Weak Interchain Interactions Research Articles

Water sorption behavior of poly(norbornene)-based anion exchange polyelectrolytes: Experiments and simulation

Poly(norbornene)s (PNBs) are great potential candidates for anion exchange polyelectrolytes (AEPs), however, PNBs-based AEPs usually suffer from excessive water sorption. Herein, the underlying mechanism behind high water sorption was proposed by using the quaternized PNBs as a model AEP. With a moderate ionic content of 2.15 mmol/g, the hydrogenated AEP has a high water uptake of 253 % at 25 °C, which is caused by heterogeneous quaternization and weak interchain interactions. When the brominated AEP was immersed in trimethylamine aqueous (TMA/H2O) solution, TMA penetrates tightly packed polymer chains, seriously destroying vdW interchain interactions. Subsequently, the quaternized cationic groups induce spontaneous water sorption. Although ionic moieties possess strong interchain electrostatic interactions, the solid AEPs restrict polymer chains to form highly cohesive domains for resisting water sorption. Additionally, carbon–carbon double bonds in the PNBs preferentially interact with TMA/H2O, further increasing water uptake. This work provides theoretical guidance for preparing high-performance AEPs based on all-hydrocarbon aliphatic backbones.

Construction of Ideal One-Dimensional Spin Chains by Topochemical Dehydration/Rehydration Route.

One-dimensional (1D) Heisenberg antiferromagnets are of great interest due to their intriguing quantum phenomena. However, the experimental realization of such systems with large spin S remains challenging because even weak interchain interactions induce long-range ordering. In this study, we present an ideal 1D S = 5/2 spin chain antiferromagnet achieved through a multistep topochemical route involving dehydration and rehydration. By desorbing three water molecules from (2,2'-bpy)FeF3(H2O)·2H2O (2,2'-bpy = 2,2'-bipyridyl) at 150 °C and then intercalating two water molecules at room temperature (giving (2,2'-bpy)FeF3·2H2O 1), the initially isolated FeF3ON2 octahedra combine to form corner-sharing FeF4N2 octahedral chains, which are effectively separated by organic and added water molecules. Mössbauer spectroscopy reveals significant dynamical fluctuations down to 2.7 K, despite the presence of strong intrachain interactions. Moreover, results from electron spin resonance (ESR) and heat capacity measurements indicate the absence of long-range order down to 0.5 K. This controlled topochemical dehydration/rehydration approach is further extended to (2,2'-bpy)CrF3·2H2O with S = 3/2 1D chains, thus opening the possibility of obtaining other low-dimensional spin lattices.

Cellulose nanofibril-guided orienting response of supramolecular network enables superstretchable, robust, and antifatigue hydrogel

<p>Hydrogels featuring randomly networked matrix typically show poor mechanical strength owing to the weak interchain interactions of the matrix. Encouragingly, the stretchability and toughness of hydrogel materials along a certain direction were recently improved to an unprecedented level with the design of structured and oriented matrix, the realization of excellent and concurrently isotropic mechanical performance for hydrogels now become the next- research goal. Herein, a self-assembling process of poly(vinyl alcohol) (PVA) macromolecular chain and cellulose nanofibril (CNF) induced by the salting-out effect was reported, which allowed the formation of a strongly hydrogen-bonded PVA-CNF supramolecular matrix. The resulting hydrogel, in any direction, can show an ultra-high stretchability of 7,400% and a true tensile strength of 420 MPa through the orientation of the supramolecular matrix. The robustness of the supramolecular interaction between PVA and CNF was experimentally demonstrated by the fact that the hydrogel showed a high fracture energy (reaching up to 95.7 kJ m<sup>−2</sup>) and low notch sensitivity (fatigue threshold of 3,203 J m<sup>−2</sup>), even outperforming most state-of-the-art anisotropic hydrogels. These results highlight that constructing supramolecular interaction among various components of gel matrix holds great promise for the design of future gel materials with the extraordinary mechanical performance.</p>

Photophysical Properties of S = 5/2 Zigzag-1D (2-Bromoethylammonium)3MnBr5 Antiferromagnet.

It has been challenging to design multifunctional lead-free organic-inorganic hybrid halides that can exhibit fascinating magnetic and photoluminescence properties since the dimensionality of the compounds has a contrasting impact on them. In this context, our newly synthesized compound (2-bromoethylammonium)3MnBr5 (BEAMBr) crystallizes in the monoclinic C2/c space group with corner-sharing zigzag 1D chains of MnBr6 distorted octahedra. Intriguingly, it exhibits a long-range antiferromagnetic ordering at low temperature (∼2.5 K) along with a typical low-dimensional broad magnetic susceptibility hump. The magnetic properties modeled by the exact diagonalization approach indicate strong intrachain and weak interchain interactions with J1 = -50.1 K, J2 = -13.0 K, and J' = -1.25 K, respectively, suggesting excellent one-dimensionality. In addition, BEAMBr displays orange-red emission with a photoluminescence quantum yield of 15.2%. Interestingly, electron-phonon coupling was observed in this soft distorted compound with coupling strength γLO = 128.3 meV, confirmed from the analysis of temperature-dependent emission line width broadening and Raman spectra.

Dynamic acylhydrazone bonds cross-linked chromotropic photonic-ionic skin with self-healing and high resilience for interactive human-machine interface

Advanced skin systems realize perception and interaction with the environment through synergistic electrical and color signals generated by transmitting ions and manipulating photonic structures. Here, inspired by chameleon skins, a novel self-healing and resilient photonic-ionic skin (PI-skin) with electro-optical dual response is ingeniously constructed integrating the ordered micro-nano array and the dynamically covalently cross-linked ionogel. The elaborately designed polycation network with weak inter-chain interactions can promote the uniform distribution of high-content low-viscosity ionic liquid (IL), effectively eliminating energy dissipation and resulting in high resilience. Dynamic acylhydrazone bonds are served as reversible chemical crosslinking to realize high-efficiency self-healing and further enhance resilience. Notably, the artificially manipulated transition of the photonic array from dense packing to non-dense packing endows sensitive chromotropic properties synchronized with electrical response under stretched (Δλ > 130 nm) and compressed (Δλ > 160 nm). Furthermore, by harnessing the correspondence between electrical and optical signals, the control of optical signals over electrical signals is achieved for inputting complex coded information and constructing interactive human–machine interfaces. This work not only inspires the design and construction of high-level artificial skins but also stimulates the development of visual interactive devices and smart electronic/ionic products.

One-Dimensional Van Der Waals Helical Crystals with an Irrational Twist

Long-range helicity in condensed materials has sternly relied on the precise ordering of cooperative intra- and inter-molecular bonding interactions. The exclusivity of these interactions in natural, organic, or molecular systems has limited the conclusive demonstration of aperiodic helical motifs in densely packed solid state lattices. In this talk, we will present a class of 1D van der Waals solids that crystallize as weakly bound helical chains that possess atomic scale order consistent with an aperiodic tetrahelix. We will describe how precise atomic level control of the local coordination environment in these 1D vdW lattices induces helical aperiodicity in periodic helical motifs based on repeating screw axis symmetry motifs. We will also highlight herein that the modularity of vdW lattices allows for the systematic engineering of helical attributes (radius, rise, and twist angle) and band gap energies across the visible to the near-UV spectral window. Owing to the intrinsic non-centrosymmetry of aperiodic helices, we will show that these 1D vdW tetrahelices exhibit visible range second harmonic generation in freestanding crystals from the bulk down to the nanoscale. Lastly, we will demonstrate that the weak vdW interchain interactions in these 1D vdW tetrahelices enables the micromechanical exfoliation into single ~1 nm diameter chiral helical chains. The realization of exfoliable 1D vdW tetrahelices presents a unique materials platform towards understanding the synthetic design rules towards helicity and chirality in low-dimensional solids. Atomically-precise helicity along these length scales will facilitate new opportunities in designing solid state materials towards sub-nanoscale nonlinear chiroptics, long-range spin polarization via chiral-induced spin selectivity, and 1D topological helicoid quantum states.

Copper(II) halide complexes of aminopyridines: Synthesis, structure, and magnetic behavior of neutral compounds of 5-IAP: (5-IAP)2CuCl2·H2O, [(5-IAP)2CuBr2]2, (5-IAP)2CuBr2 and (5-IAP)3CuCl2·nH2O (5IAP = 2-amino-5-iodopyridine)

Reaction of 2-amino-5-iodopyridine (5IAP) with copper(II) bromide or chloride in alcoholic solution led to four coordination complexes: [(5-IAP)2CuCl2](H2O) (1), (5-IAP)2CuBr2 (2), [(5-IAP)2CuBr2]2 (3) and [(5-IAP)3CuCl2](H2O)n (4). The compounds were characterized by single crystal X-ray diffraction and variable temperature magnetic susceptibility measurements. 1 crystallizes as monomeric units with the 5IAP ligands in the syn-conformation and one lattice water molecule. 2 also exhibits syn-conformation 5IAP ligands, but forms a common bromide bibridged dimer structure. 3 is a conformational polymorph of 2 with anti-oriented 5IAP ligands. Long Cu⋯Br contacts link the molecules into chains. 4 crystallizes with 1.67 lattice water molecules, disordered over three positions. All four compounds exhibit strong halogen bonding. Variable field and temperature magnetic data were obtained on 1–3. 1 is paramagnetic, with no indication of magnetic exchange down to 1.8 K. 2 is well modeled as an antiferromagnetic dimer (J/kB = −22 K) with significant antiferromagnetic interactions between the dimers. 3 is well modeled as a uniform antiferromagnetic chain (J/kB = −6 K) with weak interchain interactions.

Interchain interactions induced multiferroicity in SrFeF5

SrFeF5 is a typical spin-chain compound with strong intrachain and moderate interchain interactions. It has been predicted to be multiferroic due to the cycloidal spin structure. Herein, we provide clear experimental evidence of multiferroicity of SrFeF5 by a systematic investigation of its magnetic, dielectric, and pyroelectric properties. The complicated interactions between neighboring Fe ions lead to the following three magnetic transitions. The divergence between field cooling (FC) and zero field cooling (ZFC) M(T) curves at TN1∼ 80 K originates from the antiparallel alignment of neighboring spins along the chains due to the strong intrachain interactions. The sudden increase in magnetization with further divergence between the FC and ZFC M(T) curves is observed at TN2 ∼ 42 K, which originates from the formation of cycloidal spin structure due to the contribution from moderate interchain interactions. An upturn of magnetization with further decreasing temperature at TN3 ∼ 6 K is due to the contribution from the much weaker interchain interactions. Exchange bias starts to emerge at around 30 K, reaches a maximum at 20 K, and further increases below 10 K. A frequency independent peak of dielectric constant is observed at around TN2, due to the cycloidal spin structure induced spontaneous polarization. This work helps to understand the multiferroic properties in the spin-chain fluorides.

Elevating the water/salt selectivity of polybenzimidazole to the empirical upper bound of desalting polymers by marrying N-substitution with chlorination

Polybenzimidazole (PBI) was modified by marrying N-substitution with chlorination in order to improve its desalination properties. Based on the solution-diffusion theory, the effect of N-substitution and then chlorination on the water/salt transport properties of PBI was systematically analyzed. Although the introduction of hydrophobic p-toluenesulfonyl groups decreases water sorption, significantly increases water diffusion by weakening the hydrogen bonding between polymer chains. As a result, the water permeability of substituted PBI (SPBI) was 20 times higher than that of PBI. In terms of salt transport, the increase in salt diffusion of SPBI caused by the weaker inter-chain interactions was offset by a substantial decrease in salt sorption due to the combined effect of electrostatic repulsion and increased accessibility of hydrophilic groups to bind water, leading to equivalent salt permeability of PBI to SPBI. Controlled chlorination of SPBI under acidic conditions can further improve polymer water diffusion and thus water/salt diffusivity selectivity. The permeation of both SPBI and chlorinated SPBI is diffusion dependent. Therefore, combining N-substitution and chlorination is an effective strategy to simultaneously improve PBI permeability and water/salt selectivity for desalination applications.

Co(NCS)2 Chain Compound with Alternating 5- and 6-Fold Coordination: Influence of Metal Coordination on the Magnetic Properties.

The reaction of Co(NCS)2 with 3-bromopyridine leads to the formation of discrete complexes [Co(NCS)2(3-bromopyridine)4] (1), [Co(NCS)2(3-bromopyridine)2(H2O)2] (2), and [Co(NCS)2(3-bromopyridine)2(MeOH)2] (3) depending on the solvent. Thermogravimetric measurements on 2 and 3 show a transformation into [Co(NCS)2(3-bromopyridine)2]n (4), which upon further heating is converted to [{Co(NCS)2}2(3-bromopyridine)3]n (5), whereas 1 transforms directly into 5 upon heating. Compound 5 can also be obtained from solution, which is not possible for 4. In 4 and 5, the cobalt(II) cations are linked by pairs of μ-1,3-bridging thiocyanate anions into chains. In compound 4, all cobalt(II) cations are octahedrally coordinated (OC-6), as is usually observed in such compounds, whereas in 5, a previously unkown alternating 5- and 6-fold coordination is observed, leading to vacant octahedral (vOC-5) and octahedral (OC-6) environments, respectively. In contrast to 4, the chains in 5 are very efficiently packed and linked by π···π stacking of the pyridine rings and interchain Co···Br interactions, which is the basis for the formation of this unusual chain. The spin chains in 4 demonstrate ferromagnetic intrachain exchange and much weaker interchain interactions, as is usually observed for such linear chain compounds. In contrast, compound 5 shows almost single-ion-like magnetic susceptibility, but the magnetic ordering temperature deduced from specific heat measurements is twice as high as that in 4, which might originate from π···π stacking and Co···Br interactions between neighboring chains. More importantly, unlike all linear Co(NCS)2 chain compounds, a dominant antiferromagnetic exchange is observed for 5, which is explained by density functional theory calculations predicting an alternating ferro- and aniferromagnetic exchange within the chains. Theoretical calculations on the two different cobalt(II) ions present in 5 predict an easy-axis anisotropy that is much stronger for the octahedral cobalt(II) ion than for the one with the vacant octahedral coordination, with the magnetic axes of the two ions being canted by an angle of 84°. This almost orthogonal orientation of the easy axis of magnetization for the two cobalt(II) ions is the rationale for the observed non-Ising behavior of 5.

Detailed Photophysical Studies of Poly(9,9-di-(2-ethylhexyl)-9-H-fluorene-2,7-vinylene) in Liquid Media and Thin Films

For the present work, solvent (toluene, o-xylene, chloroform, chlorobenzene, and 1,2-dichloroethane) and concentration-dependent (∼10-6-10-3 gml-1) photophysical properties of poly(9,9-di-(2-ethylhexyl)-9-H-fluorene-2,7-vinylene) (PEFV) were investigated in detail in liquid media as well as thin films. Also, temperature-dependent (3-60oC) fluorescence emission measurements of PEFV were conducted in liquid media. The steady-state and time-resolved data indicate the existence of weak interchain interaction in liquid media at high concentration. However, both ground-state aggregation and interchain interaction are present for PEFV in thin film. The interchain interaction plays a dominant role on the fluorescence emission of PEFV in thin film on the red side of the spectra.

Partially Ordered Lanthanide Carboxylates with a Highly Adaptable 1D Polymeric Structure.

A new family of 14 isostructural [Ln(piv)3(en)]∞ lanthanide pivalate (piv−, 2,2-dimethylpropanoate) complexes with ethylenediamine (en) was synthesized by a topology-preserving transformation from 1D coordination polymers [Ln(piv)3]∞. The crystal structures of the compounds were determined by single-crystal and powder X-ray diffraction, which demonstrated that despite the regular ligand arrangement within the chains, the latter are intricately packed within the partially ordered crystal, as only two of four ligands are strictly bound by the translational symmetry. The peculiarities of the lanthanide coordination environment were explored by total X-ray scattering with pair distribution function analysis. Periodic DFT calculations revealed the chain stabilization by intrachain H-bonds and weak interchain interactions. Noticeably, the energy difference was infinitesimally small even between the two considered extreme variants of ordered packing, which is in line with the disturbed packing order of the chains. The luminescent properties of Eu and Tb complexes were investigated in order to prove the energy transfer between lanthanide ions within the heterometallic complex. This opens up the prospect of creating new materials for optical applications. The heterometallic compound Eu0.05Tb0.95(piv)3(en) was synthesized, and was found to demonstrate temperature-dependent luminescence with a linear dependence of the thermometric parameter I(Eu)/I(Tb) within the temperature range from −80 °C to 80 °C, and had a maximum relative sensitivity value of 0.2%/K.

Fabrication of high-temperature aromatic polyamides with ultra-high breakdown strength via complex-assisted chain arrangement

• Highly orientated polyamides were prepared via complex-assisted chain arrangement. • The breakdown strength of the polyamide increased from 460 to 641 kV/mm. • Cross-linking enhanced breakdown strength to 706 and 572 kV/mm at 25 and 150 °C. • Breakdown strength of the cross-linked polymer is higher than that of commercial film. • The polymer films presented excellent mechanical properties and dimensional stability. Improving the breakdown strength ( Eb ) of high-performance polymer films is critical for their use as high-temperature insulation films. In this study, we demonstrated HCl can complex with the benzimidazole units of heterocyclic aramid polymers, temporarily suppressing the intermolecular hydrogen-bonding interactions. Moreover, the weak interchain interactions led to improved mobility and extended the conformation of the macromolecular chain. Therefore, after HCl decomplexation, the macromolecular chains presented higher orientations and degrees of order during subsequent high temperature annealing, resulting in an increase the Eb of the films from 460 to 641 kV/mm at 25 °C. The Fourier-transform infrared spectroscopy and theoretical calculation results indicated that the hydrogen-bonding interactions were restored and enhanced after HCl decomplexation via annealing. In addition, trace amounts of O 2 were used to catalyze the cross-linking reaction between phenyl groups based on the high electron density of the benzimidazole moieties. Owing to the chemical cross-linking reaction, the Eb of the films further increased to 706 and 572 kV/mm at 25 °C and 150 °C, respectively, whereas the tensile strength of the films reached 337.4 MPa.

Intrinsically Viscoelastic Supramolecular Conjugated Polymer toward Suppressing Coffee-Ring Effect

Intrinsically Viscoelastic Supramolecular Conjugated Polymer toward Suppressing Coffee-Ring Effect

Coexistence of Spin Canting and Metamagnetism in a One-Dimensional Mn(II) Compound Bridged by Alternating Double End-to-End and Double End-On Azido Ligands and the Analog Co(II) Compound

Two new compounds of general formula [M(N3)2(dmbpy)] in which dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and M = Mn(II) or Co(II), have been solvothermally synthesized and characterized structurally and magnetically. The structures consist of zig-zag polymeric chains with alternating bis-µ(azide-N1)2M and bis-µ(azide-N1,N3)2M units in which the cis-octahedrally based coordination geometry is completed by the N,N’-chelating ligand dmbpy. The molecular structures are basically the same for each metal. The Mn(II) compound has a slightly different packing mode compared to the Co(II) compound, resulting from their different space groups. Interestingly, relatively weak interchain interactions are present in both compounds and this originates from π–π stacking between the dmbpy rings. The magnetic properties of both compounds have been investigated down to 2 K. The measurements indicate that the manganese compound shows spin-canted antiferromagnetic ordering with a Néel temperature of TN = 3.4 K and further, a field-induced magnetic transition of metamagnetism at temperatures below the TN. This finding affords the first example of an 1D Mn(II) compound with alternating double end-on (EO) and double end-to-end (EE) azido-bridged ligands, showing the coexistence of spin canting and metamagnetism. The cobalt compound shows a weak ferromagnetism resulting from a spin-canted antiferromagnetism and long-range magnetic ordering with a critical temperature, TC = 16.2 K.

Surface critical behavior of coupled Haldane chains

The special surface transition at (2+1)-dimensional quantum critical point is precluded in corresponding classical critical point. The mechanism of such behavior which is only found in dimerized Heisenberg models so far is still under debate. To illuminate the role of symmetry protected topological (SPT) phase in inducing such nonordinary behaviors, we study a system on a two-dimensional square lattice consisted by interacting spin-1 Haldane chains, which has a genuine SPT phase--the Haldane phase--at weak interchain interactions and a quantum critical point belonging to the classical 3D O(3) universality class to the N\'eel phase. Different from models studied previously, there is no dimerization in the current model. Cutting the system along the chain direction or perpendicular to the chain direction exposes two different surfaces. Using unbiased quantum Monte Carlo simulations, we find that the two different types of surface show completely different surface critical behaviors at the bulk critical point, resulted from different surface states in the SPT phase. For the system with surfaces along the chain direction, the surface critical behavior is of ordinary type of the bulk 3D O(3) critical point, while for the surfaces perpendicular to the chain direction, the surface critical behavior is nonordinary, consistent with special transitions found in dimerized Heisenberg models. Our numerical results demonstrate that the gapless surface state in the gapped SPT phase together with the gapless mode of critical point is a pure quantum scenario that leads to the nonordinary transition.

Looking for charge order

Physics At low temperatures, ions in some one-dimensional (1D) crystal lattices are predicted to transition into a chain of dimers. The resulting charge order has been observed in quasi-1D solids consisting of ionic chains with weak interchain interactions. Aiming to find out whether this transition occurs in purely 1D systems, Yang et al. synthesized nanowires of Mo6Se6 from monolayers of the transition metal dichalcogenide MoSe2. This resulted in two types of nanowires: those attached along the edges of MoSe2 and those connecting adjacent MoSe2 flakes. Scanning tunneling spectroscopy revealed coherent charge order in the former, but not the latter, type. The loss of coherence might be caused by the formation of polaronic quasiparticles in the 1D system. Phys. Rev. X 10 , 031061 (2020).

Shear-Induced Adhesion of Alternating Peptides Prepared by Ugi Four-Center Three-Component Reaction.

The development of new peptide-based glues has been strongly urged from the viewpoints of industrial applications and biomedical engineering. However, the large-scale synthesis of polypeptides with an ordered sequence is highly challenging, which strictly restricts materials resources for the research and development of polypeptides. In this work, the framework of adhesive alternating peptides has been designed to be glycine (Gly)-N-substituted valine (Val) as the dipeptide repeating sequence, considering the peptapeptide repeating sequence of viscoelastic natural elastin as a motif. The alternating peptides are prepared via three-component polymerization exploiting Ugi four-center three-component reaction as the elemental polymerization reaction. The adhesive strength (SAdh ) values of the polymers are evaluated by a shear adhesive test method using two glass plates. Alternating peptides with Gly-N-benzylated Val dipeptide repeating units exhibit the optimal adhesive properties such as much higher SAdh than that of conventional fibrin glue and a unique readhesion capability. It is indicated that the remarkably high SAdh would be attributed to the shear-induced structural change of single polymer chain, the slow relaxation of extended structure, and the weak interchain interactions. Due to the favorable adhesive properties of alternating peptides, these adhesives may be highly suitable for real-world applications.

Uniform Spin-1/2-Chain System with a Weak Interchain Interaction.

A new hydroxyl sulfate-fluoride compound, Lu2Cu(SO4)2(OH)3F·H2O, was obtained using a hydrothermal method. This compound is found to crystallize in a monoclinic space group of P21/c, exhibiting a uniform chain structure along the b axis, in which the chains are composed of elongated CuO4+2 octahedra and further separated by SO4 tetrahedra and Lu3+ ions. The shortest Cu-Cu distance inside the chains is ∼3.394(1) Å, while that between neighboring chains is ∼7.878(1) Å. Magnetic and heat capacity measurements indicate that this compound does not possess long-range magnetic order until 2 K. The fitting of spin-chain models suggests a strong intrachain interaction J and a weak interchain interaction J' with a small value of |J'/J| < 3.20(2) × 10-3, indicating that Lu2Cu(SO4)2(OH)3F·H2O may be a nearly ideal one-dimensional spin-1/2-chain system.

Multifunctional Ni(II)-Based Metamagnetic Coordination Polymers for Electronic Device Fabrication.

The combination of two 8-aminoquinoline-based Schiff base ligands (L1 and L2) with SCN- and Ni(II) has led to the synthesis of two new one-dimensional thiocyanato-bridged coordination polymers: [Ni(L1)(NCS)2]n (1) and [Ni(L2)(NCS)2]n (2). Both compounds are isostructural and consists of regular zigzag thiocyanato-bridged chains with very weak S···S interchain interactions. The measured room-temperature conductivities of compounds 1 and 2 (7.0 × 10-5 and 2.0 × 10-5 S m-1, respectively) are indicative of semiconductor behavior which increases in the presence of photoillumination (3.5 × 10-4 and 4.9 × 10-4 S m-1, respectively). The measured I-V characteristics of compound 1 and 2 based thin film metal-semiconductor (MS) junction devices under irradiation and nonirradiation conditions show a nonlinear rectifying behavior, typical of a Schottky diode (SD). The rectification ratios (Ion/Ioff) of the SDs in the dark at ±2 V (26.96 and 31.96 for 1- and 2-based devices, respectively) increase to 44.19 and 79.42, respectively, upon light irradiation. The photoinduced behavior has been analyzed by thermionic emission theory, and to determine the diode parameters, the Cheung's method has been employed. These diode parameters indicate that compound 2 has a better performance in comparison to compound 1 and that these materials are good candidates for applications in electrochemical devices. Magnetic measurements show that both compounds present ferromagnetic Ni-Ni intrachain and weak antiferromagnetic interchain interactions. The isothermal magnetizations at 2 K show that both compounds are metamagnets with critical fields of ca. 130 mT in 1 and 90 mT in 2 at 2 K. In the ferromagnetic phase (above the critical field), both compounds exhibit a long-range ferromagnetic order with critical temperatures of around 3.5 K in 1 and 3.0 K in 2. DC and AC measurements with different applied DC fields confirm the metamagnetic behaviors and have allowed the determination of the magnetic phase diagram in both compounds.