hydrogenation of M1 catalyzed by 10% palladium on charcoal. The obtained P1 was soluble in common organic solvents such as tetrahydrofuran, chloroform, dichloromethane, toluene, and so forth as well as in highly polar solvents as ethanol and methanol in which poly(tetramethyl-1,3-silphenylenesiloxane) is insoluble. The glass transition temperature (Tg) of P1 was determined to be 40 °C from DSC, which was much higher than that of poly(tetramethyl-1,3-silphenylenesiloxane) (−52 °C), indicating that the intermolecular and/or intramolecular hydrogen bondings based on hydroxyl groups restricted the mobility of the main chain. The temperature at 5% weight loss (Td5) of P1 (393 °C) determined by TG was lower than that of poly(tetramethyl-1,3-silphenylenesiloxane) (ca. 500 °C), indicating that the phenol moieties decline the thermal stability; however, the obtained P1 would promise to be a new reactive-polymer with phenolic–hydroxyl moieties to develop new functional materials. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 692–701, 2008
Co-reporter:Issei Sato;Shihori Takeda;Yuki Arai;Hideharu Miwa;Yu Nagase
Polymer Bulletin 2007 Volume 59( Issue 5) pp:607-617
Publication Date(Web):2007 December
DOI:10.1007/s00289-007-0804-7
Novel poly(tetramethylsilarylenesiloxane) derivatives, i.e. poly(tetramethyl-2,6-silanthrylenesiloxane) (P1), poly(tetramethyl-9,10-silanthrylenesiloxane) (P2), and poly(tetramethyl-1,8-silphenanthrylenesiloxane) (P3), were synthesized by polycondensation of novel disilanol monomers, i.e. 2,6-bis(dimethylhydroxysilyl)-anthracene (M1), 9,10-bis(dimethylhydroxysilyl)anthracene (M2), and 1,8-bis(dimethylhydroxysilyl)phenanthrene (M3), respectively. P1 and P3 were soluble in common organic solvents, such as benzene, toluene, chloroform, dichloromethane, tetrahydrofuran, etc. whereas P2 was almost insoluble in common organic solvents. It was revealed that P1 and P3 were amorphous and that P2 exhibited the crystallinity, as deduced from differential scanning calorimetry (DSC) and X-ray diffraction measurements. The glass transition temperatures (Tg’s) of P1 (118 °C) and P3 (100 °C) were much higher than that of poly(tetramethyl-1,4-silphenylenesiloxane). The temperature at 5% weight loss (Td5) of P3 was 500 °C, which was higher than those of P1 and P2, and comparable to that of poly(tetramethyl-1,4-silphenylenesiloxane). It would be speculated that the thermostability of the series of poly(tetramethyl-silarylenesiloxane) derivatives is dependent on the stability of arylene moieties incorporated.
![Benzo[1,2-b:4,5-b']dithiophene](/data/chemimg/477000/267-65-2.png)
![Benzo[1,2-b:4,5-b']dithiophene](/data/chemimg/477000/267-65-2_b.png)
![Benzo[2,1-b:3,4-b']dithiophene](/data/chemimg/3730400/211-53-0.png)
![Benzo[2,1-b:3,4-b']dithiophene](/data/chemimg/3730400/211-53-0_b.png)
