Hydrated Fullerenes vs. Hydroxylated Fullerenes (Fullerenols): What’s the Difference?

Carbon 60 (C60) is a unique carbon molecule shaped like a hollow soccer ball. Because of its structure, scientists have developed different ways to prepare and use it. Two common forms people hear about are hydrated fullerenes and hydroxylated fullerenes, also known as fullerenols.

Although the names sound similar, they are very different in how they are made and how they behave.

1️⃣ Hydrated Fullerenes

What they are:

• Intact C60 molecules
  
  

• The C60 molecule is surrounded or encapsulated by a structured water layer
  
  

• Not chemically altered
  
  

How they’re made:

• C60 is dispersed into ultra-pure or distilled water
  
  

• No chemical groups are added to the carbon structure
  
  

• No solvents are required in the hydration stage
  
  

Key characteristics:

• The C60 molecule remains structurally unchanged
  
  

• Water interacts physically, not chemically
  
  

• Sometimes described as “C60 in structured water”
  
  

Important distinction:
The carbon cage remains pure and intact. Nothing is chemically attached to it.

2️⃣ Hydroxylated Fullerenes (Fullerenols)

Also known as:

• Fullerenols
  
  

• Polyhydroxylated C60
  
  

What they are:

• Chemically modified C60 molecules
  
  

• Hydroxyl groups (–OH) are attached directly to the carbon cage
  
  

How they’re made (general process):

• The C60 powder is typically dissolved in an organic solvent (often toluene in laboratory settings)
  
  

• Oxidizing agents such as hydrogen peroxide (H2O2) are used
  
  

• Hydroxyl (–OH) groups are chemically bonded to the carbon atoms
  
  

• Solvents are evaporated off after reaction
  
  

What happens chemically:

• The carbon structure is no longer “pure” C60
  
  

• The molecule now carries multiple hydroxyl groups
  
  

• Often 12–24+ OH groups may be attached
  
  

• This makes the molecule water-soluble
  
  

Key difference:
Fullerenols are no longer pristine C60 — they are chemically altered derivatives.

Hydrated vs. Hydroxylated — Side-by-Side

Why the Distinction Matters

When comparing fullerene products or research, it’s important to understand:

• Hydrated C60 refers to unmodified carbon 60 interacting with water.
  
  

• Fullerenols are a different chemical compound entirely.
  
  

• The presence of hydroxyl groups changes physical and chemical behavior.
  
  

• They should not be considered interchangeable forms.
  
  

In chemistry, even small modifications can dramatically change how a molecule behaves. Adding multiple hydroxyl groups transforms C60 into a new substance with different solubility, structure, and characteristics.