Oxygen square pyramid

Figure 13.11 Structure of the binuclear anion [Sbj OCle] " showing the bridging oxygen and chlorine atoms and the pseudooctahedral coordination about Sb the O atom is at the common apex of the face-shared square pyramids and the lone-pairs are trans- to this below the SbCU bases. The bridging distances Sb-Cl are substantially longer than the terminal distances Sb-Cl,.

Mixed 6),Af-donor ligands such as Schiff bases are of interest in that they provide examples not only of square-planar coordination but also, in the solid state, examples of square-pyramidal coordination by dimerization (Fig. 28.6(b)). A similar situation occurs in the bis-dimethylglyoximato complex, which dimerizes by sharing oxygen atoms, though the 4 coplanar donor atoms are all nitrogen atoms. Copper(II) carboxylates are easily obtained by crystallization from aqueous solution or, in the case of the higher carboxylates, by precipitation with the appropriate acid from ethanolic solutions... 

Figure 10. The structures of (a) LinhV2, v04 s H20 and (b) Li06V2 i504,s. Hatched regions represent V05 square pyramids. The circles in (a) show the positions of the oxygen ions from the water molecules (adapted from Refs. [91,92J).

The coordinatively flexible P/N-donor ligand PNra (411) reacts with [IrCl(cod)]2 in the presence of AgPFg to yield [Ir(cod)(PNra)](PF6), (412).665 The X-ray structure of (412) PN =i, R = H, complex confirms the cis geometry of the ligand attached via N and P donor atoms to a square-pyramidal Ir1 cod fragment with a long ethereal oxygen—Ir bond in an apical position. The Ir1... 

Oxygen-exchange reactions of square-pyramidal metal(V) complexes have been reported [14]. In monooxotechnetium(V) and monooxorhenium(V) complexes with N,iV -bis(mercaptoaeetyl)butane-l,4-diamine(DBDS), the exchange of oxygen between the complexes and water in DMSO medium ... 

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