Themed collection Supramolecular & Polymorphism

Substitutional change and controlling intra and intermolecular interactions of ESIPT molecules resulted in realizing multifunctional fluorescence properties.

This highlight evidences the existence and importance of spodium bonds (SpB) in solid state structures involving five-coordinated square-pyramidal Zn(II) spodium atom.

This highlight presents an overview of the current advances in the preparation of halogen bonded metal–organic multi-component solids, including salts and cocrystals comprising neutral and ionic constituents.

A recent update on how solid state NMR has aided the interpretation and understanding of host–guest interactions in the field of supramolecular assemblies is provided.

A comprehensive account of the F⁻/OH⁻-induced atmospheric CO₂ fixation as carbonate/bicarbonate anion(s) within the self-assemblies of artificial receptors are demonstrated in the highlight.

The formation of three isostructural co-crystals that utilize iodoperchlorobenzene as a dual halogen-bond donor is reported.

A series of new halogenated bis(acenaphthylene)dione (BAN) derivatives was synthesized, and the effect of halogen bonding on both molecular and crystal structure, and charge transport in n-type thin film transistors was investigated.

We report and design a simple and robust process to obtain a single and pure crystalline form I (1) of the cocrystal, containing Rongliflozin (2) with L-pyroglutamic acid (L-PA), based on coformer-induced purification (CoIP).

Polymorph control of 5-fluorouracil was achieved by ball milling. Forms II and III were prepared separately through ball milling with different amounts of ethanol as an additive at the same period without influencing each other.

Exploring covalent organic frameworks with new linkages is regarded as an efficient method to modulate the corresponding properties, and a new linkage is essential to the progress of this field.

Tetracenequninone fused porphyrin exhibits remarkable π,π-stacking, which can be regulated by solvents to afford various biomorphs or cubic-shaped architectures.

Under the guidance of the ESI-MS result for [TeO₆@Ag₃₆(CC^tBu)₁₈(tfa)₁₂] (1, tfa = trifluoroacetate), a new 36-nucleus silver-alkynyl cluster substituted by four pentafluorobenzoates, named as [TeO₆@Ag₃₆(CC^tBu)₁₈(tfa)₈(F₅PhCO₂)₄] (2), has been fabricated.

An adamantane-based macrocycle afforded three inclusion crystals with diverse 1D channels. Single-crystal to single-crystal guest exchanges occurred for two crystals, where their frameworks displayed distinctive structural transformations.

In this communication, we report the switchable phase transition occurring between the crystalline and amorphous states of CuSO₄·5H₂O, influenced by dynamic shock waves, and the results have been evaluated by XRD and Raman techniques.

We present a spironolactone–saccharin cocrystal hydrate as the first example of a crystal that jumps without changes in either the lattice parameter or the molecular conformation to highlight the unique advantages of the jumping-mate strategy.

Mechanical deformation-induced physical property changes of elastically flexible molecular crystals were successfully investigated by spatially resolved μ-photoluminescence (PL) spectroscopy for the PL analysis at both the outer and inner sides.

Orange (Cry-1O) and red (Cry-1R) emissive crystals were obtained based on a green emissive molecule 1. The light transducing capability of Cry-1R in both the straight and bent states can be applied as an active optical waveguiding medium.

Sandwich, macrocyclic and box supramolecular assemblies were synthesized. They can further self assemble to form a double-layer supramolecular polymer, nanotubes and one-dimensional “iron chain type” supramolecular polymer.

Trinuclear Mo₃S₇ cluster complexes with sulfide bridges as potential anionic receptors due to chalcogen bonding.

Unusual rotation of the ligand (blue dotted circle) in organometallic crystals is disclosed by X-ray diffraction experiments.

The nuclearity of the coordination complexes of carboxylated pillar[5]arene and strontium(II) can be varied with the aid of phenanthroline as a coligand.

The title compound crystallises in the triclinic centrosymmetric space group P with an intriguing high number of crystallographically unique binary salt-like adducts (Z′ = 8) and a total number of ionic species (Z′′ = 16) in the asymmetric unit.

Here it deliberates the relationships between explicit crystal structures and biopharmaceutical properties of two polymorphs of remdesivir.

The transformation from the piroxicam monohydrate to form I or form II could be achieved precisely by adjusting the particle size itself in the 99% acetone-1% H₂O solvent at 31 °C.

The second and third crystalline forms of lactic acid are described, yet along with the known structure, they together fail to reproduce any of the supramolecular aggregates that have long been observed in isotropic media.

Reversible and facile single-crystal-to-single-crystal transformation between two polymorphs of diphenhydramine citrate leads to molecular level understanding of crystal phase change.

We report on nanoindentation data for two pairs of polymorphic compounds of p-aminobenzoic acid (pABA) and p-nitrobenzoic acid (pNBA) and compare it with existing data in the literature. We also explore on a new parameter, s-PBC, as a tool to estimate hardness.

Halogen-bonded (XB) supramolecular polymers from two heteroditopic, emissive hydroxyquinoline-based structural isomers displayed distinctly different crystal packing & stimuli-responsive morphologies, due to the varying XB directionality & strength.

An adamantane-bearing macrocycle exhibited permanent intrinsic porosity and adsorption of small guests in single-crystal-to-single-crystal fashions. The guest capture resulted in the structural transformations of supramolecular organic frameworks.

A selective cocrystallization technology based on non-covalent interactions between the target compound and cocrystal conformers was developed to effectively separate isomer mixtures.

Hydrogen bonds (i.e., N⁺–H⋯N) in combination with cation⋯π interactions enable a cascade-like [2 + 2] photodimerization of 4-stilbazole in a salt cocrystal.

Here, we present the first example of sp³ hybridized carbon centered (C_sp³) tetrel bonding mediated 3D BODIPY assembly via the exceptional synergy of C_sp³⋯N and C_sp³⋯F pair interactions.

(Bu₄N)₂[β-{Ag(N₂-py)}₂Mo₈O₂₆] demonstrates monomer/polymer dualism and a colouration phenomenon. The polymeric phase reveals a Ag assisted phase transition. Such complexes can act as precursors for catalytically active materials.

In the crystal lattice of two novel Re^IV compounds, the paramagnetic [ReCl₆]²⁻ and [ReBr₆]²⁻ anions are well separated from each other through two protonated forms of the antibiotic ciprofloxacin. These compounds behave as single-ion magnets (SIMs).

Novel supramolecular assemblies built from Keggin-type polyoxometalate and [18]-crown-6 ether building blocks exhibit unique propeller-like supramolecular host–guest structures.

It is demonstrated that laser-induced nucleation enables preferential crystallization of metastable anhydrous solids from solution.

A comparison of galunisertib in crystal structures of pure polymorphs and solvates enables studying the effects of solvate molecules on galunisertib conformations and highlights the features of realized noncovalent interactions.

Studying the aggregation and nucleation of proteins in the presence of organic molecules is helpful for disclosing the mechanisms of protein crystallization.

Two pairs of HOFs were prepared with H₄TCPE ligand under different conditions, and 3 and 4 have high stability and exhibit fluorescence quenching and enhancement toward Fe³⁺ and Al³⁺ ions, respectively.

Amino acid hydrogen oxalate quasiracemates form robust crystal structure motifs that are assessed for conformational similarity and degree of inversion symmetry.

A new family of quasiracemic materials constructed from sulfur-containing amino acid hydrogen oxalates form supramolecular assemblies that divert significantly from near centrosymmetric alignment.

Six novel co-crystals of tetrabromoquinone with iodide salts of organic cations displaying short contacts between iodide anions and the quinoid rings have been structurally characterised.

A series of 1-aminopyridinium base derivative ionic liquids without alkyl groups were synthesized. Hirshfeld surface analysis was used to understand the intricacies of interactions.

A peptide having miniature (P)3₁₀/α-helix conformation, forms intermolecular H-bonded supramolecular helical bundle structure which further self-assembled to interdigited supramolecular sheet-like structure that eventually from the brittle crystal.

Two bis-urea receptors bearing aromatic meta-substituted electron-withdrawing groups demonstrated  halide-coordination-triggered self-assemblies with contrasting coordination numbers and variation in morphology.

Combining surface-confined reactions with supramolecular self-assembly allows the chemical transformation of simple molecular precursors into higher-level tectons to generate complex tessellations with unique structural and functional properties.

A 1D rotor-like organic perovskite, {[Na(15-crown-5)]PbBr₃}_n, features a high-κ nature and experiences a reversible isostructural phase transition near room temperature.

The β–δ crystal transformation of HMX is examined using a self-made constant temperature decomposition gas measuring device, and the isothermal decomposition kinetic parameters of HMX with different crystal phases are obtained.

We successfully obtained a Pt square complex having an electron-accepting ligand, which shows a strong similarity to the high-pressure phase of the natural mineral katoite in the solid state.

Five new multicomponent solid forms of 2,4-D were successfully synthesized. The equilibrium solubility measurement confirmed the improvements in water solubility of new multicomponent crystals.

The anhydrate and hemihydrate structures of the marketed drug, clopamide, are described the first time. Structural landscape of its copper complexes is presented: three polymorphic modifications and an isostructural series of its alcohol clathrates.

This study highlights the comparison of electrical properties and device applications of d¹⁰ metal ion based coordination polymers.

This manuscript reports the synthesis, X-ray characterization and theoretical study of all-cis 1,4:2,3:5,8:6,7-tetraepoxynaphthalenes focusing on the importance of α-effect hydrogen bonds.

α,α-Diphenyl-9,10-dihydro-9,10-ethanoanthracene-11-methanol possessed an enhanced selectivity for o-Xy when recrystallized from various xylene and EB mixed solvents (84.5–93.7%).

The nature and role of non-covalent interactions involving fluorous molecules and aromatic molecules are studied by a combined theoretical/crystallographic approach.

New structural description of Fe₂WO₆ powder with incommensurate modulations providing valuable microstructural information and impacting on cation ordering.

The nanoconfinement of the three liquid guests within a MOF has been fully investigated in terms of host–guest interactions and framework rearrangement.

Noticeable differences in mechanically induced elastic responses were observed for isostructural crystalline coordination polymers, and their mechanical properties were examined through a highly integrated approach, using both theory and experiment.

Four polymorphs of the bis-phthalocyanine lanthanoid(III) double-decker complexes are crystallized by solution evaporation methods, and their structures determined by single-crystal X-ray crystallography.

Combined crystallographic and quantum chemical study was performed to reveal the influence of halogen bonding on the sensitivity towards detonation of high-energy molecules.

Synthons guided the types of N–H⋯π interactions and stacking to cause quenching of emissions.

An unusual crossed dimer motif is present in the solid state in the infinite TCNQ˙⁻ columns of the bis-12-crown-4 complexes of Li and NaTCNQ.

Excited state intramolecular proton transfer (ESIPT) process-based organic fluorophores provide an opportunity to develop large Stokes-shifted multifunctional fluorescence systems for light emitting, chemosensing and bioimaging applications.

Based on the design concept of supramolecular synthons, “–NH₂⋯N_pyridine” was used to prepare cocrystals of DAP: (1 : 1) and (2 : 1) DAP-PYR, which could be transformed into each other by mechanochemistry.

Strong hydrogen bonding interactions are observed in a hydronium ion trapped nickel(II) Schiff base complex. The energetics regarding these interactions which provide the stability to the supramolecular structure are analysed by DFT calculations.

Disordering of ET in dual-layered organic metal with incoherent interlayer electron transport (ET)₄ZnBr₄(C₆H₄Cl₂) begins already in the LT-phase when approaching T_p.

Valproic acid (VAL) forms complexes with natural and derivatised cyclodextrins (CDs). Stoichiometries were deduced from NMR spectra, thermal and X-ray diffraction analyses, the latter revealing modes of VAL inclusion in CDs for the first time.

Structural properties of various FeGe_x compounds are explored by Raman spectroscopy in order to provide reference Raman spectra, and enable fast and local phase determination in FeGe thin films.

Butyl substituents enhance solution processing, but undermine the short Pt⋯Pt contacts that enable metallisation under pressure.

In this study, the efficiency of halogen bonding strategies to control over the supramolecular assemblies of boron dipyrromethene (BODIPY) (B-1, B-2, and B-3) derivatives was explored.