The syntheses of benzoxaphospholes and new benzobisoxaphospholes that display blue fluorescence are presented. The latter compounds were accessed by the use of a new precursor, 2,5-diphosphinohydroquinone. The new compounds were fully characterized, including a structural study of 2,6-tert-butylbenzo[1,2-d;4,5-d']bisoxaphosphole. Quantum yields for photoluminescence were determined for a series of compounds. These materials feature bona fide P horizontal lineC p-p pi bonds suitable for conjugated materials having phosphorus as a participatory atom and can thus "photocopy" the properties of other conjugated organic molecules.

Seven new fluorescent 2-R-naphtho[2,3-d]oxaphospholes (R-NOPs) (4a–g; R = tBu (a), Ad (b), C(6)H(5) (c), 4-MeC(6)H(4) (d), 4-ClC(6)H(4) (e), 4-BrC(6)H(4) (f ), 4-MeOC(6)H(4) (g)), have been synthesized by cyclocondensation reactions of benzimidoyl chlorides with 3-phosphino-2-naphthol (3). The compounds were characterized by multinuclear NMR, UV-vis, and fluorescence spectroscopy. Compounds 4a–d and 4g were characterized by cyclic voltammetry experiments. The solid state structures of compounds 4b and 4d were also determined by single-crystal X-ray diffraction experiments.

An air-stable primary phosphine, 2,6-diphosphinonaphthalene-1,5-diol (4), has been synthesized and structurally characterized. A series of π-conjugated heteroacenes containing two phosphaalkene (PC) units, 2,7-R 2 -naphtho[1,2-d:5,6-d′]bi-(soxaphosphole)s [R 2 -NBOP, R = t Bu (5a), Ad (5b), and Ph (5c)], have been synthesized from reactions of 4 and benzimidoyl chlorides. These novel fluorescent analogues of organic acenes were characterized by multinuclear NMR, UV−vis, and fluorescence spectroscopy, cyclic voltammetry, and single-crystal X-ray diffraction experiments.