Spin-crossover in an iron(iii) complex showing a broad thermal hysteresis

Abstract

A pentadentate Schiff-base ligand 3,5Cl-L2− and NCSe− form a iron(iii) mononuclear complex [Fe(3,5Cl-L)(NCSe)], which shows a thermally induced spin crossover with a broad hysteresis width of 24 K between 123 K (warming) and 99 K (cooling).

Pressure effect on long-term heat storage ceramics based on Mg-substituted λ-Ti3O5

“…13 An example is lambda-trititanium-pentoxide (l-Ti 3 O 5 ), which shows a reversible phase transition to beta-trititanium-pentoxide (b-Ti 3 O 5 ) by external stimuli such as light, heat, and pressure. [13][14][15][16][17][18][19] Moreover, solid-solid phase transition materials such as charge transfer phase transition materials, [20][21][22][23][24][25][26] spin crossover transition materials, [27][28][29][30][31][32][33][34][35][36][37][38][39][40] and metal insulator phase transition materials, 14,41,42 may also be good candidates for long-term heat storage materials. In this study, we synthesize a long-term heat-storage material based on magnesium-substituted lambdatrititanium-pentoxide, l-Mg x Ti 3Àx O 5 .…”

Hexacoordinate high-spin Fe(iii) complexes composed of a pentadentate amino-type ligand and pseudohalido coligands

“…Recently, in a couple of S = 5/2 spin systems (Mn( ii ), Fe( iii )) a slow magnetic relaxation supported by the external magnetic field has been detected 3–5 This phenomenon is a “dance on thin ice” as well.…”

Structural, Magnetic, and Electrochemical Characterization of Iron(III) and Cobalt Complexes with Penta‐N3O2‐dentate Ligands

“…[21][22][23][24][25][26][27] The Co(III) complexes are in low spin (LS) states, [27] whereas some Fe(III) complexes showed temperature induced reversible conversions between LS and high spin (HS) states, called spin crossover (SCO). [21][22][23][24][25][26]28,29] The spin state and SCO properties of these iron(III) complexes can be changed by introducing substituents to the Schiff base ligand and by exchanging the monodentate ligand. Especially the complexes [Fe III (L H,Cl )X], [22] [Fe III (L H,Br )X] [24] and [Fe III (L Cl,Cl )X] [29] (X=N 3 , NCS, NCSe) should be mentioned, which show a temperature induced SCO, whereas the compounds [Fe III (L Br,Br )X] [29] are only in the HS state.…”

“…[21][22][23][24][25][26]28,29] The spin state and SCO properties of these iron(III) complexes can be changed by introducing substituents to the Schiff base ligand and by exchanging the monodentate ligand. Especially the complexes [Fe III (L H,Cl )X], [22] [Fe III (L H,Br )X] [24] and [Fe III (L Cl,Cl )X] [29] (X=N 3 , NCS, NCSe) should be mentioned, which show a temperature induced SCO, whereas the compounds [Fe III (L Br,Br )X] [29] are only in the HS state. Complexes with X=CN À are always in the LS state, [21,22,30] but some cyanide bridged multinuclear complexes such as [Fe II-(CN) 6 {Fe(L H,H )} 6 ]Cl 2 were reported to show SCO.…”

“…[27,[30][31][32][33]43,44] Herein we report a series of six new [Fe(L Br,Cl )X] (X: Cl À , N 3 À , NCO À , NCS À , NCSe À , NC À ) complexes. In extension to the previously reported complexes [Fe III (L Cl,Cl )X] and [Fe III (L Br,Br )X], [29] which show SCO and HS behavior, respectively, the temperature depending magnetic behavior of the six new complexes was analyzed. In order to use [M III (L R1,R2 )X] building blocks for designing ETCST complexes, we analyzed the redox properties of the [Fe(L Br,Cl )X] complexes and of different derivates.…”