Károly Antal Than de Apát – also called as Carl von Than – (20 December 1834 – 5 July 1908) was a Hungarian chemist who discovered carbonyl sulfide in 1867.

AKároly Than was born in Óbecse, Kingdom of Hungary, Austrian Empire (today Bečej, Serbia).

[1][2][3] The University of Budapest was in need of Hungarian-speaking professors due to a change from German to Hungarian teaching language in 1860.

Theodor Wertheim changed to the University of Graz and Than was offered the vacant position which he occupied until his retirement in 1908.

The reaction of potassium thiocyanate and sulfuric acid yielded a gas containing significant amount of byproducts (HCN, H2O and CS2) and required purification.