Patent ID: 8580845

Claim:
A compound having the formula: wherein each R 1 is, independent of the others, hydrogen, a substituted or unsubstituted alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, or aryl; and wherein each L is, independent of the other, alkyl oxycarbonyl, carboxy or salt thereof, halocarbonyl, alkyl thiocarbonyl, hydroxy, amino, substituted amino, carbamoyl, substituted carbamoyl, azido, isocyano, thioisocyanato, sulfanyl, disulfanyl, halide, alkoxy, substituted alkoxy, acylamino, alkenyl, alkynyl, or anhydride group, wherein each L is attached to the compound directly or wherein each L is attached to the compound by a spacer of from 1-20 atoms in length.