SYNTHESIS, CRYSTAL STRUCTURE, AND MAGNETIC PROPERTIES OF A FERRIMAGNETIC LAYERED COMPOUND [NET(4)][MN(5-CL-SALEN)](2)[FE(CN)(6)] (NET(4) EQUALS TETRAETHYLAMMONIUM, 5-CL-SALEN EQUALS N,N'-ETHYLENEBIS((5-CHLOROSALICYLIDENE)AMINATO))

摘要

The discrete trinuclear complex [(NEt(4)){Mn(H2O)(5-Cl-salen)}(2){Fe(CN)(6)}]. H2O, 3, and a two-dimensional heterometal assembly [(NEt(4)){Mn(5-Cl-salen)}2{Fe(CN)(6)}](n), 4, have been prepared (NEt(4) = tetraethylammonium, 5-Cl-salen = N,N'-ethylenebis(5-chlorosalicylidene)aminato) djanion). Compound 4 crystallizes in the monoclinic space group P2(1)/c with cell dimensions of a = 13.104(3) Angstrom, b = 12.861(3) Angstrom, c = 15.526(2) Angstrom, beta = 105.98(1)degrees, Z = 2 and is isostructural to the previously synthesized metamagnetic compound, [K{Mn(3-MeOsalen}(2){Fe(CN)(6)}. 2DMF](n), 5. The structure assumes a two-dimensional network consisting of the cyclic tetramer (-Mn-NC-Fe-CN-)(4) as a net unit [with dimensions of Fe-C1 = 1.947(8) Angstrom, Fe-C2 = 1.951(8) A, Mn-N1 = 2.286(7) Angstrom, Mn-N2 = 2.266(7) Angstrom, Mn-N-C = 154.4(7)degrees, Mn-N-C = 146.1(7)degrees]. The magnetic study (magnetic susceptibility vs T, field-cooled magnetization and zero-field cooled magnetization vs T, hysteresis loop and saturation magnetization vs Hup to 55 kOe) shows that the compound is a metamagnet with ferrimagnetic layers and antiferromagnetic interlayer interactions, and with a Neel temperature T-N = 4.0 K. The distinctly different magnetic properties of 4 and 5 are discussed and correlated with the structural parameters. The magnetic cm(-1), zJ' = -0.38 cm(-1) on the basis of a trinuclear spin system (S-Mn hs, SFe, SMn hS) = (2, 1/2, 2) and includes a zero-field splitting term D and an intermolecular interaction term zJ' within the molecular field approach. The dehydration reaction of 3 in the solid state also leads to 4. [References: 37]