Mononuclear five-coordinate

Since copper enzymes are involved in redox processes, it was pertinent to explore Cu" complexes of 87 as the same with 54 were less stable. The first such stable complex 91 formed from 87 and Cu° perchlorate constituted a typical mononuclear five coordinate species with three imidazole groups and two water molecules in the coordination sphere. The small sized alkylnitriles displaced water molecules and 92, formed in acetonitrile, in its X-ray structure revealed a distorted tetragonal N4O environment provided by the N3 ligand, an acetonitrile buried inside the cavity and a water molecule placed outside (Figure 4 2000IC3436). 

Fig. 12 Structures of key mononuclear, five-coordinate iron complexes capable of proton reduction, (a) Fe(CO)(bdt) (PPh2NPh2), (b) (bdt)Fe (CO)(dppf), and (c) (bdt)Fe (CO)(P2) for P2 is 0,0 -(CH3CH2)2-2- bis-(diphenylphosphinomethyl) ammo -acetate [57, 72, 73]...

Antimony pentamethoxide forms a dinuclear molecule [Sb2(M-OMe)2(OMe)g] with the familiar edge-sharing bi-octahedral structure (Fig. 4.2). Thep-tolyl antimony-bis-tetramethylethyleneglycolate forms a mononuclear five-coordinated Sb(v) com-... 

The reactions of mercury(II) salts with oligo-amines afford informative examples for the fact that counterions induce the formation of a distinct complex or select a distinct complex in an equilibrium to crystallize with. Thus, Hg11 acetate with dien under exactly the same reaction conditions, in the presence of C104- or PF6-, yields the dinuclear complex [Hg2(dien)3](C104)4 or the mononuclear species [Hg(dien)(H20)](PF6)2, respectively, both characterized by IR, H, and 13C NMR spectrometries, by fast-atom bombardment (FAB) MS, cyclovoltammetry, and X-ray structure analyses.209 In the first compound Pna2, Z = 4), one Hg adopts five-coordination with one tridentate and one bidentate dien ligand, which with the remaining N-donor binds to the... 

Fe(tmen)l2] to be tetrahedral the Fe in [Fe(dienm)Cl2] (dienm = bis(2-dimethylaminoethyl)-methylamine) is five-coordinated. Both complexes are mononuclear with no halide bridging in the solid state." " ... 

---