Infinite One-dimensional Chains Research Articles

Synthesis and crystal structure of a 6-chloro-nicotinate salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4'-bi-pyridine.

A 6-chloro-nicotinate (6-Clnic) salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4'-bi-pyridine (4,4'-bpy), namely, catena-poly[[[tetra-aqua-nickel(II)]-μ-4,4'-bi-pyridine-κ2 N:N'] bis-(6-chloro-nicotinate) tetra-hydrate], {[Ni(C10H8N2)(H2O)4](C6H3ClNO2)2·4H2O} n or {[Ni(4,4'-bpy)(H2O)4](6-Clnic)2·4H2O} n , (1), was prepared by the reaction of nickel(II) sulfate hepta-hydrate, 6-chloro-nicotinic acid and 4,4'-bi-pyridine in a mixture of water and ethanol. The mol-ecular structure of 1 comprises a one-dimensional polymeric {[Ni(4,4'-bpy)(H2O)4]2+} n cation, two 6-chloro-nicotinate anions and four water mol-ecules of crystallization per repeating polymeric unit. The nickel(II) ion in the polymeric cation is octa-hedrally coordinated by four water mol-ecule O atoms and by two 4,4'-bi-pyridine N atoms in the trans position. The 4,4'-bi-pyridine ligands act as bridges and, thus, connect the symmetry-related nickel(II) ions into an infinite one-dimensional polymeric chain extending along the b-axis direction. In the extended structure of 1, the polymeric chains of {[Ni(4,4'-bpy)(H2O)4]2+} n , the 6-chloro-nicotinate anions and the water mol-ecules of crystallization are assembled into an infinite three-dimensional hydrogen-bonded network via strong O-H⋯O and O-H⋯N hydrogen bonds, leading to the formation of the representative hydrogen-bonded ring motifs: tetra-meric R 2 4(8) and R 4 4(10) loops, a dimeric R 2 2(8) loop and a penta-meric R 4 5(16) loop.

Particles in finite and infinite one-dimensional periodic chains

Particle motion in one-dimensional crystal chains is studied with the help of the transfer matrix method. The transition from a finite to an infinite chain is analyzed. In the cases where an analytic solution is impossible, the method allows calculating the energy spectra with reasonable accuracy, based on the known cell potential. It turns out that the structure of allowed and forbidden energy bands arising in an ideal lattice contains some features that are absent in the real world. This means that the model of an ideal lattice should be extended in order to describe reality. We show that accounting for small random perturbations of periodicity may serve as such an extension. Light propagation in a layered medium (including a photonic crystal) is studied using the same method.

Blue luminescent silver(I) complexes constructed by 2-diphenylphosphinopyridine and dicyanamide or tricyanomethanide

Two new silver(I) complexes 2-diphenylphosphinopyridine (dppy), {Ag2(dppy)2[N(CN)2]}2[μ-N(CN)2]2 (1) and {Ag2(dppy)2[μ-C(CN)3]2}n (2) linked by dicyanamide (N(CN)2−) or tricyanomethanide (C(CN)3−) were synthesized and characterized by X-ray crystallography. Complex 1 forms a tetranuclear structure with two binucleate moieties [Ag2(dppy)2]+ linked by two dicyanamide ligands. Interestingly, when bridging ligand is changed to tricyanomethanide, complex 2 displays one-dimensional infinite chain structure. Both complexes exhibit strong blue emission with phosphorescent quantum yields of 13.4% for 1 and 39.2% for 2 in solid state.

The first coordination compound of 6-fluoro-nicotinate: the crystal structure of a one-dimensional nickel(II) coordination polymer containing the mixed ligands 6-fluoro-nicotinate and 4,4'-bi-pyridine.

A one-dimensional nickel(II) coordination polymer with the mixed ligands 6-fluoro-nicotinate (6-Fnic) and 4,4'-bi-pyridine (4,4'-bpy), namely, catena-poly[[di-aqua-bis-(6-fluoro-pyridine-3-carboxyl-ato-κO)nickel(II)]-μ-4,4'-bi-pyri-dine-κ2 N:N'] trihydrate], {[Ni(6-Fnic)2(4,4'-bpy)(H2O)2]·3H2O} n , (1), was prepared by the reaction of nickel(II) sulfate hepta-hydrate, 6-fluoro-nicotinic acid (C6H4FNO2) and 4,4'-bi-pyridine (C10H8N2) in a mixture of water and ethanol. The nickel(II) ion in 1 is octa-hedrally coordinated by the O atoms of two water mol-ecules, two O atoms from O-monodentate 6-fluoro-nicotinate ligands and two N atoms from bridging 4,4'-bi-pyridine ligands, forming a trans isomer. The bridging 4,4'-bi-pyridine ligands connect symmetry-related nickel(II) ions into infinite one-dimensional polymeric chains running in the [10] direction. In the extended structure of 1, the polymeric chains and lattice water mol-ecules are connected into a three-dimensional hydrogen-bonded network via strong O-H⋯O and O-H⋯N hydrogen bonds, leading to the formation of distinct hydrogen-bond ring motifs: octa-meric R 8 8(24) and hexa-meric R 8 6(16) loops.

Enhanced optical anisotropy via dimensional control in alkali-metal chalcogenides.

Crystals with both large birefringence and wide transparent range are suitable for broad applications in the areas of optical communications, the laser industry and modulation of the light polarization requirement. In this work, to assist the design of urgently needed crystals with large birefringence in the infrared (IR) region, typical alkali-metal chalcogenides, KPSe6, Na2Ge2Se5, and Li2In2GeSe6 have been studied. They exhibit a hierarchical characteristic in the calculated birefringence by about 0.21, 0.11, and 0.04, respectively. To explore the origin of the birefringence difference, the polarizability anisotropy and the effect of electron distribution anisotropy are analyzed. The alkali-metal chalcogenides KPSe6, Na2Ge2Se5, and Li2In2GeSe6 feature infinite one-dimensional (1D) chains of [PSe6], 2D anionic framework of [Ge2Se5] layers and 3D [In2GeSe9] networks, respectively. It is found that the anionic group with low-dimensional configuration could enhance polarizability anisotropy and render large birefringence for the macroscopic structure. This provides evidence that a low-dimensionality configuration in the structure would be beneficial for the enhancement of optical anisotropy, which can motivate the exploration and design of novel IR birefringent materials.

Низкоразмерные структуры карбида кремния: аналитические оценки характеристик электронного спектра

Abstract Using the Green’s function method within the tight-binding approximation, the electronic structure of an infinite silicon-carbide sheet, and nanoribbons and one-dimensional chains cut from it, is considered. Analytical expressions for band gaps, electron effective masses and characteristic velocities are derived. The effect of metal and dielectric substrates on the band characteristics is discussed.

First-principles study of Ca<sub>5</sub>N<sub>4</sub> at high pressure

Recent studies have shown that introducing metal elements into nitrogen matrix can induce more stable poly-nitrogen structures than the pure nitrogen phase due to the ionic interaction between metal elements and nitrogen matrix. Many types of poly-nitrogen structures have been reported by using the alkaline earth metal elements (<i>M</i> = Be, Mg, Ca, Sr, Ba) as the coordinate elements. For example, the one-dimensional (1D) infinite armchair poly-nitrogen chain (N<sub>∞</sub>) structure and N<sub>6</sub> ring structure are obtained for the <i>M</i>N<sub>4</sub> and <i>M</i>N<sub>3</sub> chemical stoichiometry, respectively. Interestingly, the stabilities of theses <i>M</i>N<sub><i>x</i></sub> structures are enhanced 2–3 times compared with that of the pure nitrogen. Therefore, exploring the novel and stable poly-nitrogen structure by introducing alkaline earth metal elements under high pressure is a great significant job. As an alkaline earth element, Ca is abundant in the earth. Its ionization energy (<i>I</i><sub>1</sub> = 590 kJ/mol) is far lower than that of Be (900 kJ/mol) and Mg (738 kJ/mol), which means that Ca can form calcium nitrides more easily. Zhu et al. (Zhu S, Peng F, Liu H, Majumdar A, Gao T, Yao Y 2016<i>Inorg. Chem.</i> <b>55</b> 7550) proposed that the Ca-N system can obtain poly-nitrogen structures under high pressure, such as CaN<sub>4</sub> structure with armchair nitrogen chain, CaN<sub>5</sub> and CaN<sub>3</sub> consisting of pentazolate “N<sub>5</sub>” and benzene-like “N<sub>6</sub>” anions. These poly-nitrogen structures have potential applications in the field of high energy density materials. Here, we report the prediction of Ca-N system at 100 GPa by using particle swarm optimization algorithm technique for crystal structure prediction. A new thermal stable phase with <i>P</i> 2<sub>1</sub>/<i>c</i>-Ca<sub>5</sub>N<sub>4</sub> space group is found at 100 GPa, which enriches the phase of Ca-N system under high pressure. The dynamic stability and mechanical stability of new phase are confirmed by phono dispersion spectrum and elastic constant calculations. The electron localization function analysis shows that the nitrogen atoms in <i>P</i> 2<sub>1</sub>/<i>c</i>-Ca<sub>5</sub>N<sub>4</sub> are bonded by N—N single bond and electron transfer from Ca atom to N atom enables Ca<sub>5</sub>N<sub>4</sub> to serve as an ionic-bonding interaction structure. Band structure calculation shows that the Ca<sub>5</sub>N<sub>4</sub> has a semiconductor structure with a direct band gap of 1.447 eV. The PDOS calculation shows the valence band near Fermi energy is mainly contributed by N_p electrons, while the conduction band is mainly contributed by Ca_d electrons, indicating that electrons are transferred from Ca atom to N atom. Bader calculation shows that each N atom obtains 1.26e from Ca atom in <i>P</i> 2<sub>1</sub>/<i>c</i>-Ca<sub>5</sub>N<sub>4</sub>. The Raman spectrum and X-ray diffraction spectrum are calculated and detailed Raman vibration modes are identified, which provides theoretical guidance for experimental synthesis.

Synthesis, Spectroscopic Studies and Crystal Structures of N, N’-bis (4-methoxybenzylidene) Ethylenediamine and an Its New Cadmium (II) Complex

Schiff base (L) ligand is prepared via condensation of P-Anisaldehyde and ethylene diamine in 2:1 ratio in ethanol. A new complex is prepared by reacting this ligand with metallic salt CdI₂. The structure of the two derivatives are confirmed using various spectroscopic techniques: C, H, N analyses, IR, UV-visible and X-ray diffraction. The IR spectrums of ligand and complex show respectively intense peaks at 1629 cm^-1 and 1639cm^-1 indicating the presence of azomethine group (N=C). The crystal structure of the ligand belongs respectively to monoclinic, space group P21/n. In the crystal packing of the ligand, molecules are linked by a pair of methyl-C-H…O(methoxy) interactions, forming to an infinite one-dimensional chain. The structural characterization of the complex reveals that it crystallizes in an orthorhombic system P with as space group Pbca with a=14.8704 Å; b=12.9618 Å; c=22.4416 Å. The crystal structure of the monomer complex shows a distorted tetrahedral geometry. The Cd^II center is coordinated by the bidentate schiff base ligand via the two imine groups (N-donor) and the two chlorine atoms. Non-classical intermolecular H-bonds of the type benzene-C—H…O(methoxy) exist and link the monomeric complex, forming one dimensional chains.

The syntheses, structures, and properties of metal-organic frameworks based on mixed multi-N donor and carboxylate ligands

Four new metal-organic frameworks [Zn3(HL)2(btc)2(H2O)2]·H2O (1), [Mn(H2L)(btc)(H2O)] (2), [Zn2(L)(HL)(SIP)(H2O)]·4H2O (3) and [Cd(H2L)(SIP)(H2O)]·3H2O (4) were obtained by reactions of the different metal(II) salts with mixed ligands including 1,2,3-benzenetricarboxylic acid (H3btc), sodium 5-sulfoisophthalate (NaH2SIP) and 1-(4-(1H-imidazole-5-yl)phenyl)-1H-1,2,4-triazole (HL), respectively. All compounds were characterized by single-crystal X-ray diffraction, FT-IR spectroscopy, and elemental analysis. The study shows that the natures of organic ligands as well as metal ions play key roles in modulating the resulting frameworks of 1–4. The complex 1 is a (3, 4, 4)-connected three-dimensional (3D) net with the point (Schläfli) symbol of (42·63·8)4(64·8·10), while 2 is a two-dimensional (2D) layer structure referred as fes net with a Point (Schläfli) symbol of (4·82). Complex 3 has 2-nodal (3, 3, 4)-connected rare tfc net with a Point (Schlafli) symbol of (83)2(85·10), while 4 is a supramolecular polymer constructed from infinite one-dimensional (1D) chains by the interaction of rich hydrogen bonds and π - π stacking. The luminescent properties have been investigated for the compounds 1, 3, and 4 containing metal d10 Zn(II) and Cd(II) atoms.

Construction of luminescent coordination polymers based on 5-(1-(carboxymethyl)-pyrazol-3-yl)isophthalic ligand for sensing Cu2+ and acetone

Two new coordination polymers (CPs), namely, [Zn3(L)2(phen)3(H2O)2·2H2O]n (phen = 1,10-phenanthroline) (1) and [Pb(HL)]n(2) were constructed from the coordination reaction of 5-(1-(carboxymethyl)-pyrazol-3-yl)isophthalic acid (H3L) ligand and Zn(II) or Pb(II) ions under hydrothermal conditions. It was found that 1 and 2 exhibited an infinite one-dimensional (1D) chain and three-dimensional (3D) framework with left-handed and right-handed helical chains based on single crystal X-ray diffraction analysis, respectively. Both of them had good luminescent property at room temperature. Meanwhile, 1 possessed highly luminescent sensing properties for environmentally relevant Cu2+ ions with a quenching coefficient Ksv of 1.509 × 104 M−1, and the fluorescence quenching efficiency of acetone reached 90%, which indicated that 1 could be taken as a potential candidate for developing multifunctional luminescent sensors. Our work thus paves a way for developing CPs as an appealing platform to construct crystalline materials for environmental applications.

Частицы в конечных и бесконечных одномерных периодических цепочках

Частицы в конечных и бесконечных одномерных периодических цепочках

Lanthanide complexes supported via benzimidazole carboxylic acid ligand: Synthesis, luminescence and magnetic properties

Abstract Six new complexes {[Gd(L1)2(H2O)3]·Cl}n (1), [Eu(HL2)2(H2O)6]·(H2O)4·3Cl (2), [Ln(HL2)2(H2O)6]·3Cl [Ln = Ho (3) and Sm (4)], {[Ln(HL3)2(H2O)2]·2Cl}n [Ln = Eu (5) and Yb (6)] (H2L1 = 2-(hydroxymethyl)-1H-benzo[d]imidazole-5-carboxylic acid, H2L2 = 2-(4-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylic acid, H3L3 = 2-(2-carboxyethyl)-1H-benzo[d]imidazole-5-carboxylic acid) have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). Complexes 1, 5 and 6 are an infinite one-dimensional (1D) chain by hydrogen bonding interactions to give a 3D supermolecular structure. Complexes 2–4 are mononuclear structure, which further formed 3D supermoleculear structure through hydrogen-bonding interactions. Furthermore, luminescent properties of these lanthanide complexes have been assessed in the solid state at ambient temperature. In addition, magnetic measurements reveal that complexes 3–6 have a weak antiferromagnetic interaction, while complex 1 has a ferromagnetic interaction.

Plasma potential distribution around an infinite one-dimensional chain of dust particles

With the help of the code modification used in the authors previous works, the self- consistent distribution of density and electric potential are calculated around a one-dimensional infinite chain of dust particles. As a result, self-consistent distributions of the electric potential and space charge around a one-dimensional chain of dust particles, as well as the dependence of the dust particles charge on the interparticle distance, are obtained.

Plasma potential around a single-dimensional dust particle chain placed in an external electric field

In this paper a model that allows to self-consistently calculate the potential distribution and plasma space charge distribution near an infinite one-dimensional chain consisting of highly charged dust particles, which is influenced by an external electric field, is presented. The results show that with a gradual increase of the external field amplitude, unlike in the case of an isolated dust particle, there is no anisotropy in the distribution of the space charge; however, with a further increase of the electric field power, zones of local potential maxima appear between the dust grains.

Assembly of two new heterometallic coordination polymers derived from 3-(1H-benzimidazol-2-yl)propanoic acid

Two new heterometallic coordination polymers, namely, [SmNa(μ2-HBIP)(μ3-HBIP)3]n (1) and {[TbAg2(μ3-HBIP)(μ3-BIP)(μ4-BIP)(H2O)]·4H2O}n (2), have been successfully synthesized under suitable conditions by selecting a N-heterocyclic carboxylic acid, 3-(1H-benzimidazol-2-yl)propanoic acid (H2BIP), as the multidentate ligand. Single-crystal X-ray diffraction studies indicate that both two compounds are one-dimensional (1D) heterometallic infinite chains, but showing distinctly different structural features. Compound 1 exhibits an interesting 1D heterometallic coordination chain constructed by the combination of two type of sub-chains [Sm(μ2-HBIP)] and [Na(μ3-HBIP)] with the μ3-HBIP− ligands. While compound 2 shows another 1D heterometallic chain built by the connection of discrete [Ag2(μ3-HBIP)(μ3-BIP)(μ4-BIP)] dinuclear units with Tb(III) centers. Moreover, various interactions, which are N–H···N hydrogen bonds and π…π stacking interactions, further link the 1D heterometallic chains into different 3D supramolecular frameworks of compounds 1 and 2, respectively. Additionally, the thermogravimetric analyses of both two compounds and the photoluminescent property of 2 have been investigated as well.

Luminescent and magnetic bifunctional coordination complex based on a chiral tartaric acid derivative and europium.

A new mononuclear europium complex incorporating the (+)-di-p-toluoyl-D-tartaric acid (D-H2DTTA) ligand, namely, catena-poly[tris{μ2-3-carboxy-2,3-bis[(4-methylphenyl)carbonyloxy]propanoato}tris(methanol)europium(III)], [Eu(C20H17O8)3(CH3OH)3]n, (I), has been synthesized and characterized by IR spectroscopy, elemental analysis, powder X-ray diffraction and single-crystal X-ray diffraction analysis. The structure analysis indicates that complex (I) crystallizes in the trigonal space group R3 and exhibits an infinite one-dimensional chain structure, in which the Eu3+ ion is surrounded by six O atoms from six D-HDTTA- ligands and three O atoms from three coordinated methanol molecules, thus forming a tricapped trigonal prism geometry. The D-H2DTTA ligand is partially deprotonated and adopts a μ1,6-coordination mode via two carboxylate groups to link adjacent Eu3+ ions, affording an infinite one-dimensional propeller-shaped coordination polymer chain along the c axis, with an Eu...Eu distance of 7.622 (1) Å. Moreover, C-H...π interactions lead to the formation of helical chains running along the c axis and the whole structure displays a snowflake pattern in the ab plane. The circular dichroism spectrum confirms the chirality of complex (I). The solid-state photoluminescence properties were also investigated at room temperature and (I) exhibits characteristic red emission bands derived from the Eu3+ ion (CIE 0.63, 0.32), with a reasonably long lifetime of 0.394 ms, indicating effective energy transfer from the ligand to the metal centre. In addition, a magnetic investigation reveals single-ion magnetic behaviour. The spin-orbit coupling parameter (λ) between the ground and excited states is fitted to be 360 (2) cm-1 through Zeeman perturbation. Therefore, complex (I) may be regarded as a chiral optical-magneto bifunctional material.

High-pressure stable phases in mercury azide

Exploring the bonding properties and polymerization mechanism of the polymer phases of nitrogen-rich compounds is one of the goals of high-pressure research. Considering first-principles calculations, a particle swarm optimization structure search method has been used to study the structural evolution behavior of nitrogen in HgN3 up to 200 GPa. Three new phases with P-1, P21/m, and P-1 structures at pressures of 38 GPa, 125 GPa, and 148 GPa are identified for the first time. The theoretical calculations show that the two P-1 structures are dynamically stable at 50 GPa and 200 GPa. In these two phases, the nitrogen atoms form an infinite one-dimensional zigzag chain and connected N6 ring, respectively. Two stable structures have semiconductor properties throughout the stable pressure range, primarily due to sp2 hybridization of nitrogen atoms. Our studies provide a theoretical basis for the synthesis of polymeric nitrogen in high-pressure experiments and indicate the direction for future studies of mercury azide.

N-Methyl-N-propyltryptamine (MPT)

The title compound {systematic name: [2-(1H-indol-3-yl)ethyl](methyl)propylamine}, C14H20N2, has a single molecule in the asymmetric unit. The molecules in the unit cell are held together in infinite one-dimensional chains along [010] through N—H...N hydrogen bonds between indole H atoms and trialkylamine N atoms.

5 / 6-Superdiffusion of Energy for Coupled Charged Harmonic Oscillators in a Magnetic Field

We consider a one-dimensional infinite chain of coupled charged har- monic oscillators in a magnetic field with a small stochastic perturbation of order $\epsilon$. We prove that for a space-time scale of order $\epsilon$^{-1} the density of energy distribution (Wigner distribution) evolves according to a linear phonon Boltzmann equation. We also prove that an appropriately scaled limit of solutions of the lin- ear phonon Boltzmann equation is a solution of the fractional diffusion equation with exponent 5/6.

Bis(4-acet-oxy-N,N-di-methyl-tryptammonium) fumarate: a new crystalline form of psilacetin, an alternative to psilocybin as a psilocin prodrug.

The title compound (systematic name: bis-{2-[4-(acet-yloxy)-1H-indol-3-yl]ethan-1-aminium} but-2-enedioate), 2C14H19N2O2 +·C4H2O4 2-, has a single protonated psilacetin cation and one half of a fumarate dianion in the asymmetric unit. There are N-H⋯O hydrogen bonds between the ammonium H atoms and the fumarate O atoms, as well as N-H⋯O hydrogen bonds between the indole H atoms and the fumarate O atoms. The hydrogen bonds hold the ions together in infinite one-dimensional chains along [111].