---
title: "Niacin Structure (C6H5NO2): 3D Model, Formula & Molar Mass | MolDraw"
url: https://www.moldraw.com/molecules/niacin.html
description: "Structure of Niacin (C6H5NO2, 123.11 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/) › Niacin structure

# Niacin structure and 3D model (C6H5NO2)

Niacin (nicotinic acid) is a pyridine ring with a carboxylic acid group at the 3-position. It is one of the simplest vitamins.

**Quick answer:** Niacin is **C6H5NO2**, molar mass **123.11 g/mol**. Small and flat; polar and moderately 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).

## Niacin at a glance

| Formula | C6H5NO2 |
| --- | --- |
| Molar mass | 123.11 g/mol |
| IUPAC name | pyridine-3-carboxylic acid |
| Atoms / bonds | 14 / 14 |
| H-bond donors / acceptors | 1 / 2 |
| logP (estimated) | 0.8 |
| SMILES | `C1=CC(=CN=C1)C(=O)O` |
| InChIKey | `PVNIIMVLHYAWGP-UHFFFAOYSA-N` |
| PubChem | [938](https://pubchem.ncbi.nlm.nih.gov/compound/938) |

![2D structural formula of Niacin (C6H5NO2)](https://www.moldraw.com/molecules/img/niacin.svg)

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

## What the 3D model of Niacin shows

The model contains **14 atoms** (9 heavy atoms and 5 hydrogens) joined by **14 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 2 hydrogen bonds, and its estimated logP of 0.8 means it is fairly balanced between water and fat. Its topological polar surface area is 50 Ų.

## Shape and bond angles

| Atom(s) | Geometry / hybridisation | Angles & lengths |
| --- | --- | --- |
| ring atoms | Trigonal planar, sp²; aromatic ring | 120° |
| carboxylic acid carbon | Trigonal planar, sp² | ≈ 120° |
| ring N | sp², lone pair in the ring plane | ≈ 117° |

### Is Niacin polar?

Yes. The ring nitrogen and the COOH group make it polar, and it dissolves in water, especially hot water.

## Elemental composition of C6H5NO2

| Element | Atoms | Mass (g/mol) | Mass % |
| --- | --- | --- | --- |
| Carbon (C) | 6 | 72.066 | 58.54% |
| Hydrogen (H) | 5 | 5.040 | 4.09% |
| Nitrogen (N) | 1 | 14.007 | 11.38% |
| Oxygen (O) | 2 | 31.998 | 25.99% |

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 niacin

- Vitamin used to make NAD and NADP in the body
- Added to flour and cereals to prevent pellagra
- Used in some treatments for blood lipids

## Interesting facts

- Niacin was first made by oxidising nicotine, which is why it was called nicotinic acid.
- The name niacin was chosen to avoid confusion with nicotine.
- Taking large amounts can cause a harmless but uncomfortable skin flush.

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

[Open MolDraw editor](https://www.moldraw.com/)

## Frequently asked questions

### What is the structure of Niacin?

Niacin (nicotinic acid) is a pyridine ring with a carboxylic acid group at the 3-position. It is one of the simplest vitamins. Its SMILES is C1=CC(=CN=C1)C(=O)O.

### Is niacin the same as nicotine?

No. Niacin is a vitamin with a COOH group on a pyridine ring. It can be made from nicotine but has none of its effects.

### What is niacinamide?

The amide of niacin (CONH₂ instead of COOH). It is another form of vitamin B3 and does not cause flushing.

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

Niacin is C6H5NO2 with a molar mass of 123.11 g/mol. It contains 14 atoms: 6 carbon, 5 hydrogen, 1 nitrogen, 2 oxygen.

### What is the IUPAC name of Niacin?

The IUPAC name is pyridine-3-carboxylic acid.

### How do I draw Niacin?

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

## More molecule models & tools

[**Vitamin A structure**C20H30O](https://www.moldraw.com/molecules/vitamin-a.html)[**Vitamin D3 structure**C27H44O](https://www.moldraw.com/molecules/vitamin-d3.html)[**Folic acid structure**C19H19N7O6](https://www.moldraw.com/molecules/folic-acid.html)[**Ibuprofen structure**C13H18O2](https://www.moldraw.com/molecules/ibuprofen.html)[**Paracetamol structure**C8H9NO2](https://www.moldraw.com/molecules/paracetamol.html)[**Nicotine structure**C10H14N2](https://www.moldraw.com/molecules/nicotine.html)[**3D molecular model viewer**Any molecule by name or SMILES](https://www.moldraw.com/tools/free-chem-tools/3d-molecular-model-viewer.html)[**Build a molecule**Molecule builder kit](https://www.moldraw.com/tools/free-chem-tools/build-a-molecule.html)[**VSEPR geometry calculator**Shapes & bond angles](https://www.moldraw.com/tools/free-chem-tools/vsepr-molecular-geometry-calculator.html)[**Molar mass calculator**Any formula](https://www.moldraw.com/tools/free-chem-tools/molar-mass-calculator.html)