Abstract: Compounds for tumor imaging (e g , magnetic resonance (MR) and fluorescence) that may be used in combination with other methods to treat an individual having or suspected of having cancer (e.g., various forms of cancer, such as, for example, solid tumors). Compounds may have the following structure: (I) or a salt, a partial salt, a hydrate, a polymorph, an isomer (e.g., a structural or stereoisomer), or a mixture thereof, where R? is an aryl group or heteroaryl group having a halogen group (e.g., I or 124I), X is chosen from O, S, or NH, n is 1-6 (e.g., 1, 2, 3, 4, 5, or 6), the dotted carbon is chiral and is R or S.