Multidentate Podand Ligands

Several other classes of polydentate amide ligands in which the ligating atoms are various types of nitrogen (and occasionally oxygen) centres have been investigated. Prominent examples of these are the podand type of ligand as shown in G-J, introduced by Verkade, Schrock, Gade and coworkers. 

These and related ligands (see below) carry a 3- (or 2-) charge and were developed in the early 1990s to stabihze metal complexes with high charges and to induce various 

They have been used almost exclusively 

Treatment of these phosphinidene complexes with R CHO afforded RP = C(H)R this is an alternative route to phosphaalkenes.The reaction of (Me3SiN)3N Li3 with M0CI4 or WCI4 gave [ (Me3SiN)3N MCl] (M = Mo or The molybdenum(IV) halide 

The formation of relatively stable species of the type (ArN)3N Mo N = N—MoN(NAr)3], in which further reduction of the N2 moiety is not very favored, can be prevented by the use of larger (ArN)3N triamido ligands. This led to the development of tris(amido)amine ligands 

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An efficient catalytic system for oxygenation of phenols to p- or o-quinones with molecular oxygen was achieved by utilization of a catalyst consisting of Co(OAc)2 and the multidentate N-heterocyclic podand ligand, A,A -bis-2-(2-pyridyl)ethyl)-2,6-pyridinedicarboxamide, 2-BPEPA (Figure... 

Various multidentate ligands were used as podands for the preparation of Ag+ ISE membranes LOD for 52 was 16 pM, for 53 and 54 ca 1 pM. The operation of these membranes was similar to that of the solid state Ag2S electrode147. 

Complexation and Applications.— The chemistry and complexation properties of multidentate non-cyclic neutral ligands ( podands ), for example (95), have been... 

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