TY - JOUR
T1 - Supported Tetrahedral Oxo-Sn Catalyst
T2 - Single Site, Two Modes of Catalysis
AU - Beletskiy, Evgeny V.
AU - Hou, Xianliang
AU - Shen, Zhongliang
AU - Gallagher, James R.
AU - Miller, Jeffrey T.
AU - Wu, Yuyang
AU - Li, Tiehu
AU - Kung, Mayfair C.
AU - Kung, Harold H.
N1 - Funding Information:
DOE Office of Basic Energy Sciences, DE-FG02-01ER15184 for support of this work; NUANCE and CleanCat facilities at Northwestern University; MR-CAT at the APS at the Argonne National Laboratory (DE-AC02-06CH11357) for characterization; Cabot Corporation for EH-5 silica sample, X.H. acknowledges support by Chinese Scholarship Fund and partial funding by Institute for Atom-efficient Chemical Transformations (IACT), an Energy Frontier Research Center funded by US DOE Office of Basic Energy Sciences. J.T.M. and J.R.G. were supported by DOE, Office of Basic Energy Sciences, DE-AC-02-06CH11357.
Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/4/20
Y1 - 2016/4/20
N2 - Mild calcination in ozone of a (POSS)-Sn-(POSS) complex grafted on silica generated a heterogenized catalyst that mostly retained the tetrahedral coordination of its homogeneous precursor, as evidenced by spectroscopic characterizations using EXAFS, NMR, UV-vis, and DRIFT. The Sn centers are accessible and uniform and can be quantified by stoichiometric pyridine poisoning. This Sn-catalyst is active in hydride transfer reactions as a typical solid Lewis acid. However, the Sn centers can also create Brønsted acidity with alcohol by binding the alcohol strongly as alkoxide and transferring the hydroxyl H to the neighboring Sn-O-Si bond. The resulting acidic silanol is active in epoxide ring opening and acetalization reactions.
AB - Mild calcination in ozone of a (POSS)-Sn-(POSS) complex grafted on silica generated a heterogenized catalyst that mostly retained the tetrahedral coordination of its homogeneous precursor, as evidenced by spectroscopic characterizations using EXAFS, NMR, UV-vis, and DRIFT. The Sn centers are accessible and uniform and can be quantified by stoichiometric pyridine poisoning. This Sn-catalyst is active in hydride transfer reactions as a typical solid Lewis acid. However, the Sn centers can also create Brønsted acidity with alcohol by binding the alcohol strongly as alkoxide and transferring the hydroxyl H to the neighboring Sn-O-Si bond. The resulting acidic silanol is active in epoxide ring opening and acetalization reactions.
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U2 - 10.1021/jacs.5b13436
DO - 10.1021/jacs.5b13436
M3 - Article
C2 - 26986621
AN - SCOPUS:84964621973
SN - 0002-7863
VL - 138
SP - 4294
EP - 4297
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 13
ER -