One-dimensional Polynuclear Spin-crossover Iron(III) Complex Axially Bridged by 1,3-Bis(4-pyridyl)propane

Abstract

A one-dimensional (1D) polynuclear spin-crossover FeIII complex, [FeIII(acacen)(bpyp)]n(BPh4)n, showed a gradual and complete SC over a wide temperature range of ca. 250 K between S = 5/2 and S = 1/2, where acacen = N,N′-bis(acetylacetonato)ethylenediamine, bpyp = 1,3-bis(4-pyridyl)propane, and BPh4− = tetraphenylborate. The single-crystal X-ray structures in the HS, LS, and midpoint between the HS and LS states were determined, and demonstrated that the SC may occur through the alternately arrayed HS- and LS-chains.

Advances in Polynuclear Iron(II), Iron(III) and Cobalt(II) Spin‐Crossover Compounds

“…As indicated earlier, we have explored 1‐D iron(III) Schiff base crossover systems using a large range of di‐pyridyl type bridges 68. Matsumoto and co‐workers have recently solved the structure, at three temperatures, of [Fe(acen)(bpyp)](BPh 4 ),95 a complex first reported by Maeda et al,96 both groups observing the same, gradual S = 5/2 to S = 1/2 transition centred at ca. 200 K, with no hysteresis.…”

Spin‐Crossover Studies on a Series of 1D Chain and Dinuclear Iron(II) Triazine‐Dipyridylamine Compounds

“…In contrast, a recent iron(III) 1D system has been reported which contains isolated alternating HS and LS chains. [29] The 1D chains in 1c run along the c-axis, where adjacent chains are generated by a translation along either the a-or b-axis as seen in 1b [ Figure 5 (c)]. In contrast to 1b, all of the 1D polymer chains in 1c run in the same direction, i.e., along the c-axis [ Figure 4 (c)].…”

Effect of the chemical structure of a tetradentate equatorial ligand on the spin‐crossover properties of the Fe (III) complexes chain structures: Electron paramagnetic resonance study

“…A large number of 1‐D chain Fe (III) compounds with a thermally induced spin crossover were obtained based on the acen with bridging ligands of the pyridine type. [ 11,12 ] Complex compounds with bzacen are less studied, although this ligand is also promising for the preparation of Fe (III) complexes with variable spin properties. [ 13–15 ] Therefore, in addition to the described series of compounds, we obtained a complex with L = bzacen containing both aromatic and aliphatic groups.…”