Volker Winkler

Adding spatial control to click chemistry: phototriggered Diels-Alder surface (bio)functionalization at ambient temperature.

A photoconjugation strategy based on light-triggered Diels–Alder addition of o-quinodimethanes is compatible with biomolecules and proceeds rapidly at ambient temperature without the need of a catalyst. Spatial control was confirmed by photopatterning of a small-molecule ATRP initiator, a polymer, and a peptide in a time-of-flight secondary-ion mass spectrometry investigation.

Hetero Diels–Alder Chemistry for the Functionalization of Single‐Walled Carbon Nanotubes with Cyclopentadienyl End‐Capped Polymer Strands

Single-walled carbon nanotubes (SWCNTs) are pre-functionalized with a pyridinyl-based dithioester to undergo a hetero Diels-Alder (HDA) reaction with cyclopentadienyl end-capped poly(methyl)methacrylate (Mn = 2700 g mol(-1) , PDI = 1.14). Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis (EA), and X-ray photoelectron spectroscopy (XPS) evidence the success of the grafting process. The estimated resulting grafting density (from XPS and EA) via the HDA reaction increases by a factor of more than two (0.0774 chains·nm(-2) via XPS) compared with typical values obtained via a direct cyclopentadiene driven Diels-Alder conjugation onto non-functional SWCNTs under similar conditions.