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.

Two phenol-based compartmental ligands of the “end-off” type, 2,6-bis{N-[2-(dimethylamino)ethyl]iminomethyl}-4-methylphenol (HL1) and 2-{N-[2-(dimethylamino)ethyl]iminomethyl}-6-{N-methyl-N-[2-(dimethylamino)ethyl]aminomethyl}-4-bromophenol (HL2), have been used to form [Ni2(L1)(AcO)(NCS)2(MeOH)] (1), [Ni2(L1)(AcO)2(MeOH)]BPh4 (2), [Ni2(L2)(AcO)(NCS)2(MeOH)] (3), [Ni2(L2)(AcO)2]BPh4 (4), and [Ni2(L2)(NCS)3(MeOH)] (5). X-ray crystallographic studies were done for 2−5. 2:  triclinic, space group P1̄, a = 13.613(3) Å, b = 16.475(4) Å, c = 11.307(4) Å, α = 99.90(2)°, β = 104.16(2)°, γ = 109.01(2)°, V = 2253(1) Å3, Z = 2. The complex cation has a dinuclear core triply bridged by the phenolic oxygen of (L1)- and two acetate groups in the syn-syn mode. One Ni has a six-coordinate geometry together with a methanol oxygen. 3: triclinic, space group P1̄, a = 10.167(1) Å, b = 16.119(2) Å, c = 9.472(3) Å, α = 103.53(2)°, β=100.91(1)°, γ = 85.62(1)°, V = 1481(1) Å3, Z = 2. A pair of Ni ions are bridged by the phenolic oxygen of (L2)-, an isothiocyanate nitrogen, and an acetate group. The sixth position of one Ni is occupied by a methanol oxygen and that of the other Ni by isothiocyanate nitrogen. 4:  monoclinic, space group P21/n, a = 15.146(2) Å, b = 9.442(3) Å, c = 30.844(2) Å, β = 93.427(9)°, V = 4402(1) Å3, Z = 4. Two Ni ions are bridged by the phenolic oxygen of (L2)- and an acetate group. The Ni bound to the iminic pendant arm is nearly planar whereas the Ni bound to the aminic pendant arm is of six-coordination together with a bidentate acetate group. 5:  monoclinic, space group C2/c, a = 26.744(5), b = 10.323(4) Å, c = 21.785(6) Å, β = 94.73(2)°, V = 5993(3) Å3, Z = 8. Two Ni ions are bridged by the phenolic oxygen of (L2)- and an isothiocyanate nitrogen. The Ni bound to the iminic pendant arm is of five-coordination along with an isothiocyanate nitrogen. The Ni bound to the aminic pendant arm has a six-coordinate geometry together with a methanol oxygen and an isothiocyanate nitrogen. 1−5 were examined regarding their ability to bind urea, and 4 and 5 were shown to form [Ni2(L2)(AcO)2(urea)]BPh4 (4‘) and [Ni2(L2)(NCS)3(urea)] (5‘), respectively. 5‘ crystallizes in the monoclinic system, space group P21/n, with a = 11.709(5), b = 15.100(4), c = 17.548(5) Å, β = 95.58(3)°, V = 3087(1) Å3, and Z = 4. Its dinuclear core is very similar to that of 5 except that the methanol of 5 is replaced by a urea molecule.

Three bimetallic assemblies, PPh4[Ni(pn)2][M(CN)6]·H2O (M = Fe (1), Cr (2), Co (3); pn = rac-1,2-diaminopropane), have been prepared and structurally and magnetically characterized. Assembly 2 crystallizes in the monoclinic system of the space group P2/c (No. 13) with a = 12.927(2) Å, b = 8.454(2) Å, c = 17.564(2) Å, β = 100.15(1)°, V = 1889.5(6) Å3, and Z = 2, and 3 crystallizes in the same space group with a = 12.971(1) Å, b = 8.437(1) Å, c = 17.118(1) Å, β = 99.84(1)°, V = 1845.7(3) Å3, and Z = 2. The crystal structure analyses of 2 and 3 reveal a one-dimensional zigzag chain structure extending through the M−CN−Ni−NC−M linkages as previously found for 1. Assemblies 1 and 2 show a ferromagnetic intrachain interaction based on the strict orthogonality of the magnetic orbitals between adjacent NiII and MIII (M = Fe, Cr) ions. Assembly 3 is essentially paramagnetic within the chain. All the assemblies show a weak antiferromagnetic interchain interaction and hence no magnetic ordering over the lattice.