Tautomeric and conformational properties of dipivaloylmethane
http://repository.vnu.edu.vn/handle/VNU_123/28155
The
tautomeric and structural properties of
5-hydroxy-2,2,6,6-tetramethyl-3-heptanone, (dipivaloylmethane,
C(CH3)3C(O)CH2C(O)C(CH3)3) have been studied by means of gas-phase electron
diffraction (GED) and quantum chemical calculations (B3LYP and MP2
approximation with different basis sets up to aug-cc-pVTZ).
Both,
quantum chemistry and GED analyses resulted in the presence of 100(5)% enol
tautomer at 296(3)K.
Quantum
chemical calculations predict the existence of two enol conformers in about
equal amounts. In both conformers the enol ring possesses Cs symmetry and they
possess different torsional orientations of the two tert-butyl groups.
The
experimental data refinement results in an enol tautomer, in which the
tert-butyl group adjacent to the carbonyl group possesses an intermediate
orientation between those in “enol1” and “enol 2” forms (torsional angle is
about 30 ), and the tert-butyl group adjacent to the hydroxyl group slightly
deviates from orientation in the theoretical conformers (by about 10 ).
The
enol ring possesses CS symmetry with a strongly asymmetric hydrogen bond.
The
experimental geometric parameters are reproduced very closely by the
B3LYP/aug-cc-pVTZ method.
Title:
Tautomeric and conformational properties of dipivaloylmethane | |
Authors: | Belova, Natalya V. Nguyen, Hoang Trang Oberhammer, Heinz |
Keywords: | Dipivaloylmethane Gas phase structure Tautomeric and conformational properties Gas electron diffraction Quantum chemical calculations |
Issue Date: | 2017 |
Publisher: | ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS |
Citation: | ISIKNOWLEDGE |
Abstract: | The tautomeric and structural properties of 5-hydroxy-2,2,6,6-tetramethyl-3-heptanone, (dipivaloylmethane, C(CH3)3C(O)CH2C(O)C(CH3)3) have been studied by means of gas-phase electron diffraction (GED) and quantum chemical calculations (B3LYP and MP2 approximation with different basis sets up to aug-cc-pVTZ). Both, quantum chemistry and GED analyses resulted in the presence of 100(5)% enol tautomer at 296(3)K. Quantum chemical calculations predict the existence of two enol conformers in about equal amounts. In both conformers the enol ring possesses Cs symmetry and they possess different torsional orientations of the two tert-butyl groups. The experimental data refinement results in an enol tautomer, in which the tert-butyl group adjacent to the carbonyl group possesses an intermediate orientation between those in “enol1” and “enol 2” forms (torsional angle is about 30 ), and the tert-butyl group adjacent to the hydroxyl group slightly deviates from orientation in the theoretical conformers (by about 10 ). The enol ring possesses CS symmetry with a strongly asymmetric hydrogen bond. The experimental geometric parameters are reproduced very closely by the B3LYP/aug-cc-pVTZ method. |
Description: | TNS06972 ; JOURNAL OF MOLECULAR STRUCTURE Volume: 1132 Special Issue: SI Pages: 63-69 Published: MAR 15 2017 |
URI: | http://repository.vnu.edu.vn/handle/VNU_123/28155 http://www.sciencedirect.com/science/article/pii/S002228601630919X |
ISSN: | 0022-2860 1872-8014 |
Appears in Collections: | Bài báo của ĐHQGHN trong Web of Science |
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