Thioketenes and Iminopropadienethiones RN=C=C=C=S from Isoxazolones

2010 ◽  
Vol 63 (12) ◽  
pp. 1694 ◽  
Author(s):  
David Kvaskoff ◽  
Curt Wentrup
Keyword(s):  
Density Functional Theory ◽  
Ir Spectroscopy ◽  
Density Functional ◽  
Functional Theory ◽  
Thermal Elimination ◽  
Matrix Ir Spectroscopy

Isoxazolones 6 undergo thermal elimination of propene and isopropylthiol to produce thioketenes 7 at 500–600°C under flash vacuum thermolysis conditions. At 700–900°C further fragmentation occurs to produce iminopropadienethiones, RNCCCS 8. In addition, 3-alkylisoxazolones 6d–e rearrange to cyanothioketenes 10d–e. Compounds 7, 8, and 10 were characterized by Ar matrix IR spectroscopy and comparison with density functional theory-calculated spectra. Thioketenes 7 reacted with amines to afford thioamides 11. Reaction of aryliminopropadienethiones 8 with amines caused cyclization to 2-aminoquinoline-4(1H)-thiones 16.

An amino–imino resonance study of 2-amino-4-methylpyridinium nitrate and 2-amino-5-methylpyridinium nitrate

2012 ◽  
Vol 69 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Xing-Chen Yan ◽  
Yu-Hua Fan ◽  
Cai-Feng Bi ◽  
Xia Zhang ◽  
Zhong-Yu Zhang
Keyword(s):  
Density Functional Theory ◽  
Ir Spectroscopy ◽  
Ground State ◽  
Density Functional ◽  
Acta Cryst ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography ◽  
Ground State Structures

The contributions of the amino and imino resonance forms to the ground-state structures of 2-amino-4-methylpyridinium nitrate, C6H9N2+·NO3−, and the previously reported 2-amino-5-methylpyridinium nitrate [Yan, Fan, Bi, Zuo & Zhang (2012).Acta Cryst.E68, o2084], were studied using a combination of IR spectroscopy, X-ray crystallography and density functional theory (DFT). The results show that the structures of 2-amino-4-methylpyridine and 2-amino-5-methylpyridine obtained upon protonation are best described as existing largely in the imino resonance forms.

Comparative Studies of H+(C6H6)(H2O)1,2 and H+(C5H5N)(H2O)1,2 by DFT Calculations and IR Spectroscopy

2004 ◽  
Vol 57 (12) ◽  
pp. 1153 ◽  
Author(s):  
Chanchal Chaudhuri ◽  
Chih-Che Wu ◽  
Jyh-Chiang Jiang ◽  
Huan-Cheng Chang
Keyword(s):  
Density Functional Theory ◽  
Ir Spectroscopy ◽  
Dft Calculations ◽  
Proton Affinity ◽  
Comparative Studies ◽  
Density Functional ◽  
Functional Theory ◽  
Spectroscopic Measurements ◽  
Vibrational Predissociation

Protonated benzene–water and pyridine–water complexes have been investigated by density functional theory (DFT) calculations and infrared (IR) spectroscopy. The calculations performed at the B3LYP/6–31+G* level predict that there exist several stable isomers for H+(C6H6)(H2O)1,2 with two distinct ion cores, C6H7+ and H3O+. In contrast, only the C5H5NH+-centred form can be found for H+(C5H5N)(H2O)1,2, arising from the higher proton affinity of pyridine compared to that of benzene and water. Vibrational predissociation spectroscopic measurements of H+(C6H6)(H2O)2 and H+(C5H5N)(H2O)2 support the predictions.

scholarly journals Carbon monoxide protonation in condensed phases and bonding to surface superacidic Brønsted centers

2016 ◽  
Vol 18 (6) ◽  
pp. 4871-4880 ◽  
Author(s):  
Evgenii S. Stoyanov ◽  
Sergei E. Malykhin
Keyword(s):  
Density Functional Theory ◽  
Carbon Monoxide ◽  
Ir Spectroscopy ◽  
Dft Calculations ◽  
Density Functional ◽  
Condensed Phases ◽  
Functional Theory

Using infrared (IR) spectroscopy and density functional theory (DFT) calculations, interaction of CO with the strongest known pure Brønsted carborane superacids, H(CHB11Hal11) (Hal = F, Cl), was studied.

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