A compound having a structure represented by formula (I) wherein Hal is Cl or Br; R 1 is R 2 is H, C 1 -C 3 alkyl, CO 2 H, CO 2 (C 1 -C 3 alkyl), C(=O)NH 2 , C(=ONH(C 1- C 3 alkyl), or C(=O)N(C 1 -C 3 alkyl) 2 ; R 3 is R 4 , R 4 ', R 5 , R 6 , or R 7 are independently H, OMe, OH, a 6-membered aryl group, a 5- or 6-membered heteroaryl group, NH 2 , NHMe, NMe 2 , NH(C 2 -C 4 alkyl), N(C 2 -C 4 alkyl) 2 , NHC(=O)X 1 , O(C 2 -C 4 alkyl), O(CH 2 ) 0-2 (C 3 -C 6 cycloalkyl), O(CH 2 ) 0-2 X 1 , or wherein a C 2 -C 4 alkyl group may unsubstituted or substituted with OCH 2 CH 2 OH, OCH 2 CH 2 NH 2 , NHCH 2 CH 2 OH, NHCH 2 CH 2 NH 2 , OH, or NH 2 and an aryl or heteroaryl group may be substituted with C 1 -C 2 alkyl, OH, NH 2 , NH(C 1 -C 2 alkyl), N(C 1 -C 2 alkyl) 2 , F, Cl, Br, NO 2 , or CN; with the proviso that at least one of R 4 , R 4' , R 5 , R 6 , and R 7 is other than H; R 8 and R 8' are independently H, OH, O(C 1 -C 3 alkyl), Cl, Br, F, O(CH 2 ) 2-4 NH 2 , or O(CH 2 ) 2-4 OH; R 9 is H, C(=O)(C 1 -C 3 alkyl), C(=O)NH(C 1 -C 3 alkyl), C(=O)( C 1 -C 3 alkyl) 2 , (CH 2 ) 2-4 OH, (CH 2 ) 2-4 O(C 1 -C 3 alkyl), (CH 2 ) 2-4 NH 2 , (CH 2 ) 2-4 NH(C 1 -C 3 alkyl), or (CH 2 ) 2-4 N(C 1 -C 3 alkyl)2; each X 1 is independently a 6-membered aryl or 5- to 6-membered heteroaryl group that is unsubstituted or substituted with C 1 -C 3 alkyl, OH, O(C 1 -C 3 alkyl), NH 2 , NH(C 1 -C 3 alkyl), N(C 1 -C 3 alkyl) 2 , F, Cl, Br, NO 2 , or CN; each X 2 is independently H, Me, or a C 2 -C 4 alkyl group that may be unsubstituted or substituted with OCH 2 CH 2 OH, OCH 2 CH 2 NH 2 , NHCH 2 CH 2 OH, NHCH 2 CH 2 NH 2 , OH, or NH 2 ; and each X 3 is independently O, NH, N(C 1 -C 3 alkyl), or S; or a pharmaceutically acceptable salt thereof. wherein Hal is Cl or Br; R 1 is R 2 is H, C 1 -C 3 alkyl, CO 2 H, CO 2 (C 1 -C 3 alkyl), C(=O)NH 2 , C(=ONH(C 1- C 3 alkyl), or C(=O)N(C 1 -C 3 alkyl) 2 ; R 3 is R 4 , R 4 ', R 5 , R 6 , or R 7 are independently H, OMe, OH, a 6-membered aryl group, a 5- or 6-membered heteroaryl group, NH 2 , NHMe, NMe 2 , NH(C 2 -C 4 alkyl), N(C 2 -C 4 alkyl) 2 , NHC(=O)X 1 , O(C 2 -C 4 alkyl), O(CH 2 ) 0-2 (C 3 -C 6 cycloalkyl), O(CH 2 ) 0-2 X 1 , or wherein a C 2 -C 4 alkyl group may unsubstituted or substituted with OCH 2 CH 2 OH, OCH 2 CH 2 NH 2 , NHCH 2 CH 2 OH, NHCH 2 CH 2 NH 2 , OH, or NH 2 and an aryl or heteroaryl group may be substituted with C 1 -C 2 alkyl, OH, NH 2 , NH(C 1 -C 2 alkyl), N(C 1 -C 2 alkyl) 2 , F, Cl, Br, NO 2 , or CN; with the proviso that at least one of R 4 , R 4' , R 5 , R 6 , and R 7 is other than H; wherein a C 2 -C 4 alkyl group may unsubstituted or substituted with OCH 2 CH 2 OH, OCH 2 CH 2 NH 2 , NHCH 2 CH 2 OH, NHCH 2 CH 2 NH 2 , OH, or NH 2 and an aryl or heteroaryl group may be substituted with C 1 -C 2 alkyl, OH, NH 2 , NH(C 1 -C 2 alkyl), N(C 1 -C 2 alkyl) 2 , F, Cl, Br, NO 2 , or CN; with the proviso that at least one of R 4 , R 4' , R 5 , R 6 , and R 7 is other than H; R 8 and R 8' are independently H, OH, O(C 1 -C 3 alkyl), Cl, Br, F, O(CH 2 ) 2-4 NH 2 , or O(CH 2 ) 2-4 OH; R 9 is H, C(=O)(C 1 -C 3 alkyl), C(=O)NH(C 1 -C 3 alkyl), C(=O)( C 1 -C 3 alkyl) 2 , (CH 2 ) 2-4 OH, (CH 2 ) 2-4 O(C 1 -C 3 alkyl), (CH 2 ) 2-4 NH 2 , (CH 2 ) 2-4 NH(C 1 -C 3 alkyl), or (CH 2 ) 2-4 N(C 1 -C 3 alkyl)2; each X 1 is independently a 6-membered aryl or 5- to 6-membered heteroaryl group that is unsubstituted or substituted with C 1 -C 3 alkyl, OH, O(C 1 -C 3 alkyl), NH 2 , NH(C 1 -C 3 alkyl), N(C 1 -C 3 alkyl) 2 , F, Cl, Br, NO 2 , or CN; each X 2 is independently H, Me, or a C 2 -C 4 alkyl group that may be unsubstituted or substituted with OCH 2 CH 2 OH, OCH 2 CH 2 NH 2 , NHCH 2 CH 2 OH, NHCH 2 CH 2 NH 2 , OH, or NH 2 ; and each X 3 is independently O, NH, N(C 1 -C 3 alkyl), or S; or a pharmaceutically acceptable salt thereof. <EOS>