Chapter 1 - Classifying Organic Compounds

• Organic chemistry: the study of compounds based on carbon
  • Ex. of organic compounds: natural gas, rubbing alcohol, aspirin, compounds that give fragrance to rose

Chapter 1.1: Bonding and the Shape of Organic Molecules

• Organic compounds: compounds based on carbon; usually contains carbon-carbon and carbon-hydrogen bonds
• Million of organic compounds, only a quarter of million of inorganic compounds
• So many organic compounds because of carbon:
  • It forms four covalent bonds and connects to four other atoms
  • It forms strong single, double, or triple bonds with other carbons
• Saturated bonds: molecules that contain only single carbon-carbon bonds
• Unsaturated bonds: molecules that contain double or triple bonds
• Carbon unique bonding properties formation of chains and rings with a variety of sizes
• The shape of a molecule depends on the type of bond, examples include:
  • Carbon with four single bonds: tetrahedral shape
  • Carbon with one double bond and two singular bonds: trigonal planar shape
  • Carbon with two double bonds or one triple bond and one single bond: linear shape
  • Oxygen with two single bonds: bent shape
• 2-D diagrams good for condensed structural diagrams and line structures
• 3-D diagrams atoms are drawn with wedges to indicate it is in front, but lines when it is pushed back
• Polar covalent bond: the covalent bond between two atoms with different electronegativities
• Electronegativity: a measure of how strongly an atom attracts electrons in a chemical bond; partial negative or partial positive atom
• Every polar bond has a bond dipole
• Bond dipole: partial negative charge and partial positive charge, separated by the length of the bond
• Polar molecule or molecular polarity: when the molecule has an overall imbalance of charge
  • A molecule has a region with a partial positive charge and a region with a partial negative charge
  • Not all molecules with polar bonds are polar molecules
  • To determine molecular polarity, must consider the shape of molecule and bond dipoles within the molecule
• If equal bond dipoles act in opposite directions in three-dimensional space, they counteract each other

1.2 Hydrocarbons

• Hydrocarbons: simplest type of organic compounds, composed of entirely carbon and hydrogen atoms
  • Aliphatic hydrocarbons: contains carbon atoms that are bonded in one or more chains and rings
  • Aromatic hydrocarbons: based on aromatic benzene group
  • Benzene is the simplest aromatic compound
• Alkane: hydrocarbon that has only single bonds
  • CnH2n+2
  • Cycloalkane: alkane in a shape of a ring
  • CnH2n
• Alkene: hydrocarbon with at least one double bond
  • CnH2n
• Functional Group: a reactive group of bonded atoms that appears in all the members of a chemical family
• Alkyne: hydrocarbon with at least one triple bond
  • CnH2n-2
• Rules for Naming Organic Compounds:
  • Prefix + root + suffix
  • Root: number of carbon atoms in the main chain or ring
    • Number of carbon atoms:
    • 1: -meth-
    • 2: -eth-
    • 3: -prop-
    • 4: -but-
    • 5: -pent-
    • 6: -hex-
    • 7: -hept-
    • 8: -oct-
    • 9: -non-
    • 10: -dec-
  • Suffix: type of compound according to functional groups present
    • Alkanes: -ane
    • Alkenes: -ene
    • Alkynes: -yne
  • Prefix: indicates name and location of each branch and functional group on the main carbon chain
    • Alkyl group: removing one hydrogen from an alkane; branches attached to the main chan, common Alkyl groups:
    • Methyl
    • Ethyl
    • Propyl
    • Isopropyl
    • Butyl
    • Sec-butyl
    • Iso-butyl
    • Tert-butyl
• Aromatic compounds*:*** cyclic compound with alternating single and double bonds, such as benzene

Chapter 1.3: Single-Bonded Functional Groups

• OH (hydroxyl) group: a functional group that contains OH
• general formula: R+ functional, family of simple organic compounds
  • R' and R’’ are used for more than one alkyl group
• Compounds with the same functional group often have similar physical properties
• Compounds with the same functional group react chemically in very similar ways
• Common Functional Groups:
  • Alkane
  • Alkyne
  • Alcohol
  • Amine
  • Aldehyde
  • Ketone
  • Carboxylic acid
  • Ester
• Intermolecular forces: forces of attraction and repulsion between particles; organic compounds with the same functional groups have the same physical properties, which are often caused by intermolecular forces, which include:
  • Hydrogen bonding: strong intermolecular attraction between the hydrogen atom with an N, O, F atom
  • Dipole-Dipole interactions: attractive forces between polar molecules
  • Dispersion forces: attractive forces that occur between all covalent molecules
• Alcohol, alkyl halides, ethers, and amines are all functional groups with single bonds
• Alcohol: an organic compound that contains the -OH functional group
  • Alcohols are named after parent alkane
  • Parent alkane: alkane with the same basic carbon structure
  • Very polar due to O-H bond, soluble in water
  • Flammable and most are poisonous
• Alkyl halide/haloalkane: alkane in which one or more hydrogen atoms have been replaced with halogen atoms (F, Cl, Br, or I); R-X Similar properties to alcohols
• Ether: organic compound that has two alkyl groups joined by an oxygen atom; R-O-RAlkoxy group: alkyl singularly bonded to oxygen Less polar than water and alcoholUsually soluble in water but decreases as the alkyl group increasesLower boiling point than water
• Amine: An organic compound with the functional group -NH2, -NHR, or -NR2
  • Polar compounds

Chapter 1.4: Functional Groups With the C=O Bond

• Carbonyl group: carbon atom double-bonded to an oxygen atom; C=O
• Aldehyde: organic compound that has double-bonded oxygen on the last carbon of a carbon chain; R-CHO
• Ketone: organic compound that has double-bonded oxygen on any carbon within the carbon chain; RCOR’
  • Contains C=O, usually polar
  • Soluble in water
  • Boiling points lower than corresponding alcohols, but higher to corresponding alkanes
• Carboxylic acid: carbon atom is bonded to an oxygen atom by a double bond and to a hydroxyl group (-OH) by a single bond
  • Polar because of O-H and C=O bonds
  • Contains hydrogen bonds, which makes it have higher boiling points
  • If it has lower mass, then it becomes soluble in water
  • Decreases in solubility as carbon atom increases
  • Unpleasant odors
  • Carboxylic acid derivative: exchange in hydroxyl group of carboxylic acid with a different organic compound
• Carboxyl group: COOH group
• Ester is a derivative of carboxylic acid
• Ester: general formula for an ester is RCOOR’
  • R is a hydrogen atom or a hydrocarbon, and R′ is a hydrocarbon
  • Polar Molecule
  • Cannot form hydrogen bonds with other ester atoms, only with water
  • Low boiling point
  • Volatile at room temperature
• Amide: carbon atom double-bonded to an oxygen atom and single-bonded to a nitrogen atom
  • C-N and N-H bonds make it polar, acts like carboxylic acids
  • Stronger hydrogen bonds than carboxylic acids
  • Soluble in water
  • High melting and boiling points
  • Simple amides are solid at room temperature

\