What Is Oxide?
The term “oxide” broadly refers to compounds composed of oxygen and elements with smaller electronegativity. More specifically, it encompasses a range of compounds, both organic and inorganic, where oxygen atoms are bonded to other elements.
In a narrower sense, when referring to organic compounds, an oxide can be:
- A cyclic ether consisting of two carbon (C) atoms bonded to an oxygen (O) atom, forming a molecule. These cyclic ethers are known as epoxides, with examples including:
- C2 three-membered ring compound ethylene oxide (oxirane)
- C3 four-membered ring compound trimethylene oxide (oxetane)
- C4 five-membered ring compound tetrahydrofuran (THF, tetramethylene oxide)
- C5 six-membered ring compound tetrahydropyran (THP, pentamethylene oxide)
- Organic compounds where heteroatoms (atoms other than carbon and hydrogen) in the molecule are coordination-bonded to oxygen atoms. Examples include pyridine-N-oxide (C5H5N→O or Py→O) and triphenylphosphine oxide (Ph3P→O).
Uses of Oxide
In the narrow sense, oxides, particularly epoxides, are known for their high reactivity due to high distortion energy, making them valuable in various chemical applications. They are used as raw materials in organic synthesis for polymers, pharmaceuticals, and fine chemicals. Epoxy resins, for instance, are made by polycondensation of compounds with two or more epoxy groups and are primarily used in adhesives.
Propylene oxide, a type of epoxide, is utilized as a synthetic raw material for polyurethane. Ethylene oxide is used in synthesizing ethylene glycol and as a sterilizer for medical equipment and instruments.
Pyridine-N-oxide serves as an oxidizing agent in organic synthesis and can be used as a ligand in complex chemistry. Triphenylphosphine oxide finds applications as a ligand for hard metals, a raw material for flame retardants, and as a catalyst in organic synthesis reactions.