Block 1- Foundations Flashcards
What is the difference between a good and bad atomic orbital (AO) overlap?
A good AO overlap is when the AO are end on forming sigma bond
A bad AO overlap is when the AO are side on forming a pie bond
What is the hybridisation of a C bonded to 4 groups, 3 groups and 2 groups. Include shape
4 groups. SP3, tetrahedral,
3 groups, SP2, trigional planar
2 groups, SP, linear
What are constitutional isomers?
Molecules with the same molecular formula but different atom-to-atom connectivity
What are stereoisomers?
Molecules with the same atom-to-atom connectivity but a different arrangement in space
What is the DBE formula?
2 + 2C - H-X +N /2
What do DBE calculate?
The number of rings and or pi-bonds
What are isomers?
Compounds with the same molecular formulae but different arrangements
What is a diastereomer?
A configurations isomer that doesn’t have a mirror image relationship and isn’t superimpossible
What is a chiral carbon
A SP3 carbon with 4 different groups attached
What is an aciral carbon
A SP3 carbon with 2 or more identical groups attached
When are E/Z configurational isomer notations used?
When there is a double bond.
What are the aspects of E vs Z configurational isomers?
Z= high priority groups on the same side
E= high priority groups on opposite sides of the
What does the presses of a pi-bond mean?
There is no free rotation about the bond, this fixes atoms in space
What do the terms cis/trans isomers mean for cyclic compounds
The term cis/trans refers to the relative position of substitutes on a ring in relation to the other
What are configurational isomers
Molecules with same molecular formula, where interconversion requires bond breaking
What are conformational isomers?
Isomers which differ by rotation about a single bond
What are the properties of enantiomers?
Non-superimposable mirror images
What methods are used to draw conformers?
Sawhorse projection and Newman projection
What are the names of the most and least stable Newman projection
Most stable is staggered anti
Least stable is eclipsed syn
What are the names of the most and least stable cyclohexane conformers?
Most stable is chair conformer
Least stable is boat conformer
What is the hybridisation notation for a C bonded to 4 atoms
Sp3 hybridised
Tetrahedral, 109.5°
What is the hybridisation notation for a C bonded to 3 atoms/ 1 pi bond
Sp2 hybridised
Trigonal planar 120°
What is the hybridisation notation for a C bonded to 2 atoms/ 2 pi bonds
Sp hybridised
Linear 180°
What group is in the equatorial position for cyclohexane conformer to be most stable?
The largest group/substituents, it has the largest molar mass
