Abstract The mass spectral. behavior of 1, 6-bis (arylsulfenyl)-2, 4-hexadiynes and 1, 6-bis (arylsulfonyl)-2, 4-hexadiynes were examined. The sulfenyl derivatives extruded the hexadiynyl moiety with the formation of Ar [BOND] S [BOND] S [BOND] Ar fragments. The sulfonyl derivatives, on the other hand, showed no extrusion of the hexadiyne fragment but an expulsion of SO 2 and even two SO 2 units.