Oligonuclear

Seven coordination in molybdenum chemistry analysis of oligonuclear structures. M. Melnik and P. Sharrock, Coord. Chem. Rev., 1985, 65, 49 (91). 

NMR, 5, 56 octahedral amines, 2, 28 electronic spectra, 5, 49 magnetic properties, 5, 60 oligonuclear... 

Di- and Oligonuclear Ni11 Complexes with Compartmental Dinucleating Ligands 424... 

Di- and oligonuclear complexes with open-chain alkoxo- or phenolato-based dinucleating ligands 427... 

Oligonuclear and polymeric complexes with other bridging ligands 475... 

Cd thiolates and selenolates tend to form q-S- or q-Se-bridged dinuclear species, even with bulky organic groups, e.g., 2,4,6-tri-t-butylphenyl.317 318 With some ligand combinations, heterocubanes with Cd4S4 core or oligonuclear species derived from heterocubanes are formed.319,320... 

Komiyama at al. have prepared two oligonuclear Zn(II) complexes (22 and 23) and tested their hydrolytic activity toward different diribonucleotides [45,46] (catalytic turnover was not demonstrated). The dimer and trimer structures of the active species were confirmed by measuring the hydrolytic activity as a function of Zn/L ratio, which show sharp maxima at the expected 2/1 and 3/1 ratios, respectively. The oligomer complexes have high ribonuclease activity (e.g. the hydrolysis of UpU is accelerated more than 4 and 5 orders of magnitude by 22 and 23, respectively), whereas the effect of the monomer complex 24 was not... 

Figure 2. Structures of the known oligonuclear binary Fe -thiolate complexes, (a) [Fe.(SPh)jJ . Only a-carbons of phenyl rings are shown. (Reproduced from ref. 84. Copyright W80 the authors.) (b) [Fe CSEt) ] ". (Reproduced from ref. 13. Copyright 1982 American Chemical Society.)...

The calculation of magnetic parameters such as the hyperfine coupling constants and g-factors for oligonuclear clusters is of fundamental importance as a tool for the evaluation of spectroscopic data from EPR and ENDOR experiments. The hyperfine interaction is experimentally interpreted with the spin Hamiltonian (SH) H = S - A-1, where S is the fictitious, electron spin operator related to the ground state of the cluster, A is the hyperfine tensor, and I is the nuclear spin operator. Consequently, it is... 

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