Organic Solid Solutions Research Articles

Mixed Yttrium and Dysprosium Lactates as the First Example of Rare-Earth Hydrogen-Bonded Organic Framework Solid Solutions

Mixed Yttrium and Dysprosium Lactates as the First Example of Rare-Earth Hydrogen-Bonded Organic Framework Solid Solutions

Designing Organic π-Conjugated Molecules for Crystalline Solid Solutions: Adamantane-Substituted Naphthalenes.

We showcase herein organic crystalline solid solutions (CSSs) based on the simplest polycyclic aromatic hydrocarbon (PAH) scaffold, naphthalene, stabilized by dispersion forces induced by adamantane substitution. High thermal stability of the host and guest molecules synthesized by cross-coupling of dibromonaphthalene derivatives and 4-(1-adamantyl)phenyl boronic ester enabled formation of crystals by sublimation. We could generate binary monocrystalline solid solution systems proven by X-ray crystallography, the first system of designed CSSs stabilized exclusively via dispersion forces with structural evidence. These observations are additionally supported by lattice energy calculations and spectroscopic examinations. For the generation of CSSs, it is of utmost importance that the host and guest molecules have similar lattice energies and spatial compatibility. We anticipate that the thermostable organic CSS design demonstrated herein would be beneficial for functional materials and further investigation towards materials with unique properties.

A deep-blue crystalline organic light-emitting diode based on a solid-solution thin-film emitting layer

Organic solid solution is a novel advantageous strategy for developing crystalline OLEDs. This work demonstrated its universality and extended the scope of material systems.

Multicomponent Crystals with Competing Intermolecular Interactions: In Situ X‐ray Diffraction and Luminescent Features Reveal Multimolecular Assembly under Mechanochemical Conditions

AbstractSupramolecular chemistry under mechanochemical conditions has drawn attention because it can induce low‐solubility molecules to self‐assemble, although most of the reported examples have been limited to two‐component systems. We applied mechanochemical synthesis to achieve multimolecular self‐assembly in more challenging three‐component systems. The produced crystals showed multicolor solid‐state luminescence depending on the components when exposed to UV light. Optical outputs and X‐ray diffraction studies were used to examine the self‐assembling behavior in greater depth. Using synchrotron radiation, in situ X‐ray diffraction permitted direct observation of the milling process, which started the self‐assembly process within 1 min. This research emphasizes the importance of multicomponent molecules with optical functions and self‐assembling behavior and offers the possibility of developing more complicated multicomponent crystals and organic solid solutions for advanced materials.

Длительная фосфоресценции в охлажденных твердых растворах органических веществ – временная динамика и эффект спектральной памяти

The paper presents the results of delayed phosphorescence study in organic substances solid solutions at cryogenic temperatures. This work continues the series of our works devoted to the study of the physical mechanism of excitation of long-term phosphorescence and the prospects for creating new active laser media based on an analogue of the Shpolsky matrix. The article also describes the observed effect of spectral memory in solid organic solutions upon excitation of long-term delayed phosphorescence by radiation from a mercury lamp.

Luminescent trade-off effect arising from Y3+ ion doping in rare earth metal–organic framework solid solutions Tb1-xYx-PTC (H3PTC = pyridine-2, 4, 6-tricarboxylate)

A series of rare earth solid solutions, Tb1-xYx-PTC with pyridine-2, 4, 6-tricarboxylic acid (H3PTC), have been prepared using a hydrothermal synthesis method and characterized by single crystal and powder X-ray diffraction, IR spectroscopy, and thermogravimetric analysis techniques etc. Tb1-xYx-PTC are isomorphous with 1D zigzag metal-oxide chains and 2D coordination polyhedral layers, which are further interlinked into 3D framework by the connection of PTC3− ligands. The photoluminescent behaviors of the solid solutions Tb1-xYx-PTC were carefully studied. The QY of Tb1-xYx-PTC with appropriate amount of Y3+ ion is obviously enhanced due to reducing dipole–dipole and quadrupole–quadrupole interaction between emitters of Tb3+ ions. This study demonstrates that the formation of solid solutions by introducing optically inactive ions is an efficient strategy to get improved photoluminescent materials.

A General Synthetic Approach of Organic Lateral Heterostructures for Optical Signal Converters in All-Color Wavelength

A General Synthetic Approach of Organic Lateral Heterostructures for Optical Signal Converters in All-Color Wavelength

Luminescent Trade-Off Effect Arising from Y3+ Ion Doping in Rare Earth Metal–Organic Framework Solid Solutions Tb1-Xyx-Ptc (H3ptc = Pyridine-2, 4, 6-Tricarboxylate)

Luminescent Trade-Off Effect Arising from Y3+ Ion Doping in Rare Earth Metal–Organic Framework Solid Solutions Tb1-Xyx-Ptc (H3ptc = Pyridine-2, 4, 6-Tricarboxylate)

Metal–organic framework solid solutions of rare earth ions Tb3+, Eu3+ and Y3+ with pyridine-2, 4, 6-tricarboxylate ligand emitting high quantum yield white light

A series of rare earth metal organic frameworks (MOFs), including Tb-PTC and solid solutions TbxEuyY1-x-y-PTC with pyridine-2, 4, 6-tricarboxylic acid (H3PTC), have been prepared using a hydrothermal synthesis method and characterized by single crystal and powder X-ray diffraction, IR spectroscopy, elemental analysis and thermogravimetric analysis techniques etc. Tb-PTC and TbxEuyY1-x-y-PTC are isomorphous with 1D zigzag metal-oxide chains, which are further interlinked into 3D framework by the connection of PTC3− ligands. The solid solutions, TbxEuyY1-x-y-PTC, are single-phase white-light emitters with higher quantum yields (47.6–69.6%) and longer millisecond-grade luminescence lifetimes. This study unveils the possibility to achieve high quantum yield white light emitter by rational design of rare earth MOF solid solutions.

Field-Induced Electron Spin Resonance of Site-Selective Carrier Accumulation in Field-Effect Transistors Composed of Organic Semiconductor Solid Solutions

The formation and characterization of solid solutions with guest (or impurity) molecules are difficult to realize in crystalline organic semiconductors. Here, we demonstrate that an operando field-induced electron spin resonance (FIESR) experiment allows the site-selective analysis of accumulated charge carriers in polycrystalline organic field-effect transistors (FETs), which comprise molecular solid solutions as channel semiconductor layers. We utilize vacuum-deposited dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) thin films with various amounts of dibenzotetrathiafulvalene (DBTTF) as guest molecules. Our measurements reveal that the field-induced carriers are first trapped at guest DBTTF sites at low gate voltages and then begin to accumulate at host DNTT sites at higher gate voltages. Furthermore, we perform dispersion-corrected density-functional theory calculations to investigate the stability of the solid-solution crystals. It is shown that the DBTTF molecules can be stably incorporated by aligning molecular long axes within the crystal lattices of DNTT, the results of which agree well with the angle-dependent FIESR measurements. We demonstrate that the mobility, threshold voltage, and subthreshold swing are controlled by the concentration of guest molecules in solid-solution organic FETs.

Solid solution of semiconducting contorted small molecules for high-performance Li/Na-ion host electrodes

Multicomponent solid solutions have attracted wide attention because they have great potential to improve the physical and chemical properties of pure materials. However, there are stringent prerequisite conditions, such as shape similarity and isomorphism of the crystal phase, for forming a solid solution. These conditions have not been studied extensively in organic solid solution materials, although they have great advantages in terms of the energy storage properties of materials. Herein, we investigate the solid solution of semiconducting contorted hexabenzocoronene (cHBC) and its tetra-fluorinated derivative (FcHBC) as small molecules for a high-performance Li/Na-ion host electrode. Our systematic study, combined with a grazing incidence wide-angle X-ray scattering (GIWAXS) characterization and a computational study thereof, reveals that the molecular interrelationship between cHBC and FcHBC molecules forms P21/n crystal phase of cHBC/FcHBC solid solution owing to their similar molecular and crystal structures. The continuous solid solution of cHBC/FcHBC electrodes, in particular, not only effectively enhances the electron charge transfer without adding the conducting agent but also delivers a better rate capability as both Li- and Na-ion hosting electrodes. Furthermore, the solid solution electrodes maintain a reliable cycling performance in the conventional aprotic electrolyte, which suggests that organic solid solution electrodes are promising organic electroactive materials for alkali ion-based energy storage cells.

Microelectrode Based Devices for Diagnosis of Electron Transport and Electrochemical Behavior of Redox-Conducting Materials

We are going to address practical issues related to the principles and analytical aspects of electrochemical studies (typically done at room temperature) of solid, rigid or semi-rigid (nonfluid) systems in the absence of a liquid solution phase. Representative examples include redox and conducting organic polymers, melts and solid solutions of redox centers in solid ionic conductors, mixed-valence polynuclear inorganic materials, transition metal salts, oxides, and zeolites. The emphasis is on the elements of dynamics for the efficient delivery of charge and on reactivity of the ‘redox conducting’ materials. The effective (apparent) diffusional mechanism is critical to the success of most analytical measurements in solid-state. Historically, electrochemistry in the absence of a bulk liquid phase has focused on the problems of energy storage and production. Recently, it has become possible to apply conventional electrochemical methods to characterize solid-state type redox electrolytes with respect to analytical characterization of materials, measurement of electron transfer rates, and determination of analytes using amperometric sensing. The characterization of materials by solid-state voltammetry primarily has focused on mixed-valence, ionically conducting compounds and on diverse organic ionomers hosting identifiable molecular (redox) sites. Potential materials for solid-state electrochemical measurements are expected to contain three-dimensionally distributed highly concentrated redox centers between which fast electron self-exchange (hopping) is feasible. Among inorganic systems, single crystals of heteropolyacids of molybdenum and tungsten, as well thin films of Prussian Blue type metal hexacyanoferrates will be considered. These redox centers are fixed and, although they may have short range mobility about an equilibrium position, they classically are macroscopically immobile. The applicable materials also must host mobile counter-ions that are capable of providing charge balance during electron transfers, thereby serving the same purpose as the supporting electrolytes in conventional electrochemistry. The population of these ions must be sufficient to support diffusive mass transport of electrons and to minimize ohmic effects. We will describe typical electrochemical cells and experimental tactics to overcome the relatively slow dynamics of transport in solid (non-fluid) systems. Application of microdimensional electrodes leads to an improvement in the quality of solid-state electrochemical data and provides new diagnostic and analytical possibilities. Basic concepts of mechanistic studies, which are relevant to the development of novel analytical methods, together with trends towards possible future applications will also be addressed.

Charge Propagation in Redox-Conducting Materials: Diagnosis of Mechanisms and Dynamics with Microelectrochemical Devices

Historically, electrochemistry in the absence of a bulk liquid phase has focused on the problems of energy storage and production. Recently, it has become possible to apply conventional electrochemical methods to characterize solid-state type redox electrolytes with respect to analytical characterization of materials, measurement of electron transfer rates, and determination of analytes using amperometric sensing. The characterization of materials by solid-state voltammetry primarily has focused on mixed-valence, ionically conducting compounds and on diverse organic ionomers hosting identifiable molecular (redox) sites. We are going to address practical issues related to the principles and analytical aspects of electrochemical studies (typically done at room temperature) of solid, rigid or semi-rigid (nonfluid) systems in the absence of a liquid solution phase. Representative examples include redox and conducting organic polymers, melts and solid solutions of redox centers in solid ionic conductors, mixed-valence polynuclear inorganic materials, transition metal salts, oxides, and zeolites. The emphasis is on the elements of dynamics for the efficient delivery of charge and on reactivity of the ‘redox conducting’ materials. The effective (apparent) diffusional mechanism is critical to the success of most analytical measurements in solid-state. The potential materials for solid-state electrochemical measurements are expected to contain three-dimensionally distributed highly concentrated redox centers between which fast electron self-exchange (hopping) is feasible. These redox centers are fixed and, although they may have short range mobility about an equilibrium position, they classically are macroscopically immobile. The applicable materials also must host mobile counter-ions that are capable of providing charge balance during electron transfers, thereby serving the same purpose as the supporting electrolytes in conventional electrochemistry. The population of these ions must be sufficient to support diffusive mass transport of electrons and to minimize ohmic effects. We will describe typical electrochemical cells and experimental tactics to overcome the relatively slow dynamics of transport in solid (non-fluid) systems. Application of microdimensional electrodes leads to an improvement in the quality of solid-state electrochemical data and provides new diagnostic and analytical possibilities. Basic concepts of mechanistic studies, which are relevant to the development of novel analytical methods, together with trends towards possible future applications will also be addressed.

Photophysical study of meso-phenothiazinyl-porphyrins metallocomplexes

Photophysical parameters of a set of metallocomplexes of meso-phenylthiazinylporphyrins with Zn (II), Pd (II) and Cu (II) ions were studied in different organic solvents, solid solutions and polymeric matrices at room and liquid nitrogen temperatures. The dependence of the spectral and photophysical parameters on changing the molecular structure with increasing number of branched substituents attached to aryl groups in different positions of the porphyrin macrocycle has been established.

Organic solid solution composed of two structurally similar porphyrins for organic solar cells.

A solid solution of a 75:25 mixture of tetrabenzoporphyrin (BP) and dichloroacenaphtho[q]tribenzo[b,g,l]porphyrin (CABP) forms when they are generated in a matrix of (dimethyl(o-anisyl)silylmethyl)(dimethylphenylsilylmethyl)[60]fullerene. This solid solution provides structural and optoelectronic properties entirely different from those of either pristine compounds or a mixture at other blending ratios. The use of this BP:CABP solid solution for organic solar cell (OSC) devices resulted in a power conversion efficiency (PCE) value higher by 16 and 300% than the PCE values obtained for the devices using the single donor BP and CABP, respectively, in a planar heterojunction architecture. This increase originates largely from the increase in short circuit current density, and hence by enhanced charge carrier separation at the donor/acceptor interface, which was probably caused by suitable energy level for the solid solution state, where electronic coupling between the two porphyrins occurred. The results suggest that physical and chemical modulation in solid solution is beneficial as an operationally simple method to enhance OSC performance.

Isomorphism and solid solution as shown by an accurate high-resolution diffraction experiment.

High-resolution crystal structure determination and spherical and multipolar refinement enabled an organic solid solution of 1-(4'-chlorophenyl)-2-methyl-4-nitro-1H-imidazole-5-carbonitrile and 5-bromo-1-(4'-chlorophenyl)-2-methyl-4-nitro-1H-imidazole to be found, which would not normally be revealed using only standard resolution data (ca 0.8 Å), as the disordered part is only visible at high resolution. Therefore, this new structure would have been reported as just another polymorphic form, even more reasonably as isostructural with other derivatives. To the best of our knowledge this is the first example of organic solid solution modelled via charge density Hansen-Coppens formalism and analysed by means of quantum theory of atoms in molecules (QTAIM) theory.

A Cationic Metal–Organic Solid Solution Based on Co(II) and Zn(II) for Chromate Trapping

We report the synthesis and characterization of a solid solution series of cationic metal–organic materials with full compositional range from pure Co(II) to Zn(II) end-members. The materials consist of [ZnxCo1–x(H2O)4(4,4′-bipy)2]2+ metal–organic clusters that π–π stack into 2-D positively charged layers, with the metal ratio tunable by molar ratio under hydrothermal conditions. The interlamellar α,ω-alkanedisulfonate serves as an anionic template and noncovalently interacts with the cationic layers. The weak interaction allows anion exchange for toxic oxometal anions, such as chromate, CrO42–. The highest chromate adsorption capacity was 68.5 mg/g (0.43 mol/mol) for the as-synthesized 50 mol % Co(II)-incorporated material. Our cationic material can also selectively trap these toxic oxo-anions when nontoxic anions (e.g., nitrate, sulfate) were present in an over 50-fold excess concentration.

Effects of UV Irradiation on ESR and Optical Properties of Cu(II) Ions in Organic Solid Solutions Containing CuCl at 77 K

The effect of uv irradiation on the solid solutions of MTHF and EtOH containing CuCl with HCl has been in- vestigated. The axial ESR spectra observed before uv irradiation at 73 K for these solutions indicate that Cu(II) ions exist in such a way that the unpaired electron density locates on 3d 9 orbital in the coordination structure associated with the ligand molecules. The new ESR signals observed after uv irradiation is inferred to Cu(II) ions of a transformed ligand structure that is formed via an exciplex adiabatically. We infer that the new species induced by uv irradiation forms strong covalent bonds between Cu(II) ions and the ligand. The formation of the exciplex has also been evidenced by the absorption and emission properties for the same solutions at 77 K. Three types of emissive exciplexes have been pro- posed.

Cross-dimerization of nitrosobenzenes in solution and in solid state

Cross-linking of nitrosobenzenes to heterodimers (azodioxides) when they are not sterically crowded with large groups in ortho-position was studied by NMR and FT-IR spectroscopy, X-ray crystallography as well as by cryogenic photolysis. It was found for the first time that cross-linked dimers (heterodimers) exist both in solution and in solid state and that they appear in the crystal together with homodimers. The system is used as a model for studying organic solid solution formation. The role of molecular packing in formation of a weak chemical bond is also discussed.

Ligand Effects on ESR and Optical Properties of Gold Atoms in γ Irradiated Organic Solid Solutions at 77 K

Ligand effects on ESR and optical properties of Au0 atoms produced at 77 K in gamma irradiated solid solutions of AuCl/MTHF and AuCl/EtOH with and without HCl were investigated. Four groups of ESR lines were observed at 73 K more clearly around the magnetic fields at about 250, 280, 340, and 400 mT for both gamma irradiated MTHF and EtOH solid solutions with HCl than those without HCl. The values of a and g(J) calculated by Breit-Rabi analysis showed a remarkable dependence on the solvent polarity. It was confirmed that the signals were the hyperfine quartet corresponding to the transitions between the Zeeman levels of Au0 atoms with nuclear spin of 3/2 in the ground state, 2S(1/2). It was also confirmed that Au0 atoms produced after gamma irradiation were located in the nuclear environment of isotropic interaction with surrounding ligand molecules. Delocalization of the unpaired spin density of Au0 onto ligands is found to be as large as one in the case of Cu0 atoms. Our previous hypothesis of the occurrence of configuration mixing of d valence orbital into the wave function of the atom in its 2S(1/2) was strongly supported. The dependence of the ESR, optical absorption, and the steady-state emission and excitation characteristics on solvent polarity was cleared in this study. We observed two kinds of emissions i.e., a band at 385 nm and a set of emission bands at 456, 482, 484, and 520 nm. These correspond to two bands out of the six kinds of emissions observed previously. The bands were attributed to exciplex (Au0 x Ln...Au+)* and the excited Au0 atoms trapped in a large cavity, respectively. The negative counterion of Au+ of the gold compound plays an important role for the formation of the exciplexes.