A compound of formula: wherein: R 1, R 2, R 3, R 4, and R 5 are each independently selected from the group consisting of hydrogen, deuterium or L-X-B, wherein at least one of R 1, R 2, R 3, R 4, or R 5 is L-X-B; wherein L is a linker which comprises a C 1-12 alkyl; X is O-PEG NH(CH 2) m O-PEG, or S(CH 2) m O-PEG; m is an integer from 1-10; wherein PEG is selected the group of mPEG (methoxy polyethylene glycol), linear PEG, branched PEG, multi-arm PEG, and PEG-lipid, wherein the PEG has a molecular weight from 40 to 1,200 daltons; B is selected from the group consisting of hydrogen, deuterium, a substituted or unsubstituted C 1 to C 6 alkyl, a substituted or unsubstituted C 1 to C 6 alkenyl, a substituted or unsubstituted C 1 to C 6 alkynyl, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroaryl, or deuterated versions thereof; and A is selected from the group consisting of hydrogen, deuterium, halogen, CF 3, CD 3, CN, OH, OCH 3, OR", SR", NR"R", NR"COR", NR"CONR"R", NR"CO 2 R", COR", CO 2 R", NOR", NO 2, CONR"R", OC NR"R", SO 2 R", SO 2 NR"R", NR"SO 2 R", NR"SO 2 NR"R", C C R", and C CH 2 C R", a substituted or unsubstituted C 1 to C 6 alkyl, a substituted or unsubstituted C 1 to C 6 alkenyl, a substituted or unsubstituted C 1 to C 6 alkynyl, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroaryl; and R" may be independently selected from the group consisting of hydrogen, substituted C 1 -C 4 aliphatic moiety, aliphatic moiety containing nitrogen, oxygen, or sulfur, or alternately, two R" moieties bound to the same nitrogen atom are optionally taken together with the nitrogen atom to form a 3-7 membered saturated or unsaturated ring having 1-2 additional heteroatoms independently selected from the group consisting of nitrogen, oxygen, or sulfur; and wherein the term "substituted" means that one or more of the hydrogen atoms bonded to carbon atoms in the chain or ring have been replaced with substituents selected from alkyl groups and alkoxy groups. R 1, R 2, R 3, R 4, and R 5 are each independently selected from the group consisting of hydrogen, deuterium or L-X-B, wherein at least one of R 1, R 2, R 3, R 4, or R 5 is L-X-B; wherein L is a linker which comprises a C 1-12 alkyl; X is O-PEG NH(CH 2) m O-PEG, or S(CH 2) m O-PEG; m is an integer from 1-10; wherein PEG is selected the group of mPEG (methoxy polyethylene glycol), linear PEG, branched PEG, multi-arm PEG, and PEG-lipid, wherein the PEG has a molecular weight from 40 to 1,200 daltons; B is selected from the group consisting of hydrogen, deuterium, a substituted or unsubstituted C 1 to C 6 alkyl, a substituted or unsubstituted C 1 to C 6 alkenyl, a substituted or unsubstituted C 1 to C 6 alkynyl, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroaryl, or deuterated versions thereof; and A is selected from the group consisting of hydrogen, deuterium, halogen, CF 3, CD 3, CN, OH, OCH 3, OR", SR", NR"R", NR"COR", NR"CONR"R", NR"CO 2 R", COR", CO 2 R", NOR", NO 2, CONR"R", OC NR"R", SO 2 R", SO 2 NR"R", NR"SO 2 R", NR"SO 2 NR"R", C C R", and C CH 2 C R", a substituted or unsubstituted C 1 to C 6 alkyl, a substituted or unsubstituted C 1 to C 6 alkenyl, a substituted or unsubstituted C 1 to C 6 alkynyl, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroaryl; and R" may be independently selected from the group consisting of hydrogen, substituted C 1 -C 4 aliphatic moiety, aliphatic moiety containing nitrogen, oxygen, or sulfur, or alternately, two R" moieties bound to the same nitrogen atom are optionally taken together with the nitrogen atom to form a 3-7 membered saturated or unsaturated ring having 1-2 additional heteroatoms independently selected from the group consisting of nitrogen, oxygen, or sulfur; and wherein the term "substituted" means that one or more of the hydrogen atoms bonded to carbon atoms in the chain or ring have been replaced with substituents selected from alkyl groups and alkoxy groups.