# Kyoto2.org

Tricks and tips for everyone

# What is the index of hydrogen deficiency of the product?

## What is the index of hydrogen deficiency of the product?

Table of Contents

By calculating the index of hydrogen deficiency (IHD), we can tell from the molecular formula whether and how many multiple bonds and rings are involved. IHD is also called the Degree of Unstaturation.

## What does an IHD of 6 mean?

It means the the number of [rings + multiple bonds] is equal to 6. That means it could have 6 rings and no double bonds, 5 rings and one multiple bond…. all the way to zero rings and six multiple bonds.

What is HDI in NMR?

The degree of unsaturation or HDI is the capacity of the molecule to connect more hydrogen atoms. The capacity is reached when the molecule has the maximum possible number of hydrogen atoms per carbon (and other atoms).

What does an HDI of 1 mean?

So, a double bond or ring (HDI = 1) means a deficiency of 2 H atoms. That’s where the factor of ½ in the formula comes from. 2C+2 is the number of hydrogen atoms in the saturated alkane. So, 2C is the number of bonds that each carbon forms to other atoms (i.e., 2 bonds per carbon atom).

### What does a IHD of 4 mean?

If you have done it correctly, you will find that IHD = 4, which means a total of 4 rings and/or pi bonds. Any rings may or may not contain the N or O, and pi bonds may be between two carbons (C=C, CC), carbon and oxygen (C=O), carbon and nitrogen (C=N, CN), two nitrogens (N=N), or nitrogen and oxygen (N=O).

### How do you find DU in chemistry?

Calculating The Degree of Unsaturation (DU) [2C+2=(2×3)+2=8.] The compound needs 4 more hydrogens in order to be fully saturated (expected number of hydrogens-observed number of hydrogens=8-4=4). Degrees of unsaturation is equal to 2, or half the number of hydrogens the molecule needs to be classified as saturated.

What is the index of hydrogen deficiency or degree of unsaturation of the following?

Therefore, the essential meaning of degree of unsaturation is the “number of rings plus π bonds” in a structure….2.5 Degree of Unsaturation/Index of Hydrogen Deficiency.

Formula Degree of Unsaturation/ Index of Hydrogen Deficiency (IHD)* Structure Unit Involved
CnH2n 1 1 double bond or 1 ring