beta-Diketones;
Tautomerism;
Electron diffraction;
Quantum chemical calculations;
Molecular structure;
KETO-ENOL-TAUTOMERISM;
MAGNETIC-RESONANCE-SPECTROSCOPY;
BETA-DIKETONES;
VIBRATIONAL ASSIGNMENT;
HYDROGEN-BOND;
ACETYLACETONE;
FORM;
COVALENT;
DFT;
D O I:
10.1016/j.molstruc.2012.03.065
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
The tautomeric and structural properties of 3-methyl-2,4-pentanedione, CH3-C(O)-CH(CH3)-C(O)-CH3, have been studied by gas-phase electron diffraction (GED) and quantum chemical calculations (B3LYP and MP2 approximation with different basis sets up to aug-cc-pVTZ). Analysis of GED intensities resulted in the presence of 100(3)% enol tautomer at 274(7)K. Quantum chemical calculations predict enol concentrations from 8% at MP216-31G(d,p) level to 100% at B3LYP/aug-cc-pVTZ. This would show the failure of the MP2/6-31G(d,p) method. The enol ring possesses C-s symmetry with a strongly asymmetric hydrogen bond. The experimental geometric parameters are reproduced very closely by the B3LYP/aug-cc-pVTZ method. (C) 2012 Elsevier B.V. All rights reserved.
机构:
PSG Coll Arts & Sci, PG & Res Dept Phys, Coimbatore 641014, Tamil Nadu, IndiaPSG Coll Arts & Sci, PG & Res Dept Phys, Coimbatore 641014, Tamil Nadu, India
Sathyanaranyamoorthi, V.
Brindha, S.
论文数: 0引用数: 0
h-index: 0
机构:
PSG Coll Arts & Sci, PG & Res Dept Phys, Coimbatore 641014, Tamil Nadu, IndiaPSG Coll Arts & Sci, PG & Res Dept Phys, Coimbatore 641014, Tamil Nadu, India
Brindha, S.
Kannappan, V.
论文数: 0引用数: 0
h-index: 0
机构:
Loyola Coll, PG & Res Dept Chem, Madras 600030, Tamil Nadu, IndiaPSG Coll Arts & Sci, PG & Res Dept Phys, Coimbatore 641014, Tamil Nadu, India