Supramolecular modulation of spin crossover profile in manganese(III)

The First Conducting Spin‐Crossover Compound Combining a MnIII Cation Complex with Electroactive TCNQ Demonstrating an Abrupt Spin Transition with a Hysteresis of 50 K

“…This gives rise to a marked Jahn–Teller distortion (axial compression of Mn−O bonds), which has a dramatic effect on the spin state of the Mn III complex and as a result promotes thermal SCO . Current research on this class of Mn III SCO compounds is aimed at tuning the Mn III spin state by varying the substituents on the phenolate ring, the anion, and the co‐crystallized solvent molecules . However, it should be noted that the vast majority of Mn III SCO complexes with the ligand L and its derivatives show a gradual and often incomplete SCO.…”

“…In the structure of II , the angles in the coordination polyhedron of Mn III N 4 O 2 deviate somewhat more and fall in the ranges 79.6(2)–109.7(2) and 163.1(2)–163.5(2)° (see Table S1 in the Supporting Information). The bond lengths and angles in the Mn III fragments of compounds I and II are in good agreement with those in other HS Mn III cation complexes bearing ligands of the sal‐N‐1,5,8,12 family …”

“…In the last decade,h exacoordinated (N 4 (O À ) 2 )M n III cation complexes with the sal-N-1,5,8,12 Schiff-base ligand L (Scheme 1) andi ts derivativesh ave been actively studied as SCO systems. [11][12][13][14][15][16][17][18][19][20][21] This ligand is ap roduct of the condensation reactionb etween salicylaldehyde and af lexible N,N'-bis(3-aminopropyl)ethylenediamine.…”

“…[11,12,16] Current research on this class of Mn III SCO compounds is aimed at tuning the Mn III spin state by varying the substituents on the phenolate ring, the anion,a nd the co-crystallized solvent molecules. [11][12][13][14][15][16][17][18][19][20][21] However,i ts hould be noted that the vast majority of Mn III SCO complexes with the ligand La nd its derivatives show ag radual and often incomplete SCO. To the best of our knowledge,o nly three manganese complexes are known, and thesee xhibit abrupt SCO behavior with hysteresis windows of 8, 14, and 18 K. [15,19,21] SCO systems with wide hysteresisl oops attract considerable attention,b ecause they have great potentialf or practical applications in memory devices.…”

Spin Crossover in cis Manganese(III) Quinolylsalicylaldiminates

“…These results are indicative of half spin crossover possibly from an equal HS:LS state to a completely HS ( S = 2) state at room temperature. Half spin crossover has previously been observed in [Mn(5‐X‐sal 2 bapen)]ClO 4 (X = Cl, Br) and in both cases is ascribed to the presence of two independent Mn III centres in the crystal structures 19,23. As we do not have the structures of [Mn(qsal‐X) 2 ]OTf we are unable to say whether this is true in our compounds.…”