Described herin are molecules for use in organic light emitting diodes. Example molecules comprise at least one acceptor moiety A, at least one donor moiety D, and optionally one or more bridge moieties B. Each moiety A is covalently attached to either the moiety B or the moeity D, each moiety D is covalently attached to either the moeity B or the moeity A, and each B is covalently attached to at least one moiety A and at least one moiety D. Values and preferred values of moieties A, D and B are defined herein.