alkene

IUPAC nomenclature

similar to that of alkane; suffix: -ene

1. Find longest carbon chain with double bond, number carbons so that double bond have lowest possible numbers
2. if double bond equidistant from both end, number it so substituent has lowest number
3. cycloalkenes are named similarly
4. a substituent on double bond: get number 1

E.g.

naming.png

halogenation

halogens	prefix
fluorine	fluoro
chlorine	chloro
bromine	bromo
iodine	iodo

alkene + halogen -> dihaloalkane;
naming: alphabetical order

e.g.

orbit hybridization

hybridized orbit: essentially probability cloud, i.e. Schrödinger's cloud model; not definite orbit, but probability.

orbit: presumably electrons fill: 1s2s2p2p2p, while in fact it's 1s2sp³2sp³2sp³2sp³ :

energy-level

• sp³, σ bond: head2head: sturdy
• sp², π bond: parallel: easy to see this makes it unable to rotate

double bond consists of:

• a σ bond formed by overlap of sp² hybrid
• a π bond formed by overlap of parallel 2*p orbitals
• 2 carbon atoms, 4 H atoms lie in a plane, bond angles: Mercedes 120 degrees;
• 2 * tetrahedral structures; in fact, each methane molecule is a tetrahedron (similar to fcc: 12 equidistant nearest-neighbor atoms, refer to MOSFET Chapter1, Page8)

ethene-structure.png

Newman projection

1. staggered conformation
2. eclipsed conformation

• because of electron cloud expelling each other, staggered conformation has lower potential energy, thus more stable
• eclipsed carbon atoms are more far away while staggered closer

• in fact, staggered are as far as hydrogen groups can go

  
  
  ethane.png

e.g. halogenation w. ethene in Newman projection

halogenizedethene.png