主权项 |
1. A compound of the general formula Id or the general formula Ie: wherein: R1, R2 and R3 are independently selected from the group consisting of C1-C5 alkyl, —OH, —SH, halogen, alkoxy, NO2, and —CN; m is 0, 1, 2, 3, 4 or 5; n is 0, 1, 2 or 3; and p is 0, 1, 2, 3 or 4. |