Platinum‐Centered Oligoynes Capped by Boron Difluoride Formazanate Dyes and Their Thin‐Film Properties

Since the Nobel prize winning discovery that polyacetylene could act as a semiconductor, there has been tremendous efforts dedicated to understanding and harnessing the unusual properties of 𝜋‐conjugated polymers. Much of this research has focused on the preparation of oligoynes and polyynes with well‐defined numbers of repeating alkyne units as models for carbyne. These studies are usually hampered by a structure‐property relationship where the stability of the resulting materials decrease with the incorporation of additional alkyne units. Here, we describe a series of oligoynes, with up to 12 alkyne units, where electron‐rich [Pt(PBu3)2]2+ units are incorporated into the center of oligoyne backbones which are capped by electron‐poor BF2 formazanate dyes. These compounds exhibit excellent stability and solubility, panchromatic absorption, and redox activity characteristic of their structural components. These traits facilitated thin‐film studies of extended oligoyne materials, where it is shown that incorporating [Pt(PBu3)2]2+ units leads to smoother films, decreased conductivity on the microscale, and increased conductivity on the nanoscale when compared to metal‐free analogs. Remarkably, our oligoynes have superior conductivity compared to the ubiquitous poly(3‐hexylthiophene) semiconductor.