thioformaldehyde

chemical compound

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 14, 2026

Quick Summary

Thioformaldehyde (CH₂=S) is an extremely reactive organosulfur compound that cannot be isolated under normal conditions. It is analogous to formaldehyde but with sulfur replacing oxygen in the thiocarbonyl group (–C=S–). While unstable, thioformaldehyde can exist in low concentrations in the gas phase and has been detected in interstellar space by radio astronomers. It is formed when certain small organosulfur compounds are heated to very high temperatures. Formaldehydesulfoxylic acid (HOCH₂SO₂H) is an unstable acid known only through its salts, which act as strong reducing agents.12

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

organosulfur compound
Thiocarbonyl compounds
The parent thiocarbonyl compound, thioformaldehyde (CH₂=S), is extremely reactive and cannot be isolated. However, it is very stable in the gas phase in low concentrations and is formed when various small organosulfur compounds are heated to extremely high temperatures. Thioformaldehyde has been detected in interstellar space by radio astronomers.
Read More
The parent thiocarbonyl compound, thioformaldehyde (CH₂=S), is extremely reactive and cannot be isolated. However, it is very stable in the gas phase in low concentrations and is formed when various small organosulfur compounds are heated to extremely high temperatures. Thioformaldehyde has been detected in interstellar space by radio astronomers.
Read More