An agent comprising the compound according to general formula (I) wherein R1, R2, R3 and R4 are each independently H or a substituent, and wherein at least one of R1, R3 and R4 is halogen, cyano, cyanate, thiocyanate or C1-C6 haloalkyl.
一种包括符合一般式(I)的化合物的试剂,其中R1、R2、R3和R4分别独立地为H或取代基,且其中至少有一个是卤素、
氰基、
氰酸酯、
硫氰酸酯或C1-C6卤代烷基。