Synthesis and Electronic Properties of 9,10-Disilylanthracenes

Abstract

The sila-functional 9,10-disilylanthracenes An(SiR 2 X) 2 (1, R ) i-Pr, X ) H; 2, R ) i-Pr, X ) Cl; 3, R ) Me, X ) H) were synthesized, and the X-ray structure is reported for 1. Compounds 1-3 as well as the related compound An(SiMe 3 ) 2 exhibit intense fluorescence (Φ f > 0.9) at room temperature.

Synthesis and characterization of poly(tetramethylsilarylenesiloxane) derivatives bearing diphenylfluorene or diphenyldibenzosilole moieties

“…The hyperchromic effects result from the enhancement of the transition moment based on the increase in the dipole moments of the HOMO and LUMO states owing to the s-p conjugation in the HOMO and the s*-p* conjugation in the LUMO. [12][13][14][15][16][17] On the other hand, the 0-0 electronic transition was observed at around 316 nm in the case of silyl-substituted diphenylfluorene derivatives (5, M1 and P1), as shown in Figure 5a, whereas it was observed at around 324 nm in the case of silyl-substituted diphenyldibenzosilole derivatives (6, M2, and P2), as shown in Figure 5b. This bathochromic shift would be due to the stabilization of the LUMO state through s*-p* conjugation induced by the replacement of the C-9 carbon in fluorene by silicon.…”

“…[12][13][14][15][16][17] The bathochromic effect has been known to be induced by lowering the energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) states because of destabilization of the HOMO state through s-p conjugation and stabilization of the LUMO state through s*-p* conjugation. The hyperchromic effects result from the enhancement of the transition moment based on the increase in the dipole moments of the HOMO and LUMO states owing to the s-p conjugation in the HOMO and the s*-p* conjugation in the LUMO.…”

“…[12][13][14][15][16][17] Kitamura et al 18 reported a polysiloxane having fluorenyl moiety in the main chain; however, the obtained polysiloxane derivative was an oil product owing to the extremely low glass transition temperature (T g ). Thus, the use of polysiloxane derivatives as polymeric OLED materials seems to be inadequate because of their extremely low T g, 19,20 which allows the formation of aggregates and/or interchain excimers to induce the decline of the color stability of light emission.…”

Absorption and Fluorescence Spectroscopic Properties of 1- and 1,4-Silyl-Substituted Naphthalene Derivatives

“…Close examination of these spectra shows that substituents on silicon of the silyl groups (SiMe 3 , SiMe 2 H, SiMe 2 n Bu, SiMe 2 t Bu, and SiMe 2 n Oct) have only a small effect on the absorption and fluorescence properties of the naphthalene chromophore/fluorophore. In contrast, silyl-substituents at C-9 of anthracene bring about dramatic changes in absorption and fluorescence properties [20,34]. A possible reason for this phenomenon is steric repulsion, which exists between the C-9 silyl groups and peri-hydrogens at C-1 and C-8 of the anthracene ring.…”

“…The photochemistry of organosilicon compounds [1] has OPEN ACCESS been investigated from the perspective of absorption and emission spectroscopic properties of polysilanes [2], the generation of silylenes and disilenes by photoirradiation to oligosilanes [3][4][5][6][7][8], the formation of intramolecular charge transfer complexes of aromatic disilanes [9,10], and photoinduced electron transfer reactions of organosilicon compounds [11][12][13][14]. In addition, the enhancing effects of silyl groups on the fluorescence intensities of aromatic hydrocarbons, such as anthracenes, naphthacenes, pentacenes, triphenylenes, and pyrenes, has been probed and discussed in detail earlier [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Our previous studies in this area have focused on the effects of silyl, silylethynyl, germyl, and stannyl groups on the absorption and fluorescence spectroscopic properties of pyrene [30][31][32][33][34].…”