TY - JOUR
T1 - Surface-Induced Deprotection of THP-Protected Hydroxamic Acids on Titanium Dioxide
AU - Brennan, Bradley J.
AU - Koenigsmann, Christopher
AU - Materna, Kelly L.
AU - Kim, Paul M.
AU - Koepf, Matthieu
AU - Crabtree, Robert H.
AU - Schmuttenmaer, Charles A.
AU - Brudvig, Gary W.
N1 - Funding Information:
This work was funded by U.S. Department of Energy Grant DE-FG02-07ER15909 and a generous gift from the TomKat Charitable Trust.
PY - 2016/6/16
Y1 - 2016/6/16
N2 - Hydroxamic acids chelate metals with high affinity and form hydrolytically stable complexes with metal oxides such as TiO2. However, these appealing binding properties can cause problems during the preparation and application of metallocatalysts with appended hydroxamate anchoring groups. Here we show that the tetrahydropyran (THP) O-protected hydroxamate group can be cleaved in situ on a TiO2 surface at room temperature, leading to the surface-bound species. Surface-mediated deprotection has several advantages over direct surface functionalization including increased hydrolytic stability of the covalent interaction with the metal oxide surface and decreased aggregation of the surface species. Application of the surface-mediated chelation method for dye-sensitized photoelectrochemical cells (DSPC) was examined using the organic dye MK-2. Results show that the surface-mediated deprotection led to improved DSPC performance attributed to a decrease in dye aggregation relative to a DSPC prepared using standard methods. This simplified approach using THP-protected hydroxamates provides a convenient new method for functionalizing metal oxides.
AB - Hydroxamic acids chelate metals with high affinity and form hydrolytically stable complexes with metal oxides such as TiO2. However, these appealing binding properties can cause problems during the preparation and application of metallocatalysts with appended hydroxamate anchoring groups. Here we show that the tetrahydropyran (THP) O-protected hydroxamate group can be cleaved in situ on a TiO2 surface at room temperature, leading to the surface-bound species. Surface-mediated deprotection has several advantages over direct surface functionalization including increased hydrolytic stability of the covalent interaction with the metal oxide surface and decreased aggregation of the surface species. Application of the surface-mediated chelation method for dye-sensitized photoelectrochemical cells (DSPC) was examined using the organic dye MK-2. Results show that the surface-mediated deprotection led to improved DSPC performance attributed to a decrease in dye aggregation relative to a DSPC prepared using standard methods. This simplified approach using THP-protected hydroxamates provides a convenient new method for functionalizing metal oxides.
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U2 - 10.1021/acs.jpcc.6b02635
DO - 10.1021/acs.jpcc.6b02635
M3 - Article
AN - SCOPUS:84975257902
VL - 120
SP - 12495
EP - 12502
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 23
ER -