Di-μ-halo-bis{[tris(2-pyridylmethyl)amine-κ4N]nickel(II)} bis(triethylammonium) tetraperchlorate: Magnetostructural studies

From antiferromagnetic to ferromagnetic exchange in a family of oxime-based MnIII dimers: a magneto-structural study

“…37 Nearest neighbour magnetic exchange is dominated by the twisting of the -N-Omoiety of the phenolic oxime and the sign and magnitude of the pairwise exchange can be controlled via chemical substitution at the oximic C-atom. An excellent candidate in this regard is the tripodal tetradentate ligand tris(2-pyridylmethyl)amine (tpa) which has been used extensively to obtain dimers and trimers of Cu II , [43][44][45] Fe III , 46,47 Cr II and Cr III , [48][49][50][51] Co II , Ni II , 52,53 Mn II and Mn III . [40][41][42] Our most recent research attempts have therefore focused on deliberately targeting Mn III clusters with the R-saoH 2 family of ligands whose building blocks are not [Mn III 3 O(R-sao) 3 ] + triangles.…”

Di-μ-bromo-bis[bis(1,2-diaminoethane-κ2N,N)nickel(II)] dibromide

“…octahedral six-coordinate, with four N atoms from two en ligands completing the coordination environment. The difference in the Ni-Br distances (0.1105 Å ) is pronounced, and appears to be typical of these types of dimers (see, for example, Tong et al, 2000;L'Haridon & Bkouche-Waksman, 1978). Similar unsymmetric bridges are observed for the analogous chloride-bridged dimers (Tong et al, 1999;Journaux & Kahn, 1979;Bkouche-Waksman et al, 1981).…”

trans-Diaquabis(N,N-dimethylethane-1,2-diamine-κ2N,N′)nickel(II) dichloride dihydrate: a redetermination at 90 K

“…We have reported magneto-structural studies of nickel(II) dimers containing the {NiX} 2 core, where X is Cl and Br (Tong et al, 1999(Tong et al, , 2000Xie & Norman, 2006), and observed that a bridging bromide mediates stronger ferromagnetic coupling between six-coordinate nickel(II) centers than does a bridging chloride for the same effective ferromagnetic coupling pathway. We do not know if this observation is general since very few compounds containing the {NiBr} 2 core, with sixcoordinate nickel(II), have been reported.…”