e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
1-Naphthyltropylium ions having condensed aromatic rings at the 8-position: dependence of the intramolecular charge-transfer interaction upon geometry of the donor
R Tsuji, K Komatsu, Y Inoue…
Index: Journal of Organic Chemistry, , vol. 57, # 2 p. 636 - 641