Bimetallic Magnetic Material [Ni(diamine)₂]₂[Fe(CN)₆]X with Two-Dimensional Network Extended by Fe(III)-CN-Ni(II) Linkages

Abstract

Cyanide-bridged bimetallic assemblies [Ni(pn)2]2[Fe(CN)6]X·catnH2O (X = ClO4 - and n = 2 (1); X = BF4 - and n = 2 (2); X = PF6 - and n = 2 (3)) and [Ni(1,1-dmen)2]2[Fe(CN)6]X·nH2O (X = ClO4 - and n = 2 (4); X = BF4 - and n = 3 (5); X = PF6 - and n = 2 (6); X = CF3SO3 - and n = 2 (7); X = BzO- and n = 6 (8); X = I- and n = 4 (9); X = N3 - and n = 4 (10); X = NCS- and n = 1 (11); X = NO3 - and n = 4 (12)) have been prepared (pn = 1,2-propanediamine, 1,1-dmen = 1,1-dimethylethylenediamine). 7 crystallizes in a monoclinic space group P21/m (no. 11), with a = 10.300(6), b = 20.632(4), c = 10.352(7) Å, β = 109.45(4)°, V = 2074(1) Å3 for Z = 4. 8 crystallizes in a triclinic space group P1̄ (no. 2), a = 10.413(6), b = 22.060(6), c = 10.377(3) Å, α = 101.78(2), β = 95.71(4), γ = 77.29(3)°, V = 2272(1) Å3 for Z = 2. 10 crystallizes in triclinic space group P1̄ (no. 2), a = 10.314(1), b = 10.374(1), c = 10.233(1) Å, α = 93.23(1), β = 106.15(1), γ = 86.37(1)°, V = 1045.0(2) Å3 for Z = 2. In each compounds [Fe(CN)6]3- coordinates to four [Ni(1,1-dmen)2]2+ cations through four cyano nitrogens on a plane, providing a 2-D sheet of a square structure extended by Fe-CN-Ni linkages. The square with four Fe(III) ions at the corners and four trans Ni(II) on the edges shows a slight distortion to a rhombus. A ferromagnetic interaction operates within the sheet in all the compounds. The overall magnetic property is governed by the intersheet separation: a small intersheet separation provides metamagnets (1, 2, 3, 4, 6, 11) owing to intersheet antiferromagnetic interaction, whereas a large intersheet separation (>10 Å) provides ferromagnets (5, 7, 8, 9, 10, 12). The ferromagnets became metamagnets on dehydration owing to shortening of the intersheet separation.

Magnetic properties of model non-carbon nanotubes with macroscopic value of ground state spin

“…Low-dimensional bimetallic ferrimagnets based on polymeric compounds of transition metals have attracted much attention due to their interesting physics and potential technological applications [1][2][3][4]. Low-temperature properties of these magnets are described adequately by Heisenberg spin model with two kinds of antiferromagnetically coupled centers.…”

“…Low-temperature properties of these magnets are described adequately by Heisenberg spin model with two kinds of antiferromagnetically coupled centers. One of them is the well-known alternating spin chain studied intensively the last two decades as a model first of some quasi-1D molecular ferrimagnets [1,[3][4][5] and second of decorated square mixed-spin lattices of bimetallic quasi-2D ferrimagnets-complex compounds of transition metals like Cu, Ni and Fe [2,6]. Recently, a new interesting model of quasi-1D mixed-spin ferrimagnets was proposed and studied [7].…”

“…But magnetic nanotubes should offer robustness with the possibilities of additional novel magnetic properties. Particularly ferrimagnetic structures offer a degree of novelty (as noted in [2,6]). And particularly lithographic patterning procedures [11] are available for the design of quasi-2D bimetallic ferrimagnets.…”

“…all spins S 1,m,l correspond to Fe 3 + ions with s 1 ¼1/2 and all other spins correspond to Ni 2 + ions with s 2 ¼1[2].…”

A New Family of Bimetallic Framework Materials Showing Reversible Structural Transformations

“…The hexacyanometalates, M II (CN) 6 4-and M III (CN) 6 3-, are good building blocks, and a number of multidimensional systems have been synthesized, some with interesting magnetic properties. [29][30][31][32][33][34] Interest in the gas sorption properties of these compounds has increased in recent years. 35 However, only a small number of coordination polymers based on hexacyanometalates have been reported as being porous.…”