---
title: "Ibuprofen Structure (C13H18O2): 3D Model, Formula & Molar Mass | MolDraw"
url: https://www.moldraw.com/molecules/ibuprofen.html
description: "Structure of Ibuprofen (C13H18O2, 206.28 g/mol): rotatable 3D model, 2D skeletal formula, IUPAC name, SMILES, shape, polarity, uses and FAQ."
lang: en
publisher: Scidart Academy
generated: 2026-10-26
---
[MolDraw](https://www.moldraw.com/) › [3D molecule models](https://www.moldraw.com/molecules/) › Ibuprofen structure

# Ibuprofen structure and 3D model (C13H18O2)

Ibuprofen is a benzene ring with an isobutyl group at one end and a propanoic acid group at the other (para). The carbon next to the COOH is a stereocentre, and the drug is sold as a 50:50 mix of both mirror images.

**Quick answer:** Ibuprofen is **C13H18O2**, molar mass **206.28 g/mol**. Flat ring with two side chains; mostly non-polar, so it is poorly soluble in water.

Atom labels Hydrogens Spin

Drag to rotate · pinch or scroll to zoom. 3D coordinates: computed with RDKit (ETKDG conformer, force-field optimised).

## Ibuprofen at a glance

| Formula | C13H18O2 |
| --- | --- |
| Molar mass | 206.28 g/mol |
| IUPAC name | 2-[4-(2-methylpropyl)phenyl]propanoic acid |
| Atoms / bonds | 33 / 33 |
| H-bond donors / acceptors | 1 / 1 |
| logP (estimated) | 3.1 |
| SMILES | `CC(C)CC1=CC=C(C=C1)C(C)C(=O)O` |
| InChIKey | `HEFNNWSXXWATRW-UHFFFAOYSA-N` |
| PubChem | [3672](https://pubchem.ncbi.nlm.nih.gov/compound/3672) |

![2D structural formula of Ibuprofen (C13H18O2)](https://www.moldraw.com/molecules/img/ibuprofen.svg)

2D structure (skeletal formula) · [Draw it in MolDraw](https://www.moldraw.com/)

## What the 3D model of Ibuprofen shows

The model contains **33 atoms** (15 heavy atoms and 18 hydrogens) joined by **33 bonds**; in ball-and-stick mode every stick is one bond, and double or aromatic bonds are drawn as multiple sticks. Switch to *space-filling* to see the molecule as its electron cloud, scaled to van der Waals radii: this is the shape other molecules actually "feel". It can donate 1 and accept 1 hydrogen bonds, and its estimated logP of 3.1 means it is fat-loving (lipophilic). Its topological polar surface area is 37 Ų.

## Shape and bond angles

| Atom(s) | Geometry / hybridisation | Angles & lengths |
| --- | --- | --- |
| ring carbons | Trigonal planar, sp²; planar ring | 120° |
| carboxylic acid carbon | Trigonal planar, sp² | ≈ 120° |
| CH, CH₂ and CH₃ carbons of the side chains | Tetrahedral, sp³ | ≈ 109.5° |

### Is Ibuprofen polar?

Only slightly. The COOH group is polar, but the large hydrocarbon part makes ibuprofen dissolve much better in oils and ethanol than in water.

## Elemental composition of C13H18O2

| Element | Atoms | Mass (g/mol) | Mass % |
| --- | --- | --- | --- |
| Carbon (C) | 13 | 156.143 | 75.69% |
| Hydrogen (H) | 18 | 18.144 | 8.80% |
| Oxygen (O) | 2 | 31.998 | 15.51% |

Calculated from IUPAC standard atomic weights. Check any formula with the [molar mass calculator](https://www.moldraw.com/tools/free-chem-tools/molar-mass-calculator.html).

## Uses of ibuprofen

- Pain relief, fever and inflammation (NSAID)
- Common over-the-counter medicine for headaches and muscle pain
- Model compound for teaching chirality in drugs

## Interesting facts

- Ibuprofen was developed by Boots in the UK in the 1960s.
- Only the (S) enantiomer blocks the COX enzymes well, but the body converts much of the (R) form into (S).
- Its name comes from parts of iso-butyl-propanoic-phenolic acid.

**Drawing structures for your notes?** MolDraw is a free online chemical structure editor for molecules, reactions and lab diagrams.

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## Frequently asked questions

### What is the structure of Ibuprofen?

Ibuprofen is a benzene ring with an isobutyl group at one end and a propanoic acid group at the other (para). The carbon next to the COOH is a stereocentre, and the drug is sold as a 50:50 mix of both mirror images. Its SMILES is CC(C)CC1=CC=C(C=C1)C(C)C(=O)O.

### Is ibuprofen an acid?

Yes. It is a weak carboxylic acid with a pKa of about 4.4, so it is mostly ionised in neutral water.

### Is ibuprofen chiral?

Yes. It has one stereocentre, next to the COOH group. Ibuprofen is normally sold as the racemate, a 50:50 mix of (R) and (S).

### What is the chemical formula and molar mass of Ibuprofen?

Ibuprofen is C13H18O2 with a molar mass of 206.28 g/mol. It contains 33 atoms: 13 carbon, 18 hydrogen, 2 oxygen.

### What is the IUPAC name of Ibuprofen?

The IUPAC name is 2-[4-(2-methylpropyl)phenyl]propanoic acid.

### How do I draw Ibuprofen?

Open the MolDraw editor, paste the SMILES CC(C)CC1=CC=C(C=C1)C(C)C(=O)O or type "Ibuprofen" in name search, and the structure is drawn for you. You can then export it as PNG, SVG, MOL or CDXML.

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