Heptanuclear complexes

Actually, the heptanuclear complexes [M7(teptra)4(X)2] (M = Cr, X = Cl 43 M = Ni, X = Cl, NCS39,44) have been structurally character-iaed, but no electrochemical information is available. The same (unfortunately) holds for the highly spectacular nonanuclear complex [Ni9(peptea)4(Cl)2] illustrated in Figure 7.45... 

An aqueous solution of K4[Fe(CN)6] (62 mg, 0.19 mmol) in 10 mL of water is added dropwise to a stirred solution of [Mn(dmptacn)(OH2)] [C104J2 (0.58 g, 1.00 mmol) in 50 mL of water, resulting in a change from colorless to pale green. Once the addition is complete, the pale green solution is left to slowly evaporate at room temperature. Pale green needles of the heptanuclear complex (0.53 g, 96%) precipitate. 

Heptanuclear Complexes Based on the Central Cyanometalate Unit... 

The heptanuclear complex [Cu°(tren)]6[Mo (CN)g] (C104)g (204) is characterized by the presence of six noninteracting Cu(ll) ions that surround the central diamagnetic [Mo (CN)g]" fragment [Fig. 45(Z))]. Upon irradiation with blue light (406 15 nm) at lOK, the compound exhibits a gradual increase in magnetic susceptibility that saturates after 10 h of continuous irradiation [Fig. 70(a)]. This effect was explained as a photoinduced electron transfer from Mo(lV) to Cu(ll) ions, which is promoted by the irradiation into the intervalence MMCT band... 

Figure 8. Scheme showing the structures of the heptanuclear complexes (67-69,127-129) assembled by attaching six [Fe(CN)5] , [Ru(NH3)5] +, or [Ru(edta)] groups to the peripheral N-atoms of the multibridging tris-bipyrazineruthenium(II) complex. 

The use of [Mn (salen)(H20)] with the potassium salt of hexacyanomet-allate(III) leads to heptanuclear complexes [27,28]. hi one case, however, a trinuclear FeMn2 complex was isolated by Long and coworkers [27] however, the crystal contains dimeric [Mn(salen)(H20)]2 species, two mononuclear Mn complexes, and one Fe(CN)g molecule. It is interesting to note here that the stoichiometry corresponds to a neutral FeMns compound. The same situation is found for the heptanuclear complex based on hexacyanoferrate that CO crystallizes with one molecule of Fe(CN)g to lead to the FeMna neutral stoichiometry as well [28]. 

The core complexes [Ru(18)3] + , [Cu(18)2]+ [Cu(21)2]+ [Cu(23)2]+ have been described. The copper complexes have been used for the preparation of a series of interlaced heteroleptic species but no further structural elaboration to the metallostars appears to have been described. The complex [Ru(18)3] " " has been developed in a divergent sense to give the heptanuclear metallostar [Ru (18)((Ru(phen)2)2 3] ". STM methods have been used to obtain images of this heptanuclear complex on a graphite support. 

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