Higher Nuclearity Complexes

It is hoped that, exploiting the coordinating ability of oligo-a-pyridylamines with more and more nitrogen atoms, longer and longer metal string complexes will become available. 

As seen, they maintain the trend the closer to the middle the Ni atoms, the shorter are the intermetallic distances. 

4 ISOCYANIDES AND NITRILE LIGANDS IN POLYNUCLEAR LINEAR COMPLEXES 

Isocyanides are long known as ligands able to afford linear polynuclear complexes. This is, for example, the case of the trinuclear [Rh3 (C6H5CH2NC)12I2]3 +, 46 and tetranuclear [Rh4 NC(CH2)3NC 8Cl]5 +, 47 complexes, the electrochemical behaviour of which is, however, unknown. 

Polymeric mixed-valent Rh(I)-Rh(II) complexes of the type [Rh2(Me-C02)(N-N)2(anion)] (N-N = bipy, phen anion = BF4, PF6) have been also structurally characterized,49 but no electrochemical intervention has been occurred in their preparation. 

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Metal fragments may add to some existing E-M compounds to give higher nuclearity complexes. If a lone pair of electrons is present on E, especially for the lighter E atoms, which are more basic, the metal fragment... 

Although it is reasonable to assume that higher-nuclearity complexes generally correspond to the use of less sterically encumbered ligands, the specific structure of a particular complex is uniquely dependent on the nature of its ligand. Thus readers are cautioned that each... 

Higher nuclearity complexes of this type can be prepared from the reaction of organostannoic acids with carboxylic acids. The hexanuclear (119) is prepared from PhSn(0)OH and cyC02H,... 

X-Ray determined structures of heterometallicjji- higher- nuclearity complexes... 

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