Synthesis and Photoelectronic Properties of Thermally Stable Poly[oxy(2,7-fluoren-9-onenylene)oxy(diorganosilylene)]s

Abstract

Melt copolymerization reactions of several bis(diethylamino)silane derivatives, bis(diethylamino)methylphenylsilane, bis(diethylamino)methyloctylsilane, 1,2-bis(diethylamino)tetramethyldisilane, and 1,3-bis(diethylamino)tetramethyldisiloxane, with 2,7-dihydroxyfluoren-9-one were carried out to yield poly[oxy(2,7-fluoren-9-onenylene)oxy(diorganosilylene)]s bearing the fluoren-9-one fluorescent aromatic group in the polymer main chain: poly[oxy(2,7-fluoren-9-onenylene)oxy(methylphenylsilylene)], poly[oxy(2,7-fluoren-9-onenylene)oxy(methyloctylsilylene)], poly[oxy(2,7-fluoren-9-onenylene)oxy(tetramethyldisilylene)], and poly[oxy-(2,7-fluoren-9-onenylene)oxy(tetramethyldisiloxanylene)]. These polymeric materials are soluble in common organic solvents such as CHCl 3 and THF. FTIR spectra of all the materials reveal characteristic Si-O-C stretching frequencies at 1012-1018 cm −1 . In the THF solution, the prepared materials show strong maximum absorption peaks at 258-270 nm, strong maximum excitation peaks at 260-280 nm, and strong maximum fluorescence emission bands at 310-420 nm. TGA thermograms suggest that most of the polymers are essentially stable to 200 °C without any weight loss and up to 300 °C with only a weight loss of less than 5% in nitrogen.

Synthesis and Properties of Poly[oxy(arylene)oxy(tetramethyldisilylene)]s via Melt Copolymerization Reaction

“…This phenomenon of the low molecular weights of materials 4a-d may be explained by considering the rigidity of aromatic diols used as the comonomer. However, the molecular weights of 4a-d were much higher than the weight-average molecular weights (827-832) of the reported previously poly[oxy(fluoren-9-onenylene)oxy(organodisilylene)]s containing fluoren-9-one, 24 and this might be ascribed to the flexibility of comonomers 3a-d being higher than that of fluoren-9-one.…”

“…24 With these results, we have extended our study to the preparation and photoelectronic properties of fluorescent poly[oxy(arylene)oxy(tetramethyldisilane)]s materials containing several aromatic fluorophore groups in the main chain.…”

“…The polymers 4a-d contained tetramethyldisilylene and several arylene groups, such as biphenylene, isopropylidenediphenylene, fluorenedimethylene, and fluorenylidenephenoxyethylene, along the polymer main chain, and the aromatic chromophores were different from the previously reported results. [20][21][22][23][24] The objective of these melt copolymerizations was to synthesize the copolymers of poly[oxy(arylene)oxy(tetramethyldisilylene)]s with high molecular weights. The synthesized materials were characterized by several spectrophotometric methods such as Si NMR in the solution state, and by using FTIR as well as elemental analysis.…”

“…The melt copolymerizations of 2 with various diol deriva- tives 3a-d, which are more flexible than the previously reported 2,7-dihydroxyfluorene-9-one, 24 produced poly[oxy-(arylene)oxy(tetramethyldisilylene)]s 4a-d, containing aromatic as well as tetramethyldisilylene groups in the polymer main chain (Scheme 2).…”

“…29,30 We also recently reported the melt copolymerizations of bis(diethylamino)silane and bis(diethylamino)disiloxane with several aryldiols. 20,21,24 We had tried copolymerization reactions between 1,2-bis(diethylamino)tetramethyldisilane 2 carrying the functionality of diethylamine group and several diol derivatives, by using a previously reported method.…”