Versatile Reactivity Of Mn-Ii Complexes In Reactions With N-Donor Heterocycles: Metamorphosis Of Labile Homometallic Pivalates Vs. Assembling Of Endurable Heterometallic Acetates

Reaction of 2,2 '-bipyridine (2,2 '-bipy) or 1,10-phenantroline (phen) with [Mn(Piv)(2)(EtOH)](n) led to the formation of binuclear complexes [Mn-2(Piv)(4)L-2] (L = 2,2 '-bipy (1), phen (2); Piv(-) is the anion of pivalic acid). Oxidation of 1 or 2 by air oxygen resulted in the formation of tetranuclear Mn-II/III complexes [Mn4O2(Piv)(6)L-2] (L = 2,2 '-bipy (3), phen (4)). The hexanuclear complex [Mn-6(OH)(2)(Piv)(10)(pym)(4)] (5) was formed in the reaction of [Mn(Piv)(2)(EtOH)](n) with pyrimidine (pym), while oxidation of 5 produced the coordination polymer [Mn6O2(Piv)(10)(pym)(2)](n) (6). Use of pyrazine (pz) instead of pyrimidine led to the 2D-coordination polymer [Mn-4(OH)(Piv)(7)(mu(2)-pz)(2)](n) (7). Interaction of [Mn(Piv)(2)(EtOH)](n) with FeCl3 resulted in the formation of the hexanuclear complex [(Mn4Fe2O2)-Fe-II-O-III(Piv)(10)(MeCN)(2)(HPiv)(2)] (8). The reactions of [MnFe2O(OAc)(6)(H2O)(3)] with 4,4 '-bipyridine (4,4 '-bipy) or trans-1,2-(4-pyridyl)ethylene (bpe) led to the formation of 1D-polymers [MnFe2O(OAc)(6)L-2](n)center dot 2nDMF, where L = 4,4 '-bipy (9Greek ano teleia2DMF), bpe (10Greek ano teleia2DMF) and [MnFe2O(OAc)(6)(bpe)(DMF)](n)center dot 3.5nDMF (11 center dot 3.5DMF). All complexes were characterized by single-crystal X-ray diffraction. Desolvation of 11 center dot 3.5DMF led to a collapse of the porous crystal lattice that was confirmed by PXRD and N-2 sorption measurements, while alcohol adsorption led to porous structure restoration. Weak antiferromagnetic exchange was found in the case of binuclear Mn-II complexes (J(Mn-Mn) = -1.03 cm(-1) for 1 and 2). According to magnetic data analysis (J(Mn-Mn) = -(2.69 divided by 0.42) cm(-1)) and DFT calculations (J(Mn-Mn) = -(6.9 divided by 0.9) cm(-1)) weak antiferromagnetic coupling between Mn-II ions also occurred in the tetranuclear {Mn-4(OH)(Piv)(7)} unit of the 2D polymer 7. In contrast, strong antiferromagnetic coupling was found in oxo-bridged trinuclear fragment {MnFe2O(OAc)(6)} in 11 center dot 3.5DMF (J(Fe-Fe) = -57.8 cm(-1), J(Fe-Mn) = -20.12 cm(-1)).