Infrared and photoelectron spectra, and keto—enol tautomerism of acetylacetones and acetoacetic esters

1975 ◽  
Vol 342 (1630) ◽  
pp. 327-339 ◽  
Keyword(s):  
Wide Temperature Range ◽  
Photoelectron Spectrum ◽  
Equilibrium Constants ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Temperature Range ◽  
Related Compounds

The infrared and photoelectron spectra of some substituted acetylacetones have been measured, and interpreted in terms of enolic and ketonic structures. Ionization potentials from specific orbitals have been assigned. With different substituents, the proportion of the two forms varies considerably. From measurements of the photoelectron spectrum over a wide temperature range, the equilibrium constants for keto-enol forms have been determined and estimates made of the enthalpy of the tautomeric change. Conclusions about the tautomerism have been correlated with earlier measurements by other methods. For comparison, the spectra of acetoacetic esters and related compounds have been measured. The proportions of keto-enol forms have been estimated and ionization potentials assigned to particular orbitals.

Photoelectron Spectrum and Electronic Structure of Tetrathiofulvalene (TTF)

1974 ◽  
Vol 52 (19) ◽  
pp. 3373-3377 ◽  
Author(s):  
A. John Berlinsky ◽  
James F. Carolan ◽  
Larry Weiler
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Molecular Orbital ◽  
Photoelectron Spectrum ◽  
Crystal Packing ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Molecular Orbital Calculations ◽  
Conducting Salt

The electronic structure of tetrathiofulvalene (TTF) has been determined from its photoelectron spectrum and the photoelectron data for the tetrahydro derivative of TTF and 1,3-dithiolane. Correlations of the ionization potentials (i.p.) and several molecular orbital calculations are used in the assignment of the photoelectron spectra of these three compounds. The first five i.p. of TTF and their assignment are as follows: 6.92 (3b1u), 8.67 (2b2g), 9.73 (2b1u), 10.16 (au) and 10.49 eV (b3g). The sixth i.p. at 11.00 eV is tentatively assigned to the 1b2g level. The electronic structure of TTF is important in understanding the crystal packing and band structure of the highly conducting salt, TTF•TCNQ.

Fuels Characterization for Use in Internal Combustion Engines

2001 ◽  
Author(s):  
R. Lanzafame ◽  
M. Messina
Keyword(s):  
Experimental Data ◽  
Wide Temperature Range ◽  
Internal Combustion Engines ◽  
Equilibrium Constants ◽  
Combustion Process ◽  
Internal Combustion ◽  
Least Square ◽  
Mathematical Functions ◽  
Temperature Range ◽  
Ic Engines

Abstract It is important provide mathematical functions able to fit with great precision experimental data on gases properties, in order to obtain reliable results when computerized models on IC engines are used. On the basis of experimental data on equilibrium constants (for dissociation phenomena occurring during combustion process in IC engines) new mathematical functions have been determined to fit experimental data. In comparison to traditional fitting polynomials, these new mathematical functions present a great accuracy in matching experimental data. These new mathematical functions have the functional forms of a V order Logarithmic Polynomial, and their coefficients have been evaluated on the basis of the least square method. The new V order Logarithmic Polynomials have been determined for several dissociation reactions according to internal combustion processes applications. V order Logarithmic Polynomials have been implemented also to describe the trend of specific heat at constant pressure Vs temperature and enthalpy Vs temperature. These new Logarithmic Polynomials have been calculated for several gases and fuels for IC engines applications. The new Logarithmic Polynomials pointed out a better precision in comparison to the others polynomial functions used in literature, and the possibility to utilize a single Logarithmic Polynomial for a wide temperature range, according to a good accuracy with experimental data. Another advantage of the Logarithmic Polynomials is the possibility to extrapolate experimental data on a wide temperature range (25% of experimental T range) in order to supply to the experimental data shortage.

scholarly journals Ionization potentials of nitriles — Photoelectron spectra of succinonitrile and glutaronitrile

2006 ◽  
Vol 84 (9) ◽  
pp. 1124-1131 ◽  
Author(s):  
Heidi M Muchall ◽  
Nick H Werstiuk
Keyword(s):  
Energy Region ◽  
Photoelectron Spectrum ◽  
Lone Pair ◽  
Low Energy ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Proton Affinities ◽  
Nitrogen Lone Pair ◽  
D Model ◽  
Highest Occupied Molecular Orbitals

The He(I) photoelectron spectra of succinonitrile (1) and glutaronitrile (2), both with extensive overlap of ionization bands in the low-energy region, are reported. To assign ionizations, we studied the conformational behaviour and resulting ionization energy dependence of 1 and 2 computationally with the B3LYP/6-31+G(d) model chemistry based on the fact that it reliably reproduces the ionization potentials of eleven mono- and di-nitriles, both saturated and unsaturated. The correlation of proton affinities with observed ionization potentials of 1, 2, and malononitrile establishes the orbital sequence of four C≡N π orbitals followed by two nitrogen lone pair orbitals as the highest occupied molecular orbitals for all three compounds.Key words: photoelectron spectrum, ionization potential, conformational dependence, nitrile, DFT.

scholarly journals Thermodynamic modeling of melt of the Bi-Pb-Sn-Cd system

2021 ◽  
Vol 2057 (1) ◽  
pp. 012104
Author(s):  
N Barbin ◽  
I Tikina ◽  
D Terentyev
Keyword(s):  
Thermodynamic Modeling ◽  
Wide Temperature Range ◽  
Software Package ◽  
Equilibrium Constants ◽  
Thermal Dissociation ◽  
Metal Compounds ◽  
Temperature Range

Abstract Thermodynamic modeling of heating of the Bi-Pb-Sn-Cd system in a wide temperature range is performed in the TERRA software package. The equilibrium constants of thermal dissociation reactions are determined. The equilibrium constants of thermal dissociation reactions for metal compounds formed in the Bi-Pb-Sn-Cd melt as a result of heating are determined: BiPb, PbSn, SnBi, Pb3Bi, Pb5Bi4Sn4, PbSn3, Bi2Sn3, Bi7Pb, CdSn, Sn3Bi, PbBi2Sn2, Pb3Bi4, Cd3Bi2, Bi7Pb3, Sn4Bi2.

Photoelectron spectra of carbonyl halides and related compounds

1972 ◽  
Vol 327 (1568) ◽  
pp. 13-22 ◽  
Keyword(s):  
Chemical Reactivity ◽  
Vibrational Structure ◽  
Molecular Orbitals ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Ionization Process ◽  
Parent Molecule ◽  
Carbonyl Cyanide ◽  
Related Compounds

Photoelectron spectra in the region 6 to 21 eV have been measured for carbonyl halides (fluoride, chloride and bromide) and carbonyl cyanide. In a number of cases, vibrational structure coupled with the ionization process has been resolved and correlated with the known frequencies of the parent molecule. Ionization potentials have been derived for the removal of an electron from orbitals of different kinds, such as the C=O π orbital and various nonbonding molecular orbitals. The results have been correlated with other data on the chemical reactivity of these molecules.

Fibre-optic temperature sensor with wide temperature range characteristics

1987 ◽  
Vol 134 (5) ◽  
pp. 291 ◽  
Author(s):  
K.T.V. Grattan ◽  
J.D. Manwell ◽  
S.M.L. Sim ◽  
C.A. Willson
Keyword(s):  
Wide Temperature Range ◽  
Temperature Sensor ◽  
Fibre Optic ◽  
Temperature Range

Enabling highly reversible sodium metal cycling across a wide temperature range with dual-salt electrolytes

2021 ◽  
Author(s):  
Akila C. Thenuwara ◽  
Pralav P. Shetty ◽  
Neha Kondekar ◽  
Chuanlong Wang ◽  
Weiyang Li ◽  
...  
Keyword(s):  
Wide Temperature Range ◽  
High Energy ◽  
Liquid Electrolyte ◽  
Metal Cycling ◽  
Temperature Range ◽  
Sodium Metal ◽  
Wide Range

A new dual-salt liquid electrolyte is developed that enables the reversible operation of high-energy sodium-metal-based batteries over a wide range of temperatures down to −50 °C.

Quantum calculations of the photoelectron spectra of the OH−·NH3 anion: implications for OH + NH3 → H2O + NH2 reaction dynamics

2021 ◽  
Vol 23 (11) ◽  
pp. 6950-6958
Author(s):  
Kohei Saito ◽  
Yutaro Sugiura ◽  
Takaaki Miyazaki ◽  
Yukinobu Takahashi ◽  
Toshiyuki Takayanagi
Keyword(s):  
Quantum Dynamics ◽  
Photoelectron Spectrum ◽  
Reaction Dynamics ◽  
Photoelectron Spectra ◽  
Quantum Calculations ◽  
Anion Complex

Quantum dynamics calculations were performed to analyze the experimentally measured photoelectron spectrum of the OH−·NH3 anion complex.

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