Lattice solvent- and substituent-dependent spin-crossover in isomeric iron(ii) complexes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F24%3APU152460" target="_blank" >RIV/00216305:26620/24:PU152460 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlelanding/2024/dt/d4dt00429a" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2024/dt/d4dt00429a</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d4dt00429a" target="_blank" >10.1039/d4dt00429a</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Lattice solvent- and substituent-dependent spin-crossover in isomeric iron(ii) complexes

Popis výsledku v původním jazyce

Spin-state switching in iron(ii) complexes composed of ligands featuring moderate ligand-field strength-for example, 2,6-bi(1H-pyrazol-1-yl)pyridine (BPP)-is dependent on many factors. Herein, we show that spin-state switching in isomeric iron(ii) complexes composed of BPP-based ligands-ethyl 2,6-bis(1H-pyrazol-1-yl)isonicotinate (BPP-COOEt, L1) and (2,6-di(1H-pyrazol-1-yl)pyridin-4-yl)methylacetate (BPP-CH2OCOMe, L2)-is dependent on the nature of the substituent at the BPP skeleton. Bi-stable spin-state switching-with a thermal hysteresis width (Delta T-1/2) of 44 K and switching temperature (T-1/2) = 298 K in the first cycle-is observed for complex 1<middle dot>CH3CN composed of L1 and BF4- counter anions. Conversely, the solvent-free isomeric counterpart of 1<middle dot>CH3CN-complex 2a, composed of L2 and BF4- counter anions-was trapped in the high-spin (HS) state. For one of the polymorphs of complex 2b<middle dot>CH3CN-2b<middle dot>CH3CN-Y, Y denotes yellow colour of the crystals-composed of L2 and ClO4- counter anions, a gradual and non-hysteretic SCO is observed with T-1/2 = 234 K. Complexes 1<middle dot>CH3CN and 2b<middle dot>CH3CN-Y also underwent light-induced spin-state switching at 5 K due to the light-induced excited spin-state trapping (LIESST) effect. Structures of the low-spin (LS) and HS forms of complex 1<middle dot>CH3CN revealed that spin-state switching goes hand-in-hand with pronounced distortion of the trans-N{pyridyl}-Fe-N{pyridyl} angle (phi), whereas such distortion is not observed for 2b<middle dot>CH3CN-Y. This observation points that distortion is one of the factors making the spin-state switching of 1<middle dot>CH3CN hysteretic in the solid state. The observation of bi-stable spin-state switching with T-1/2 centred at room temperature for 1<middle dot>CH3CN indicates that technologically relevant spin-state switching profiles based on mononuclear iron(ii) complexes can be obtained.

Název v anglickém jazyce

Lattice solvent- and substituent-dependent spin-crossover in isomeric iron(ii) complexes

Popis výsledku anglicky

Spin-state switching in iron(ii) complexes composed of ligands featuring moderate ligand-field strength-for example, 2,6-bi(1H-pyrazol-1-yl)pyridine (BPP)-is dependent on many factors. Herein, we show that spin-state switching in isomeric iron(ii) complexes composed of BPP-based ligands-ethyl 2,6-bis(1H-pyrazol-1-yl)isonicotinate (BPP-COOEt, L1) and (2,6-di(1H-pyrazol-1-yl)pyridin-4-yl)methylacetate (BPP-CH2OCOMe, L2)-is dependent on the nature of the substituent at the BPP skeleton. Bi-stable spin-state switching-with a thermal hysteresis width (Delta T-1/2) of 44 K and switching temperature (T-1/2) = 298 K in the first cycle-is observed for complex 1<middle dot>CH3CN composed of L1 and BF4- counter anions. Conversely, the solvent-free isomeric counterpart of 1<middle dot>CH3CN-complex 2a, composed of L2 and BF4- counter anions-was trapped in the high-spin (HS) state. For one of the polymorphs of complex 2b<middle dot>CH3CN-2b<middle dot>CH3CN-Y, Y denotes yellow colour of the crystals-composed of L2 and ClO4- counter anions, a gradual and non-hysteretic SCO is observed with T-1/2 = 234 K. Complexes 1<middle dot>CH3CN and 2b<middle dot>CH3CN-Y also underwent light-induced spin-state switching at 5 K due to the light-induced excited spin-state trapping (LIESST) effect. Structures of the low-spin (LS) and HS forms of complex 1<middle dot>CH3CN revealed that spin-state switching goes hand-in-hand with pronounced distortion of the trans-N{pyridyl}-Fe-N{pyridyl} angle (phi), whereas such distortion is not observed for 2b<middle dot>CH3CN-Y. This observation points that distortion is one of the factors making the spin-state switching of 1<middle dot>CH3CN hysteretic in the solid state. The observation of bi-stable spin-state switching with T-1/2 centred at room temperature for 1<middle dot>CH3CN indicates that technologically relevant spin-state switching profiles based on mononuclear iron(ii) complexes can be obtained.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

<a href="/cs/project/GA22-23760S" target="_blank" >GA22-23760S: Sublimovatelné jednomolekulárni magnety pro přípravu nanostrukturních tenkých filmů</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Dalton Transactions

ISSN

1477-9226

e-ISSN

1477-9234

Svazek periodika

53

Číslo periodika v rámci svazku

26

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

16

Strana od-do

1-16

Kód UT WoS článku

001237715400001

EID výsledku v databázi Scopus

2-s2.0-85195041968