Diphenylcyanoarsine, also called Clark 2 (Chlor-Arsen-Kampfstoff 2, being the successor of Clark 1) by the Germans, was discovered in 1918 by Sturniolo and Bellinzoni and shortly thereafter used like the related diphenylchlorarsine "Clark 1" gas by the Germans for chemical warfare in the First World War.
The compounds of every Wikipedia article carrying a Chembox or a Drugbox, refreshed daily, with the values their infoboxes give. The pages need JavaScript; the API does not.