Abstract: The specification discloses quenchers of excited state energy, probes and other conjugates comprising the same, and methods for their use. The quenchers of excited state energy have a structure comprising at least one reactive functional group for linking the quencher to a carrier molecule and at least three radicals covalently linked via exocyclic diazo bonds, the at least three radicals including at least one comprising a julolidine of the nominal formula: and the remainder of the at least three radicals being selected from the group of substituted and unsubstituted aryls, substituted and unsubstituted heteroaryls, and combinations thereof.