Photochromic and electrochromic hexadiene compounds that are reversibly convertible between ring-open and ring-closed isomeric forms. The conversion between the different isomeric forms may be induced by light or electricity. The compounds may include a charge transfer moiety including electron donor and acceptor groups. The electron donor and acceptor are linearly conjugated in the ring-open form to enable electron transfer but are electrically insulated in the ring-closed form. Photoresponsive compounds may be synthesized by any of several methods disclosed, e.g., by reacting diene precursors with dienophiles in a condensation reaction. The compounds may be utilized in reactivity-gated photochromic or electrochromic applications. Compounds may be used in a method to selectively release a releasable agent, such as a small molecule.