Disclosed herein are conjugates that include a ligand, and a compound having the structure of formula (I) M is Pt, Pd or Ni; Q is As, Sb or Bi; Z1 is N; Z2 is O or S; L1 and L2 are independently C(O), C—R1 or C—R2; X is a Lewis base; Y1 and Y2 are independently selected from —OR3, —OR4, —SR3 and —SR4, wherein R1 and R2 are independently selected from hydrogen, halogen, cyano, keto, ester, ether, thiol, thioether, thioester, imino, C1-C10 alkyl, C1-C10 alkenyl, alkynyl, alkoxyl, amino, amidyl, immino, sulfonyl, sulfoxyl, phosphoryl, phosphoryl ester, glycosyl, aryl, C3-C15 cycloalkyl, heteroaryl, and C3-C15 heterocycloalkyl; and R3 and R4 are independently selected from hydrogen, C1-C10 alkyl, C1-C10 alkenyl, alkynyl, alkoxyl, amino, amidyl, immino, sulfonyl, sulfoxyl, phosphoryl, phosphoryl ester, glycosyl, aryl, C3-C15 cycloalkyl, heteroaryl, and C3-C15 heterocycloalkyl.