The Complexes of Triphosphate Ion with Alkali Metal Ions¹

Anion Coordination Chemistry: Polyguanidinium Salts as Anion Complexones

“…Ionic strength 0.2M ((nPr)4NC1, 25") [30]. Ionic strength 0.2M ((nPr)4NCI, 25") [37]. Ionic strength 0 .…”

“…This restriction is of importance with respect to the complexation of PO:-(and other basic anions). Neither the polyammonium salts investigated, nor alkaline-earth cations can be presumed to form complexes in solution with this anion; the former are not sufficiently protonated while the latter form insoluble precipitates [27] [36] [37] in basic solutions. Since the degree of protonation of (hence the complexation of anions by) polyguanidinium salts is independent of pH, they are more generally applicable as anion complexones than polyammonium salts.…”

Metal Complexing By Phosphates

“…The problem here of how to apply the Law of Mass Action in computing a dissociation constant for a long-chain polyelectrolyte will be more fully considered later in this paper. The same general method has been used recently (60,126) to study the pyroand tripolyphosphate complexes with the alkali metals. Since these chain phosphates are small, the usual mass action calculations were employed.…”

“…The observed changes in pH are closely tied in with precipitate formation but are not directly interpretable in terms of the formation of soluble complex ions. The technique of interpreting pH titrations on the assumption that the quaternary ammonium ion is essentially uncomplexed, as used by Van Wazer (118) and Watters (60,126), has also been applied to the adenosine phosphates. Smith and Alberty investigated complexing of the ions of the alkali (101) and alkaline earth (100) metals in considerable detail.…”

“…The geometry of the chain phosphates is such that an oxygen atom from each of three neighboring PO4 groups making up the chain can be brought into close proximity with a metal atom. This has led several authors (68,126) to propose the following structure for site-binding in the metal complexes with the chain phosphates: This is a very reasonable structure, which may explain why the chain phosphates form far more stable complexes with the multiply charged cations than do the ring phosphates, since the latter are sterically hindered from assuming all possible configurations. This structure implies that there should be a considerable difference in the complexing ability of the boat and chair forms (45) of the ring phosphates.…”