Single-molecule magnets (SMMs) that can be trapped in one of the bistable magnetic states separated by an energy barrier are among most promising candidates for high-density information storage, quantum processing, and spintronics. To date, a considerable series achievements have been made. However, presence fast tunnelling magnetization (QTM) SMMs, especially single-ion (SIMs), provides rapid relaxation route often sets up limit time. Here, we pursue pentagonal bipyramidal symmetry to...

Hydro(solvo)thermal reactions between a new flexible multicarboxylate ligand of 2,2',3,3'-oxydiphthalic acid (2,2',3,3'-H(4)ODPA) and M(NO(3))(2).xH(2)O (M = Zn, x 6; M Cd, 4) in the presence 4,4'-bipyridine (bpy) afford two novel homochiral helical coordination polymers [[Zn(2)(2,2',3,3'-ODPA)(bpy)(H(2)O)(3)].(H(2)O)(2) for 1 [Cd(2)(2,2',3,3'-ODPA)(bpy)(H(2)O)(3)].(H(2)O)(2) 2]. Though having almost same chemical formula, they have different space groups (P2(1)2(1)2(1) P2(1) 2) bridging...

Abstract Materials with hysteretic multi‐step spin‐crossover (SCO) have potential application in high‐order data storage. Here, an unprecedented four‐step SCO behavior the sequence of LS↔HS 0.25 LS 0.75 ↔HS 0.5 ↔ HS is found a three‐dimensional (3D) Hofmann‐type metal–organic framework (MOF), which evidenced by magnetic, differential scanning calorimetry, and crystal data. Further experiments involving guest exchange leads to first reversible modulation four‐, two‐, one‐stepped behaviors,...

Stimuli-responsive materials that can be reversibly switched by light are of immense interest. Among them, photo-responsive spin crossover (SCO) complexes have great promises to combine the photoactive inputs with multifaceted outputs into switchable and devices. However, reversible control spin-state change photochromic guests is still challenging. Herein, we report an unprecedented guest-driven light-induced (GD-LISC) in a Hofmann-type metal-organic framework (MOF), [Fe(bpn){Ag(CN)2 }2...

Magnetic switchable maleonitriledithiolate (mnt) complexes were studied by density functional theory. The calculations performed for anion dimers of [RBzPyR'][Ni(mnt)2] (RBzPyR' = derivatives benzylpyridinium) to elucidate magnetostructural correlations and the nature weak intermolecular chemical bonding. calculated results showed that spin delocalization, favored eclipsed stacking shorter interlayer distance, was responsible diamagnetic character [1-benzyl-4-aminopyridinium][Ni(mnt)2] at...

This study reports the first modulation of spin-crossover (SCO) behavior via a photochemical [2 + 2] cycloaddition reaction. Here we construct two no-solvent Fe(ii)-Ag(i) bimetallic Hofmann-type frameworks, [Fe(4-spy)2{Ag(CN)2}2] (1) and [Fe(2,4-bpe)2{Ag(CN)2}2] (2) (4-spy = 4-styrylpyridine, 2,4-bpe trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene). For 1, dimerization 4-spy results in single-crystal to (SCSC) transformation from 2D interdigitated layers 3D interpenetrated structure. Additionally,...

Metal-organic frameworks (MOFs) provide versatile platforms to construct multi-responsive materials. Herein, by introducing the neutral tetradentate ligand and linear dicyanoaurate(I) anion, we reported a rare cationic MOF [FeII(TPB){AuI(CN)2}]I·4H2O·4DMF (TPB = 1,2,4,5-tetra(pyridin-4-yl)benzene) with hysteretic spin-crossover (SCO) behavior near room temperature. This hybrid framework an open metal site (AuI) exhibits redox-programmable capability toward dihalogen molecules. By means of...

Bidirectional photomagnetism, exciplex fluorescence and dielectric anomalies are first observed in a spin crossover Hofmann-type metal–organic framework with bent pillar ligand pyrene guest.

A novel 3D metal-organic framework [Cd2(m-bptc)(4,4'-bpy)(0.5)(H2O)4].H2O (1; m-H4bptc = 1,1'-biphenyl-2,3',3,4'-tetracarboxylic acid, 4,4'-bpy 4,4'-bipyridine) with interweaving of triple- and single-helical chains has been obtained based on hydro(solvo)thermal reactions.

Many spin-crossover complexes exhibit high sensitivity to small environmental changes. Here, we demonstrate proof-of-concept exploitation of this property report anion binding events in solution. Dichloromethane solutions the cationic receptor complex [Fe(H2bip)3](BPh4)2 (bip = 2,2′-bi-1,4,5,6-tetrahydropyrimidine) (1) undergo subtle color changes at room temperature when interrogated by anions capable hydrogen bonding interactions. Significantly, −40 °C, these secondary interactions cause a...

We report the synthesis, characterization, and representative anion-binding studies on a series of heteroleptic FeII diimine complexes that have been designed to show anion-triggered spin state switching at ambient temperatures. Starting with [(H2bip)2FeBr2] (1), ligand substitution affords [(H2bip)2Fe(NN)]2+ complexes, where (NN) = pipi (2), bpy (3), phen (4). In solid state, tetraphenylborate bromide salts display different thermally induced crossover properties, transition temperatures...

A flexible heterostructure is reported herein, which elastically couples the volumetric variation during SCO to electrical conductivity of a strain-sensitive metallic conductor, thereby resulting in synergistic bistability.

A chiral metal-organic framework exhibiting spin crossover (SCO) property, [Fe(II)(mptpy)2]·EtOH·0.2DMF (·solv), has been solvothermally synthesized through spontaneous resolution. It displays remarkable stability and two-step SCO at (Tc1 = 200 K) above (Tc2 357 room temperature.

Hysteretic four-step spin crossover behaviour with the sequence of LS ↔ HS_0.25LS_0.75 HS_0.5LS_0.5 HS_0.67LS_0.33 HS is observed for first time.

Two new two-stage manipulation protocols, namely light- and temperature-assisted spin state annealing (LASSA/TASSA), are applied to a crossover coordination polymer, [Fe(isoq)₂{Au(CN)₂}₂], revealing the hidden multistability of states.

An unprecedented hysteretic seven-/eight-step spin-crossover behavior is revealed. Most importantly, a molecular alloy based on Hofmann-type framework used as strategy to explore multi-step materials for the first time.

Four novel interesting coordination polymers, [Cd3(bix)3(SSA)2(H2O)4]n (1), [Co(bix)2(HSSA)(H2O)·H2O]n (2), [Ni(bix)2(HSSA)(H2O)·H2O]n (3) and [Mn(bix)2·(HSSA)·2H2O]n (4) (bix = 1,4-bis(imidazol-1-ylmethyl)-benzene; H3SSA 5-sulfosalicylic acid), have been synthesized under hydrothermal conditions structurally characterized. Polymer 1 features a two-dimensional (2D) infinite layer framework built from tri-cadmium clusters, which is further stacked along the c-axis via strong interlayer...

A new approach to synthesize 3D structures through a [2+2] photodimerization process has been carried out by transforming two isostructures of 1D staggered-sculls chains [M(1,2-chdc)(bpe)(2)(H(2)O)(2)]⋅H(2)O (M = Zn, Mn) into NbO-type metal-organic frameworks UV irradiation in single-crystal-to-single-crystal mode. (see figure; bpe trans-1,2-(bis(4-pyridyl)ethene, chdc =cyclohexanedicarboxylate).

Abstract A Hoffman‐like coordination polymer with appreciable porosity and uncoordinated pyridyl groups, namely, [Fe(2,5‐bpp){Au(CN) 2 } ] ⋅ x Solv (2,5‐bpp=2,5‐bis(pyrid‐4‐yl)pyridine; Solv=solvent), was synthesised characterised. series of fascinating spin‐crossover behaviours abrupt, stepwise hysteretic features were obtained by exchange a range protic solvents (ethanol, n ‐propanol, isopropyl alcohol, sec ‐butanol isobutanol). Guest–host hydrogen‐bonding interactions involving the...

The spin-crossover cooperativity of a Hoffman-like metal–organic framework is dramatically modulated by introducing different aromatic guest molecules (benzene, naphthalene, anthracene, and ferrocene) with the thermal hysteresis width ranging from 0 K to 73 K.

Three new two-dimensional (2D) Hofmann-type coordination polymers with general formula [Fe(3-NH2py)2M(CN)4] (3-NH2py = 3-aminopyridine, M Ni (1), Pd (2), Pt (3)) have been synthesized. Magnetic susceptibility measurements show that they exhibited cooperative spin crossover (SCO) remarkable hysteretic behaviors. Their hysteresis widths are 25, 37, and 30 K for 1–3, respectively. The single-crystal structure of 1 suggest the pseudo-octahedral Fe sites equatorially bridged by [M(CN)4]2– to form...

An extremely rare bidirectional light-induced excited spin-state trapping effect is firstly observed in a 3D Hofmann-type metal–organic framework with 1-fluoronaphthalene guests.