Experimental and computational thermochemistry of 1-phenylpyrrole and 1-(4-methylphenyl)pyrrole

The standard (p° = 0.1 MPa) molar enthalpies of formation, in the crystalline phase, of 1-phenylpyrrole and 1-(4-methylphenyl)pyrrole, at T = 298.15 K, were derived from the standard molar energies of combustion in oxygen, measured by static-bomb combustion calorimetry. For these compounds, the standard molar enthalpies of sublimation, at T = 298.15 K, were determined from the temperature–vapour pressure dependence, obtained by the Knudsen mass-loss effusion method. Using estimated values for the heat capacity differences between the gas and the crystal phases of the studied compounds, the standard (p° = 0.1 MPa) molar enthalpies, entropies, and Gibbs energies of sublimation, at T = 298.15 K, were derived. From the experimental values, the standard molar enthalpies of formation, in the gaseous phase, at T = 298.15 K, were calculated.Additionally, the enthalpies of formation of both compounds were estimated using the composite G3(MP2)//B3LYP approach together with adequate gas-phase working reactions. There is a very good agreement between computational and experimental results.     

The action of organolithium compounds on phthalazine and I (2H)-phthalazinone

Phthalazine and 1(2H)-phthalazinone undergo 1,2-addition of organolithium compounds to C = N to give, following hydrolysis, 1 - substituted - 1,2 - dihydrophthalazines and 4-substituted-3,4-dihydro-1(2H)-phthalazinones respectively. These dihydro-derivatives may be easily autoxidized to the corresponding 1-substituted phthalazines and 4-substituted-1(2H)-phthalazinones.     

Partial Dehydrogenation of Saturated 4-Phenyl-1(2H)-phthalazinone Derivatives by Thionyl Chloride

cis-4a, 5,6,7,8,8a-Hexahydro-4-phenyl-1(2H)-phthalazinones (2) react with thionyl chloride in benzene to give tetrahydro derivatives (3); the corresponding reaction of methylene bridged derivatives (5) is also described.     

Experimental and computational study on the thermochemistry of ethylpiperidines

The standard (p^∘ = 0.1 MPa) massic energies of combustion in oxygen of 1-ethylpiperidine and 2-ethylpiperidine, both in the liquid phase, were measured at T = 298.15 K by static bomb calorimetry. These values were used to derive the standard molar enthalpies of combustion and the standard molar enthalpies of formation, in the condensed phase, for these compounds. Further, the standard molar enthalpies of vaporization, at T = 298.15 K, of these two ethylpiperidine isomers were determined by Calvet microcalorimetry. The combustion calorimetry results together with those from the Calvet microcalorimetry, were used to derive the standard molar enthalpies of formation, at T = 298.15 K, in the gaseous phase.     

8.

Structures of the Schiff-base ligands 1-[(1-adamantylamino)methylene]-2(1H)-naphthalenone (1) and 1-[(2-adamantylamino)methylene]-2(1H)-naphthalenone (2) and their corresponding copper(II) complexes     

E. Acevedo-Arauz  J. M. Fernndez-G.  M. J. Rosales-Hoz  R. A. Toscano 《Acta Crystallographica. Section C, Structural Chemistry》1992,48(1):115-120

     

9.

Structure of photostable 1-(hydroxyalkyl)-2(1H)-pyrazinones     

Y. Mori  A. Hayakawa  K. Maeda 《Acta Crystallographica. Section C, Structural Chemistry》1992,48(1):123-126

     

10.

2-phenyl-3-(1-methyl-2-indolyl)-4(1H)-quinolone     

B Staskun 《The Journal of organic chemistry》1966,31(8):2674-2676

     

11.

Studies on antiatherosclerotic agents. Synthesis of 7-ethoxycarbonyl-4-formyl-6,8-dimethyl-1(2H)-phthalazinone derivatives and related compounds     

Y Eguchi  F Sasaki  Y Takashima  M Nakajima  M Ishikawa 《Chemical & pharmaceutical bulletin》1991,39(3):795-797

Derivatives of 7-ethoxycarbonyl-4-formyl-6,8-dimethyl-1(2H)-phthalazinone and closely related compounds were synthesized using Wittig and epoxidation reactions. Ring opening amination of the epoxides were carried out using dimethylaluminum amide reagents under mild reaction conditions. beta-Keto ester and beta-diketone moieties were introduced through diazo derivatives. These moieties were reacted with hydrazine hydrate to produce 4-pyrazolyl derivatives. The derivatives were tested for their inhibitory effect on platelet aggregation, and their relaxing effect on blood vessels.     

12.

4-(9-Fluorenoxy)-2-phenylphthalazin-1(2H)-one     

M. J. Bausch  P. D. Robinson  Y. Gong 《Acta Crystallographica. Section C, Structural Chemistry》1997,53(4):517-519

     

13.

A theoretical study on 1-(thiophen-2-yl-methyl)-2-(thiophen-2-yl)-1H-benzimidazole     

Sekerci M  Atalay Y  Yakuphanoglu F  Avci D  Başoğlu A 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,67(2):503-508

The molecular geometry and vibrational frequencies of 1-(thiophen-2-yl-methyl)-2-(thiophen-2-yl)-1H-benzimidazole (C(16)H(12)N(2)S(2)) in the ground state has been calculated using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-31G(d) basis set. The optimized geometric bond lengths and bond angles obtained by using HF and DFT (B3LYP) show the best agreement with the experimental data. Comparison of the observed fundamental vibrational frequencies of 1-(thiophen-2-yl-methyl)-2-(thiophen-2-yl)-1H-benzimidazole (C(16)H(12)N(2)S(2)) and calculated results by density functional B3LYP and Hartree-Fock methods indicate that B3LYP is superior to the scaled Hartree-Fock approach for molecular vibrational problems.     

14.

Experimental study on the thermochemistry of 5-nitroindole and 5-nitroindoline     

Manuel A.V. Ribeiro da Silva  Joana I.T.A. Cabral 《The Journal of chemical thermodynamics》2009,41(3):355-360

     

15.

Syntheses and Structural Characterization of 1-（4-Phenyl-2-thiazolyl）-3-（4-methylphenyl）-5-（2-furyl）-4,5-dihydro-（1H）-pyrazole and 1-（4-（4-Fluoro）phenyl-2-thiazolyl）-3-（4-methyl-phenyl）-5-（2-furyl）-4,5-dihydro-（1H）-pyrazole     

AHIN Zarife Sibel  ISIK Samil  SALGIN-GOKSEN Umut  GOKHAN-KELEKCI Nesrin 《结构化学》2010,29(5):700-705

The title compounds were synthesized and characterized by IR,1H-NMR,Mass and elementary analysis and single-crystal X-ray diffraction.In 1a,intermolecular C-H…π interactions produce a three-dimensional network.In 1b,intermolecular C-H…O hydrogen bonds generate an R22(22) ring.The hydrogen bonding is supported by C-H…π interactions.     

16.

Experimental and computational studies on zwitterionic (E)-2-(1-(2-(4-methylphenylsulfonamido)ethyliminio)ethyl) phenolate     

Gökhan Alpaslan  Hasan Tanak  Ayşen Alaman Ağar  Ahmet Erdönmez  Şamil Işık 《Structural chemistry》2010,21(5):1027-1036

The Schiff base compound (E)-2-(1-(2-(4-methylphenylsulfonamido)ethyliminio)ethyl) phenolate has been synthesised and characterized by IR, UV–Vis, and X-ray single-crystal determination. Ab initio calculations have been carried out for the title compound using the density functional theory (DFT) and Hartree–Fock (HF) methods at 6-31G(d) basis set. The calculated results show that the DFT/B3LYP and HF can well reproduce the structure of the title compound. Using the TD-DFT and TD-HF methods, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental ones is determined. Molecular orbital coefficient analyses reveal that the electronic transitions are mainly assigned to n → π* and π → π* electronic transitions. To investigate the tautomeric stability, optimization calculations at B3LYP/6-31G(d) level were performed for the NH and OH forms of the title compound. Calculated results reveal that the OH form is more stable than NH form. In addition, molecular electrostatic potential and NBO analysis of the title compound were performed at B3LYP/6-31G(d) level of theory.     

17.

Electronic effects of 1-(1, 7-B6H6C2H) and 1-(1,6-B7H7C2H) groups     

L. I. Zakharkin  V. N. Kalinin  E. G. Rys  B. A. Kvasov 《Russian Chemical Bulletin》1972,21(3):531-532

Conclusions 1-[1,7-Dicarbaclozooctaboran(8)yl] (induction constant _i=0.08 and resonance constant _R°=–0.02) and 1-[1,6-dicarbaclozononaboran(9)yl] (=0.09 and _R°=0.05) groups are weak electron-acceptor groupings.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 574–576, March, 1972.     

18.

Electroplating of Steel in the Presence of 5,6-Dihydropyrimidine-2-(1H)-thione, 2-Methylthiopyrimidine-4-(1H)-one, 2-Thiopyrimidine-4-(1H)-ones,and 2,4-Pyrimidine(1H,3H)-dione Derivatives as Organic Additives     

Abdel-Monem M. Ahmed 《Journal of Dispersion Science and Technology》2013,34(3):343-352

The electrode processes on steel in acidified CuSO₄ were finding to depend on the organic additives as well as their concentrations. They also depend on the type of the anode and temperature. The activation energy proves that the reaction is diffusion controlled. The percentage of inhibition for all solutions ranged from 6.9% to 44.7% and depended on the type of the cathode and the concentration of the additive. The order of inhibition efficiency of steel cathode is: compound 4 > compound 5 > compound 3 > compound 2 > compound 6 > compound 1. The overall mass transfer correlation proves that the electroplating reaction is natural convection, which is in accordance with our previous studies.     

19.

Structure of 2-(2-hydroxyethyl)-1-p-tolyl-4,5,6,7-tetrahydro-3(1H)-isoindolone     

A. Kapor  G. Stjer  G. Bernth 《Acta Crystallographica. Section C, Structural Chemistry》1993,49(11):1967-1969

     

20.

Experimental, theoretical and biological activity study on 1-(4,5-dihydro-3-arylpyrazol-1-yl)-2-(1H-1,2,4-triazol-1-yl)-ethanone     

Liangzhong Xu  Yongwei Huang  Guanping Yu  Guodong Si  Qi Zhu 《Structural chemistry》2006,17(2):235-239

Four compounds have been synthesized and characterized by¹H NMR spectroscopy and elemental analyses, among which 1-(4,5-dihydro-3-phenyl-pyrazol-1-yl)-2-(1H-1,2,4-triazol-1-yl)ethanone 3a was further confirmed by X-ray crystallographic analysis. The biological activities of these compounds were tested, with the result that they displayed moderate fungicidal activities. In addition, a MO calculations using density functional theory (DFT) at B3LYP/6-31G^* level have also been carried out, and the structure–activity relationships for these compounds are discussed.     

Studies on antiatherosclerotic agents. Synthesis of 7-ethoxycarbonyl-4-formyl-6,8-dimethyl-1(2H)-phthalazinone derivatives and related compounds

Derivatives of 7-ethoxycarbonyl-4-formyl-6,8-dimethyl-1(2H)-phthalazinone and closely related compounds were synthesized using Wittig and epoxidation reactions. Ring opening amination of the epoxides were carried out using dimethylaluminum amide reagents under mild reaction conditions. beta-Keto ester and beta-diketone moieties were introduced through diazo derivatives. These moieties were reacted with hydrazine hydrate to produce 4-pyrazolyl derivatives. The derivatives were tested for their inhibitory effect on platelet aggregation, and their relaxing effect on blood vessels.     

A theoretical study on 1-(thiophen-2-yl-methyl)-2-(thiophen-2-yl)-1H-benzimidazole

The molecular geometry and vibrational frequencies of 1-(thiophen-2-yl-methyl)-2-(thiophen-2-yl)-1H-benzimidazole (C(16)H(12)N(2)S(2)) in the ground state has been calculated using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-31G(d) basis set. The optimized geometric bond lengths and bond angles obtained by using HF and DFT (B3LYP) show the best agreement with the experimental data. Comparison of the observed fundamental vibrational frequencies of 1-(thiophen-2-yl-methyl)-2-(thiophen-2-yl)-1H-benzimidazole (C(16)H(12)N(2)S(2)) and calculated results by density functional B3LYP and Hartree-Fock methods indicate that B3LYP is superior to the scaled Hartree-Fock approach for molecular vibrational problems.     

Syntheses and Structural Characterization of 1-（4-Phenyl-2-thiazolyl）-3-（4-methylphenyl）-5-（2-furyl）-4,5-dihydro-（1H）-pyrazole and 1-（4-（4-Fluoro）phenyl-2-thiazolyl）-3-（4-methyl-phenyl）-5-（2-furyl）-4,5-dihydro-（1H）-pyrazole

The title compounds were synthesized and characterized by IR,1H-NMR,Mass and elementary analysis and single-crystal X-ray diffraction.In 1a,intermolecular C-H…π interactions produce a three-dimensional network.In 1b,intermolecular C-H…O hydrogen bonds generate an R22(22) ring.The hydrogen bonding is supported by C-H…π interactions.     

Experimental and computational studies on zwitterionic (E)-2-(1-(2-(4-methylphenylsulfonamido)ethyliminio)ethyl) phenolate

The Schiff base compound (E)-2-(1-(2-(4-methylphenylsulfonamido)ethyliminio)ethyl) phenolate has been synthesised and characterized by IR, UV–Vis, and X-ray single-crystal determination. Ab initio calculations have been carried out for the title compound using the density functional theory (DFT) and Hartree–Fock (HF) methods at 6-31G(d) basis set. The calculated results show that the DFT/B3LYP and HF can well reproduce the structure of the title compound. Using the TD-DFT and TD-HF methods, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental ones is determined. Molecular orbital coefficient analyses reveal that the electronic transitions are mainly assigned to n → π* and π → π* electronic transitions. To investigate the tautomeric stability, optimization calculations at B3LYP/6-31G(d) level were performed for the NH and OH forms of the title compound. Calculated results reveal that the OH form is more stable than NH form. In addition, molecular electrostatic potential and NBO analysis of the title compound were performed at B3LYP/6-31G(d) level of theory.     

Electronic effects of 1-(1, 7-B6H6C2H) and 1-(1,6-B7H7C2H) groups

Conclusions 1-[1,7-Dicarbaclozooctaboran(8)yl] (induction constant _i=0.08 and resonance constant _R°=–0.02) and 1-[1,6-dicarbaclozononaboran(9)yl] (=0.09 and _R°=0.05) groups are weak electron-acceptor groupings.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 574–576, March, 1972.     

Electroplating of Steel in the Presence of 5,6-Dihydropyrimidine-2-(1H)-thione, 2-Methylthiopyrimidine-4-(1H)-one, 2-Thiopyrimidine-4-(1H)-ones,and 2,4-Pyrimidine(1H,3H)-dione Derivatives as Organic Additives

The electrode processes on steel in acidified CuSO₄ were finding to depend on the organic additives as well as their concentrations. They also depend on the type of the anode and temperature. The activation energy proves that the reaction is diffusion controlled. The percentage of inhibition for all solutions ranged from 6.9% to 44.7% and depended on the type of the cathode and the concentration of the additive. The order of inhibition efficiency of steel cathode is: compound 4 > compound 5 > compound 3 > compound 2 > compound 6 > compound 1. The overall mass transfer correlation proves that the electroplating reaction is natural convection, which is in accordance with our previous studies.     

Experimental, theoretical and biological activity study on 1-(4,5-dihydro-3-arylpyrazol-1-yl)-2-(1H-1,2,4-triazol-1-yl)-ethanone

Four compounds have been synthesized and characterized by¹H NMR spectroscopy and elemental analyses, among which 1-(4,5-dihydro-3-phenyl-pyrazol-1-yl)-2-(1H-1,2,4-triazol-1-yl)ethanone 3a was further confirmed by X-ray crystallographic analysis. The biological activities of these compounds were tested, with the result that they displayed moderate fungicidal activities. In addition, a MO calculations using density functional theory (DFT) at B3LYP/6-31G^* level have also been carried out, and the structure–activity relationships for these compounds are discussed.