Thermodynamic Functions of 1,2,4-0xadiazole. Comparison with Related Molecules

The usual therm6dynamic functions, namely the enthalpy function (reduced enthalpy), (Ho - E ~ )/T, free energy function (reduced free energy), - (G0 -E~ )/T, entropy, S 0 and heat capacity, C ~ of 1,2,4-oxadiazole were ca lculated for one atmosphere pressure and assuming ideal gaseous behavio ur throughout the temperature range 298.16-1000° K. The rigid rotator - harmonic oscillator approximation was used in combination with published molecular and spectroscopic data. A slight modification of the published vibrational assignment of the molecule is suggested and the calculations were carried out using both sets of fundamental frequencies. The results are compared with the v alues obtained previously for the related molecules furan, isoxazo le, oxazole, 1,2,5-oxadiazole and 1,3, 4-oxadiazole

Thermodynamic Functions of Thiadiazoles

Using the harmonic oscillator - rigid rotor approximation and the published data on the moments of inertia and the vibrational assignments of 1,3,4-thiadiazole, 1,2,5-thiadiazole, and 1,2,5-thiadiazole- d2, the thermodynamic functions (enthalpy and free energy functions, entropy and heat capacity) have been calculated. The results are tabulated in Tables III-V. A comparison between the thermodynamic functions calculated in the present work and those of the closely related thiophene is given in Table VI. The vibrational assignment used in the calculation are discussed

Thermodynamic Functions of 1,2,4-0xadiazole. Comparison with Related Molecules

The usual therm6dynamic functions, namely the enthalpy function (reduced enthalpy), (Ho - E ~ )/T, free energy function (reduced free energy), - (G0 -E~ )/T, entropy, S 0 and heat capacity, C ~ of 1,2,4-oxadiazole were ca lculated for one atmosphere pressure and assuming ideal gaseous behavio ur throughout the temperature range 298.16-1000° K. The rigid rotator - harmonic oscillator approximation was used in combination with published molecular and spectroscopic data. A slight modification of the published vibrational assignment of the molecule is suggested and the calculations were carried out using both sets of fundamental frequencies. The results are compared with the v alues obtained previously for the related molecules furan, isoxazo le, oxazole, 1,2,5-oxadiazole and 1,3, 4-oxadiazole

Thermodynamic Functions of Oxazole and Isoxazole

Some thermodynami.c functions (enthalpy, free energy, entropy and heat capacity) of oxazole and isoxazole were calculated (298.16°- 10000 K) for the pressure of on e atmosphere and ideal gaseous state. The calculated thermodynamic functions are compared with the results obtained previously for the related thiazoJe and iso-thiazole. The values for the two oxygen-containing molecules w ere found to be appreciably lower than those oif the corresponding sulfur-containing heterocycles

Thermodynamic Functions of Thiazole and iso-Thiazole

Some thermodynamic functions (the enthalpy and free energy functi ons, entropy and heat capacity) of thiazole and iso-thiazole have been calculated (300-1000° K), using the harmonic-oscillator, rigid-rotor approximation. The reported assignments for the two molecules were us ed, as were the published values for the moments of inertia of thiazole. Approximate values for the moments of inertia of iso-thiazole have been calculated, assuming bond lengths and angles similar to those of thiophene and 1,2,5-thiadiazole. The calculated thermodynamic functions are compared with the results obtained previously for thiadiazoles and thiophene

Stability and Hydrolyzation of Metal Organic Frameworks with Paddle-Wheel SBUs upon Hydration

Instability of most prototypical metal organic frameworks (MOFs) in the presence of moisture is always a limita- tion for industrial scale development. In this work, we examine the dissociation mechanism of microporous paddle wheel frameworks M(bdc)(ted)0.5 [M=Cu, Zn, Ni, Co; bdc= 1,4-benzenedicarboxylate; ted= triethylenediamine] in controlled humidity environments. Combined in-situ IR spectroscopy, Raman, and Powder x-ray diffraction measurements show that the stability and modification of isostructual M(bdc)(ted)0.5 compounds upon exposure to water vapor critically depend on the central metal ion. A hydrolysis reaction of water molecules with Cu-O-C is observed in the case of Cu(bdc)(ted)0.5. Displacement reactions of ted linkers by water molecules are identified with Zn(bdc)(ted)0.5 and Co(bdc)(ted)0.5. In contrast,. Ni(bdc)(ted)0.5 is less suscept- ible to reaction with water vapors than the other three compounds. In addition, the condensation of water vapors into the framework is necessary to initiate the dissociation reaction. These findings, supported by supported by first principles theoretical van der Waals density functional (vdW-DF) calculations of overall reaction enthalpies, provide the necessary information for de- termining operation conditions of this class of MOFs with paddle wheel secondary building units and guidance for developing more robust units

Thermodynamic Functions of Oxazole and Isoxazole

Some thermodynami.c functions (enthalpy, free energy, entropy and heat capacity) of oxazole and isoxazole were calculated (298.16°- 10000 K) for the pressure of on e atmosphere and ideal gaseous state. The calculated thermodynamic functions are compared with the results obtained previously for the related thiazoJe and iso-thiazole. The values for the two oxygen-containing molecules w ere found to be appreciably lower than those oif the corresponding sulfur-containing heterocycles

Thermodynamic Functions of Furan and Deuterated Furans

Using the har monic oscillator - rigid rotator approximation and available mole cular and spe ctroscopi c data, the thermodynamic functions (enthalpy and free energy functions, entropy and heat capacity) w ere calculated for furan and three deuterate d .Eurans at one atmosphe r e pressure and for the ideal gaseous state in the temperature range 298.16-1000° K

Thermodynamic Functions of Thiazole and iso-Thiazole

Some thermodynamic functions (the enthalpy and free energy functi ons, entropy and heat capacity) of thiazole and iso-thiazole have been calculated (300-1000° K), using the harmonic-oscillator, rigid-rotor approximation. The reported assignments for the two molecules were us ed, as were the published values for the moments of inertia of thiazole. Approximate values for the moments of inertia of iso-thiazole have been calculated, assuming bond lengths and angles similar to those of thiophene and 1,2,5-thiadiazole. The calculated thermodynamic functions are compared with the results obtained previously for thiadiazoles and thiophene

Thermodynamic Functions of Thiadiazoles

Using the harmonic oscillator - rigid rotor approximation and the published data on the moments of inertia and the vibrational assignments of 1,3,4-thiadiazole, 1,2,5-thiadiazole, and 1,2,5-thiadiazole- d2, the thermodynamic functions (enthalpy and free energy functions, entropy and heat capacity) have been calculated. The results are tabulated in Tables III-V. A comparison between the thermodynamic functions calculated in the present work and those of the closely related thiophene is given in Table VI. The vibrational assignment used in the calculation are discussed