Provided are chlorin derivatives with narrow band emission. In some embodiments, the bacteriochlorin derivatives are PEGylated. In some embodiments, the chlorin derivatives have high water solubility (e.g., 10 mg/mL or more). In some embodiments, the chlorin derivatives are PEGylated and have high water solubility. The chlorin derivatives can include bioconjugatable groups for forming conjugates, for example, with antibodies and nanoparticles. The chlorin derivatives and their conjugates can be used in imaging and therapeutic applications. Methods of synthesizing the chlorin derivatives are also provided.