Organic-inorganic Hybrid Salt Research Articles

Multi-stimuli responsive behaviors in a new chiral hybrid nitroprusside salt (R-3-hydroxypyrrolidinium)2[Fe(CN)5(NO)

Multi-stimuli responsive materials controlled and coupled by two or more channels have a broad range of applications in the field of switches, memories, and molecular machines. The exploration of the material is currently focused on the pure organic system, which limits the development of such materials greatly. In this work, we present a new chiral organic-inorganic hybrid salt, (R-3-hydroxypyrrolidinium)2[Fe(CN)5(NO)] (1), which exhibits rare multi-stimuli responsive behaviors in thermal, mechanical and optical channels. In detail, 1 undergoes a C2-P21221 phase transition deriving from the thermal motion of organic cations with the increase of temperature, but the reverse transition can only be induced by mechanical pressure. Moreover, polycrystalline hybrid salt showed photo-responsive performance, i.e., the ground-state N-bound nitrosyl ligand adopts two configurations in excited states caused by light in 532 nm irradiation, accompanying with a photo-induced structural transformation of the anionic framework. Namely, the thermal motion characteristics of organic cations, the photoresponse characteristics of anionic inorganic skeleton and the pressure characteristics from hydrogen bonds are simultaneously integrated in 1. This unprecedented coupling mechanism of multi-stimuli responses makes 1 a potential candidate for future multichannel data storage applications.

Noncovalent Dualism in Perylene-Diimide-Based Keggin Anion Complexes: Theoretical and Experimental studies.

We report the synthesis and comprehensive characterization of organic-inorganic hybrid salts formed by bis-cationic N,N'-bis(2-(trimethylammonium)ethylene)perylene-3,4,9,10-tetracarboxylic acid bisimide (PTCD2+) and Keggin-type [XW12O40]n- (X = Si, n = 4; X = P, n = 3) polyoxometalates. (PTCD)3[PW12O40]2·3DMSO·2H2O (2) and (PTCD)2[SiW12O40]·DMSO·2H2O (3) were structurally characterized by single crystal X-ray diffraction. The cations in both structures exhibited infinite chainlike arrangements through π-π interactions, contrasting with the previously reported cation-anion stacking observed in naphthalene diimide derivatives. A detailed theoretical study employing topological analysis of the electron density distribution within the quantum theory of atoms in molecules approach provided further insights into this structural dualism. Atomic force microscopy analyses revealed the formation of self-assembled supramolecular structures on graphite from molecular monolayers (3 nm of thick) to submicrometer aggregates for 2. Hyperspectral Raman spectroscopy imaging revealed that such heterostructures are likely formed by an enhanced π-π interactions. Both complexes demonstrated interesting electrochemical behavior, photoluminescence and X-ray-induced luminescence. Electron spin resonance analysis confirmed charge separation in both compounds, with enhanced efficiency observed in compound 2. Our findings of these perylene-based organic-inorganic hybrid salts offer the potential for their application in optoelectronic devices and functional materials.

Organic-inorganic hybrid salt and mixed ligand Cr(III) complexes containing the natural flavonoid chrysin: Synthesis, characterization, computational, and biological studies.

Organic-inorganic hybrid salt and mixed ligand Cr(III) complexes (Cr1 and Cr2) containing the natural flavonoid chrysin were synthesized. The metal complexes were characterized using UV-Vis, Fourier-transform infrared, MS, SEM-EDX, XRD, and molar conductance measurements. Based on experimental and DFT/TD-DFT calculations, octahedral geometries for the synthesized complexes were suggested. The powder XRD analysis confirms that the synthesized complexes were polycrystalline, with orthorhombic and monoclinic crystal systems having average crystallite sizes of 21.453 and 19.600 nm, percent crystallinities of 51% and 31.37%, and dislocation densities of 2.324 × 10-3 and 2.603 × 10-3nm-2 for Cr1 and Cr2, respectively. The complexes were subjected to cytotoxicity, antibacterial, and antioxidant studies. The in vitro biological studies were supported with quantum chemical and molecular docking computational studies. Cr1 showed significant cytotoxicity to the MCF-7 cell line, with an IC50 value of 8.08μM compared to 30.85μM for Cr2 and 18.62μM for cisplatin. Cr2 showed better antibacterial activity than Cr1. The higher E HOMO (-5.959eV) and dipole moment (10.838 Debye) values of Cr2 obtained from the quantum chemical calculations support the observed in vitro antibacterial activities. The overall results indicated that Cr1 is a promising cytotoxic drug candidate.

Synthesis, crystal structure, magnetic properties and Hirshfeld surface analysis of two cobalt(II) complex anions templated by pyridinium-based cations

Two organic–inorganic hybrid salts, (C6H9N2)2[Co(C2O4)2]·H2O (1) and (C5H7N2)2[Co(C2O4)2(H2O)2] (2) (C6H9N2+ = 2-amino-3-methylpyridinium; C5H7N2+ = 4-aminopyridinium) have been obtained. Salt 1 is characterized by the formation of one-dimensional chains of the anionic complexes [Co(C2O4)2]2-, with the Co(II) centers located in a distorted (2 + 2 + 2) octahedral environment of six oxygen atoms from three chelating oxalato(2 − ) ligands. By contrast, salt 2 features discrete anionic complexes [Co(C2O4)2(H2O)2]2- with distorted (4 + 2) octahedral CoO6 coordination sphere formed by two bidentate O,O-donor oxalato(2 − ) ligands in the equatorial plane and two aqua ligands in the axial positions. Hydrogen bonding interactions of the type OH∙∙∙O and NH∙∙∙O along with π–π stacking interactions between pyridine rings contribute to the stabilization of the 3-D supramolecular frameworks in 1 and 2. Temperature-dependence magnetic moment (µ) collected under zero-field cooled (ZFC) and field-cooled (FC) conditions revealed strong antiferromagnetic ordering below TN = 25 K for 1, a behavior which is confirmed by the negative Weiss constant, θ = − 27.6 K. By contrast, in 2, the Weiss constant, θ = 0 K is in line with a paramagnetic behavior. The three-dimensional Hirshfeld surface (3D-HS) analysis and the two-dimensional fingerprint plots (2D-FP) revealed that in 2, the structure is dominated by H∙∙∙O/ H∙∙∙O and H∙∙∙H contacts.

A new bis(oxalato)ferrate(III) hybrid salt associated with guanidinium cations : Synthesis, crystal structure, magnetic properties and Hirshfeld surface analysis

A new organic-inorganic hybrid salt (CH6N3)2[Fe(C2O4)2(H2O)Cl] (1) (CH6N3+ = guanidinium cation) has been synthesized and characterized by elemental and thermal analyses, IR spectroscopy, single-crystal X-ray diffraction, EPR, SQUID magnetometry and Hirshfeld surface analysis. The asymmetric unit of salt 1 consists of one [Fe(C2O4)2(H2O)Cl]2– complex anion and two protonated guanidine molecules 2 CH6N3+. The FeIII ion in the complex anion shows a distorted octahedral coordination environment, with four O atoms from two chelating oxalate dianions, one O atom from a water molecule and one Cl− anion. A packing diagram of 1 highlights pillars of the [Fe(C2O4)2(H2O)Cl]2– complex anions and guanidinium CH6N3+ cations along the crystallographic a axis. These ionic entities are connected via intermolecular O–H···O, N–H···O and N–H···Cl hydrogen bonds into a three-dimensional network. Investigation of the thermal behavior of the compound confirmed its anhydrous character. The EPR spectrum of 1 corresponds to the Fe(III) oxidation state in an octahedral environment. The magnetic susceptibility measurements in the 2–300 K temperature range revealed weak antiferromagnetic interactions in salt 1. Hirshfeld surface analysis has also been evaluated to reveal various intermolecular interactions in 1.

An Exceptional Thermally Induced Four-State Nonlinear Optical Switch Arising from Stepwise Molecular Dynamic Changes in a New Hybrid Salt.

Switching materials in channels of nonlinear optics (NLOs) are of particular interest in NLO material science. Numerous crystalline NLO switches based on structural phase transition have emerged, but most of them reveal a single-step switch between two different second-harmonic-generation (SHG) states, and only very rare cases involve three or more SHG states. Herein, we report a new organic-inorganic hybrid salt, (Me3 NNH2 )2 [CdI4 ], which is an unprecedented case of a reversible three-step NLO switch between SHG-silent, -medium, -low, and -high states, with high contrasts of 25.5/4.3/9.2 in a temperature range of 213-303 K. By using the combined techniques of variable-temperature X-ray single-crystal structural analyses, dielectric constants, solid-state 13 C nuclear magnetic resonance spectroscopy, and Hirshfeld surface analyses, we disclose that this four-state switchable SHG behavior is highly associated with the stepwise-changed molecular dynamics of the polar organic cations. This finding demonstrates well the complexity of molecular dynamics in simple hybrid salts and their potential in designing new advanced multistep switching materials.

Structure and properties of the (α-PicH)3[RhCl6] salt containing 2-methylpyridinium cations

The organic-inorganic hybrid salt consisting of 2-methylpyridinium cation (α-picoline, α-Pic) and hexachlororhodate(III) anion (α-PicH)3[RhCl6] was prepared in high yield. The compound was characterized using a variety of spectral techniques (UV–Vis, IR, Raman, XAFS) and its crystal structure was determined by X-ray single crystal diffraction. The system of strong NH…Cl hydrogen bonds is observed in the structure between organic cations and complex anions resulting in the formation of oppositely charged conglomerates {(α-PicH)4[RhCl6]}+ and {(α-PicH)2[RhCl6]}−. The chemical processes taking place during the thermal decomposition of the salt in He and H2/He atmospheres were studied, and the products of these transformations were identified. The unique thermal stability of [RhCl6]3− anions in an α-PicHCl ionic liquid and a range of temperature up to 250 °C was demonstrated using UV–Vis absorption spectroscopy.

Synthesis and characterization of a novel organic–inorganic hybrid salt and its application as a highly effectual Brønsted–Lewis acidic catalyst for the production of N,N′‐alkylidene bisamides

In this research, a novel organic–inorganic hybrid salt, namely, N1,N1,N2,N2‐tetramethyl‐N1,N2‐bis(sulfo)ethane‐1,2‐diaminium tetrachloroferrate ([TMBSED][FeCl4]2) was prepared and characterized by Fourier‐transform infrared spectroscopy (FT‐IR), energy‐dispersive X‐ray spectroscopy (EDX), elemental mapping, field emission scanning electron microscopy (FE‐SEM), X‐ray diffraction (XRD), thermal gravimetric (TG), differential thermal gravimetric (DTG), and vibrating‐sample magnetometry (VSM) analyses. Catalytic activity of the hybrid salt was tested for the synthesis of N,N′‐alkylidene bisamides through the reaction of benzamide (2 eq.) and aromatic aldehydes (1 eq.) under solvent‐free conditions in which the products were obtained in high yields and short reaction times. The catalyst was superior to many of the reported catalysts in terms of two or more of these factors: the reaction medium and temperature, yield, time, and turnover frequency (TOF). [TMBSED][FeCl4]2 is a Brønsted–Lewis acidic catalyst; there are two SO3H groups (as Brønsted acidic sites) and two tetrachloroferrate anions (as Lewis acidic sites) in its structure. Highly effectiveness of the catalyst for the synthesis of N,N′‐alkylidene bisamides can be attributed to synergy of the Brønsted and Lewis acids and also possessing two sites of each acid.

Thermal Lens and All-Optical Switching of the Salt: [C12H14N2][Fe(CN)5(NO)]·5H2O

The effect of the thermal lens was demonstrated with all-optical switching for the new organic–inorganic hybrid salt: 1,1′-(ethylene-1,2-diyl)dipyridinium pentacyanidonitrosoferrate(II)pentahydrate. The development of thermal blooming of the probe laser beam at three input powers 20, 60, and 100 mW was observed. The evolution time of the thermal lens and the fitting of the experimental transient curve were useful to evaluate the parameters of θ, tc, D, dn/dT, n2, and ∆n of the sample solution. The new results have led to possible potential applications of this complex as future promising materials in optoelectronic devices.

Piezoelectric Energy Harvesting from a Ferroelectric Hybrid Salt [Ph3MeP]4[Ni(NCS)6] Embedded in a Polymer Matrix

AbstractOrganic–inorganic hybrid ferroelectrics are an exciting class of molecular materials with promising applications in the area of energy and electronics. The synthesis, ferroelectric and piezoelectric energy harvesting behavior of a 3d metal ion‐containing A4BX6 type organic–inorganic hybrid salt [Ph3MeP]4[Ni(NCS)6] (1) is now presented. P‐E hysteresis loop studies on 1 show a remnant ferroelectric polarization value of 18.71 μC cm−2, at room temperature. Composite thermoplastic polyurethane (TPU) devices with 5, 10, 15 and 20 wt % compositions of 1 were prepared and employed for piezoelectric energy harvesting studies. A maximum output voltage of 19.29 V and a calculated power density value of 2.51 mW cm−3 were observed for the 15 wt % 1‐TPU device. The capacitor charging experiments on the 15 wt % 1‐TPU composite device shows an excellent energy storage performance with the highest stored energies and measured charges of 198.8 μJ and 600 μC, respectively.

Piezoelectric Energy Harvesting from a Ferroelectric Hybrid Salt [Ph3 MeP]4 [Ni(NCS)6 ] Embedded in a Polymer Matrix.

Organic-inorganic hybrid ferroelectrics are an exciting class of molecular materials with promising applications in the area of energy and electronics. The synthesis, ferroelectric and piezoelectric energy harvesting behavior of a 3d metal ion-containing A4 BX6 type organic-inorganic hybrid salt [Ph3 MeP]4 [Ni(NCS)6 ] (1) is now presented. P-E hysteresis loop studies on 1 show a remnant ferroelectric polarization value of 18.71 μC cm-2 , at room temperature. Composite thermoplastic polyurethane (TPU) devices with 5, 10, 15 and 20 wt % compositions of 1 were prepared and employed for piezoelectric energy harvesting studies. A maximum output voltage of 19.29 V and a calculated power density value of 2.51 mW cm-3 were observed for the 15 wt % 1-TPU device. The capacitor charging experiments on the 15 wt % 1-TPU composite device shows an excellent energy storage performance with the highest stored energies and measured charges of 198.8 μJ and 600 μC, respectively.

Elaboration, crystal structure, vibrational, optical properties, thermal analysis and theoretical study of a new inorganic-organic hybrid salt [C4H12N2]4·Pb2Cl11·Cl·4H2O

A new organic–inorganic hybrid salt[C4H12N2]4·Pb2Cl11·Cl·4H2O, containing [Pb2Cl11]7−anions, has been synthesized and characterized by several techniques. X-ray diffraction study shows that the compound crystallizes in the orthorhombic system and Pnnm space group with a = 8.210 (5), b = 25.782 (5), c = 9.467 (5) Å and V = 2003.9 (17) Å3.The structure of the title compound can be described by organic-inorganic layers extending parallel to the (a, b) plane at z = 0 and z = ½. These layers are built up by means of hydrogen bonds forming a three-dimensional network. Intermolecular interactions were investigated by Hirshfeld surfaces. Scanning electronic microscopy (SEM) and energy-dispersive X-ray (EDX) were carried out. Vibrational assignments of the title compound are discussed by FT-IR and FT-Raman spectroscopic studies and DFT calculations allowed the attribution of the spectral bands. The optical study was also investigated by UV–Vis absorption and photoluminescence spectroscopy. The thermal behavior was studied by TGA/DTA analysis.

Crystal structure of imidazo[1,5-a]pyridinium-based hybrid salt (C13H12N3)2[MnCl4

A new organic-inorganic hybrid salt [L]2[MnCl4] (I) where L + is the 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, is built of discrete organic cations and tetra-chlorido-manganate(II) anions. The L + cation was formed in situ in the oxidative cyclo-condensation of 2-pyridine-carbaldehyde and CH3NH2·HCl in methanol. The structure was refined as a two-component twin using PLATON (Spek, 2020 ▸) to de-twin the data. The twin law (-1 0 0 0-1 0 0.5 0 1) was applied in the refinement where the twin component fraction refined to 0.155 (1). The compound crystallizes in the space group P21/c with two crystallographically non-equivalent cations in the asymmetric unit, which possess similar structural conformations. The fused pyridinium and imidazolium rings of the cations are virtually coplanar [dihedral angles are 0.89 (18) and 0.78 (17)°]; the pendant pyridyl rings are twisted by 36.83 (14) and 36.14 (13)° with respect to the planes of the remaining atoms of the cations. The tetra-hedral MnCl4 2- anion is slightly distorted with the Mn-Cl distances falling in the range 2.3469 (10)-2.3941 (9) Å. The distortion value of 0.044 relative to the ideal tetra-hedron was obtained by continuous shape measurement (CShM) analysis. In the crystal, the cations and anions form separate stacks propagating along the a-axis direction. The organic cations display weak π-π stacking. The anions, which are stacked identically one above the other, demonstrate loose packing; the minimum Mn⋯Mn separation in the cation stack is approximately 7.49 Å. The investigation of the fluorescent properties of a powdered sample of (I) showed no emission. X-band EPR data for (I) at 293 and 77 K revealed broad fine structure signals, indicating moderate zero-field splitting.

Synthesis, Characterization and Thermal Analysis of an Organic-Inorganic Hybrid Salt Involving <i>Trans</i>-Diaquabis(oxalato-κ<sup>2</sup><i>O</i><sup>1</sup>,<i>O</i><sup>2</sup>)chromate(III) Complex Anion with Piperidinium as Counter Cation

A new organic-inorganic hybrid salt pipéridinium trans-diaquabis(oxalato)- chromate(III) tetrahydrate, (C5H10NH2)[Cr(C2O4)2(H2O)2]·4H2O (1), has been synthesized in water and characterized by FTIR and UV-Vis spectroscopies, elemental and thermal analyses and by single-crystal X-ray diffraction. 1 crystallizes in the orthorhombic non-centrosymmetric space group Cmc21 with the unit cell parameters a = 7.4329(3), b = 9.9356(5), c = 23.6756(11) Å, α = β = γ = 90°, V = 1748.45(14) Å3 and Z = 4. The structure of 1 consists of [Cr(C2O4)2(H2O)2]- mononuclear anions, piperidinium cations and uncoordinated water molecules. The CrIII ion in the complex [Cr(C2O4)2(H2O)2]- is coordinated in a slightly distorted octahedral environment by four O atoms from two chelating oxalate dianions in the equatorial plane, and two O atoms from trans-coordinated water molecules occupying the apical positions. In the crystal, N-H···O and O-H···O hydrogen bond interactions connect the components into a 3-D framework. The IR spectrum of 1 is consistent with the presence of the various molecular building constituents, namely oxalato and aqua ligands, piperidinium cations and solvent water molecules. The UV-Vis spectrum shows two absorption bands around 564 and 416 nm which are compatible with an anionic chromium(III) complex in an octahedral environment. Thermal analysis shows a three-step decomposition of 1, leading to formation of a metal oxide residue.

Sodium bis(2-methyllactato)borate

The asymmetric unit of the title organic–inorganic hybrid salt, poly[[μ4-bis(2-methyllactato)borato]sodium], [Na(C8H12BO6)] n , comprises a sodium cation and a bis(2-methyllactato)borate anion. The sodium cation exhibits a [4 + 1] coordination by borate and carbonyl O atoms of the bis(2-methyllactato)borate anion, leading to a three-dimensional polymeric structure.

Potassium bis(2-methyllactato)borate hemihydrate

The asymmetric unit of the title organic–inorganic hybrid salt poly[aquabis[μ3-bis(2-methyllactato)borato]dipotassium], [K(C8H12BO6)(H2O)0.5] n , consists of one bis(2-methyllactato)borate anion, one potassium cation and one water molecule that shows half occupancy due to disorder around a twofold rotation axis. The potassium cation is pseudo-octahedrally coordinated by five O atoms of four symmetry-related bis(2-methyllactato)borate ligands and by the half-occupied water molecule. O—H...O hydrogen bonds between the water molecule and one of the borate O atoms of the bis(2-methyllactato)borate ligand are present in the crystal structure.

Superweak Coordinating Anion as Superstrong Enhancer of Cyanine Organic Semiconductor Properties.

The superweak tetrakis(nonafluoro-tert-butoxy)aluminate coordinating anion was employed to introduce pseudo-gas-phase conditions to the 2-[5-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3-pentadien-1-yl]-1,3,3-trimethyl-3H-indolium chromophore. The resulting formation of a photoactive organic-inorganic hybrid salt has led to a highly stabilized excited state of the organic chromophore mainly due to the minimized lattice energy and Coulomb interactions. These highly beneficial features caused by the well dispersed negative charge of the anion have led to an enhanced neat spin-casted film fluorescence intensity, prolonged fluorescence lifetime, smooth thin film surfaces and a record power photovoltaic efficiency of 3.8 % when compared to organic salts of this particular chromophore containing anions with localised negative charge. Clear evidence is given that a superweak coordinating anion is an emerging key parameter in cyanine dye photochemistry. This approach can be seen as a general guideline to prepare highly efficient ionic dyes for organic semiconductor applications.

Polymorphism and Structural Filiations in Five New Organic–Inorganic Hybrid Salts of the Heteroleptic Cationic Iridium(III) Complex and Polyoxometalates

Five new hybrid compounds ionically associating the phosphorescent heteroleptic cationic iridium(III) complex [IrIII(ppy)2(bpy)]+ ([Ir]+) (ppy = 2-phenylpyridine, bpy = 2,2′-bipyridine) and anionic...

Bis(4-methoxybenzylammonium) tetrabromidocadmate(II)

The asymmetric unit of the organic–inorganic hybrid salt, (C8H12NO)2[CdBr4], consists of two 4-methoxybenzylammonium cations and one [CdBr4]2− anion. The cations and anions are connected by a complex series of N—H...Br and C—H...Br hydrogen bonds. No π–π stacking interactions occur between the benzene rings but two C—H...π interactions are observed.

Catena-Poly[bis(4-methylbenzylammonium) [[dibromidocadmate(II)]-di-μ-bromido

The asymmetric unit of the centrosymmetric organic–inorganic hybrid salt, {(C8H12N)2[CdBr4]} n , comprises of one 4-methylbenzylammonium cation and one half of a disordered [CdBr4]2− anion that is completed by application of mirror symmetry. The resulting CdBr6 octahedra share edges to form 2 ∞[CdBr4/2Br2/2]2− layers parallel to the ac plane. Cations and anions are connected by N—H...Br and C—H...Br hydrogen bonds. No π–π stacking interactions are observed between the benzene rings, but C—H...π interactions towards them are found.