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[32](1,4)Naphthalenophanes, bearing carbon-bridge chains (syn- and anti-NPs) and nitrogen-bridge chains (syn- and anti-ANPs), were synthesized, and their X-ray structures and photoreactions were investigated. The intramolecular separation distance between the naphthalene cores for ANPs was shorter than that for NPs, suggesting that intramolecular interactions between the naphthalene rings were more efficient for ANPs compared to NPs. Upon photoirradiation at 300 nm, anti-NP, syn-ANP and anti-ANP produced the corresponding intramolecular [π4s + π4s] cycloadducts, whereas syn-NP gave an unidentified complex product mixture. Quantum yields for the photo-consumption (ΦPC) of NPs and ANPs were evaluated to quantitatively compare their photoreactivity. The ΦPC values of ANPs were approximately two-fold higher than those of ANPs.Noteworthily, the ΦPC value of syn-ANP was estimated to be unity. Based on these results we discuss the effects of the alignments of the naphthalene cores (antivs. syn) and the bridging elements (C-bridge vs. N-bridge) on the photoreaction efficiencies of [32](1,4)naphthalenophanes. [ABSTRACT FROM AUTHOR]

We prepared amide-heterocycle (HC) compounds having various aromatic π-electron systems (Ar), such as phenyl, naphthyl, furyl, thienyl and phenanthryl moieties, and converted them as ligands to difluoroboronated complexes, Ar@HCs. Blue fluorescence from Ar@HCs was observed in solution and the solid state, and the fluorescence quantum yields (Φf) and lifetimes (τf) were determined. The Φf values in CHCl3 were as small as 0.1 except for the phenanthrene derivatives (0.4–0.6). Observation of the triplet–triplet absorption upon laser flash photolysis of Ar@HCs in solution indicated that the fluorescence process competes with intersystem crossing to the triplet state. Blue fluorescence in the solid state was observed with the Φf values of 0.3–0.7. Based on the crystallographic data, the relationship between the crystal structures and emission features of Ar@HCs in the solid state is discussed. [ABSTRACT FROM AUTHOR]