“…Luminol anion binds to Tl(OH) 2 þ , which is the predominant Tl(III) species at neutral pH. Supporting that, it has been reported that Tl(III) coordinates with N-containing compounds such as heme [23,24], iminophenolate [25], and a triamino-derivative of inositol [7], among others. In all these cases the average distance between Tl(III) and N atoms (2.1-2.7 Å) confers this interaction a covalent rather than ionic character.…”