1D Motifs Research Articles

Achieving the 1D Atomic Chain Limit in Van der Waals Crystals.

Experiments with graphene have demonstrated that 2D van der Waals materials can be stable, robust, and efficiently manipulated at the level of individual atomic planes. However, the stability and manipulation of 1D van der Waals materials and individual atomic chains remains elusive. Here, the ability to exfoliate and process two representative van der Waals materials containing 1D motifs, namely MoI3 and Ta2Se8I, at the scale of individual atomic chains is demonstrated. High-resolution transmission electron microscopy and atomic force microscopy studies confirm the presence of stable individual atomic chains of MoI3 at room temperature. It is further shown that 1D van der Waals materials with low exfoliation energy, such as Ta2Se8I, can be processed with electron beams to achieve suspended individual atomic chains. Ab initio calculations corroborate the findings regarding the cleavage energies and the thermodynamic stability of individual atomic chains in these 1D van der Waals materials. These results demonstrate that the top-down approach in material processing can be extended to the scale of individual chains.

3D Hierarchical-Architectured Nanoarray Electrode for Boosted and Sustained Urea Electro-Oxidation.

Exploring active and durable Ni-based materials with optimized electronic and architectural engineering to promote the urea oxidation reaction (UOR) is pivotal for the urea-related technologies. Herein a 3D self-supported hierarchical-architectured nanoarray electrode (CC/MnNi@NC) is proposed in which 1D N-doped carbon nanotubes (N-CNTs) with 0D MnNi nanoparticles (NPs) encapsulation are intertwined into 2D nanosheet aligned on the carbon cloth for prominently boosted and sustained UOR electrocatalysis. From combined experimental and theoretical investigations, Mn-alloying can regulate Ni electronic state with downshift of the d-band center, facilitating active Ni3+ species generation and prompting the rate-determining step (*COO intermediate desorption). Meanwhile, the micro/nano-hierarchical nanoarray configuration with N-CNTs encapsulating MnNi NPs can not only endow strong operational durability against metal corrosion/agglomeration and enrich the density of active sites, but also accelerate electron transfer, and more intriguingly, promote mass transfer as a result of desirable superhydrophilic and quasi-superaerophobic characteristics. Therefore, with such elegant integration of 0D, 1D and 2D motifs into 3D micro/nano-hierarchical architecture, the resulting CC/MnNi@NC can deliver admirable UOR performance, favorably comparable to the best-performing UOR electrocatalysts reported thus far. This work opens a fresh prospect in developing advanced electrocatalysts via electronic manipulation coupled with architectural engineering for various energy conversion technologies.

On the origin of the combinatorial complexity of the crystal structures with 0D, 1D, or 2D primary motifs

Based on Krivovichev information measures for crystal structures and the universal partitioning scheme for different sources of information described previously by Hornfeck, we proposed a general scheme of complexity calculation for heterodesmic crystals.

Printed Electronic Devices with Inks of TiS3 Quasi-One-Dimensional van der Waals Material.

We report on the fabrication and characterization of electronic devices printed with inks of quasi-one-dimensional (1D) van der Waals materials. The quasi-1D van der Waals materials are characterized by 1D motifs in their crystal structure, which allow for their exfoliation into bundles of atomic chains. The ink was prepared by the liquid-phase exfoliation of crystals of TiS3 into quasi-1D nanoribbons dispersed in a mixture of ethanol and ethylene glycol. The temperature-dependent electrical measurements indicate that the electron transport in the printed devices is dominated by the electron hopping mechanisms. The low-frequency electronic noise in the printed devices is of 1/fγ-type with γ ∼ 1 near-room temperature (f is the frequency). The abrupt changes in the temperature dependence of the noise spectral density and γ parameter can be indicative of the phase transition in individual TiS3 nanoribbons as well as modifications in the hopping transport regime. The obtained results attest to the potential of quasi-1D van der Waals materials for applications in printed electronics.

Factors Controlling Persistent Needle Crystal Growth: The Importance of Dominant One-Dimensional Secondary Bonding, Stacked Structures, and van der Waals Contact.

Needle crystals can cause filtering and handling problems in industrial settings, and the factors leading to a needle crystal morphology have been investigated. The crystal growth of the amide and methyl, ethyl, isopropyl, and t-butyl esters of diflunisal have been examined, and needle growth has been observed for all except the t-butyl ester. Their crystal structures show that the t-butyl ester is the only structure that does not contain molecular stacking. A second polymorph of a persistent needle forming phenylsulfonamide with a block like habit has been isolated. The structure analysis has been extended to known needle forming systems from the literature. The intermolecular interactions in needle forming structures have been analyzed using the PIXEL program, and the properties driving needle crystal growth were found to include a 1D motif with interaction energy greater than −30 kJ/mol, at least 50% vdW contact between the motif neighbors, and a filled unit cell which is a monolayer. Crystal structures are classified into persistent and controllable needle formers. Needle growth in the latter class can be controlled by choice of solvent. The factors shown here to be drivers of needle growth will help in the design of processes for the production of less problematic crystal products.

Molecular Structure Effects on the Aggregation Motif of Porphyrins: Computational Insights

AbstractThe latest advancements in semiempirical Hamiltonians have inspired new confidence for the supramolecular computational predictivity. The advanced accuracy of newly developed semiempirical methods is offered for computations of what can provide a valuable database of molecular tuning recommendations for the synthesis of new supramolecular materials. In this work the very versatile and impactful porphyrin is employed for examination of the first basic chemical tuning factors that may drive specific aggregation motifs. The 1D motifs are examined as a function of peripheral substituent steric bulk. Subsequently, a 1D‐wire versus a 3D‐square motif is investigated as a function of the metal–ligand effect. For the first time, an interesting effect of misprediction of semiempirical computations is encountered for a small class of these aggregates and is briefly examined with a conformational search analysis. These findings encourage further in silico work which is greatly required for diminishing the current discovery bottleneck in supramolecular chemistry.

Two types of Ln2Cu2 hydroxo-trimethylacetate complexes with 0D and 1D motifs: synthetic features, structural differences, and slow magnetic relaxation

The insertion of Na+ ions into the structure of LnIII2CuII2 hydroxo-trimethylacetate complexes leads to a change in the butterfly-like metal core geometry giving rise to a significant change in their slow magnetic relaxation.

Synthesis, Crystal Structure and Docking Studies as Potential Anti-Inflammatory Agents of Novel Antipyrine Sulfanyl Derivatives

The InCl3-catalyzed green synthesis of sulfanyl- and oxasulfanyl-substituted antipyrine derivatives (10 examples) through the thiomethylation of the substrate at the С(4)-Н position by formaldehyde and thiols or α,ω-mercaptoalkanols in water has been first developed. An X-ray diffraction study of the structures and molecular packing of compounds 4a, 4c-e demonstrated that the extension of the substitution chain with one methylene unit for compound 4d versus compounds 4а, 4c, and 4e results in the formation of a 2D (network) instead of 1D motif (chains). Using the molecular docking method, objective assumptions were made about the selectivity of anti-inflammatory action for S- and O,S-derivatives of antipyrine.

Alkyl-Substituted Selenium-Bridged V-Shaped Organic Semiconductors Exhibiting High Hole Mobility and Unusual Aggregation Behavior.

Toward the development of high-performance organic semiconductors (OSCs), carrier mobility is the most important requirement for next-generation OSC-based electronics. The strategy is that OSCs consisting of a highly extended π-electron core exhibit two-dimensional (2D) aggregated structures to offer effective charge transport. However, such OSCs, in general, show poor solubility in common organic solvents, resulting in limited solution processability. This is a critical trade-off between the development of OSCs with simultaneous high carrier mobility and suitable solubility. To address this issue, herein, five-membered ring-fused selenium-bridged V-shaped binaphthalene with decyl substituents (C10-DNS-VW) is developed and synthesized by an efficient method. C10-DNS-VW exhibits significantly high solubility for solution processes. Notably, C10-DNS-VW forms a one-dimensional π-stacked packing motif (1D motif) and a 2D herringbone (HB) packing motif (2D motif), depending on the crystal growth condition. On the other hand, the fabrication of thin films by means of both solution process and vacuum deposition techniques forms only the 2D HB motif. External stress tests such as heating and exposure to solvent vapor indicated that 1D and 2D motifs could be synergistically induced by the total balance of intermolecular interactions. Finally, the single-crystalline films of C10-DNS-VW by solution process exhibit carrier mobility up to 11 cm2 V-1 s-1 with suitable transistor stability under ambient conditions for more than two months, indicating that C10-DNS-VW is one of the most promising candidates for breaking the trade-off in the field of solution-processed technologies.

Unconventional Defects in a Quasi-One-Dimensional KMn6Bi5.

Quasi-one-dimensional (Q1D) structures comprising a compact array of indefinitely long 1D nanowires (NWs) are scarce, especially in a bulk device-scale showingmetallic and semiconducting behaviors along differentaxes.Unlike plentiful observations of nature of defects in three-/two-dimensional materials, there is a notable paucity of such reports in Q1D. Herein we present unconventional motific defects and their properties in a bulk Q1D KMn6Bi5 crystal, in which an individual NW motif acts as one body. We discovered motific inter- and intra-NW defects, such that a linear set of 1D motifs are displaced. Stress generates two domains with alteredinter-NW spacings and a Bi-Mn solid solution grain, leading to a local bulk plasmon shift due to NW array reconfiguration as well as atomic rearrangement. The observation of such exotic defects and associated phenomena in this Q1D may provide guidance on overall defect mechanism in other Q1D systems and their collective anisotropic properties.

Syntheses, Structures, and Catalytic Hydrocarbon Oxidation Properties of N-Heterocycle-Sulfonated Schiff Base Copper(II) Complexes

Reaction of the o-[(o-hydroxyphenyl)methylideneamino]benzenesulfonic acid (H2L) (1) with CuCl2·2H2O in the presence of pyridine (py) leads to [Cu(L)(py)(EtOH)] (2) which, upon further reaction with 2,2’-bipyridine (bipy), pyrazine (pyr), or piperazine (pip), forms [Cu(L)(bipy)]·MeOH (3), [Cu2(L)2(μ-pyr)(MeOH)2] (4), or [Cu2(L)2(μ-pip)(MeOH)2] (5), respectively. The Schiff base (1) and the metal complexes (2–5) are stabilized by a number of non-covalent interactions to form interesting H-bonded multidimensional polymeric networks (except 3), such as zigzag 1D chain (in 1), linear 1D chain (in 2), hacksaw double chain 1D (in 4) and 2D motifs (in 5). These copper(II) complexes (2–5) catalyze the peroxidative oxidation of cyclic hydrocarbons (cyclooctane, cyclohexane, and cyclohexene) to the corresponding products (alcohol and ketone from alkane; alcohols, ketone, and epoxide from alkene), under mild conditions. For the oxidation of cyclooctane with hydrogen peroxide as oxidant, used as a model reaction, the best yields were generally achieved for complex 3 in the absence of any promoter (20%) or in the presence of py or HNO3 (26% or 30%, respectively), whereas 2 displayed the highest catalytic activity in the presence of HNO3 (35%). While the catalytic reactions were significantly faster with py, the best product yields were achieved with the acidic additive.

Solvates of Zwitterionic Rifampicin: Recurring Packing Motifs via Nonspecific Interactions

Antibiotic rifampicin was recrystallized from solutions containing aliphatic alcohols, ketones or DMSO. Thirteen new solvates were obtained that were studied by X-ray crystallography. In these solvates rifampicin exists in a zwitterionic form. The reported solvates are classified into eight different structural types. Whereas rifampicin molecules in the solvates form diverse assemblies via hydrogen bonds, the recurring structural motif in these crystals is generated by nonspecific intermolecular interactions. This motif has the form of a periodic 1D rod and similar 1D motifs were found in the structures of other zwitterionic or ionic rifamycins. In rifampicin solvates, these rods form a basis for the construction of two types of 2D periodic modules: monolayers found in six structural types of rifampicin solvates and bilayers observed in two types of solvates. Diverse mutual arrangements of these 2D modules lead to the formation of channels with accommodated solvent molecules that consist 10-40% of the cry...

Structural Evolution in BaSn2F5X (X = Cl, Br, I): A Family of Alkaline Earth Metal Tin Mixed Halides.

As the first family of Sn-based alkaline earth metal mixed halides, three new compounds, BaSn2F5X (X = Cl, Br, and I), are synthesized by hydrothermal method. These compounds are crystallized in the centrosymmetric space groups of P21/c, P4/nmm, and Pmma for BaSn2F5Cl, BaSn2F5Br, and BaSn2F5I, respectively, and their microscopic frameworks are all composed of the fundamental structural unit [SnF4]2- and its derivatives ([SnF4Cl]3- and [SnF5]3- groups). Interestingly, the structures in BaSn2F5X are significantly changed from one-dimensional (1D) to two-dimensional (2D) and then to 1D motifs as X varies from Cl, Br, to I. Structural analysis combined with theoretical calculations reveals that the structural diversities are caused by the difference of ionic radius and electronegativity of X- anions as well as the orientation of the lone-pair electrons on Sn2+ cations. Moreover, the optical, electronic, and thermal properties for these three compounds are determined. This work provides a representative example to show how microscopic ions influence the structures, thus in favor of the design for new mixed halides, a type of important functional materials with many optoelectronic applications.

Pb2F2](SeO4): a heavier analogue of grandreefite, the first layered fluoride selenate

Co-precipitation of PbF2 and PbSeO4 in weakly acidic media results in the formation of [Pb2F2](SeO4), the selenate analogue of the naturally occurring mineral grandreefite, [Pb2F2](SO4). The new compound is monoclinic, C2/c, a = 14.0784(2) A, b = 4.6267(1) A, c = 8.8628(1) A, β = 108.98(1)°, V = 545.93(1) A3. Its structure has been refined from powder data to R B = 1.55%. From thermal studies, it is established that the compound is stable in air up to about 300 °C, after which it gradually converts into a single phase with composition [Pb2O](SeO4), space group C2/m, and lattice parameters a = 14.0332(1) A, b = 5.7532(1) A, c = 7.2113(1) A, β = 115.07(1)°, V = 527.37(1) A3. It is the selenate analogue of lanarkite, [Pb2O](SO4), and phoenicochroite, [Pb2O](CrO4), and its crystal structure was refined to R B = 1.21%. The formation of a single decomposition product upon heating in air suggests that this happens by a thermal hydrolysis mechanism, i.e., Pb2F2SeO4 + H2O (vapor) → Pb2OSeO4 + 2HF↑. This relatively low-temperature process involves complete rearrangement of the crystal structure—from a 2D architecture featuring slabs [Pb2F2]2+ formed by fluorine-centered tetrahedra into a structure characterized by 1D motifs based on [OPb2]2+ chains of oxocentered tetrahedra. The comparative crystal chemistry of the obtained anion-centered structural architectures is discussed.

Structure, solution assembly, and electroconductivity of nanosized argento-organic-cluster/framework templated by chromate.

In view of elucidating potential structures and assembly mechanism of silver clusters and silver cluster-based metal-organic frameworks, we prepared four argento-organic-clusters/frameworks where the structures were directed by chromate in the presence of different thiolates. All four structures with tBuC6H4S-, SiBu-, and SiPr- consist of three core-shells, an inner CrO42-, an intermediate Ag-S aggregate and finally the protective organic moieties. {(HNEt3)3[Ag(CrO4)4@Ag46(SC6H4tBu)24(CF3COO)18(DMF)4]} (1) is a supertetrahedron with an inner Ag(CrO4)4 tetrahedron shelled by four fused Ag11.5S6 lobes. [(CrO4)5@Ag40(SiBu)27(CF3COO)3]n (2) is an undulated snake-like tube housing the infinite CrO42- tetrahedra. [(CrO4)2@Ag41(SiBu)30(NO3)3(CN)4]n (3) forms an uncommon 7-connected kwh network incorporating hexagonal layers of Ag19(SiBu)15 balls with a single inner CrO42- connected by another Ag atom. Both enantiomeric chiral qtz frameworks of [CrO4@Ag20(SiPr)10(Cr2O7)2(COOCF3)4(DMF)4]n (4) were structurally characterized. In 4, Cr2O72- connects the Ag20(SiPr)10 clusters with a trapped CrO42- into a 3D quartz (qtz) structure, where the spherical cluster acts like oxygen and Cr2O72- takes the place of Si in SiO2. Electrospray ionization mass spectrometry (ESI-MS) analysis of the reaction solutions of 1-4 clearly indicated that (i) the Ag(CrO4)4@Ag46 core of 1 can retain its molecular structure in the solution and (ii) the chromate-templated polynuclear silver-thiolate species in solution are important building blocks to construct the 1D or 3D motif for 2-4. The electrochemistry in sulfuric acid and enhancement of the electrical conductivity upon I2 doping have also been reported.

Structure of liquid chlorobenzene in the temperature range 293-363 K

The classical molecular dynamics method is used to simulate the structure of liquid chlorobenzene in the temperature range 293-363 K. Theradial angular distribution functions for the distances between the benzene molecular planes and the angle between them; the radial distribution functions for the distances between chlorine atoms; self-diffusion coefficients, local dipole moments, and permittivities are calculated. In the entire temperature range molecules are joined into agglomerates due to contacts between chlorine atoms (halogen aggregation) and to the specific interactions of benzene rings, which causes mainly parallel and perpendicular orientations of the rings in the first coordination sphere. The molecules in the agglomerates are mostly organized in the 1D motif: chains of chlorine atoms and stacks of benzene rings. With increasing temperature, the agglomerate structure is reorganized, with the most visible changes occurring in temperature ranges 293-298 K, 313-323 K, and 343-353 K.

Syntheses, crystal structures and luminescent properties of three metal coordination polymers based on aromatic carboxylic acids and 2-(pyridine-4-yl)-(1H)-benzoimidazole

Three new metal coordination complexes, namely [Co(IPA)(4PBI)]·H2O (1), [Cd(IPA)(4PBI)(H2O)] (2) and [Cd(TPA)(4PBI)(H2O)] (3) [4PBI=2-(pyridine-4-yl)-(1H)-benzoimidazole, IPA=isophthalate and TPA=terephthalate], were obtained under hydrothermal conditions by reacting cobalt and cadmium salts with 4PBI and IPA or TPA. Complexes 1–3 were structurally characterized by X-ray single-crystal diffraction, EA, IR and PXRD. All of these complexes display low dimensional features with one-dimensional (1D) motifs. Complex 1 is a 1D tape-like structure containing bi-nuclear units, which is further extended into a 3D supramolecular architecture through intermolecular hydrogen bonds and stacking interactions. Complex 2 shows a 1D structural motif, which is further assembled into a 3D supramolecular architecture by hydrogen bonds and packing interactions. Complex 3 is also a 1D chain. Through intermolecular hydrogen bonds and π⋯π packing interactions, a 3D supramolecular network is also generated for 3. The luminescent properties of complexes 2 and 3 were investigated in the solid state at room temperature. Additionally, thermogravimetric analysis (TGA) of 1–3 has been discussed in details.

Selective Guest Inclusion in Oxalate-Based Iron(III) Magnetic Coordination Polymers.

The preparation and structural characterization of four novel oxalate-based iron(III) compounds of formulas {(MeNH3)2[Fe2(ox)2Cl4]·2.5H2O}n (1), K(MeNH3)[Fe(ox)Cl3(H2O)] (2), {MeNH3[Fe2(OH)(ox)2Cl2]·2H2O}n (3), and {(H3O)(MeNH3)[Fe2O(ox)2Cl2]·3H2O}n (4) (MeNH3+ = methylammonium cation and H2ox = oxalic acid) are reported here. 1 is an anionic waving chain of oxalato-bridged iron(III) ions with peripheral chloro ligands, the charge balance being ensured by methylammonium cations. 2 is a mononuclear complex with a bidentate oxalate, three terminal chloro ligands, and a coordinated water molecule achieving the six-coordination around each iron(III) ion. Its negative charge is balanced by potassium(I) and methylammonium cations. 3 and 4 are made up of oxalate-bridged and either hydroxo (3)- or oxo-bridged (4) iron(III) chiral three-dimensional (3D) networks of formulas [Fe2(OH)(ox)2Cl2]nn- (3) and [Fe2O(ox)2Cl2]n2n- (4) with methylammonium (3 and 4) and hydronium (4) as counterions. The common point these compounds share is related to their synthetic strategy, which consists of the use of mixed alkaline/alkylammonium cations as templating agents for the growth of the 1D or 3D iron(III) motifs. Interestingly, even in the presence of any given alkaline cation in the reaction solutions, the resulting coordination polymers (1, 3, and 4) exclusively contain the methylammonium cation, revealing the highly selective character of the 1D and 3D networks. Furthermore, the isolation of the very unstable compound 1 could be only achieved in the presence of the KCl salt, suggesting a probable templating effect of the potassium(I) cations. Finally, a study of the variable-temperature magnetic properties of the 3D compounds 3 and 4 showed the occurrence of weak ferromagnetic ordering due to a spin canting, the value of the critical temperature (Tc) being as high as 70 K.

Supramolecular architecture of crystals of perfluorinated 3-alkylphthalides

The molecular and crystal structures of perfluoro-3-alkylphthalides (3-hydroxyperfluoro-3-methylphthalide and its hydrate, two polymorphs of 3-hydroxyperfluoro-3-ethylphthalide and 3-hydroxyperfluoro-3-isopropylphthalide) are determined by single crystal X-ray diffraction. In the crystals, the supramolecular O–Н…O=C synthon occurs leading, except the crystallohydrate, to the formation of C11 (6) hydrogen bonded chains (supramolecular 1D motifs). According to the DFT/M06-2X/TZV calculations, the interaction energy of hydrogen bonded molecular pairs increases in this series, which can be explained by additional C=O…π, O…π, and C–F…π interactions.

Systematic Investigation of High-Sensitivity Luminescent Sensing for Polyoxometalates and Iron(III) by MOFs Assembled with a New Resorcin[4]arene-Functionalized Tetracarboxylate.

A new family of resorcin[4]arene-based metal-organic frameworks (MOFs), namely, [Eu(HL)(DMF)(H2 O)2 ]⋅3 H2 O (1), [Tb(HL)(DMF)(H2 O)2 ] 3 H2 O (2), [Cd4 (L)2 (DMF)4 (H2 O)2 ] 3 H2 O (3) and [Zn3 (HL)2 (H2 O)2 ] 2 DMF⋅7 H2 O (4), have been constructed from a new resorcin[4]arene-functionalized tetracarboxylic acid (H4 L=2,8,14,20-tetra-ethyl-6,12,18,24-tetra-methoxy-4,10,16,22-tetra-carboxy-methoxy-calix[4]arene). Isostructural 1 and 2 exhibit charming 1D motifs built with the cup-like HL(3-) anions and rare earth cations. Compounds 3 and 4 show a unique sandwich-based 2D layer and a fascinating 3D framework, respectively. Remarkably, compounds 1 and 2 display intensive red and green emissions triggered by the efficient antenna effect of organic ligands under UV light. More importantly, systematic luminescence studies demonstrate that Ln-MOFs 1 and 2, as efficient multifunctional fluorescent materials, show highly selective and sensitive sensing of Fe(3+) , polyoxometalates (POMs), and acetone, which represents a rare example of a sensor for quantitatively detecting three different types of analytes. This is also an exceedingly rare example of Fe(3+) and POMs detection in aqueous solutions employing resorcin[4]arene-based luminescent Ln-MOFs. Furthermore, the possible mechanism of the sensing properties is deduced.