The development of catalyst-transfer polycondensation (CTP) has enabled the synthesis of sophisticated conjugated polymers (CP) architectures, such as surface-grafted CPs. To do this, the surface is modified with a self-assembled monolayer (SAM) that is then functionalized with a metal(II) complex, which serves as the catalytic initiator for growth of the polymer. One common surface that has been used for these surface-grafted CPs is silica. However, after polymerization, de-grafting from the silica surface requires the use of the toxic strong acid HF. We have designed an alternative silane structure for creating a SAM capable of surface-initiated CTP, but which can be easily cleaved in its middle using mild reagents rather than at the siloxy-functionalized surface using HF. We present our preparation of the SAM functionalized with a Ni(II) complex through oxidative insertion of Ni(dppp)<sub>2</sub> into the terminal aryl halide functionality. This Ni-functionalized SAM initiates a Kumada CTP of (5-bromo-4-hexylthiophen-2-yl)magnesium chloride to prepare surface-grafted poly(3-hexylthiophene). The SAM grafting the polymer to the surface is then cleaved under mild conditions. Atomic force microscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy, and contact angle measurements are used to characterize the surface before and after cleavage. The liberated polymer is examined by NMR spectroscopy and molecular weight determination.

Development of a self-assembled monolayer that is cleavable under mild conditions for surface-grafted conjugated polymers

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.