1286707-49-0Relevant articles and documents
N,N′-bis(2,2′-bipyridine-6-ylmethyl)-2,2′- biphenylenediamines: A tuneable ligand scaffold for room temperature Fe 2+ SCO complexes
Petzold, Holm,Heider, Silvio
, p. 1249 - 1254 (2011/06/10)
Condensation and subsequent reduction of 2,2′-diaminobiphenyls 5 with 6′- and 5′-substituted 6-carbaldehyde-2,2′-bipyridines 4 yielded N,N′-bis(2,2′-bipyridine-6-ylmethyl)-2,2′-biphenyl- enediamines 7, which were employed as hexadendate ligands with N6 donor sets in the synthesis of dicationic [Fe2+(7-κ6N)] complexes 8. Dependent on the substitution pattern the respective complexes are found in the HS state (8b and 8c) or show SCO behaviour. By means of temperature- dependent susceptibility measurements, usingEvans' method, the thermodynamic parameters ΔH, ΔS and T1/2 for the SCO have been determined. T1/2 as well as ΔH are remarkably susceptible to substitution next to the central C-C bond of the biphenyl bridge. A new series of ligands with an AB2 structure were synthesized and employed in Fe2+ SCO complexes. ΔH, ΔS and T1/2 for the SCO were determined using Evans' method. The results clearly show a dependency of the spin state on the substitution pattern. The steric effects of substituents placed at the 6 and 6′ positions in the biphenyl moiety are effectively transported through the biphenyl bridge. Copyright
