From metal cyanides clusters

Interestingly, aU cyanide SMMs reported thus far are characterized by the presence of ions with appreciable spin-orbit coupling. In the prototypical Mnj2 SMMs, the orbital angular momenta of Mn(III) centers are quenched due to the tetragonal Jahn-Teller distortion. This is not the case for the compounds listed in Table XI. In the molecules based solely on 3d transition metals, important orbital contribution results from the presence of low-spin Fe(III) centers. The only exception is the pentanuclear TBP cluster [Mn (tmphen)2l3[Mn (CN)6]2 (177). This compound was subjected to a detailed theoretical treatment that... 

This is a remarkable reaction because the transition metal chemistry of N2O is sparse, especially with copper. Most N2O reductases are soluble, periplasmic homodimers however, there are examples of membrane-associated enzymes. " The best characterized N2O reductases are from Paracoccus denitrificans, Pseudomonas nautica, and Pseudomonas stutzeri, and most of the information presented here is derived from experiments on these enzymes. Where comparable data are available, N2O reductases from various organisms appear to be fairly similar, with the exception of the enzyme from Wolinella succinogenes, as noted above. The crystal stractmes of N2O reductase from P. nautica and more recently from P. denitrificans show two distinct copper clusters per subunit a bis-thiolate bridged dinuclear electron-transfer site (Cua), which is analogous to the Cua site in cytochrome c oxidase see Cyanide Complexes of the Transition Metals), and a novel four-copper cluster ligated by seven histidines, the catalytic copper site (Cuz), where N2O is thought to bind and be reduced. Cuz was proposed to be a copper-histidine cluster on the basis of the presence of nine strictly conserved histidine residues, and this was supported by a H NMR study that identified two non-CuA associated resonances that were assigned as copper-histidine N-H protons. ... 

A new avenue in cyanide chemistry was opened up when it became apparent that under the right experimental conditions it is possible to crystallize high-nuclearity clusters from hexacyano-metalates when the Lewis acid is a complex specifically designed to present more than one labile position, e.g., [M L5(H20)3] (L5 is a pentadentate ligand). Under these conditions, the labile water can be substituted by one cyanide ion from [M(CN)6] (Figure 14). ... 

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