The diatomic molecule tellurium monoxide has been found as a transient species.^[2] Previous work that claimed the existence of TeO solid has not been substantiated.^[3] The coating on DVDs called tellurium suboxide may be a mixture of tellurium dioxide and tellurium metal.^[4]

Tellurium monoxide was first reported in 1883 by E. Divers and M. Shimose.^[5] It was supposedly created by the thermal decomposition of tellurium sulfoxide in a vacuum,^{[citation needed]} and was shown to react with hydrogen chloride in a 1913 report.^[6] Later work has not substantiated the claim that this was a pure solid compound.^[2] By 1984, the company Panasonic was working on an erasable optical disk drive containing "tellurium monoxide" (really a mixture of Te and TeO₂).^[7]

• Tellurium dioxide
• Tellurium trioxide
• Lead carbide – originally thought to be a pure compound, but now considered more likely to be a mixture of carbon and lead
• Iodine pentabromide – originally thought to be a pure compound, but now considered to probably be a mixture of iodine monobromide and excess unreacted bromine