Synthesis, Crystal and Network Structures, and Magnetic Properties of a Hybrid Layered Compound: [K(18-cr)(2-PrOH)(2)][{Mn(acacen)}(2){Fe(CN)(6)}] (18-cr = 18-Crown-6-ether, acacen = N,N'-Ethylenebis(acetylacetonylideneiminate)).
A hybrid layered compound [{K(18-cr)(2-PrOH)(2)}{Mn(acacen)}(2){Fe(CN)(6)}] has been prepared by the reaction of [Mn(acacen)(Cl)] with [K(18-cr)(H(2)O)(2)](3)[Fe(CN)(6)].3H(2)O in an ethanol/2-propanol mixed solvent (18-cr = 18-crown-6-ether, acacen = N,N'-ethylenebis(acetylacetonylideneiminate)). It crystallizes in the monoclinic space group P2(1)/a with cell dimensions of a = 13.272(3) Å, b = 15.768 (2) Å, c = 14.771(2) Å, beta = 105.64(1) degrees, Z = 2. It assumes a hybrid layered structure of alternating arrays of two types of layers. One of the layers is formed by the anionic part [{Mn(acacen)}(2){Fe(CN)(6)}](n)()(n)()(-), where [Fe(CN)(6)](3)(-) coordinates through its four cyanide groups on a plane to the axial sites of four [Mn(acacen)](+) entities. The two-dimensional layer consists of the cyclic octamer [-Mn-NC-Fe-CN-](4) having the Fe ions at the corners and the Mn ions on the edges of a deformed square. Another layer is formed by the cationic part [K(18-cr)(2-PrOH)(2)](+) that has a hexagonal-bipyramidal geometry about the metal with two 2-PrOH molecules at the apexes of the nearly planar [K(18-cr)](+). The anionic and cationic layers are combined by the hydrogen bond between the cyanide groups (free from coordination) of the anionic layer and the 2-propanol groups of the cationic layer with bond distance of N.O = 2.861(5) Å. Magnetic studies (magnetic susceptibility vs T, field-cooled magnetization vs T, saturation magnetization vs H) indicate that the compound is a metamagnet with a Néel temperature T(N) = 5.0 K, showing the onset of ferromagnetic ordering within the anionic layer and an antiferromagnetic interlayer interaction. Magnetization as a function of the applied magnetic field indicates a spin-flipping from antiferromagnetic arrangement to ferromagnetic arrangement between the layers around 1200 Oe and exhibits hysteresis behavior.
Miyasaka
Hitoshi
H
Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-81, Japan, and Department of Chemistry, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo 152-8551, Japan.
Okawa
Hisashi
H
Miyazaki
Akira
A
Enoki
Toshiaki
T