Peter Sebej, Jürgen Wintner, Pavel Müller, Tomas Slanina, Jamaludin Al Anshori, Lovely Angel Panamparambil Antony, Petr Klan, and Jakob Wirz, "Fluorescein Analogues as Photoremovable Protecting Groups Absorbing at 520 nm", J. Org. Chem., 2013, 78, 1833.
Abstract: A new photoremovable protecting group, (6-hydroxy-3-oxo-3H-xanthen-9-yl)methyl (1), with a molar absorption
coefficient eps of 4 x 10E4 M-1 cm-1 at 520 nm for the release of carboxylates or phosphates is reported. Three derivatives of 1
(diethyl phosphate, acetate, and bromide) were isolated as complexes with DDQ and shown to release the ligands with quantum
yields <2.4% in aqueous solution.