Thymine

C₅H₆N₂O₂

IUPAC: 5-Methylpyrimidine-2,4(1H,3H)-dione

CAS: 65-71-4

Overview

Thymine is a pyrimidine nucleobase found exclusively in DNA, where it pairs with adenine through two hydrogen bonds. It is distinguished from uracil (found in RNA) by having a methyl group at the 5 position. This methylation helps DNA repair enzymes distinguish DNA from RNA.

Composition

Element	Symbol	Atoms	Atomic Mass
Hydrogen	H	6	1.0080
Carbon	C	5	12.0110
Nitrogen	N	2	14.0070
Oxygen	O	2	15.9990

Elemental Composition

Hydrogen ×6

4.8%

Carbon ×5

47.6%

Nitrogen ×2

22.2%

Oxygen ×2

25.4%

Uses

• DNA component
• Genetic research
• Molecular biology
• UV mutation studies

Fun Facts

✦ UV light can cause adjacent thymine bases to fuse into thymine dimers, a primary cause of skin cancer

Safety

⚠ Low toxicity

Structure

SMILES

CC1=CNC(=O)NC1=O

Properties

Type: organic
State: solid
Molar Mass: 126.12 g/mol
Density: 1.2230 g/cm³
Melting Point: 316.0 °C
Boiling Point: 335.0 °C
Solubility: 4.0 g/L at 25°C

Molecular Descriptors

Exact Mass: 126.0429
XLogP: -0.6
TPSA: 58.2 Å²
H-Bond Donors: 2
H-Bond Acceptors: 2
Rotatable Bonds: 0
Heavy Atoms: 9
Complexity: 195.0

Also Known As

5-Methyluracil

Related Compounds

1,2-Dichloroethane

C₂H₄Cl₂

1,3-Butadiene

C₄H₆

1,4-Dioxane

C₄H₈O₂

1-Butanol

C₄H₁₀O

2-Propanol

C₃H₈O

Acetaldehyde

CH₃CHO

Acetamide

C₂H₅NO

Acetic Anhydride

C₄H₆O₃

Acetone

(CH₃)₂CO

Acetonitrile

C₂H₃N

Frequently Asked Questions

What is Thymine?

Thymine (C₅H₆N₂O₂) is a organic compound with the IUPAC name 5-Methylpyrimidine-2,4(1H,3H)-dione.

What is the molecular weight of Thymine?

Thymine has a molar mass of 126.115 g/mol.

What state is Thymine at room temperature?

Thymine is a solid at room temperature.

Is Thymine organic or inorganic?

Thymine is classified as an organic compound.

What elements make up Thymine?

Thymine (C₅H₆N₂O₂) is composed of Hydrogen (H), Carbon (C), Nitrogen (N), Oxygen (O).