XB Interactions Research Articles

Photoregulated Supramolecular Polymerization through Halogen Bonding

Supramolecular polymers are able to change their structure, morphology and function in response to external stimuli. However, controlling the independence of stimuli‐responses in these systems is challenging. Herein, we exploit halogen bonding (XB) as a reversible network element to regulate the photoresponsive and adaptive behavior of supramolecular polymers. To this end, we have designed a system comprising an amphiphilic XB acceptor with the ability to self‐assemble in aqueous media (OPE‐Py) and a molecule with a dual photoresponsive and XB donor function [(E)‐Azo‐I]. OPE‐Py self‐assembles in aqueous media into supramolecular polymers, which transform into nanoparticle assemblies upon co‐assembly with (E)‐Azo‐I. Interestingly, a third type of assembly (2D sheets) is obtained if OPE‐Py is treated with (E)‐Azo‐I and exposed to photoirradiation. At ambient conditions, both nanoparticles and 2D sheets remain invariant over time. However, heating dissociates the XB interactions present in both assemblies, resulting in their transformation to the original fiber‐like morphology of OPE‐Py. Thus, breaking the communication between self‐assembly and the stimuli‐responses upon heating restores the original state of the system, drawing parallels to feedback loops in programming language. This work broadens the still limited scope of XB in solution assemblies and paves the way for multifunctional adaptive supramolecular systems.

Photoregulated Supramolecular Polymerization through Halogen Bonding.

Supramolecular polymers are able to change their structure, morphology and function in response to external stimuli. However, controlling the independence of stimuli-responses in these systems is challenging. Herein, we exploit halogen bonding (XB) as a reversible network element to regulate the photoresponsive and adaptive behavior of supramolecular polymers. To this end, we have designed a system comprising an amphiphilic XB acceptor with the ability to self-assemble in aqueous media (OPE-Py) and a molecule with a dual photoresponsive and XB donor function [(E)-Azo-I]. OPE-Py self-assembles in aqueous media into supramolecular polymers, which transform into nanoparticle assemblies upon co-assembly with (E)-Azo-I. Interestingly, a third type of assembly (2D sheets) is obtained if OPE-Py is treated with (E)-Azo-I and exposed to photoirradiation. At ambient conditions, both nanoparticles and 2D sheets remain invariant over time. However, heating dissociates the XB interactions present in both assemblies, resulting in their transformation to the original fiber-like morphology of OPE-Py. Thus, breaking the communication between self-assembly and the stimuli-responses upon heating restores the original state of the system, drawing parallels to feedback loops in programming language. This work broadens the still limited scope of XB in solution assemblies and paves the way for multifunctional adaptive supramolecular systems.

Halogen Bond-Assisted Supramolecular Dimerization of Pyridinium-Fused 1,2,4-Selenadiazoles via Four-Center Se2N2 Chalcogen Bonding.

The synthesis and structural characterization of α-haloalkyl-substituted pyridinium-fused 1,2,4-selenadiazoles with various counterions is reported herein, demonstrating a strategy for directed supramolecular dimerization in the solid state. The compounds were obtained through a recently discovered 1,3-dipolar cycloaddition reaction between nitriles and bifunctional 2-pyridylselenyl reagents, and their structures were confirmed by the X-ray crystallography. α-Haloalkyl-substituted pyridinium-fused 1,2,4-selenadiazoles exclusively formed supramolecular dimers via four-center Se···N chalcogen bonding, supported by additional halogen bonding involving α-haloalkyl substituents. The introduction of halogens at the α-position of the substituent R in the selenadiazole core proved effective in promoting supramolecular dimerization, which was unaffected by variation of counterions. Additionally, the impact of cocrystallization with a classical halogen bond donor C6F3I3 on the supramolecular assembly was investigated. Non-covalent interactions were studied using density functional theory calculations and topological analysis of the electron density distribution, which indicated that all ChB, XB and HB interactions are purely non-covalent and attractive in nature. This study underscores the potential of halogen and chalcogen bonding in directing the self-assembly of functional supramolecular materials employing 1,2,4-selenadiazoles derived from recently discovered cycloaddition between nitriles and bifunctional 2-pyridylselenyl reagents.

Dichlorine-pyridine N-oxide halogen-bonded complexes.

A new Cl-Cl···-O-N+ halogen-bonded paradigm has been demonstrated, using dichlorine as a halogen bond (XB) donor and N-oxide as an XB acceptor. Their crystalline complexes were formed during the warm-up process from -196 °C to -80 °C for X-ray diffraction analysis. They exhibit high instability in the crystalline state, even at these low temperatures, leading to rapid decomposition and the formation of Cl⋯H-O-N hydrogen-bonded complexes. The normalized XB interaction ratio (R XB) of Cl⋯O interactions in the solid-state demonstrates affinity comparable to traditional I⋯O interactions observed in I-I···-O-N+ halogen-bonded systems. The Cl-Cl⋯O XB angles vary from 172° to 177°, manifesting the structure-guiding influence of the electronegative chlorine atom's σ-hole on these XB interactions.

Halogen bonding BODIPY-appended pillar[5]arene for the optical sensing of dicarboxylates and a chemical warfare agent simulant.

A pillar[5]arene host, functionalised with halogen bonding (XB) recognition sites and BODIPY fluorophores, demonstrates strong binding and optical sensing of environmentally relevant dicarboxylates and a chemical warfare agent simulant, in organic and competitive aqueous-organic media - enabled by the unprecedented combination of fluorophore-conjugated XB interactions with the hydrophobic pillar[5]arene host cavity.

Halogen Bonding Interactions of Haloaromatic Endocrine Disruptors and the Potential for Inhibition of Iodothyronine Deiodinases

AbstractHalogen bonding (XB) is a potential mechanism for the inhibition of the thyroid‐activating/deactivating iodothyronine deiodinase family of selenoproteins through interactions with halogenated endocrine disrupting compounds (EDCs). Trends in XB interactions were examined using density functional theory for a series of polyhalogenated dibenzo‐1,4‐dioxins, biphenyls, and other EDCs with methylselenolate, a simple model of the Dio active site selenocysteine. The strengths of the interactions depend upon the halogen (Br>Cl), the degree of substitution, and the position of the acceptor. In terms of donor‐acceptor energies, interactions at the meta position are often the strongest, suggesting a link to the topology of THs, especially for outer‐ring deiodination of thyroxine, which occurs at a meta iodine, and produces the active TH. However, relationships between XB interaction strengths and potential for Dio inhibition should be made in the context of the binding to the active sites, the topology of which are not fully characterized.

Mesomorphic and computational evaluation of C[tbnd]N‧‧‧I halogen bonded complexes of 4-alkoxy-4′-cyanobiphenyls systems with 1,6- diiodoperfluorohexane

Thermotropic halogen bonded (XB) liquid crystalline complex (A-n XB) of 4-alkoxy-4′- cyano biphenyls (A-n) systems containing nitrile (-CN) group with variable alkoxy chain length (-CnH2n+1, where n = 3 to 10) acting as halogen bond acceptor with 1,6-diiodoperfluorohexane, (I-atom) acting as halogen bond donor were prepared by the liquid-assisted grinding method. The A-n XB complex formations, through CN‧‧‧I XB interactions, were established by the FTIR, Raman, PXRD, polarizing optical microscope (POM) with hot stage, DSC and TGA techniques. Further, POM study of these homologous XB complex series showed liquid crystalline phases with a alteration of (1–10 °C) compared to their respective parent mesogenic molecules. The computational study was carried out using Frontier Molecular Orbitals (FMOs), Molecular Electrostatic Potential (MEP), Non-covalent interactions (NCI) and Quantum theory of atoms in molecule (QTAIM) analysis to evaluate the reactivity parameters and strength of XB in the complexes.

Development of Novel Hypervalent Iodine Compounds Bearing Intramolecular Halogen Bonding

In recent years, halogen bonding (XB) interaction has attracted much attention in organic synthesis, especially for the activation of substrates. On the other hand, the use of XB interaction for the “stabilization” of molecules has been less explored. In this manuscript, the authors described our recent work on the development of new class of N-acyliminoiodinanes and iodonium ylides, which can be used as nitrene and carbene equivalents, respectively. The intramolecular XB interactions were confirmed by X-ray structure and natural bond orbital (NBO) analyses. The synthesized N-acyliminoiodinanes were found to be activated by photo-irradiation to react with silyl enol ethers, glycals, alkynes, and(hetero)aromatic compounds to afford the corresponding aminated adducts. In addition, the iodonium ylides baring intramolecular XB interaction underwent additive-free chemoselective coupling reaction of thioamides, even in protic polar solvents. The intramolecular XB could also control the coordination mode of the nucleophile via σ-holes, suppressing undesired side reactions. These findings would pave new avenues chemoselective coupling reactions using hypervalent iodine compounds.

Solid-State 19F NMR Chemical Shift in Square-Planar Nickel-Fluoride Complexes Linked by Halogen Bonds.

The halogen bond (XB) is a highly directional class of noncovalent interactions widely explored by experimental and computational studies. However, the NMR signature of the XB has attracted limited attention. The prediction and analysis of the solid-state NMR (SSNMR) chemical shift tensor provide useful strategies to better understand XB interactions. In this work, we employ a computational protocol for modeling and analyzing the 19F SSNMR chemical shifts previously measured in a family of square-planar trans NiII-L2-iodoaryl-fluoride (L = PEt3) complexes capable of forming self-complementary networks held by a NiF···I(C) halogen bond [Thangavadivale, V.; Chem. Sci. 2018, 9, 3767-3781]. To understand how the 19F NMR resonances of the nickel-bonded fluoride are affected by the XB, we investigate the origin of the shielding in trans-[NiF(2,3,5,6-C6F4I)(PEt3)2], trans-[NiF(2,3,4,5-C6F4I)(PEt3)2], and trans-[NiF(C6F5)(PEt3)2] in the solid state, where a XB is present in the two former systems but not in the last. We perform the 19F NMR chemical shift calculations both in periodic and molecular models. The results show that the crystal packing has little influence on the NMR signatures of the XB, and the NMR can be modeled successfully with a pair of molecules interacting via the XB. Thus, the observed difference in chemical shift between solid-state and solution NMR can be essentially attributed to the XB interaction. The very high shielding of the fluoride and its driving contributor, the most shielded component of the chemical shift tensor, are well reproduced at the 2c-ZORA level. Analysis of the factors controlling the shielding shows how the highest occupied Ni/F orbitals shield the fluoride in the directions perpendicular to the Ni-F bond and specifically perpendicular to the coordination plane. This shielding arises from the magnetic coupling of the Ni(3d)/F(2p lone pair) orbitals with the vacant σNi-F* orbital, thereby rationalizing the very highly upfield (shielded) resonance of the component (δ33) along this direction. We show that these features are characteristic of square-planar nickel-fluoride complexes. The deshielding of the fluoride in the halogen-bonded systems is attributed to an increase in the energy gap between the occupied and vacant orbitals that are mostly responsible for the paramagnetic terms, notably along the most shielded direction.

Self-Assembly of Supramolecular Architectures Driven by σ-Hole Interactions: A Halogen-Bonded 2D Network Based on a Diiminedibromido Gold(III) Complex and Tribromide Building Blocks.

The reaction of the complex [Au(phen)Br2](PF6) (phen = 1,10-phenanthroline) with molecular dibromine afforded {[Au(phen)Br2](Br3)}∞ (1). Single crystal diffraction analysis showed that the [Au(phen)Br2]+ complex cations were bridged by asymmetric tribromide anions to form infinite zig-zag chains featuring the motif ···Au–Br···Br–Br–Br···Au–Br···Br–Br–Br···. The complex cation played an unprecedented halogen bonding (XB) donor role engaging type-I and type-II XB noncovalent interactions of comparable strength with symmetry related [Br3]− anions. A network of hydrogen bonds connects parallel chains in an infinite 2D network, contributing to the layered supramolecular architecture. DFT calculations allowed clarification of the nature of the XB interactions, showing the interplay between orbital mixing, analyzed at the NBO level, and electrostatic contribution, explored based on the molecular potential energy (MEP) maps of the interacting synthons.

Monolayer-Protected Gold Nanoparticles Functionalized with Halogen Bonding Capability─An Avenue for Molecular Detection Schemes.

The use of functionalized nanoparticles (NPs) and their aggregation in the presence of a targeted analyte is a well-established molecular detection strategy predicated on harnessing specific molecular interactions to the NP periphery. Molecules able to specifically interact with the functionalized NPs alter the unique optical and electrochemical properties of the NPs as a function of interparticle spacing. While many intermolecular interactions have been successfully exploited in this manner in conjunction with aqueous NP systems, the use of non-aqueous NPs in the same capacity is significantly less explored. A fundamental interaction that has not been previously investigated in NP schemes is halogen bonding (XB). XB is an orthogonal, electrostatic interaction between a region of positive electrostatic potential (δ+) on a halogen atom (i.e., XB donor) and a negative (δ-) Lewis base (XB acceptor) molecule. To couple XB with NP systems, ligands featuring a molecular structure that promotes XB interactions need to be identified, optimized, and synthesized for subsequent attachment to NPs. Herein, density functional theory (DFT) and NMR techniques are used to identify a strong XB-donor moiety (-C6F4I) and a synthetic scheme for a thiolate ligand featuring that functionality is devised and executed with high purity/yield (78%). Ligand-exchange reactions allow functionalization of non-aqueous alkanethiolate-protected gold NPs or monolayer-protected clusters (MPCs) with the XB-donor ligands. Functionalized MPCs (f-MPCs), within both assembled films and in solution, are shown to engage in XB interactions with target XB-acceptor molecules. Molecular recognition events, including induced aggregation of the f-MPCs, are characterized with UV-vis spectroscopy, cyclic voltammetry, TEM imaging, and diffusion-ordered spectroscopy NMR with limits of detection of 50-100 nM for strong XB acceptors. While fundamental exploration of XB interactions is ongoing, this study represents a step toward utilizing XB within molecular detection schemes, an application with implications for supramolecular chemistry, forensic, and environmental chemical sensing.

Halogen Bonding Ionophore for Potentiometric Iodide Sensing.

Iodide (I-) is an essential micronutrient for thyroid function. Hence, rapid and portable sensing is important for I- quantification in food and biological samples. Herein, we report the first example of a halogen bonding (XB) tripodal ionophore (XB1) which is selective for the I- anion. NMR binding studies of XB1 and its H-triazole analog HB2 with I- demonstrated the dominant influence of XB interactions between the ionophore and the I- analyte. The phase boundary model was applied to formulate iodide-selective electrodes with the ionophore XB1. The optimal electrode exhibited a near-Nernstian response of -51.9 mV per decade within a large dynamic range (10-1 to 10-6 M) and notably anti-Hofmeister selectivity for I- over thiocyanate (SCN-), enabling the in situ determination of I- in complex samples. This work establishes XB as a viable supramolecular interaction in the potentiometric sensing of anions.

Evaluating Halogen-Bond Strength as a Function of Molecular Structure Using Nuclear Magnetic Resonance Spectroscopy and Computational Analysis.

Halogen bonding (XB) is a highly directional, non-covalent intermolecular interaction between a molecule (XB donor) presenting a halogen with an electron-deficient region or sigma hole (σ-hole) and an electron-rich or Lewis-base molecule (XB acceptor). A systematic, experimental, and theoretical study of solution-phase XB strength as a function of the molecular structure for both XB donor and acceptor molecules is presented. The impact of specific structural features is assessed using 19F and 1H nuclear magnetic resonance (NMR) titrations to determine association constants, density functional theory calculations for interaction energies and bond lengths, as well as 19F-1H HOESY NMR measurements of intermolecular cross-relaxation between the interacting XB donor-acceptor adducts. For XB donor molecules (perfluoro-halogenated benzenes), results indicate the critical importance of iodine coupled with electron-withdrawing entities. Prominent structural components of XB acceptor molecules include a central atom working in conjunction with a Lewis-base atom to present high electron density directed at the σ-hole (e.g., tributylphosphine oxide). Additionally, larger surrounding aliphatic R groups (e.g., butyl and octyl) were found to significantly stabilize strong XB, particularly in solvents that promote the interaction. With a more thorough understanding of structure-optimized XB, one can envision harnessing XB interactions more strategically for specific design of optimal materials and chemical applications.

Halogen Bonding between Thiocarbonyl Compounds and 1,2- and 1,4-Diiodotetrafluorobenzenes

The halogen bonding (XB) between 1,2-diiodotetrafluorobenzene (1,2-DITFB) or 1,4-diiodotetrafluorobenzene (1,4-DITFB) and the selection of different thiocarbonyl acceptors was studied by the single-crystal X-ray diffraction method. Diiodotetrafluorobenzenes (DITFBs) were found to form C-I···S halogen-bonded 1:1, 2:1, and 1:2 (donor/acceptor ratio) complexes with thiocarbonyls. Lengths of contacts were found to be clearly shorter than the sum of van der Waals radii of iodine and sulfur as well as the contact angles showed values close to linear, so the XB interactions could be verified. One sulfur atom showed the ability to accept one, two, or four XB interactions, and the acceptor angle can vary more than 35°. Solid-state packing of thiocarbonyl-XB complexes was found to be greatly affected by the size and type of the acceptor used. Halogen and hydrogen bonding cooperativity was found in some of the complexes if the used acceptor was suitable to form both bonds. Here, we present 19 new structures of these complexes, which can be rather easily prepared by mixing the components in the solutions and letting them crystallize in loosely sealed tubes. Computational analysis carried out for the XB complexes of N,N′-dimethylthiourea supported very closely the findings of the experimental study.

Halogen and Chalcogen Bonding Between the Triphenylphosphine Chalcogenides (Ph3P=E; E=O, S, Se) and Iodofluorobenzenes

AbstractA series of cocrystals of Ph3P=E (E=O, S, Se) with organoiodines were studied to understand the roles of noncovalent interactions including chalcogen (ChB) and halogen (XB) bonding in their formation. The structure of the cocrystal of Ph3P=S and 1,2‐diiodotetrafluorobezene was determined, which demonstrates a similar chalcogen⋅⋅⋅iodine XB pattern to the previously reported isomorphic Ph3P=Se structure. The cocrystalline structures resulting from the combination of 1,3‐diiodotetrafluorobenzene (1,3‐F4DIB), as well as iodopentafluorobenzene, with all three triphenylphosphine chalcogenides, were also determined. The (Ph3P=Se) ⋅ (1,3‐F4DIB) cocrystal presents a rare example of a selenium⋅⋅⋅organoiodine ChB. The observed ChB and XB interactions have normalized distance parameters (RXB) ranging from 0.80 to 0.98. The strength of the XB and ChB interactions were analyzed using natural bond orbital (NBO) theory, with calculated energies falling between 3.14 kcal/mol and 12.81 kcal/mol.

Classics Meet Classics: Theoretical and Experimental Studies of Halogen Bonding in Adducts of Platinum(II) 1,5-Cyclooctadiene Halide Complexes with Diiodine, Iodoform, and 1,4-Diiodotetrafluorobenzene

Complexes of PtX2COD (X = Cl, Br, I; COD = 1,5-cyclooctadiene) were cocrystallized with classical halogen-bond donors (CHI3, I2, and 1,4-diiodotetrafluorobenzene (FIB)), resulting in noncovalently bound supramolecular aggregates of various lengths—from heterotrimers to polymers. The influence of halides in the complexes on the geometry and strength of the halogen bond (XB) was studied both experimentally by single-crystal XRD and theoretically by quantum chemical methods such as noncovalent interaction plots (NCI-plot), electrostatic potential (ESP) surface analysis, and a combination of electron localization function (ELF) and quantum theory of atoms in molecules (QTAIM) analyses. It was shown that strength of XB interactions in the adducts increases in the order CHI3 > FIB > I2. Although halogen bonding was found to be the main preorganizing force in the structures, in the case of FIB adducts a rare Pt···I interaction was involved in additional stabilization of the structure. Hence, fine-tuning of halogen bonding can influence the length of the polymer, as well as the strength and directionality of interactions in the adduct.

Halogen-Bonded BODIPY Frameworks with Tunable Optical Features*.

The ability to tune the optical features of BODIPY materials in the solid state is essential for their photorelated application and requires efficient control of the crystal packing. In this study, such control of BODIPY supramolecular assemblies was achieved by deliberate design and synthesis of a BODIPY containing a strong halogen-bond (XB) acceptor (-NO2 ) and donor (I, Br) to mediate XB interactions. The di-halogenated structures formed isostructural mono-coordinate motif B3, B4 (1D tubular structure) and symmetric bifurcated motif B4-II (1D zigzag chains structure) through N-O⋅⋅⋅I, Br XB interactions. These XB interactions promote singlet-to-triplet intersystem crossing and triplet-to-singlet reverse intersystem crossing due to partial delocalization of oxygen electrons onto Br and I, which leads to unexpected fluorescence enhancement of B4-II. Finally, the indirect optical band gaps of B3, B4 and B4-II were amenable to tuning in the range of 1.85-2.50 eV by XB-driven crystal packings.

Activating both Halogen and Chalcogen Bonding Interactions in Cation Radical Salts of Iodinated Tetrathiafulavalene Derivatives.

Halogen bonding (XB) interactions are investigated in cation radical salts of bis(methylthio)-5,5'-diiodotetrathiafulvalene (1). Electrocrystallization of 1 in the presence of Bu4 NCl affords a 1 : 1 salt formulated as (E-1)Cl. Particularly strong I⋅⋅⋅Cl- XB interactions are observed around the Cl- anion with the distances at 78 % the sum of the van der Waals radii, a consequence of the XB charge activation in the cation radical. Moreover, the Cl- environment is complemented by two extra S⋅⋅⋅Cl- chalcogen bonding (ChB) interactions, an original feature among reported halide salts of TTF derivatives. Electrostatic potential calculations on the cation radical further demonstrate the efficient activation of the S atoms of the 1,3-dithiole rings (Vs,max =87.2 kcal/mol), as strong as with the iodine atoms (Vs,max =87.9 kcal/mol). The radical cations form weakly dimerized stacks, as confirmed by the variable-temperature magnetic susceptibility and the weak conductivity (4.8×10-5 S cm-1 ).

A Halogen Bonding Perspective on Iodothyronine Deiodinase Activity.

Iodothyronine deiodinases (Dios) are involved in the regioselective removal of iodine from thyroid hormones (THs). Deiodination is essential to maintain TH homeostasis, and disruption can have detrimental effects. Halogen bonding (XB) to the selenium of the selenocysteine (Sec) residue in the Dio active site has been proposed to contribute to the mechanism for iodine removal. Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are known disruptors of various pathways of the endocrine system. Experimental evidence shows PBDEs and their hydroxylated metabolites (OH-BDEs) can inhibit Dio, while data regarding PCB inhibition are limited. These xenobiotics could inhibit Dio activity by competitively binding to the active site Sec through XB to prevent deiodination. XB interactions calculated using density functional theory (DFT) of THs, PBDEs, and PCBs to a methyl selenolate (MeSe−) arrange XB strengths in the order THs > PBDEs > PCBs in agreement with known XB trends. THs have the lowest energy C–X*-type unoccupied orbitals and overlap with the Se lp donor leads to high donor-acceptor energies and the greatest activation of the C–X bond. The higher energy C–Br* and C–Cl* orbitals similarly result in weaker donor-acceptor complexes and less activation of the C–X bond. Comparison of the I···Se interactions for the TH group suggest that a threshold XB strength may be required for dehalogenation. Only highly brominated PBDEs have binding energies in the same range as THs, suggesting that these compounds may inhibit Dio and undergo debromination. While these small models provide insight on the I···Se XB interaction itself, interactions with other active site residues are governed by regioselective preferences observed in Dios.

Supramolecular Assemblies in Silver Complexes: Phase Transitions and the Role of the Halogen Bond.

Weak interactions (hydrogen bonds, halogen bonds, CH···π and π-π stacking) can play a significant role in the formation of supramolecular assemblies with desired structural features. In this contribution, we report a systematic investigation on how a halogen bond (XB) can modulate the structural arrangement of silver supramolecular complexes. The complexes are composed of X-phenyl(bispyrazolyl)methane (X = Br, I) and I-alkynophenyl(bispyrazolyl)methane ligands functionalized in meta (L3Br, L3I) and para (L4Br, L4I, L4CCI) positions on a phenyl ring with the purpose of providing different directionalities of the X function with respect to the N,N coordination system. The obtained [Ag(L)2]+ moieties show remarkable geometric similarities, and the L4Br, L4I, and L4CCI ligands exhibit the most conserved types of supramolecular arrangement that are sustained by XB. The increased σ-hole in L4CCI with respect to L4I leads to an occurrence of short (and strong) XB interactions with the anions. [Ag(L4I)2]PF6 and [Ag(L4I)2]CF3SO3 are characterized by the presence of three different phases, and the single-crystal evolution from phase-1 (a honeycomb structure with large 1D cavities) to phase-3 (solventless) occurs by a stepwise decrease in the crystallization solvent content, which promotes an increase in XB interactions in the lattice. The present paper aims to provide useful tools for the selection of appropriate components for the use of coordination compounds to build supramolecular systems based on the halogen bond.