Structure 3.2

• 2nd row elements only have enough sub levels for 8 valance electrons so they can only have complete or incomplete octets
• 3rd row elements can have up to 18 valance electrons which means they can have incomplete octets (rare), completed octets, or expanded octets
• Incomplete octets

  When 1 or more elements in a compound have less than 8 electrons in their valance shell
• Expanded octets

  When 1 or more elements in a compound have more than 8 electrons in their valance shell
• When there is a charge to be taken , it USUALLY goes to the most electronegative elements SANS IN RESONANCE STRUCTURES
• The best Lewis structure for a compounds is produced when

  The central atom's charge is neutral (0)
• Formal charge = valance electrons (central atom) - (bonds + lone electrons (NOT PAIRS))
• # lone pairs around central atom = (valance - 8(# non-central atoms))/2

  ex. CO2 -> (16 - 8(2))/2 = 0
• Alkane - "a beginning" - single bonded carbons in sp3 domain with 109.5 bond angle
• Alkene - "twins" - doubly bonded carbons in sp2 domain with 120 bond angle
• Alkyne - "y thou?" - triply bonded carbon in sp domain with 180 bond angle
• All functional groups (except alkane, alkene, alkyne) are either primary, secondary, or tertiary, depending on how many carbons they're linked to

  
• Haloalkanes - "a beginning halogen" - singly bonded halogen
• AmiNe - "nitrogen" - "R - NH2" - substituent = amino
• Alcohol - "COH = C - OH" - hydroxyl group
• Thiol - "Halogen= sulfur" - "C-SH"
• Nitrile - N = nitrogen, Tri = three - triply bonded nitrogen to carbon
• Phenyl - Benzene ring connected to R ("R"est of hydrocarbon)
• Ether - "either" - [R-O-R] which can be either straight or cyclic
• Special Ether; Epoxide

  
• Ester - "s" = second functional group, "e" = either, "t" = three bonds - [R-CO2-R]
• Carbonyl - "carbo" = CO - Carbon doubly bonded to oxygen within a chain usually in sp2 domain with 120 bond angle
• Ketone - "one" = singular oxygen, "ken" = not interrupting - [R-CO-R] oxygen double bonded to an oxygen as a side chain
• Aldehyde - "hyde" = hydrogen at the end [R-CO] a carbon doubly bonded to an oxygen at THE END of a chain
• Carboxylic acid - "oxy" = oxygen, "a" = again - [R-COOH] Carbon double bonded to an oxygen and then singly bonded to another oxygen which is bonded to a hydrogen (like a Aldehyde- at the end- and an alcohol)
• Amide - "ID" = two different functional groups - [R-CO-NH3] oxygen doubly bonded to the last carbon bonded to a nitrogen bonded to two hydrogens (basically a aldehyde with an Amine)
• Naming ethers

  "smaller molecule's name" + oxy + "larger molecule's name" + ane
• Two identical short molecules in a combined Ether?

  Place, place, di____

  ex. 1, 2 dimethoxyethane

  
• Ethers lose solubility with larger molecular size
• Ethers are made of two alkyl groups that are split into alkyl substituent (small) and the alkane stem (larger)
• Common names:

  Ethanoate - Acetate

  Methanoate - Formate

  Butanoate - Butyrate
• Naming esters


  "molecule without doubly bonded oxygen" + yl + "molecule with doubly bonded oxygen" + oate

  
• Benzene ring bonded to a carbon (Phenyl) as a substituent

  Benzyl
• Kentone as a substituent

  oxo
• Amine as a substituent

  Amino
• Numbering starts towards the side closest to the strongest functional group
• Naming Esters with overlapping molecules

  End the last name with "-dioate"

  ex. diethyl pentandioate

  
• Naming Esters with multiple functional groups


  Find the proper name of the molecule without considering the Ester then join the two

  ex. "2-Bromo Butyl 4-Amino 3-Methoxy Pentanoate"

  
• Polar molecules are those with an unequal pull of electrons- non-polar molecules have an overall stable pull of electrons

  
• Non polar substances include diatomic molecules (two of its own element), hydrocarbons, and elements with the same electronegativity on both ends.