Titre :	α???-methyle -β -dicyaαnostyrene structure : dynamique moléculaire.
Type de document :	texte imprimé
Auteurs :	Adel Guffef, Auteur ; Lamine Hamdellou, Directeur de thèse
Editeur :	constantine [Algérie] : Université Constantine 1
Année de publication :	2014
Importance :	91 f.
Format :	30 cm.
Note générale :	2 copies imprimées disponibles
Langues :	Français (fre)
Catégories :	Français - Anglais Physique
Tags :	Styrènes  Substitution  Donneur  Accepteur  Méthyle  Conjugaison moléculaire  Effet stérique  Diffraction des rayons X et des neutrons  Théorie de la fonctionnelle de la densité  styrenes  Donor  Acceptor  Methyl molecular Conjugation  Steric effect  X-ray diffraction  Density Functional Theory  الستایرین  استبدال  مجموعة اخذة  مجموعة مانحة  المیثیل  الإقتران الجزیئي تأثیر الفراغیة  حیود الأشعة السینیة  نظریة وظیفیة الكثافة
Index. décimale :	530 Physique
Résumé :	This work presents a continuation of study of the influence of substitution on the conformation of aromatic molecules. The crystal structure of β?-methyl-α dicyanostyréne (C11H8N2) was determined at room temperature by X-ray diffraction The crystal is Orthorhombic with a space group P 21 21 21 and Z = 4. The refinements of the molecule led from the CRYSTALS program. We have shown for a styrene substituted in position to the vinyl group that their structure is not flat and the predictions of the theoretical calculations by DFT are in agreement with the experimental results, we used the chain GAUSSIAN03 programs. The first calculation on the fully released molecule leads to another isomer.In the case where the calculations are made with a constraint that requires the double bond C (α ) -C (?β) obtaining a conformation similar to that observed in the crystal but with a double bond this time equal to 1.370 Å . the calculated length of this bond present in the worse agreement with experiment against other distances. These theoretical calculations predict the conformation of the molecule of -methyl-?- dicyanostyréne made clearly show the possibility of achieving several different solutions so that the solution that has the minimum training energy, ie most favorable, do not always correspond to the desired conformation. IR spectroscopy theoretical calculations allowed the assignment of different modes of ibration movements of the molecule.
Diplôme :	Magistère
En ligne :	../theses/physique/GUE6627.pdf
Format de la ressource électronique :	pdf
Permalink :	index.php?lvl=notice_display&id=9754

α???-methyle -β -dicyaαnostyrene structure : dynamique moléculaire. [texte imprimé] / Adel Guffef, Auteur ; Lamine Hamdellou, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2014 . - 91 f. ; 30 cm.
2 copies imprimées disponibles

Langues : Français (fre)

Catégories :	Français - Anglais Physique
Tags :	Styrènes  Substitution  Donneur  Accepteur  Méthyle  Conjugaison moléculaire  Effet stérique  Diffraction des rayons X et des neutrons  Théorie de la fonctionnelle de la densité  styrenes  Donor  Acceptor  Methyl molecular Conjugation  Steric effect  X-ray diffraction  Density Functional Theory  الستایرین  استبدال  مجموعة اخذة  مجموعة مانحة  المیثیل  الإقتران الجزیئي تأثیر الفراغیة  حیود الأشعة السینیة  نظریة وظیفیة الكثافة
Index. décimale :	530 Physique
Résumé :	This work presents a continuation of study of the influence of substitution on the conformation of aromatic molecules. The crystal structure of β?-methyl-α dicyanostyréne (C11H8N2) was determined at room temperature by X-ray diffraction The crystal is Orthorhombic with a space group P 21 21 21 and Z = 4. The refinements of the molecule led from the CRYSTALS program. We have shown for a styrene substituted in position to the vinyl group that their structure is not flat and the predictions of the theoretical calculations by DFT are in agreement with the experimental results, we used the chain GAUSSIAN03 programs. The first calculation on the fully released molecule leads to another isomer.In the case where the calculations are made with a constraint that requires the double bond C (α ) -C (?β) obtaining a conformation similar to that observed in the crystal but with a double bond this time equal to 1.370 Å . the calculated length of this bond present in the worse agreement with experiment against other distances. These theoretical calculations predict the conformation of the molecule of -methyl-?- dicyanostyréne made clearly show the possibility of achieving several different solutions so that the solution that has the minimum training energy, ie most favorable, do not always correspond to the desired conformation. IR spectroscopy theoretical calculations allowed the assignment of different modes of ibration movements of the molecule.
Diplôme :	Magistère
En ligne :	../theses/physique/GUE6627.pdf
Format de la ressource électronique :	pdf
Permalink :	index.php?lvl=notice_display&id=9754