Synthesis of σ−π Conjugated Alternating Silylene-Diacetylene Copolymers and Their Optical and Electrical Properties

Abstract

New σ-π conjugated alternating silylene-diacetylene copolymers, –[(SiMe2)m–C≡C–C≡C]n–, m = 1, 3, 4, and 6, were synthesized by the reaction of α,ω-dichloropermethylated oligosilanes with dilithiobutadiyne, LiC≡C–C≡CLi. The IR spectra clearly indicated the presence of diyne unit in the polymer backbone. The influence of the chain length m of the dimethylsilylene unit in the –[(SiMe2)m–C≡C–C≡C]n– backbone on the optical and the electrical properties was investigated.

Polymers with alternating organosilicon and π-conjugated units

“…Recently, Matsuda and coworkers have prepared polymers having repeating units of a permethyloligosilanylene and p-conjugated system (Chart 1) by way of condensation of a,x-dichloropermethyloligosilanes, Cl(SiMe 2 ) m Cl (m = 1 -6) with organodilithium reagents including dilithioacetylene [35], diacetylene [33], benzene [36], biphenyl [35,36], thiophene [34], and anthracene [35,36] (Scheme 6). The yields of the polymers are 29 -49% and the molecular weights range from M w = 2 460 to 10 900.…”

“…This method offers polymers with more controlled structures than anionic and thermal ROP. Platinum-complex-catalyzed ROP of an unsymmetrically substituted silylene-bridged ferrocene (32) gives a regular alternating polymer (33) in which a single environment of Cp1Si1Cp* is observed for the dimethylsilylene unit in the polymer backbone (Scheme 32), in marked contrast to thermal ROP of the same monomer, which produces a random polymer bearing Cp1Si1Cp, Cp1Si1Cp*, and Cp*1Si1Cp* units in a ratio of 1 : 2 : 1 [64].…”

“…2.2) [33 -37]. They have reported that the UV absorption maxima of the polymers slightly shift, depending on the temperature [33,34]. The degree of the thermochromic shifts of the polymers increases with the number of silicon atoms in an oligosilanylene unit, indicating the existence of enhanced r-p conjugation in a longer oligosilanylene chain.…”

Organic electroluminescent devices using organosilicon polymers containing phenylene or diethynylanthracene units

“…[8][9][10][11][12] However, there have been only a few reports thus far regarding the optical emission of this type of polymer. Fang et al have recently studied the emission spectra of a series of s-p-conjugated organosilicon polymers with an alternating arrangement of oligosilanylene units and p-electron system, [13][14][15][16][17] demonstrating that the emission changes from the type from a s-conjugation unit such as silanylene to the that from a p-conjugation unit response to increasing the chain length of the oligosilanylene units, as well as in response to reducing the extension of the pelectron system. 17 The emission lifetime and the quantum yield also depend on the dimethylsilanylene chain length.…”

Spectroelectrochemical Characterization of Si-Bridged Diphenylamines: Influence of Si-Bridging upon Electronic Structures of Diphenylamines

“…[2][3][4] While silicon-based materials and their polymers also have been a subject of recent interest in connection with their potential utility as organic devices because of singular opto-electronic properties which originate from the Si-Si σ unit and π-electron system. 5,6 Phenazasiline having silicon bridged diphenylamine structures has interesting properties. [7][8][9][10] We have already reported that poly(phenazasiline) is effective as a hole transport layer of EL devices and electrochromic displays.…”