Organic electroluminescent devices using organosilicon polymers containing phenylene or diethynylanthracene units

Synthesis of Polymers with Alternating Organosilanylene and Oligothienylene Units and Their Optical, Conducting, and Hole-Transporting Properties

“…We have recently reported that a disilanylene−phenylene polymer (DS1P in Chart 1) reveals better hole-transporting properties than the monosilanylene analogue (MS1P) . In contrast, for organosilanylene−diethynylanthracene polymers (MSDEA-TSDEA in Chart 1), the hole-transporting properties are improved by reducing the silicon chain length. , These results indicate that the σ−π conjugation is significantly operative for the polymers with a rather small π-electron system, but for the polymers with an extended π-electron system, reducing the silicon chain length leads to higher concentration of the π-conjugated units in the unit volume of the polymer film to facilitate the hole transport by the hopping process between the π-conjugated units.…”

“…We have recently reported that a disilanylene−phenylene polymer (DS1P in Chart 1) reveals better hole-transporting properties than the monosilanylene analogue (MS1P) . In contrast, for organosilanylene−diethynylanthracene polymers (MSDEA-TSDEA in Chart 1), the hole-transporting properties are improved by reducing the silicon chain length. , These results indicate that the σ−π conjugation is significantly operative for the polymers with a rather small π-electron system, but for the polymers with an extended π-electron system, reducing the silicon chain length leads to higher concentration of the π-conjugated units in the unit volume of the polymer film to facilitate the hole transport by the hopping process between the π-conjugated units. As discussed in the preceding section, some of the oligothienylene units in the present polymers would possess a limited degree of extension of the π-conjugation in the units in the solid states due to the flexibility of the oligothienylene units, which would allow significant twisting between the rings in part, and hence, the σ−π conjugation still plays an important role for the hole-transporting properties of the polymers.…”

Synthesis and characterisation of new oligoacetylenic silanes

“…[1][2][3][4][5] The lower ionisation energy of the silicon atom compared with carbon is expected to enhance the through-bond interaction of ethynyl units along the backbone. 6,7 In this context, the chemistry of linear inorganic polymers containing alternating arrangements of silylene and p-electron moieties represents an important area of current active research because they possess good potential as functional materials such as semiconductors, 8 hole-transporting [9][10][11] and heat-resistant materials, [12][13][14] photoresists 15,16 and ceramic precursors. 1,17 The unusual electrical and optical properties associated with these materials are generally attributed to the delocalisation of electrons through the silylene linkages via p-d Si interactions 18,19 or s-p conjugation.…”