Synthesis and unexpected reactivity of Si-H functionalized dithieno[3,2-b:2',3'-d]phospholes

[reaction: see text]. Si-H functionalized, blue light-emitting dithieno[3,2-b:2',3'-d]phospholes are accessible by reaction of an appropriate bithiophene precursor with a dichlorophosphane. Subsequent functionalization of the central phosphorus center allows for a fine-tuning of the optoelectronic properties of the material. Pt-catalyzed reaction of the Si-H functionalities with alkynes affords the hydrosilation products including a polymer by reaction with 1,7-octadiyne. By contrast, the absence of any substrate leads to the exclusive formation of a polymer via dehydrogenative homocoupling.