Purify it via the HgCl2 addition compound formed when phenanthridine (20g) in 1:1 HCl (100mL) is added to aqueous HgCl2 (60g in 3L), and the mixture is heated to boiling. The HgCl2 complex separates as yellow red crystals with m 195-198o [Arcus & Mesley J Chem Soc 1780 1953]. Conc HCl is then added until all of the solid has dissolved. The compound separates on cooling and is decomposed with aqueous NaOH (ca 5M). Phenanthridine is extracted into Et2O, evaporated, and the residue is crystallised from pet ether (b 80-100o) or EtOAc. [Cumper et al. J Chem Soc 45218 1962.] It is also purified by chromatography on activated alumina from *benzene solution, with diethyl ether as eluent. Evaporation of ether gives crystalline material which is freed from residual solvent under vacuum, then further purified by fractional crystallisation, under N2, from its melt. It was purified by zone melting and sublimes in a vacuum. The picrate has m 218.5-219.5o (from iso-PrOH) (also reported are m 244-245o and 247-248o, from EtOH or H2O). [Slough & Ubbelhode J Chem Soc 911 1957.] [Beilstein 20 H 466, 20 III/IV 4016, 20/8 V 223.]
A ligand employed in the spectrophotometric determination of metals and photocatalytic reduction of carbon dioxide.
As an analytical reagent for determination of metals in chemical and biological systems through complex formation. As an indicator ("Ferroin") in combination with ferrous ions for oxidation/reduction reactions. In organic syntheses as an activator.
A chelating agent, forming complexes with most metal ions.