Solid-state Assembly Research Articles

Synthesis, crystal structure, hirshfeld surface analysis, and computational studies of dimeric and polymeric cadmium complexes

In the current investigation, a new dimeric [Cd(DNBA)2(py)2]2 and a polymeric [Cd(DNBA)2(pyz)2]n cadmium complexes have been prepared by the reaction of 3,5-dinitrobenzoic acid (main ligand), nitrogen donor auxiliary ligands (pyridine and pyrazine), and Cd(II) sulphate in aqueous media. The crystal structures of the synthesized compounds were determined by single-crystal X-ray diffraction analysis. The crystal structures were investigated in terms of the coordination geometry, dihedral angles between various rings, and intermolecular interactions. The solid-state assembly was stabilized by various interatomic contacts, explored by Hirshfeld surface analysis. Void analysis was performed to predict the response of crystals to the applied stress. The optimized molecular geometries of the compounds were achieved utilizing the DFT approach along with the B3LYP functional/6–311G(d,p)/LANL2DZ basic set. MEP maps, molecular orbital theory, and quantum chemical parameters for the synthesized compounds were generated using the same level of theory.

Amphiphilic Nanoscale Antifog Coatings: Improved Chemical Robustness by Continuous Assembly of Polymers.

Designing effective antifog coatings poses challenges in resisting physical and chemical damage, with persistent susceptibility to decomposition in aggressive environments. As their robustness is dictated by physicochemical structural features, precise control through unique fabrication strategies is crucial. To address this challenge, a novel method for crafting nanoscale antifog films with simultaneous directional growth and cross-linking is presented, utilizing solid-state continuous assembly of polymers via ring-opening metathesis polymerization (ssCAPROMP). A new amphiphilic copolymer (specified as macrocross-linker) is designed by incorporating polydimethylsiloxane, poly(2-(methacryloyloxy)ethyl) trimethylammonium chloride (PMETAC), and polymerizable norbornene (NB) pendant groups, allowing ssCAPROMP to produce antifog films under ambient conditions. This novel approach results in distinctive surface and molecular characteristics. Adjusting water-absorption and nanoscale assembly parameters produced ultra-thin (≤100nm) antifog films with enhanced durability, particularly against strong acidic and alkaline environments, surpassing commercial antifog glasses. Thickness loss analysis against external disturbances further validated the stable surface-tethered chemistries introduced through ssCAPROMP, even with the incorporation of minimal content of cross-linkable NB moieties (5mol%). Additionally, a potential zwitter-wettability mechanism elucidates antifog observations. This work establishes a unique avenue for exploring nanoengineered antifog coatings through facile and robust surface chemistries.

Solid-State Assembly and Photoluminescent Behavior of 5-(9H-Carbazol-9-yl)isophthalic Acid–Based Molecular Crystals Influenced by Solvents and Organic Counterparts

Solid-State Assembly and Photoluminescent Behavior of 5-(9H-Carbazol-9-yl)isophthalic Acid–Based Molecular Crystals Influenced by Solvents and Organic Counterparts

Influence of Controlled Chirality on the Crystallization of Maleimide-Functionalized 3,4-Ethylenedioxythiophene (EDOT-MA) Monomers.

Conjugated poly(alkoxythiophenes) such as poly(3,4-ethylenedioxythiophene) (PEDOT) have attracted considerable interest for use in a variety of applications such as biomedical devices, energy storage, and chemical sensing. Functionalized versions of the 3,4-ethylenedioxythiophene (EDOT) monomer make it possible to create polymers with properties tailored for specific applications. The maleimide functional group shows particular promise due to the wide variety of chemical modifications that it can undergo. Here, we examine the role that control of the chirality of the maleimide (MA) substituent has on the crystal structure and crystallization of the EDOT-MA monomer. We describe a method for the synthesis of a homochiral (S) variant of EDOT-MA and compare its crystallography, morphology, and thermal properties to that of the (R,S) EDOT-MA racemic compound. The conformation of the EDOT-MA molecule was substantially different, with the molecules adopting an "L" shape in the homochiral crystal, while in the racemic crystals, they were more colinear. The thermal stability of the homochiral crystals (Tm = 128.6 °C) was slightly higher than the racemic ones (Tm = 102.8 °C). We expect these results to be important in better understanding the solid-state assembly of the corresponding polymers prepared from these monomers.

Synthesis of a new hydrazone-based schiff base: Spectroscopy, single crystal, DNA binding and theoretical studies

A new thiosemicarbazide-based Schiff base (TSDHB) was synthesized from thiosemicarbazide and 2,3-dihydroxybenzaldehyde. The prepared thiosemicarbazone was characterized by elemental (CHN), FT-IR, 1H and 13C NMR techniques. Furthermore, the molecular structure was probed using the single-crystal X-ray diffraction (SC-XRD) technique, which confirmed the enol tautomeric form with two independent molecules in asymmetric unit. The dissimilarity between the molecular units was determined by molecular overlay plots. The various intermolecular interactions and solid-state assembly stabilization were explored by Hirshfeld surface analysis. Void analysis was executed to examine the mechanical stability of crystalline units. The bioactivity of thiosemicarbazone was probed with the help of its binding capacity with salmon sperm DNA (SS-DNA) by means of the absorption interaction method. Accompanied by biological activity, optoelectronic properties such as nonlinear optical properties of yielded crystal were also explored through the DFT approach at M06/6–311 G (d,p). For this, various kinds of investigations such as frontier molecular orbital (FMO), UV–Vis, global reactivity parameters (GRPs), transition density matrix (TDM), density of states (DOS), natural population analysis (NPA), and natural bond orbital analysis (NBO) were executed at M06 functional. A good agreement was examined between XRD and DFT findings of molecular geometric parameters. Notably, in comparison with urea, TSDHB demonstrated enhanced nonlinear optical properties (linear polarizability=4.766 × 10−23esu and third-order hyperpolarizability=5.939 × 10−35esu). These findings position TSDHB as a promising candidate for DNA binding as well as for photonic materials due to its unique molecular characteristics and enhanced nonlinear optical behavior.

Synthesis, Characterization, Single Crystal XRD, Solid State Assembly Inspection by Hirshfeld Surface Analysis, and Theoretical Studies of Pb(II) complex with Thiourea Derivative

The current work describes the synthesis of a new Pb(II) complex Pb[ROMLIP]2 with a thiourea derivative. The synthesized complex was characterized by FT-IR, elemental analysis, and single crystal X-ray diffraction (XRD) analysis. The spectroscopic data confirmed that the thiourea ligands coordinate with the Pb center in a way that forms a dimeric structure with a distorted square pyramidal coordination geometry. Hirshfeld surface analysis was used to elaborate on the numerous intermolecular interactions responsible for the stabilization of the supramolecular assembly of the complex. Voids analysis was used to predict the crystal response to an applied stress. Geometry optimization of the synthesized complex was also explored through density functional theory (DFT) analysis. The structural parameters obtained through the DFT study at B3LYP/6-311g(d,p) level of theory with basis set 6-311G(d,p) are in good match with X-ray diffraction analysis. Additionally, the electronic energy band gap of the prepared complex was explored, which revealed the electronic transition during excitation from the ground state to the excited state.

Bis(diphenyl)phosphinomethane Platinum(II) complex of 1-(benzo[d]thiazol-2-yl)-3-phenylthiourea: Crystal structure and DFT study

This study extensively describes synthesizing and characterizing a novel Pt(II) thiourea complex and its mixed ligand bisdiphenylphosphinomethane complex. The first complex [Pt(BtztH)2] is obtained by reacting K2PtCl4 and 1-(benzo[d]thiazol-2-yl)-3-phenylthiourea in 1:2 molar ratio. The second complex [Pt(Btzt)(dppm)] was synthesized by reacting dichlorobis(diphenyl)phosphinomethane platinum(II) complex with 1-(benzo[d]thiazol-2-yl)-3-phenylthioure in equimolar ratio with the presence of Et3N. Both complexes adopt square planar geometry, which were determined by FT-IR, 1H-nmr and X-ray crystallography. In comparison with the first complex, the second complex has doubly deprotonated, resulting in a dianion Pt(II) complex, which was determined by X-ray single crystal measurement. The asymmetric unit contained two unique molecules with distorted square planar geometry. A couple of non-covalent or intermolecular interactions stabilized the solid-state supramolecular assembly. Hirshfeld surface analysis was conducted in order to have a deeper understanding of the supramolecular assembly. Enrichment ratio calculations determined the pair of chemical species with the highest propensity for making interatomic contact. The [Pt(Btzt)(dppm)] compound was also investigated theoretically. The DFT study was performed by using B3LYP/Def2-TZVP method. Theoretical findings indicate that the HOMO-LUMO gaps range from 2.2 to 3.22 eV, indicating that the compounds possess favorable semiconductor properties. Within these complexes, the coordinated atoms exhibit strong electron donations to the Pt cation, while the Pt cation demonstrates significant back-donation to the ligand.

A Hydrazone Derivative: Synthesis, Crystal Structure, Supramolecular Assembly Exploration by Hirshfeld Surface Analysis and Computational Study

The diazotization reaction of o-trifluoromethyl aniline from aromatic amines with 5,5-dimethylcyclohexane-1,3-dione was studied, as a result, 2-(2-(o-trifluoromethylphenyl)hydrazono)-5,5-dimethylcyclohexane-1 ,3-dione (THDCD) was synthesized and its structure was confirmed by X-ray diffraction analysis. The solid state assembly is stabilized by numerous intermolecular interactions which are deeply probed by Hirshfeld surface analysis. The enrichment ratio was computed for getting the contact with the highest propensity to form crystal packing interaction. The mechanical response of the crystal is predicted by voids analysis. Moreover, interaction energy calculations were performed at HF/3-21G electron density model to further inspect the supramolecular assembly of the crystal. DFT calculation was conducted using B3LYP level with 6–311++G(d, p) basic set with the help of Gaussian 09W and GaussView 6.0 packages. MEP surface, HOMO-LUMO orbitals, and NBO theory were analyzed via DFT approach. Theoretical method confirms the proposed geometry of THDCD by X-ray analysis.

Enhanced solid-state phosphorescence of organoplatinum π-systems by ion-pairing assembly.

Anion binding and ion pairing of dipyrrolyldiketone PtII complexes as anion-responsive π-electronic molecules resulted in photophysical modulations, as observed in solid-state phosphorescence properties. Modifications to arylpyridine ligands in the PtII complexes significantly impacted the assembling behaviour and photophysical properties of anion-free and anion-binding (ion-pairing) forms. The PtII complexes, in the presence of guest anions and their countercations, formed various anion-binding modes and ion-pairing assembled structures depending on constituents and forms (solutions and crystals). The PtII complexes emitted strong phosphorescence in deoxygenated solutions but showed extremely weak phosphorescence in the solid state owing to self-association. In contrast, the solid-state ion-pairing assemblies with tetraalkylammonium cations exhibited enhanced phosphorescence owing to the formation of hydrogen-bonding 1D-chain PtII complexes dispersed by stacking with aliphatic cations. Theoretical studies revealed that the enhanced phosphorescence in the solid-state ion-pairing assembly was attributed to preventing the delocalisation of the electron wavefunction over PtII complexes.

Crystal structure, Hirshfeld surface analysis and energy framework calculations of different metal complexes of a biphenol-based ligand: Role of solvent and transition metal ion

A new Pd(II) complex of the previously reported ligand N,N′-bis[(2,2′-dihydroxybiphen-3-yl)methyl]-N,N′-dimethylethylenediamine (L) was obtained from N,N-dimethylformamide/water. The roles in the solid state assembly of solvent molecules and molecular conformation were studied by comparing six complexes of L containing different metal centers (Ni(II), Cd(II), Cu(II), Pd(II)). Hirshfeld surface analysis, 2D fingerprint plots and energy frameworks calculations were used to investigate the intermolecular interactions within the crystal packings. Pd(II) and Ni(II) complexes arrange to form ribbons, while Cd(II) and Cu(II) complexes form 3D networks. Interactions between complexes and solvent molecules in the previously reported Pd(II) complex are replaced by complex-complex interactions in the new Pd(II) complex, while butanol and methanol are interchangeable in the interactions within the Ni(II) complexes. The present study suggested that the solid state assembly of these systems is mainly driven by the molecular conformation, that depends in turn by the metal ion involved, while the solvent only plays a minor role.

One-dimensional polymer of copper with salicylic acid and pyridine linkers: Synthesis, characterizations, solid state assembly investigation by hirshfeld surface analysis, and computational studies

A new one-dimensional polymeric copper complex [Cu(DNSA)py] with salicylic acid and pyridine was synthesized and characterized by many techniques, including FT-IR, UV–Visible, elemental, TGA/DSC, and single crystal XRD analysis. In the crystal structure, two 3,5-dinitrosalicylic ligands were chelated by the copper cation, in which one ligand was coordinated by the carbonyl O-atom and one of the carboxylate O-atoms, while another symmetry-related ligand was coordinated by the O-atoms of the carboxylate group to form distorted square pyramidal geometry. Thus, a one-dimensional polymer structure is formed, extending along the b-axis. The solid-state assembly was stabilized by various intermolecular interactions, as examined through Hirshfeld surface analysis. Voids analysis was carried out to predict the response of the crystal under external pressure. The most stable structure of the [Cu(DNSA)py] monomer resulted from density functional theory (DFT) using the B3LYP/def2-TZVPP. The 6–311G(d,p) level of theory demonstrated that the Cu atom adapts distorted square pyramidal geometry. The MEP surface and Mulliken charge distribution identified the Cu monomer atoms suitable for electrophilic and nucleophilic attacks. Frontier molecular orbital (FMO) analyses were conducted to anticipate the stability and chemical reactivity of the [Cu(DNSA)py] monomer and its ligand (DNSA). Furthermore, the quantum chemical descriptors of the title compound were obtained from EHOMO and ELUMO energy values.

Naphthylacetonitrile isomerism and donor conformational flexibility controlled molecular self-assembly and solid-state fluorescence properties

Organic fluorophores with propellor/partially planar donor unit and naphthylacetonitrile positional isomer were synthesized and explored their impact on the solid-state structural assembly, fluorescence properties and stimuli-induced fluorescence switching. Partially planar phenyl carbazole (Cz) and propeller shaped triphenylamine (TPA) donor units integrated with 1-naphthylacetonitrile/2-naphthylacetonitrile acceptors (Cz-1-Naph, Cz-2-Naph and TPA-2-Naph) by simple condensation reaction. All three compounds showed weak and tunable fluorescence in solution (λmax = 452–520 nm, Φf = 0.24 compared to quinine sulphate standard). However, Cz-Naph isomers showed relatively strong solid-state fluorescence compared to TPA-Naph (Φf = 5.9% (Cz-1-Naph), 13.8% (Cz-2-Naph) and 1.2% (TPA-2-Naph)). Further, Cz-Naph isomers showed relatively blue shifted emission (λmax = 517 (Cz-1-Naph) and 498 nm (Cz-2-Naph)) compared to TPA-2-Naph isomer (λmax 543 nm). Solid-state structural analysis revealed varied molecular conformation and arrangement depending on the naphthyl isomerism and donor units. The modulation of molecular conformation and packing contributed for fluorescence tuning. Computational studies indicated a clear intramolecular electron transfer from TPA/Cz donor to naphthylacetonitrile acceptor unit. Interestingly, Cz-2-Naph exhibited reversible mechanical crushing and heating induced fluorescence switching that was attributed to the reversible phase transformation between crystalline and amorphous phase and vice versa.

Precisely Designed Difunctionalized Cyclodextrin Produces a Solid-State Organic Porous Hierarchical Supramolecular Assembly.

Regioselective di-functionalization of a cyclodextrin allows hydrophobic domains to be directed in a geometrically controlled manner. This controlled orientation ultimately gives access to an original hierarchical assembly in the solid state. This assembly spans over three levels of hierarchy which are governed by synergistic host-guest inclusions, directed hydrophobic effect and hydrogen bonding. This combination of interactions precisely positioned in space through regioselective functionalization of a cyclodextrin creates a porous organic architecture.

Synthesis of ESIPT fluorophores with two intramolecular H-bonding functionalities: Reversible mechanofluorochromism and conformation controlled solid state fluorescence efficiency

We have synthesized two new ESIPT fluorophores (1-((E)-((E)-((2-hydroxyphenyl)(phenyl)methylene)hydrazono)methyl) naphthalen-2-ol (Naph-2-OH) and 5-(diphenylamino)-2-((E)-((E)-((2-hydroxyphenyl)(phenyl) methylene)hydrazono)methyl) phenol (TPA-2-OH)) with two unsymmetrical intramolecular H-bonding functionalities and investigated the solid-state structural assembly and fluorescence properties. The crystal structure analysis confirmed the formation of strong intramolecular H-bonding and twisted molecular conformation. The nonplanar twisted molecular conformation produced well separated molecules in the crystal lattice that lead to strongly enhanced emission ((λmax = 538 nm, Φf = 5.2% (Naph-2-OH), λmax = 562 nm, Φf = 13.4% (TPA-2-OH)). Density functional theoretical (DFT) calculation supported the fluorescence tuning and intramolecular charge transfer (ICT) from TPA donor to imine acceptor. Both Naph-2-OH and TPA-2-OH showed mechanical crushing and heating induced reversible fluorescence switching due to the reversible phase transformation between crystalline and amorphous state.

A quantum information processing machine for computing by observables

A quantum machine that accepts an input and processes it in parallel is described. The logic variables of the machine are not wavefunctions (qubits) but observables (i.e.,operators) and its operation is described in the Heisenberg picture. The active core is a solid-state assembly of small nanosized colloidal quantum dots (QDs) or dimers of dots. The size dispersion of the QDs that causes fluctuations in their discrete electronic energies is a limiting factor. The input to the machine is provided by a train of very brief laser pulses, at least four in number. The coherent band width of each ultrashort pulse needs to span at least several and preferably all the single electron excited states of the dots. The spectrum of the QD assembly is measured as a function of the time delays between the input laser pulses. The dependence of the spectrum on the time delays can be Fourier transformed to a frequency spectrum. This spectrum of a finite range in time is made up of discrete pixels. These are the visible, raw, basic logic variables. Thespectrum is analyzed to determine a possibly smaller number of principal components. ALie-algebraic point of view is used to explore the use of the machine to emulate the dynamics of other quantum systems. An explicit example demonstrates the considerable quantum advantage of our scheme.

Full-Color and Switchable Circularly Polarized Light from a Macroscopic Chiral Dendritic Film through a Solid-State Supramolecular Assembly.

Chiral materials displaying chirality across multiple length scales have attracted increasing interest due to their potential applications in diverse fields. Herein, we report an efficient approach for the construction of macroscopic crystal dendrites with hierarchical chirality based on an in situ solid assembly in a block copolymer film. Chiral fluorescent crystals are formed by enantiopure d-/l-dibenzoyl tartaric acid and pyrenecarboxylic acid in a poly(1,4-butadiene)-b-poly(ethylene oxide) film. The chiro-optical activity of the crystalline dendrites can be greatly amplified in the absorption and scattering regions and goes along with the dimension of dendrites. Notably, the chiral dendrites exhibited strong circularly polarized luminescence emission with a high dissymmetric factor (0.03). The enhancement of the quantum yield of the chiral film was up to 28%, which was 14 times higher that of the corresponding fluorescent molecules. The circularly polarized emission bands of the films can be fine-tuned by contriving the emissive bands of fluorescent molecules. More importantly, the chiral signals are able to be wiped when the fluorescent group photodimerizes under UV irradiation. This work provides an efficient way to develop functional materials through solid self-assembly.

Synthetic approach to achieve halo imine units: Solid-state assembly, DFT based electronic and non linear optical behavior

Herein, two crystalline schiff bases: (E)-2,4-dibromo-6-(((3,4-dichlorophenyl)imino)methyl)phenol (DCBA) and (E)-2,4-dichloro-6-(((2,4,5-trichlorophenyl)imino)methyl)phenol(TCCA) were prepared by treating halo-substituted benzaldehydes with chloro-substituted aniline through condensation reaction. The crystal structures of DCBA and TCCA were confirmed by SC-XRD analysis, which unambiguously revealed that C-H···Br, C-Cl···π, and off-set π···π stacking interactions were the key aspects of crystal packing of DCBA, whereas π···π off-set stacking interactions were the main aspect ofcrystal packing of TCCA. Hirshfeld surface analysis had been implemented for the further probe of intermolecular interactions. Accompanying with experimental, DFT investigation had also been performed at M06/6-311G(d,p) level to analyze these crystalline architectures. By comparative analysis of geometrical parameters, an efficient agreement was observed between DFT and SC-XRD data. Additionally, natural bond orbital (NBO) findings revealed that most dominant hyper-conjugative transitions with higher stability (31.06 and 30.70 kcal/mol) had been examined for DCBA and TCCA, respectively, which may cause the stability of these molecules. Further, global reactivity parameters disclosed that both compounds showed larger value of hardness (η = 2.181–2.205 eV) with least value of softness (σ = 0.226–0.229 eV) which indicated them kinetically enormous stable and show excellent concurrence with NBO and SC-XRD. The band gaps of DCBA and TCCA had been rationalized to be 4.40 and 4.36 eV, respectively. Interestingly, significant values of dipole moment [µtotal = 1.03 and 4.16 a.u.], linear polarizability [<α>=309 and 1167.51 a.u.] and second order hyperpolarizability [<γ> =3.90–4.18 × 105a.u.] were investigated in the entitled compounds. Remarkable NLO response of aforesaid compounds designated them as outstanding NLO materials for the hi-tech optoelectronic applications.

Hybrid Halide Solid Electrolytes and Bottom-up Cell Assembly Enable High Voltage Solid-State Lithium Batteries

Interface between halide based solid electrolytes and layered transition metal oxide cathodes has been found to be electro-chemically stable due to stability of chloride compounds, in particular, at >4V range. The extent of interfacial stability is correlated with the type of cationic and anionic species in the solid electrolyte compound, a fact supported by theoretical prediction and yet, not accurately measured in composite cathode mixtures. By altering the architecture of cathode into a dense additive-free structure, we have identified differences in interfacial stability of chloride compounds which are hidden in composite cathode formats. In this work, we report the use of dense cathode to track the electrochemical evolution of interface between a hybrid halide solid electrolyte composed of chloride and fluoride species. Introducing fluoride compounds is known to be a promising method to expand the oxidation stability while the nature of such expansion is found to be related to kinetics rather than thermodynamics, we report. Furthermore, fluorination of solid electrolyte is generally accompanied with loss of ionic conductivity due to strong electronegative fluoride ions. We demonstrate a fundamental change of solid-state battery assembly from conventional electrolyte pelletizing followed by electrode placement, to a bottom-up assembly route starting with dense cathode, thin (<20µm) layer of SE and anode addition, which compensates for the suppressed conductivity of fluorinated halide solid electrolytes. Through extensive characterization, compositional optimization, and electrochemical interfacial analysis, we demonstrate stable cycling of LiCoO2/hybrid halide solid electrolyte up to 4.4V vs. Li. Our findings pave the way for expanding the voltage stability of solid electrolytes without compromising the cell performance due to ionic conductivity overpotential issues.

Water-driven solid self-assembled catalysis

The power of self-assembly lies in its potential to realize highly ordered, intricate structures from simple components. Water-driven ternary self-assembled processes of barely soluble solids was found in asymmetric palladium(II) catalysis, albeit counterintuitive. Interfacial solid-state assembly that is insensitive to insolubility of components may offer a convenient technique to convert the surfaces of inert and almost insoluble materials into catalytically active forms without plasma treatment or ball milling. The privileged position occupied by water over organic solvents in this study is manifest in both the self-assembly process and electrophilic palladation, and is at odds with its typical role as a solvent to dissolve substances.

Triazine- and Binaphthol-Based Chiral Macrocycles and Cages: Synthesis, Structure, and Solid-State Assembly.

A series of triazine- and binaphthol-based homochiral and heterochiral macrocycles and cages were easily synthesized. Either fragment coupling or a one-pot approach afforded the desired products in 52-91% yields on a multigram scale as enantiopure forms. As disclosed by the crystal structures, these macrocycles and cages possess intriguing chiral cavities and assembly properties. In particular, (S,S,S)-Cage features a D3-symmetric double-faced propeller-like structure with three chiral pockets at the side. It forms a highly ordered hexagonal column-like assembly and multiple distinct helical channels in its crystal.