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Brominated nanoscale diamond enables room temperature and catalysis free functionalization chemistry

Published

Author(s)

Cynthia Melendrez, Jorge Lopez-Rosas, Tsz Cheung, Camron Stokes, Sang-Jun Lee, Jan Vavra, Helena Raabova, Vaclav Vanek, Sami Sainio, Dennis Nordlund, W.Bertrand (Randy) Doriese, Galen O'Neil, Daniel Swetz, Joel Ullom, Kent Irwin, Peter Cigler, Polo Tran, Halim Muhammad, Virginia Altoe, Charles Titus, Jocelyn Valenzuela, Grace Jeanpierre, Abraham Wolcott

Abstract

Bromination of diamond surfaces has not been explored and can potentially open new avenues for increased chemical reactivity. Aerobically oxidized high-pressure high-temperature nanoscale diamond (ND) is a widely used host for the nitrogen vacancy centers (NVC) and has been observed to generate quasi-stable NV- charge states for biologically labeling quantum sensing applications. Methodologies to control the atomic and molecular structure of NDs can be expanded when diamond lattice-oxygen bonds have been removed. The majority of chemical protocols on NDs focuses on targeting carboxylates through standard linking protocols, yet protocols that remove oxygen species to form new covalent bonds to the diamond lattice are lacking. Here we convert the tertiary-alcohol rich ND surface to a highly reactive alkyl-bromide intermediate and realize room temperature and catalyst free carbon-nitrogen bond formation. These findings reveal that alkyl-bromide moieties are highly labile on NDs and produce long-lived carbocations after debromination. The alkyl-bromide bond readily dissociates in open-air conditions and at 90C in inert conditions within seconds. The chemical lability of the brominated ND surface leads to efficient amination with NH3•THF at 298 K and weak conversion rates with condensed NH3 at 195 K. A catalyst-free Sonogarisha-type reaction with an alkyne-amine and brominated NDs was found to increase amination 11X fold and shows that multiple routes to exploit this hyper reactive surface are available. Overlapping surface sensitive spectroscopies confirm our chemical assignments. Amide bond formation with amine terminated NDs and folic acid was also demonstrated using sulfo-NHS/EDC coupling reagents and confirms that standard amine chemistry is viable. Our work demonstrates that a robust pathway exists to activate a chemically inert diamond surface at room temperature and broadens the pathways of carbon-heteroatom covalent bond formation. These findings should be applicable to researchers who wish to chemically tune the NVC diamond surface for a variety of quantum sensing applications.
Citation
Journal of Physical Chemistry Letters

Keywords

NV diamond, spectroscopy

Citation

Melendrez, C. , Lopez-Rosas, J. , Cheung, T. , Stokes, C. , Lee, S. , Vavra, J. , Raabova, H. , Vanek, V. , Sainio, S. , Nordlund, D. , Doriese, W. , O'Neil, G. , Swetz, D. , Ullom, J. , Irwin, K. , Cigler, P. , Tran, P. , Muhammad, H. , Altoe, V. , Titus, C. , Valenzuela, J. , Jeanpierre, G. and Wolcott, A. (2022), Brominated nanoscale diamond enables room temperature and catalysis free functionalization chemistry, Journal of Physical Chemistry Letters, [online], https://doi.org/10.1021/acs.jpclett.1c04090, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932162 (Accessed April 12, 2024)
Created January 27, 2022, Updated January 26, 2023