CH 2: Families of Carbon - Functional Groups and IR Spectroscopy

Vocabulary flashcards covering hydrocarbons, polar covalent bonds, functional groups, physical properties, and IR spectroscopy from Chapter 2.

Hydrocarbons

Compounds whose molecules contain only carbon and hydrogen atoms.

Saturated Compounds

Compounds containing only single bonds.

Unsaturated Compounds

Compounds containing one or more double or triple bonds.

Alkanes

A subgroup of hydrocarbons whose members only contain single $C-C$ bonds, where all carbons are $sp^3$ hybridized with tetrahedral shape and $\sim 109.5^\circ$ bond angles.

Alkenes

A subgroup of hydrocarbons whose members contain one or more $C=C$ double bonds, characterized by $sp^2$ hybridization, trigonal planar shape, and $\sim 120^\circ$ bond angles.

Alkynes

A subgroup of hydrocarbons whose members contain one or more $C \equiv C$ triple bonds, characterized by $sp$ hybridization, linear shape, and $\sim 180^\circ$ bond angles.

Aromatic Compounds (Arenes)

Compounds containing a special type of ring with alternating single and double bonds, such as benzene ($C_6H_6$).

Covalent Bond

A type of bond that results in a sharing of electrons, which are not equally shared unless the electronegativity of the atoms is the same.

Electronegativity

A measure of the ability of an atom to attract electrons it is sharing with another atom, thereby polarizing the bond, based on an arbitrary scale with fluorine ($EN = 4.0$) being the most electronegative and cesium ($EN = 0.7$) the least.

Dipole Moment

The direction of polarity of a polar bond, calculated as charge times distance.

Net Dipole Moment

The overall resultant dipole moment of a molecule, calculated by considering its three-dimensional shape and adding up its dipole vectors.

Functional Groups

Common and specific arrangement of atoms that impart predictable properties and reactivity on a molecule.

Alkyl Group Substituents

Alkane-derived side chains used for naming (symbolized as $R-$), formed by dropping "-ane" and adding "+yl" to the parent alkane name.

Phenyl Group

A benzene-based substituent side chain symbolized as $-C_6H_5$, $\text{Ph}-$, or $\phi-$.

Benzyl Group

A benzene-based substituent side chain containing a methylene bridge, symbolized as $-CH_2C_6H_5$ or $\text{Bn}-$.

Alkyl Halides (Haloalkanes)

Compounds containing a halogen atom (symbolized as $-X$, where $X = F, Cl, Br, I$) attached to an alkyl group, represented as $R-X$.

Primary ($1^\circ$) Alkyl Chloride

An alkyl chloride in which the carbon atom attached to the halogen $-X$ is bound to $0$ or $1$ other carbon atom.

Secondary ($2^\circ$) Alkyl Chloride

An alkyl chloride in which the carbon atom attached to the halogen $-X$ is bound to $2$ other carbon atoms.

Tertiary Alkyl Chloride

An alkyl chloride in which the carbon atom attached to the halogen $-X$ is bound to $3$ other carbon atoms.

Alcohols

Compounds containing a hydroxyl group substituent, symbolized as $R-O-H$.

Ethers

Compounds containing an oxygen atom attached to two alkyl groups, symbolized as $R-O-R'$.

Amines

Compounds containing a nitrogen atom attached to $1$, $2$, or $3$ alkyl groups (symbolized as $H_2N-R$, $R-HN-R'$, or $N(R)_3$), considered derivatives of ammonia ($NH_3$).

Carbonyl Group

A functional moiety consisting of a carbon atom double-bonded to an oxygen atom ($C=O$), characterized by $sp^2$ hybridization and trigonal planar geometry.

Aldehydes

Compounds containing a carbonyl group ($C=O$) attached to at least one hydrogen atom, symbolized as $R-(C=O)-H$ or $RCOH$ (where $R = \text{alkyl}$ or $H$).

Ketones

Compounds containing a carbonyl group ($C=O$) attached to two alkyl groups, symbolized as $R-(C=O)-R'$.

Carboxylic Acids

Compounds containing a carbonyl group ($C=O$) attached to a hydroxyl group and an alkyl group or hydrogen, symbolized as $RCOOH$ or $RCO_2H$.

Esters

Compounds containing a carbonyl group ($C=O$) attached to an $-O-R$ group and an alkyl group or hydrogen, symbolized as $RCOOR'$ or $RCO_2R'$.

Amides

Compounds containing a carbonyl group ($C=O$) attached to an amine and an alkyl group or hydrogen, symbolized as $RCONH_2$, $RCONHR'$, or $RCONR'R''$.

Acid Chloride

Compounds containing a carbonyl group ($C=O$) attached to a chlorine atom, symbolized as $RCOCl$.

Acid Anhydride

Compounds containing a carbonyl group ($C=O$) attached to a $-O-COR$ group, symbolized as $RCO_2COR'$.

Nitriles

Compounds containing a carbon atom triple-bonded to a nitrogen atom ($C \equiv N$), symbolized as $RCN$.

Melting Point

The temperature at which an equilibrium exists between the well-ordered crystalline state and the more random liquid state.

Boiling Point Range

The temperature at which the vapor pressure of the liquid equals the pressure of the atmosphere above it.

Solubility

The dissolution of a solid in a liquid.

Miscibility

The dissolution of a liquid in a liquid.

Hydrophobic

Incompatible with water.

Hydrophilic

Compatible with water.

Infrared (IR) Spectroscopy

A vibrational spectroscopy technique that supplies thermal energy to vibrate molecular bonds, providing evidence for the presence of various functional groups.

Wavenumber

The unit of frequency used in IR absorption spectroscopy, expressed in reciprocal centimeters ($cm^{-1}$).

Fingerprint Region

The IR spectral region below $1500\,cm^{-1}$ containing atom-atom single bond stretches (such as $C-O$, $C-N$, $C-X$, $C-S$) and atom-H bends or wags.