Boron-, Silicon-, and Phosphorus-Containing Polymers

Introducing heteroatoms such as O, N, S in the backbone of conjugated polymers is routinely used to modify their electronic properties, and particularly, the HOMO-LUMO energies. Other heteroatoms only recently have been studied in this aspect [703], 

Yamaguchi and coworkers [709] have prepared luminescent silole polymers 615a-e. The blue emission of the homopolymers 615a,b can be shifted into the red region by copolymerization with other conjugated units (but for the price of lowered PLQY). Although no device studies have been reported yet, excellent electron-transport properties are expected from such materials [710]. 

Introducing heteroaromatic moieties (mainly with N and, to a lesser extent, with O and S) in the backbone of the polymer or as a pendant group, can substantially modify the LUMO level of the materials, improving their electron-transport properties and facilitating electron injection in PLEDs, but the efficiencies still lag behind the other systems. 

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