7-Methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (mTBD) is a bicyclic strong guanidine base (pK<sub>a</sub> = 25.43 in CH<sub>3</sub>CN and pK<sub>a</sub> = 17.9 in THF). mTBD, like 1,5,7-triazabicyclo[4.4.0]dec-5-ene and other guanidine super bases, can be used as a catalyst in a variety of chemical reactions. It also reacts with CO<sub>2</sub>, which could make it useful for carbon capture and storage.
When brought into contact with some acids, mTBD reacts to form an ionic liquid. Some of these ionic liquids can dissolve cellulose.