Other Multidentate Ligands

Pecoraro. 1988. Vanadium complexes of the tridentate Schiff base ligand A,-salicydene-/V -(2-hydroxyethyl)ethylenediamine Acid-base and redox conversion between vanadium(IV) and vanadium(V) imino phenolates. Inorg. Chem. 27 4657 -664. 

Angus-Dunne, S.J., R.J. Batchelor, A.S. Tracey, and F.W.B. Einstein. 1995. The crystal and solution structures of the major products of the reaction of vanadate with adenosine. J. Am. Chem. Soc. 117 5292-5296. 

Hambley, T.W., R.J. Judd, and P.A. Lay. 1992. Synthesis and crystal structure of a vanadium(V) complex with a 2-hydroxy acid ligand A structural model of both vanadium(V) transferrin and ribonuclease complexes with inhibitors. Inorg. Chem. 31 343-345. 

Schwendt, P., P. Svancarek, I. Smatanova, and J. Marek. 2000. Stereospecific formation of a-hydroxycarboxylato oxo peroxo complexes of vanadium(V). Crystal structure of (NBu jfVjOjtPjXL-lactXj FIjO and (NBu lA C fC lD-LactXL-lact)] H20. J. Inorg. Biochem. 80 59-64. 

Tracey, A.S., J.S. Jaswal, M.J. Gresser, and D. Rehder. 1990. Condensation of aqueous vanadate with the common nucleosides. Inorg. Chem. 29 4283-4288. 

---

A variety of chelate complexes of Al3+ with N and/or O donor atoms are known through stability constant data.7,8 Their formation illustrates several aspects of A1 coordination chemistry. Chelates and other multidentate ligand systems provide a means of regulating the reactivity of aluminum compounds. For example, A1 alkoxides can be converted to amino alcohol derivatives to confer water solubility and a degree of hydrolytic stability on otherwise water-sensitive materials. 

Other multidentate ligands have been prepared and their structures determined. The bisphosphinine 64 crystallized with the two phosphinine planes almost orthogonal (91.59°), and the two phosphorus atoms oriented away from each other (P-P distance 5.8 A). However, even at low temperature (—95 °C) there was no evidence in either the 31P... 

OTHER MULTIDENTATE LIGANDS DERIVED FROM THE 1,8-NAPHTHYRIDINE RING... 

Table 24 References to kinetic studies of the replacement of multidentate ligands by other multidentate ligands...

Ligand Replacement Multidentate by Multidentate.—References to kinetic studies of reactions which involve simple replacement of multidentate ligands by other multidentate ligands are listed in Table 24. " Closely related investigations include an e.s.r, study of ligand-replacement reactions in the system [Cu(dtp)2HCu(dtp)(dtc)]-[Cu(dtc)2], for which rate constants and activation parameters are available, and a qualitative study of the yttrium(m)-hexafluoroacetylacetone-trifluoroacetylacetone system. ... 

The vast majority of complexation titrations are carried out using multidentate ligands such as EDTA or similar substances as the complexone. However, there are other more simple processes which also involve complexation using monodentate or bidentate ligands and which also serve to exemplify the nature of this type of titration. This is demonstrated in the determination outlined in Section 10.44. 

Dendrimers can be constructed from chemical species other than purely organic monomers. For example, they can be built up from metal branching centres such as ruthenium or osmium with multidentate ligands. The resulting molecules are known as metallodendrimers. Such molecules can retain their structure by a variety of mechanisms, including complexation, hydrogen bonding and ionic interactions. 

In the first step, a substrate coordinates to a metal catalyst and forms an intermediate mixed complex (LMS in Scheme 13). The substrate is then activated by metal ions and dissociates from the catalyst. The complex catalyst, having accomplished its purpose, is regenerated to the original complex. The catalytic action of a metal ion depends substantially on the nature of the ligands in the intermediate mixed complex. Certain ligands induce an increase in catalytic activity, while others, e.g. multidentate ligands such as ethylenediaminetetracetic acid, inhibit the catalytic action of a metal ion. Therefore, if a polymer ligand is used as one component of a metal-complex catalyst, its properties may affect the catalytic action of the metal ion. 

---