Building Fe(III) clusters with derivatised salicylaldoximes

The syntheses, structures and magnetic properties of nine new iron complexes containing salicylaldoxime (saoH(2)) or derivatised salicylaldoximes (R-saoH(2)), [Fe3O(OMe)(Ph-sao)(2) Cl-2(py)(3)] center dot 2MeOH (1 center dot 2MeOH), [Fe3O(OMe)(Ph-sao)(2)Br-2(py)(3)] center dot Et2O (2 center dot Et2O), [Fe-4(Ph-sao)(4)F-4(py)(4)] center dot 1.5MeOH (3 center dot 1.5MeOH), [Fe6O2(OH)(2)(Et-sao)(2)(Et-saoH)(2)(O2CPh)(6)] (4), [HNEt3](2)[Fe6O2(OH)(2)(Etsao) (4)(O2CPh(Me)(2))(6)] center dot 2MeCN (5 center dot 2MeCN), [Fe6O2(O2CPh)(10)(3-tBut-5-NO2-sao)(2)(H2O)(2)] center dot 2MeCN (6 center dot 2MeCN), [Fe6O2(O2CCH2Ph)(10)(3-tBut-sao)(2)(H2O)(2)] center dot 5MeCN (7 center dot 5MeCN), {[Fe6Na3O(OH)(4)(Mesao) (6)(OMe)(3)(H2O)(3)(MeOH)(6)] center dot MeOH}(n)(8 center dot MeOH) and [HNEt3](2)[Fe12Na4O2(OH)(8)(sao)(12)(OMe)(6)(MeOH)(10)] (9) are discussed. The predominant building block appears to be the triangular [Fe3O(R-sao)(3)](+) species which can self-assemble into more elaborate arrays depending on reaction conditions. An interesting observation is that the R-saoH(-)/R-sao(2-) ligand system tends to adopt coordination modes similar to carboxylates. The most unusual molecule is the [Fe4F4] molecular square, 3. While Cl- and Br- appear to act only as terminal ligands, the F- ions bridge making a telling impact on molecular structure and topology.