Read More
Date: 18-5-2017
![]()
Date: 7-7-2019
![]()
Date: 24-5-2017
![]() |
As the table below shows, the dissociation energy for the allylic C-H bond is lower than the dissociation energies for the C-H bonds at the vinylic and alkylic positions. This is because the radical formed when the allylic hydrogen is removed is resonance-stabilized. Hence, given that the halogen concentration is low, substitution at the allylic position is favored over competing reactions. However, when the halogen concentration is high, addition at the double bond is favored because a polar reaction outcompetes the radical chain reaction.
|
|
دخلت غرفة فنسيت ماذا تريد من داخلها.. خبير يفسر الحالة
|
|
|
|
|
ثورة طبية.. ابتكار أصغر جهاز لتنظيم ضربات القلب في العالم
|
|
|
|
|
سماحة السيد الصافي يؤكد ضرورة تعريف المجتمعات بأهمية مبادئ أهل البيت (عليهم السلام) في إيجاد حلول للمشاكل الاجتماعية
|
|
|