Quantum Chemical Modeling of Pressure-Induced Spin Crossover in Octahedral Metal-Ligand Complexes

10.26434/chemrxiv.9741434.v1 ◽

2019 ◽

Author(s):

Tim Stauch ◽

Romit Chakraborty ◽

Martin Head-Gordon

Keyword(s):

Carbon Monoxide ◽

Molecular Electronics ◽

Spin Crossover ◽

Strong Field ◽

Spin Transition ◽

Nuclear Forces ◽

Chemical Modeling ◽

Metal Centers ◽

State Switching ◽

External Stimuli

Spin state switching on external stimuli is a phenomenon with wide applicability ranging from molecular electronics to gas activation in nanoporous frameworks. Here we model spin crossover as a function of hydrostatic pressure in octahedrally coordinated transition metal centers by applying a field of effective nuclear forces that compress the molecule towards its centroid. For spin crossover in first-row transition metals coordinated by hydrogen, nitrogen, and carbon monoxide, we find the pressure required for spin transition to be a function of ligand position in the spectrochemical sequence. While pressures on the order of 1 GPa are required to flip spins in homogeneously ligated octahedral sites, we demonstrate a five-fold decrease in spin transition pressure for the archetypal strong field ligand carbon monoxide in octahedrally coordinated Fe2+ in [Fe(II)(NH3)5CO]2+.

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Spin state switching in iron coordination compounds

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.9.39 ◽

2013 ◽

Vol 9 ◽

pp. 342-391 ◽

Cited By ~ 446

Author(s):

Philipp Gütlich ◽

Ana B Gaspar ◽

Yann Garcia

Keyword(s):

Spin State ◽

Coordination Compounds ◽

Spin Crossover ◽

Spin Transition ◽

Pressure Sensors ◽

Ligand Field ◽

Thermally Induced ◽

Practical Applications ◽

State Switching ◽

Switching Phenomenon

The article deals with coordination compounds of iron(II) that may exhibit thermally induced spin transition, known as spin crossover, depending on the nature of the coordinating ligand sphere. Spin transition in such compounds also occurs under pressure and irradiation with light. The spin states involved have different magnetic and optical properties suitable for their detection and characterization. Spin crossover compounds, though known for more than eight decades, have become most attractive in recent years and are extensively studied by chemists and physicists. The switching properties make such materials potential candidates for practical applications in thermal and pressure sensors as well as optical devices. The article begins with a brief description of the principle of molecular spin state switching using simple concepts of ligand field theory. Conditions to be fulfilled in order to observe spin crossover will be explained and general remarks regarding the chemical nature that is important for the occurrence of spin crossover will be made. A subsequent section describes the molecular consequences of spin crossover and the variety of physical techniques usually applied for their characterization. The effects of light irradiation (LIESST) and application of pressure are subjects of two separate sections. The major part of this account concentrates on selected spin crossover compounds of iron(II), with particular emphasis on the chemical and physical influences on the spin crossover behavior. The vast variety of compounds exhibiting this fascinating switching phenomenon encompasses mono-, oligo- and polynuclear iron(II) complexes and cages, polymeric 1D, 2D and 3D systems, nanomaterials, and polyfunctional materials that combine spin crossover with another physical or chemical property.

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An iron(II) complex tripodally chelated with 1,1,1-tris(pyridin-2-yl)ethane showing room-temperature spin-crossover behaviour

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229616004174 ◽

2016 ◽

Vol 72 (11) ◽

pp. 797-801 ◽

Cited By ~ 6

Author(s):

Takayuki Ishida ◽

Takuya Kanetomo ◽

Masaru Yamasaki

Keyword(s):

High Spin ◽

Room Temperature ◽

Spin Crossover ◽

Spin Transition ◽

Complex Salt ◽

Magnetic Study ◽

The Novel ◽

Bond Lengths ◽

External Stimuli ◽

Spin Species

The spin-crossover phenomenon is a reversible low- and high-spin transition caused by external stimuli such as heat. In the novel iron(II) complex salt tetraphenylphosphonium tris(thiocyanato-κN)[1,1,1-tris(pyridin-2-yl)ethane-κ3N,N′,N′′]ferrate(II), (C24H20P)[Fe(NCS)3(C17H15N3)], the Fe—N bond lengths are in the range 2.027 (2)–2.089 (2) Å, indicating that the specimen consists of comparable molar fractions of the low- and high-spin species at 296 K. A magnetic study confirmed that spin-crossover takes place at around 290 K.

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Quantum chemical modeling of magnetically bistable metal coordination compounds. Synchronization of spin crossover, valence tautomerism and charge transfer induced spin transition mechanisms

Dalton Transactions ◽

10.1039/c6dt01687a ◽

2016 ◽

Vol 45 (30) ◽

pp. 12103-12113 ◽

Cited By ~ 20

Author(s):

V. I. Minkin ◽

A. A. Starikova ◽

A. G. Starikov

Keyword(s):

Quantum Chemical ◽

Coordination Compounds ◽

Spin Crossover ◽

Dynamic Behaviour ◽

Spin Transition ◽

Heterometallic Complexes ◽

Chemical Modeling ◽

Valence Tautomerism ◽

Thermally Induced ◽

Intramolecular Rearrangements

Heterometallic complexes of 1,10-phenanthroline-5,6-dione exhibiting unprecedented dynamic behaviour due to synchronized thermally induced intramolecular rearrangements were computationally studied.

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Abrupt spin crossover in iron(iii) complexes with aromatic anions

Dalton Transactions ◽

10.1039/c9dt02373a ◽

2019 ◽

Vol 48 (41) ◽

pp. 15515-15520 ◽

Cited By ~ 5

Author(s):

Sharon E. Lazaro ◽

Adil Alkaş ◽

Seok J. Lee ◽

Shane G. Telfer ◽

Keith S. Murray ◽

...

Keyword(s):

Transition Temperature ◽

Spin Crossover ◽

Spin Transition ◽

Halogen Bonds ◽

Aromatic Anions

Two iron(iii) complexes, [Fe(qsal-X)2]OTs·nH2O, are found to exhibit abrupt spin crossover with the spin transition temperature substituent dependent, and X⋯O halogen bonds linking the spin centres.

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Electrical read-out of light-induced spin transition in thin film spin crossover/graphene heterostructures

Journal of Materials Chemistry C ◽

10.1039/d0tc05202g ◽

2021 ◽

Author(s):

Nikita Konstantinov ◽

Arthur Tauzin ◽

Ulrich Nguetchuissi Noumbé ◽

Diana Dragoe ◽

Bohdan Kundys ◽

...

Keyword(s):

Thin Film ◽

Spin Crossover ◽

Spin Transition ◽

Switching Device ◽

Electronic Switching ◽

Spin Transitions

An opto-electronic switching device made from an evaporated spin crossover thin film over a graphene sensor is presented. The electrical transduction of both temperature and light-induced reversible spin transitions are demonstrated.

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Spin-crossover in a trans-[FeL2(NCS)2] family (L = triaryltriazole): remote substituent effects on spin transition modes and temperature

Dalton Transactions ◽

10.1039/c3dt50821h ◽

2013 ◽

Vol 42 (28) ◽

pp. 10144 ◽

Cited By ~ 15

Author(s):

Guo-Ping Shen ◽

Li Qi ◽

Lei Wang ◽

Yan Xu ◽

Jing-Jing Jiang ◽

...

Keyword(s):

Spin Crossover ◽

Spin Transition ◽

Substituent Effects ◽

Transition Modes ◽

Remote Substituent

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Spin Crossover in Nickel(II) Tetraphenylporphyrinate via Forced Axial Coordination at the Air/Water Interface

Molecules ◽

10.3390/molecules26144155 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4155

Author(s):

Alexander V. Shokurov ◽

Daria S. Kutsybala ◽

Andrey P. Kroitor ◽

Alexander A. Dmitrienko ◽

Alexander G. Martynov ◽

...

Keyword(s):

Spin State ◽

Spin Crossover ◽

High Spin State ◽

Water Interface ◽

Metal Centers ◽

Axial Coordination ◽

Vis Spectroscopy ◽

Air Water Interface ◽

Nickel Cation

Coordination-induced spin crossover (CISCO) in nickel(II) porphyrinates is an intriguing phenomenon that is interesting from both fundamental and practical standpoints. However, in most cases, realization of this effect requires extensive synthetic protocols or extreme concentrations of extra-ligands. Herein we show that CISCO effect can be prompted for the commonly available nickel(II) tetraphenylporphyrinate, NiTPP, upon deposition of this complex at the air/water interface together with a ruthenium(II) phthalocyaninate, CRPcRu(pyz)2, bearing two axial pyrazine ligands. The latter was used as a molecular guiderail to align Ni···Ru···Ni metal centers for pyrazine coordination upon lateral compression of the system, which helps bring the two macrocycles closer together and forces the formation of Ni–pyz bonds. The fact of Ni(II) porphyrinate switching from low- to high-spin state upon acquiring additional ligands can be conveniently observed in situ via reflection-absorption UV-vis spectroscopy. The reversible nature of this interaction allows for dissociation of Ni–pyz bonds, and thus, change of nickel cation spin state, upon expansion of the monolayer.

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