The key difference between oxirane glycidyl and epoxy groups is their reactivity. Oxirane is a chemical compound that is less reactive while the glycidyl group is a functional group that is reactive and an epoxy group is a functional group that is comparatively more reactive.
The term oxirane is used by the IUPAC to refer to the ethylene oxide compound. Glycidyl group and epoxy group are functional groups of oxirane, which can be recognized as derivatives of ethylene oxide or oxirane.
What is Oxirane?
Oxirane or ethylene oxide is an organic compound having the chemical formula C2H4O. This compound can be observed as a cyclic structure, which can be classified as an ether. It is also the simplest epoxide compound. The structure of oxirane can be described as a three-membered carbon ring containing one oxygen atom along with two carbon atoms. Here, each carbon atom is bonded to two hydrogen atoms.
Ethylene oxide is a colourless and flammable gas at room temperature. It has a faintly sweet odour. However, due to the very low number of atoms in the cyclic structure, this compound has a highly strained ring, which makes it easier to participate in various chemical reactions, mainly addition reactions. These addition reactions cause the ring-opening of this molecule. Industrially, this compound is produced through the oxidation reaction of ethylene in the presence of a silver catalyst.
When considering the chemical structure of oxirane, there is an epoxy cycle that is an almost regular triangle with a bond angle of about 60 degrees. In this molecule, carbon-oxygen bonds (C-O) are relatively unstable. This instability correlates with the high reactivity of oxirane.
What is a Glycidyl Group?
Glycidyl group is a functional group having an epoxy group attached to a methyl group. The reactivity of this functional group is at the carbon atom of the methyl group; one hydrogen atom is eliminated from the methyl group, forming a vacant point for another chemical moiety. The chemical formula for this functional group is C3H5O-. The chemical name for this functional group is oxiran-1-ylmethyl group.
What is an Epoxy Group?
Epoxy group is a functional group having a cyclic structure with the chemical formula C2H3O-. In this functional group, there is an oxygen atom joined to two carbon atoms through single covalent bonds (sigma bonds) forming a three-membered epoxide ring. This chemical moiety is the functional group of epoxides. The IUPAC chemical name of this group is oxiranyl group.
What is the Difference Between Oxirane Glycidyl and Epoxy Groups?
We can distinguish oxiran, glycidyl group and epoxy group based on their chemical reactivity. The key difference between oxirane glycidyl and epoxy groups is that oxirane is a chemical compound that is less reactive and a glycidyl group is a functional group that is reactive whereas an epoxy group is a functional group that is more reactive comparatively.
The below infographic lists more differences between oxirane glycidyl and epoxy groups in tabular form.
Summary – Oxirane vs Glycidyl vs Epoxy Groups
We can distinguish the oxirane, glycidyl group and epoxy group based on their chemical reactivity. The term oxirane refers to ethylene oxide, as per the definition of IUPAC. The key difference between oxirane glycidyl and epoxy groups is that oxirane is a chemical compound that is less reactive and a glycidyl group is a functional group that is reactive whereas an epoxy group is a functional group that is more reactive comparatively.
1. “Ethylene Oxide.” Pubchem, Available here.
1. “Ethylene oxide” By Cwbm – Own work (Public Domain) via Commons Wikimedia