synthesis Flashcards
What happens when an organic reaction takes place?
What is this process called?
bonds in the reactant molecules are broken and bonds in the product molecules are made?
This process of bond breaking is known as bond fission
What is homolyctic fission?
-results in the process of 2 neutral radicals
-occurs when each atom retains one electron from the sigma covalent bond and the bond breaks evenly
-normally occurs when non-polar covalent bonds are broken
What do reactions involving homolyctic fission tend to result in?
the formation of very complex mixtures of products, making them unsuitable for organic synthesis
What is heterolyctic fission?
-results in the formation of 2 oppositely charged ions
-occurs when one atom retains both electrons in the sigma covalent bond and the bond breaks unevenly
-normally occurs when polar covalent bonds are broken
What do reactions involving heterolyctic fission tend to result in?
far fewer products than reactions involving homolyctic fission, and so are better suited for organic shnthesis
what does single-headed arrow indicate?
the movement of a single electron
what does a double-headed arrow indicate ?
the movement if an electron pair
what does the tail of the arrow show?
the source of the electron(s)
what does the head of the arrow indicate?
the destination of the electrons(s)
What dk two single-headed arrows starting at the middle of a covalent bond indicate?
homolyctic bond fission occurring
what does a double-headed arrow starting at the middle of a covalent bond indicate?
heterolyctic bond fission is occurring
What does an arrow drawn with the head pointing to the space between two atoms indicate?
that a covalent bond will be formed between those 2 atoms
In reactions involving heterolyctic bond fission, what are attacking groups classified as?
nucleofiles or electrophiles
What is a nucleophile?
-negatively charged ions or neutral molecules that are electron rich
-e.g. Cl-, Br-, OH-, CN-, NH3, H2O (the O)
-attracted towards atoms bearing a partial positive or full positive charge
-capable of donating an electron pair to form a new covalent bond
What are electrophiles?
-positively charged ions or neutral molecules that are electron deficient
-e.g. H+, NO2+, SO3, H in H2O, carbocations
-attracted towards atoms bearing a partial negative or full negative charge
-capable if accepting an electron pair to form a new covalent bond
