Complexation of Hg(II)with Iodide and Ammonia in Alkaline Solutions

摘要

Reactions of K_2HgI_4 with NaOH and NH_3 are studied.A poorly soluble compound with the composition NHHg_2IOH and colored soluble polymeric complexes containing nitride nitrogen,formed in complex autocatalytic reactions,are characterized.It is well known that,in neutral or weakly alkaline solutions,Hg(II)reacts with ammonia to form ordinary ammine complexes,and in strongly alkaline solutions,particularly,in the presence of iodide or other halides,to form insoluble or soluble complexes containing ammonia in an anionic (amide,imide,or nitride)form [1].Such compounds are formed,e.g.,by the reaction of ammonia with dipotassium tetra-iodomercurate(II)(its mixture with KOH or NaOH known as Nessler's reagent is widely used in ammonium analysis)[2-5].