IR Spectroscopy

Xray Crysallography

Xray beam onto crystal structure to determine structure.

Mass Spectrometry

Characterizes by mass.

IR Spectroscopy

Data produced in a spectra based on how a compound interacts with light

Heavier atoms = frequency > or <

Lower frequency

The stronger the bond the frequency …

Increases

Dipole moment

Polar covalent bond where electrons are shared unequally due to differences in electronegativity.

Covalent bonds

Electrons are shared.

Nonpolar

Share electrons equally, same en

Polar

Unequal sharing of electrons between atoms in a bond, resulting in a dipole moment. Different en.

C-H Polarity Exception

They are nonpolar

Fingerprint Region

<1400

C-C Wavenumbers

1200 cm^-1

C=C Wavenumbers

1660 cm^-1

C3C Wavenumbers

<2200 cm^-1

Symmetrical cc bonds are IR active or inactive?

Inactive

sp3 hybridized C wavenumbers

2800-3000 cm^-1

sp2 hybridized C

3000-3200 cm^-1 (3000 cutoff)

sp hybridized C

3300 cm^-1 (sharp peak)

Alcohol Wavenumber

3300 cm^-1, BROAD

Carboxylic Acid Wavenumber

3000 cm^-1, Extra BROAD

Amines C-H Wavenumbers

3300 cm^-1, Broad with spikes

C=O Wavenumbers

1710-1725 cm^-1

Carboxylic Ester C=C Wavenumbers

1735 cm^-1

Aldehyde C-H Wavenumbers

2700-2800 cm^-1

C-N Wavenumbers (All)

Same as C-C but more intense