tert-Octylamine
[CAS 107-45-9]

Identification

• Classification: Organic raw materials >> Amino compound >> Acyclic monoamines, polyamines and their derivatives and salts
• Name: tert-Octylamine
• Synonyms: 1,1,3,3-Tetramethylbutylamine; 2,4,4-Trimethyl-2-pentanamine; 2-Amino-2,4,4-trimethylpentane
• Molecular Formula: C₈H₁₉N
• Molecular Weight: 129.24
• CAS Registry Number: 107-45-9
• EC Number: 203-491-1
• SMILES: CC(C)(C)CC(C)(C)N

Properties

• Density: 0.8±0.1 g/cm³ Calc.^*
• Melting point: -67 °C (Expl.)
• Boiling point: 143.4±8.0 °C 760 mmHg (Calc.)^*, 137 - 143 °C (Expl.)
• Flash point: 32.2 °C (Calc.)^*, 33 °C (Expl.)
• Solubility: water insoluble (Expl.)
• Index of refraction: 1.431 (Calc.)^*, 1.424 (Expl.)
• Melting point: -67 °C
• Boiling point: 137-143 °C
• Refractive index: 1.4235-1.4255
• Flash point: 32 °C
• Water solubility: insoluble

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS06;GHS07;GHS09 DangerGHS02;GHS05
• Risk Statements: H226-H290-H301-H302-H314-H318-H411
• Safety Statements: P210-P233-P234-P240-P241-P242-P243-P260-P264-P264+P265-P270-P273-P280-P301+P316-P301+P317-P301+P330+P331-P302+P361+P354-P303+P361+P353-P304+P340-P305+P354+P338-P316-P317-P321-P330-P363-P370+P378-P390-P391-P403+P235-P405-P406-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Acute toxicity	Acute Tox.	4	H302
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1C	H314
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Skin corrosion	Skin Corr.	1B	H314
Acute toxicity	Acute Tox.	3	H301
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H412
Skin corrosion	Skin Corr.	1A	H314
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412

• Transport Information: UN 2734

chemBlink Chemical Story

tert-Octylamine is a useful reminder that a common name can hide an unusual shape. CAS 107-45-9 is not a straight C8 amine. Its IUPAC name is 2,4,4-trimethylpentan-2-amine: a primary amine attached to a highly branched hydrocarbon framework. NIST and PubChem both identify the formula as C₈H₁₉N. The branching makes its behavior different from that of n-octylamine even though both contain eight carbon atoms.

Alkylamines combine two contrasting features. The nitrogen lone pair makes the amine basic and able to bind a proton, while the hydrocarbon portion is nonpolar. In the free-base form an alkylamine can prefer organic phases; after protonation it becomes an ammonium ion and interacts much more strongly with water and negatively charged surfaces. This reversible change is the chemical foundation behind many applications of alkylamines in separations, surface treatment, extraction, corrosion control, and synthesis.

Branching changes that balance. A linear C8 chain presents a relatively extended hydrophobic tail, while tert-octylamine packs several methyl groups around a compact skeleton near the carbon bearing the amino group. Steric bulk can affect how easily the nitrogen approaches electrophiles or surfaces, how molecules pack at interfaces, and how the corresponding salts crystallize. The compound is therefore best understood as a specialized branched primary amine rather than merely 'another octylamine.'

The acid-base switch also provides a broader connection to modern responsive chemistry. Amines can be reversibly protonated by acids, including carbonic acid generated when carbon dioxide dissolves in water. Related amine systems have been designed as CO₂-switchable solvents and surfactants: exposure to CO₂ increases ionic character and water affinity, while removal of CO₂ can restore the neutral form. This general principle does not mean tert-octylamine is interchangeable with every switchable surfactant, but it explains why alkylamine protonation is such a powerful design tool.

For CAS 107-45-9, the high-quality public literature is much richer in identity and physical-property data than in one famous named application. That itself is worth stating rather than inventing a discovery story. NIST records its spectroscopic and phase-change information, while PubChem consolidates its registry identity and hazard data. Commercial use should be evaluated from product specifications and application-specific sources rather than inferred from generic claims about all fatty amines.

What makes tert-octylamine memorable is molecular shape. Eight carbons can be arranged as a flexible chain or as a compact, heavily branched skeleton, and the same amino group then operates in a different steric and interfacial environment. The compound is a small example of a large lesson in organic chemistry: formula tells composition, but architecture determines behavior.

References:
1. PubChem. tert-Octylamine, CID 61017, CAS 107-45-9.
2. NIST Chemistry WebBook. 2-Pentanamine, 2,4,4-trimethyl-, CAS 107-45-9.
3. Jessop P.G., Mercer S.M., Heldebrant D.J. CO2-triggered switchable solvents, surfactants, and other materials. Energy & Environmental Science. 2012, 5, 7240-7253. DOI: 10.1039/C2EE02912J.
4. General alkylamine acid-base and interfacial chemistry literature; application should be interpreted for the specific branched amine rather than by family name alone.

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