Abstract: Surface functionalization of two-dimensional crystals is a key path to tuning their intrinsic physical and chemical properties. However,
synthetic protocols and experimental strategies to directly probe chemical bonding in modified surfaces are scarce. Introduced here is a mild,
surface-specific protocol for the surface functionalization of few-layer black phosphorus nanosheets using a family of photolytically generated
nitrenes (RN) from the corresponding azides. By embedding spectroscopic tags in the organic backbone, a multitude of characterization
techniques are employed to investigate in detail the chemical structure of the modified nanosheets, including vibrational (infrared, Raman), Xray
(emission, photoelectron), CPMAS NMR, and UV-vis spectroscopy. To directly probe the functional groups introduced on the surface, R
fragments were selected such that in conjunction with vibrational spectroscopy, 15N-labeling experiments, and DFT methods, diagnostic P=N
vibrational modes indicative of iminophosphorane units on the nanosheet surface could be conclusively identified.
Published: May 20, 2021
Citation
Walz K., C.H. Chang, M.P. Hanrahan, J. Yang, D. Tofan, W. Holden, and N. Govind, et al. 2021.Surface Functionalization of Black Phosphorus with Nitrenes: Identification of P=N Bonds Using Isotopic Labeling.Angewandte Chemie International Edition 60, no. 16:9127-9134.PNNL-SA-156794.doi:10.1002/anie.202016033