Octet

Octet / Ir Table

Alkene C=C

Alkene C=C absorbs in the IR at 1620-1680 cm⁻¹. Intensity: variable, band shape: Sharp (weak if symmetric). Use this range to identify the group from an IR spectrum.

Ir Table details

Functional Group

Alkene C=C

Wavenumber Range

1620-1680

Intensity

variable

Appearance

Sharp (weak if symmetric)

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Ir Table

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Alcohol O-H

Alcohol O-H absorbs in the IR at 3200-3600 cm⁻¹. Intensity: strong, band shape: Broad. Use this range to identify the group from an IR spectrum.

Carboxylic acid O-H

Carboxylic acid O-H absorbs in the IR at 2500-3300 cm⁻¹. Intensity: strong, band shape: Very broad, often overlaps C-H. Use this range to identify the group from an IR spectrum.

Phenol O-H

Phenol O-H absorbs in the IR at 3200-3600 cm⁻¹. Intensity: strong, band shape: Broad. Use this range to identify the group from an IR spectrum.

Primary amine N-H

Primary amine N-H absorbs in the IR at 3300-3500 cm⁻¹. Intensity: medium, band shape: Two peaks (symmetric/asymmetric). Use this range to identify the group from an IR spectrum.

Secondary amine N-H

Secondary amine N-H absorbs in the IR at 3300-3500 cm⁻¹. Intensity: medium, band shape: One peak. Use this range to identify the group from an IR spectrum.

Amide N-H

Amide N-H absorbs in the IR at 3150-3400 cm⁻¹. Intensity: medium, band shape: Broad, may have two peaks. Use this range to identify the group from an IR spectrum.

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