The key difference between hydrogen bond donor and acceptor is that hydrogen bond donor contains the hydrogen atom which participates in the hydrogen bond formation whereas hydrogen bond acceptor contains lone electron pairs.
A hydrogen bond is a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other. These two compounds which participate in the hydrogen bond formation are called hydrogen bond donor and acceptor.
CONTENTS
1. Overview and Key Difference
2. What is Hydrogen Bond Donor
3. What is Hydrogen Bond Acceptor
4. Side by Side Comparison – Hydrogen Bond Donor vs Acceptor in Tabular Form
5. Summary
What is Hydrogen Bond Donor?
Hydrogen bond donor is the chemical compound which contains protons to be donated. Here, protons are hydrogen atoms. The hydrogen bond donor should contain these hydrogen atoms covalently bound to itself. For example, water has two hydrogen atoms attached to the oxygen atom directly via covalent chemical bonds. Therefore, it can form hydrogen bonds with other molecules.
Figure 01: Hydrogen Bonds Between Water Molecules
Although aldehydes and ketones contain hydrogen atoms, they do not have hydrogen atoms directly bound to the oxygen atoms. Therefore, they are not hydrogen bond donors.
What is Hydrogen Bond Acceptor?
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. This compound should contain a more electronegative atom (more electronegative than hydrogen) with lone electron pairs. Then it can attract protons from a donor. Moreover, the electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine.
What is the Difference Between Hydrogen Bond Donor and Acceptor?
A hydrogen bond forms between a hydrogen donor and acceptor. The key difference between hydrogen bond donor and acceptor is that hydrogen bond donor contains the hydrogen atom which participates in the hydrogen bond formation whereas hydrogen bond acceptor contains lone electron pairs. Another difference between hydrogen bond donor and acceptor is that hydrogen bond donor must contain hydrogen atoms directly bound to the compound via covalent bonds while hydrogen bond acceptor must contain a more electronegative atom such as oxygen, nitrogen and fluorine, which contain lone electron pairs.
Summary – Hydrogen Bond Donor vs Acceptor
Basically, a hydrogen bond is a bond that forms between a hydrogen donor and acceptor. The key difference between hydrogen bond donor and acceptor is that hydrogen bond donor contains the hydrogen atom which participates in the hydrogen bond formation whereas hydrogen bond acceptor contains lone electron pairs.
Reference:
1. “Hydrogen Bonding.” Chemistry LibreTexts, Libretexts, 5 June 2019, Available here.
Image Courtesy:
1. “210 Hydrogen Bonds Between Water Molecules-01” By OpenStax College – Anatomy & Physiology, Connexions Web site. Jun 19, 2013 (CC BY 3.0) via Commons Wikimedia