1. Electron paramagnetic resonance of 9,9'-dianthrylmethylene. Linear aromatic ground-state triplet methylene
2. The unusual reactivity of 9,9'-dianthrylcarbene
3. 1a: orange solid; mp 122−126 °C (dec);1H NMR (CDCl3) δ 6.91 (dd,J= 7.3, 1.2 Hz, 2 H), 7.03−7.09 (m, 1 H), 7.25−7.41 (m, 1 H), 7.46−7.52 (m, 4 H), 7.56−7.61 (m, 3 H), 7.73 (dd,J= 8.6, 1.0 Hz, 2 H), 8.14 (dd,J= 8.8, 0.9 Hz, 2 H); IR (KBr) ν 2032 cm-1.1b: orange crystal; mp 142−146 °C (dec);1H NMR (CDCl3) δ 2.17 (s, 6 H), 2.33 (s, 3 H), 6.97 (s, 2 H), 7.29−7.35 (m, 2 H), 7.40−7.46 (m, 4 H), 7.53−7.61 (m, 3 H), 7.67 (d,J= 8.6 Hz, 2 H), 8.06 (d,J= 8.8 Hz, 2 H); IR (KBr) ν 2032 cm-1.1c: orange solid; mp 150−153 °C (dec);1H NMR (CDCl3) δ 1.12−1.19 (m, 4 H), 1.35−1.50 (m, 4 H), 1.52−1.56 (m, 4 H), 1.65−1.73 (m, 4 H), 2.97 (bs, 2 H), 3.15 (bs, 2 H), 6.99 (s, 1 H), 7.29−7.45 (m, 6 H), 7.53−7.59 (m, 3 H), 7.69 (d,J= 8.3 Hz, 2 H), 8.16 (d,J= 8.8 Hz, 2 H); IR (KBr) ν 2032 cm-1.