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Register a new userDetermination of The Enthalpy of Formation of Three- and Seven- Membered Heterocyclic Theoethers in Gas State by Different Theoretical Methods via Atomization Energy and Bond Separation Schemes
تحديد انتالبيات تشكل المركبات التيوايتيرات الحلقية الثلاثية حتى السباعية غير المتجانسة في الحالة الغازية بالطرائق النظرية المختلفة عبر طاقات التذري و مخططات فصل الروابط
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تم تحديد انتالبيات تشكل المركبات التيوايتيرات الحلقية الثلاثية حتى السباعية (11مركباً) في الحالة الغازية بالطرائق المركبة Gn و CBS، و السويتين النظريتين و من خلال التقريبين: طاقات التذري (AE) و مخططات فصل الروابط (BS). حدد الانحراف الوسطي المطلق (MAD) و الانحراف القياسي (SD) للمعطيات النظرية عن القيم التجريبية. لوحظ أن طريقة فصل الروابط تقدم انحرافات وسطية مطلقة لمعظم الطرائق النظرية مقارنة بتقريب طاقة التذري؛ إذ تقدم السوية النظرية G3MP2 اقل قيمة لـ MAD، في حين تكون الانحرافات الموافقة للسويتين النظريتين و قريبة من انحرافات الطرائق المركبة. لا تبدي المجموعة الأساسية 6-31g(d,p) تأثيراً جوهرياً في النتائج النظرية.
Enthalpy of formation for three- and seven- membered heterocyclic theoethers (11 compound) in gas state have been determined by different theoretical methods: compo-site methods (Gn, CBS) and two levels of theory B3LYP/6-31g(d) and MP2/6-31g(d) via two approaches: atomization energy (AE) and bond separation (BS). Median abs-lute deviations (MAD) and standard deviations (SD) of calculation values from experi-ment data have been determined for every used theoretical method. It has been observed that the bond separation approach produce lower value of MAD in most of the theoretical methods in comparison to the atomization energy approach; where the G3MP2 method produce lower value of MAD, while the deviations corresponding to the two levels of theory MP2/6-31g(d)//B3LYP/6-31g(d) and MP2/6-31g(d)//B3LYP /6-31g(d) is close to the deviations of the composite methods. The 6-31g(d,p) basic set doesn't show substantial effect in the theoretical results.
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Enthalpies of formation for three- and eight- membered heterocyclic ethers (15
compounds) in gas state have been determined by different theoretical methods: levels of
theory B3LYP/6-31g(d), MP2/6-31g(d) and chemical composite methods (Gn and CBS)
via two approach’s: atomization energy (AE) and bond separations (BS). Median absolute
deviations (MAD) and standard deviations (SD) of calculated values from experimental
data have been determined for every using method’s. The bond separation method has the
smallest MAD at most of theoretical methods in comparison to the atomization energy
approach. The 6-31g(d,p) basis set doesn’t seen clear effect in the theoretical results.
The Diels - Alder reactions of furan and some derivatives with maleic anhydride
have been studied using methods of density functional theory (DFT): B3LYP, B3PW91,
MPW1PW91 and MPW1BPE with 6-31g(d) bases set and proceeding energy cor-relation
at M
P4 level of theory with same bases set. The results of this study showed that, for the
Diels - Alder reaction of Furan and 2-methyl furan with maleic anhydride, the reaction of
formation of exo-adduct proceeds under thermodynamical control, and the reaction of
formation of endo-adduct proceeds under kinatic control, but for the 2-furylmethanol, 2-
furylmethyl acetate and 2-furylmethyl benzoate, the reactions of formation of exo-adduct
proceed under thermodynamical and kinetic controls. The MPW1BPE/6-31g(d) level of
theory was advanced susceptible results by comparison with the reference experimental
data; exactly for furan-maleic anhydride Diels - Alder reaction.
The 1,3-dipolar cycloaddition of the aryl azide and some its of derivatives with cinnamic
acid was studied theoretically using different methods of Density Functional Theory
(DFT): B3LYP, B3PW91, MPW1PBE, MPW1PW91 and M062X with the basic set 6-
3
1g(d). Most of the used levels of theories provide closed results qualitatively, and the
results of the level of theory M062X / 6-31g (d) show that these reactions in the gas state
carried out spontaneously to form several stable energy products; the products P1 and P2
are most stable, but all the reactions are very slow and one of the products P1 is more
spontaneous than P2 , but the formation reaction of P2 is faster.
On the other hand, when these reactions were studied with different solvents, it is found
that solvents to have no actual effects on the rates of these reactions.
The 1,3-dipolar cycloaddition of the aryl azide and some its of derivatives with cyclohex-
2-en-1-one was studied theoretically using different methods of Density Functional
Theory (DFT): B3LYP, B3PW91, MPW1PBE, MPW1PW91 and M062X with the basic
s
et 6-31g(d). Most of the used levels of theories provide closed results qualitatively, and
the results of the level of theory M062X / 6-31g (d) show that these reactions in the gas
state are spontaneously to form two products, but all the reactions are very slow and one of
the products P1 is more spontaneous and faster than the other P2 , and when these
reactions were studied with different solvents, it is found that solvents to have no actual
effects on the rates of these reactions.
The results of the level of theory M062X / 6-31g (d) indicate that the Gibbs free energy of
the reactions for the substitutes of Aryl increases in negative values in order of 2,6-Cl, -4
NO2, 4-OCH3, 3-OCH3, 3-Cl, 2 -Cl, H-; i.e., the substitutes do not have a significant
effect on the spontaneity of reactions compared to the substitute-H. It was observed that
TS-P1 transition state energy for all substitutes was lower than TS-P2 transition state
energy.
We have synthesized some new compounds from 2-Acetyl Fluorene\ Thiophene
2-carbaldehyde chalcone via condensation and cyclization reactions between the chalcone and each of thiourea and urea, hydroxylamine hydrochloride and hydrazine hydrate, these
reactions afford these compounds:
3-(2-fluorenyl)-5-(2-thienyl) pyrazoline(4), 3-(2-fluorenyl)-5-(2-thienyl) Isoxazoline(3), 4-(2-fluorenyl)-6-(2-thienyl) pyrimidinone-2 (2) and 4-(2-fluorenyl)-6-(2-thienyl) pyrimidine-2 tione (1). Also 3-(2-fluorenyl)-5-(2-thienyl) isoxazole (5), were prepared via bromination of chalcon and cyclization the later with hydroxylamine hydrochloride.
Identification and determination of compounds structurs were carried out by (IR,
1H-NMR, 13C-NMR, LC-MS) spectrum Analysis.
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