| abstract |
Compounds of the following formula are disclosed: n nwherein R B is a substituted or unsubstituted aryl or heteroaryl moiety; at least one of R U and R L is a phosphorus-containing moiety, J, and the other of R U and R L is independently chosen from H; halogen; —CN; —NO 2 ; -J; —SO 2 R; —SO 2 NRR′; or —ZR J , wherein each occurrence of Z is independently —O—, —S— or —NR— and each occurrence of R J is independently —R, —COR, —COOR or —CONRR′. |