Novel conjugated silole‐containing polyfluorenes, with green‐ and red‐emissive siloles on the backbone of the blue‐emissive polyfluorene are synthesized for white light electroluminescence (EL) from a single polymer with simultaneous red, green, and blue (RGB) emission. The CIE coordinates (0.33, 0.36) of the white light EL spectra are very close to that for pure white light (0.33, 0.33). The EL spectra are also quite stable at different applied voltages or brightness. The relative intensities for the three RGB peaks, at 450, 505, and 574 nm, were 0.94, 1, and 0.97, respectively, which demonstrates a balanced simultaneous RGB emission. A maximum luminous efficiency of 2.03 cd · A−1 for a brightness of 344 cd · m−2, and a luminous efficiency of 1.86 cd · A−1 for a more practical brightness of 2 703 cd · m−2, were achieved.
Five new C19 diterpene alkaloids, leucanthumsines A ( 1 ), B ( 2 ), C ( 3 ), D ( 4 ), and E ( 5 ), were isolated from the Chinese medicinal herb Aconitum sungpanense var. leucanthum, together with the known C19 diterpene alkaloids pseudaconine, neoline, 1‐O‐methyldelphisine, crassicaudine, chasmanine, talatisamine, indaconitine, ezochansmanine, and leueantine D. The structures of these new alkaloids were elucidated by HR‐MS and advanced NMR methods, including 1H‐ and 13C‐NMR (DEPT), 1H,1H‐COSY, HMQC, and HMBC experiments. 相似文献
