Oxygen Atoms Of Anions Research Articles

Effect of Metal Coordination Environment on the Stability of Zinc Complexes and Their Reactivity with NaSH

AbstractMetal complexes with multidentate ligands are frequently used as model compounds to shed light on the (bio)‐inorganic chemistry of H2S. Zinc complexes bearing salen‐type ONNO ligands with different bridging groups are particularly relevant in this respect. Here, we describe the use of zinc complexes with the sulfur‐analogues of the ONNO ligands with the S‐donors replacing either the neutral nitrogen donors or the anionic oxygen atoms of the classical salen ligands. In addition, we studied a hexadentate cyclic ligand, with four neutral sulfur atoms and two anionic oxygens. Having two coordinative pockets this ligand is able to form a bimetallic zinc complex. We report how the different coordinative environments of the explored ligands influence the stability of the zinc complexes and their abilities to form the related hydrosulfide species.

Synthesis, characterization, crystal structures and biological activity of 4-chloro-2-(2-hydroxy-3-ethoxybenzylideneamino)phenol and complexes

Molecular nanoclusters comprising a heterometallic 3d-4f stoichiometry are an interesting class of compounds. In this paper, a chloro-containing Schiff base 4-chloro-2-(2-hydroxy-3-ethoxybenzylideneamino)phenol (H2L) was prepared by condensation reaction of 3-ethoxysalicylaldehyde with 2-amino-4-chlorophenol in methanol. The Schiff base is predisposed to chelate within a cluster core both 3d and 4f metal ions. Reaction of H2L with nickel salts afforded a tetranuclear NiII complex [Ni4L4(MeOH)4] (1), while with nickel salts and lanthanide(III) nitrate three tetranuclear NiII-LnIII complexes [Ni2Eu2L4(NO3)2(DMF)2] (2), [Ni2Er2L4(NO3)2(DMF)2] (3), [Ni2Tb2L4(CH3COO)2(DMF)2]·4DMF (4) were obtained. H2L and the complexes have been characterized by elemental analysis, IR, UV–Vis spectra. H2L has also been characterized by 1H and 13C NMR spectra. Molecular structures of the compounds have been determined by single crystal X-ray determination. In the complexes, the Schiff base ligands coordinate to the metal atoms via ether oxygen, imino nitrogen and two phenolate oxygen atoms. All the Ni atoms in the complexes are in octahedral coordination. The rare earth metal atoms are eight coordinated by the phenolate and ether oxygen of the Schiff base ligands, and anionic and solvent oxygen atoms, forming square antiprismatic coordination. The compounds were evaluated for their antibacterial activities on Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens, and antifungal activities on Candida albicans and Aspergillus niger, and gave interesting results.

Mechanical Strength and Conductivity of Cementitious Composites with Multiwalled Carbon Nanotubes: To Functionalize or Not?

The incorporation of carbon nanotubes into cementitious composites increases their compressive and flexural strength, as well as their electrical and thermal conductivity. Multiwalled carbon nanotubes (MWCNTs) covalently functionalized with hydroxyl and carboxyl moieties are thought to offer superior performance over bare nanotubes, based on the chemistry of cement binder and nanotubes. Anionic carboxylate can bind to cationic calcium in the hydration products, while hydroxyl groups participate in hydrogen bonding to anionic and nonionic oxygen atoms. Results in the literature for mechanical properties vary widely for both bare and modified filler, so any added benefits with functionalization are not clearly evident. This mini-review seeks to resolve the issue using an analysis of reports where direct comparisons of cementitious composites with plain and functionalized nanotubes were made at the same concentrations, with the same methods of preparation and under the same conditions of testing. A focus on observations related to the mechanisms underlying the enhancement of mechanical strength and conductivity helps to clarify the benefits of using functionalized MWCNTs.

Copper(II) and Zinc(II) Complexes with Heterocyclic Acid Anions and 3,5-Dimethylpyrazole: Synthesis, Structure, and Biological Properties

The reaction of copper(II) and zinc(II) acetates with 3-furancarboxylic (HFur) and 2-thiophenecarboxylic (HTph) acids with subsequent addition of 3,5-dimethylpyrazole (HDmpz) gave mononuclear complexes [M(L)2(HDmpz)2] (M = Cu(II), L = Fur– (I), Tph– (II); Zn(II), L = Fur– (III)). The structures of compounds I–III were determined by X-ray diffraction. According to X-ray diffraction data, I and II are isostructural: the central Cu(II) atom occurs in a square planar environment formed by two oxygen atoms of carboxylate anions and HDmpz nitrogen atoms; in III, the Zn atom is in the tetrahedral environment of two furoate anions and HDmpz molecules, thus forming the {MO2N2} groups. The complexes are additionally stabilized in the crystal by inter- (I and II) and intramolecular (III) hydrogen bonds. The biological activity of I–III was determined in relation to the non-pathogenic Mycolicibacterium smegmatis.

Interaction of Three-Pole ions of carnosine and anserine with an anionic micelle of SDS: Molecular dynamics simulations

Molecular dynamics simulations of the interaction of an anionic micelle of 64 SDS molecules with carnosine and anserine (a substituted analogue) in their three-pole cationic form were performed. The formation of hydrogen bonds between the peptides and the micelle has been established. The H-bond lengths range from 0.184 to 0.198 nm. The H-binding sites in the peptides are the protonated amino group and the NH group in the protonated imidazole fragment, and in the case of carnosine, the uncharged NH group in the OCNH peptide fragment. The binding sites in the micelle are the anionic oxygen atoms located closer to the micelle surface. The ethereal oxygen atoms that bind the sulfo group to the surfactant hydrophobic tail do not show noticeable activity in the formation of hydrogen bonds. The average numbers and the lifetimes of the peptide - SDS and peptide - water H-bonds were determined. The differences in the orientations of equally charged three-pole ions of carnosine and anserine relative to the anionic micelle were discussed. For carnosine associated with the micelle, the ψ-dihedral angle in the alanine residue appears in two discrete zones due to the COO– group rotation. The two zones correspond to two peptide conformers differing in the about-turn of the CH2NH3+ fragment on the micelle surface. The steric correspondence of the peptides and micelle controls the process of H-bonding between them and leads to significant differences in the orientation of equally charged ions of the peptides on an anionic micelle.

From Pb(H2C3N3O3)(OH) to Pb(H2C3N3O3)F: Homovalent Anion Substitution-Induced Band Gap Enlargement and Birefringence Enhancement.

Birefringent materials capable of modulating the polarization of light have attracted intensive studies because of their wide utilization in optical communication and the laser industry. Herein, two new lead(II)-based cyanurates, namely, Pb(H2C3N3O3)X (X = OH, F), were synthesized by hydrothermal methods, and the first halogen-containing metal cyanurate Pb(H2C3N3O3)F was successfully obtained by the rational substitution of a homovalent anion. Pb(H2C3N3O3)X (X = OH, F) belong to space group P1̅, and their structures display a neutral [Pb(H2C3N3O3)X] (X = OH, F) layer. The Pb2+ ions in Pb(H2C3N3O3)(OH) are interconnected by hydroxyl groups and oxygen atoms of cyanurate anions into a 1D [PbO(OH)]- chain, whereas the Pb2+ ions in Pb(H2C3N3O3)F are interconnected by F- anions and oxygen atoms of cyanurate anions into a 2D [PbOF]- layer. The π-π interactions between adjacent hydroisocyanurate rings and the hydrogen bonds between neighboring neutral layers provide additional stability to the structures. Luminescent studies show that Pb(H2C3N3O3)(OH) and Pb(H2C3N3O3)F emit yellow-green and blue light, respectively. Theoretical calculations unveiled their birefringences of 0.079 and 0.203@1064 nm and their band gaps of 3.96 and 4.96 eV, respectively, for OH- and F- containing materials. Obviously, the substitution of OH- by F- with the largest electronegativity can simultaneously improve both the birefringence and band gap.

Synthesis, crystal structure and Hirshfeld surface analysis of copper(I) nitrate -complex based on 1-(2,6-dimethylphenyl)-5-allylsulfanyl-1H-tetrazole

By means of the alternating current electrochemical technique and starting from copper wire electrodes in propanol solution of corresponding ligand and copper(II) nitrate, novel copper(I) -complex [Cu2(C12H14SN4)2(NO3)2] (1) has been obtained and X-ray structurally investigated: sp. gr. , a=7.352(3) Å, b=8.269(3) Å, c=12.723(4) Å, =82.08(3)0, =82.74(3)0, =88.37(3)0, V=759.9(5) Å3, Z=2, dcalc=1.625 g cm–3, (CuK)=3.502 mm–1, max=67.960, 4119 measured reflections, 1248 used reflections, 201 refined parameters, R(F2)=0.0915, S=0.95. The trigonal-pyramidal copper(I) coordination environment consists of nitrogen atom and allylic group of ligand, and of two oxygen atoms from crystallographically distinct nitrate anions. Due to a bridging function of oxygen atoms of nitrate anions, two metal-containing polyhedra are connected into {Cu2L2(NO3)2} topological units which are additionally stabilized by noncovalent interaction CuO(2). Comparatively weak hydrogen bonds C–HO exist in the crystal structure of [Cu2(C12H14SN4)2(NO3)2] (1).

Implications of Electron Detachment in Associative Collisions of Atomic Oxygen Anion with Molecular Nitrogen for Modeling of Transient Luminous Events

AbstractElectron detachment from O− is important for understanding of lightning‐induced upper atmospheric discharges. Contrary to previous studies, Rayment and Moruzzi (1978) (RM78) argue that the associative detachment reaction of O− with N2 proceeds with N2 in its ground state. Here, we analyze the experimental setup in RM78 and demonstrate that vibrationally excited N2 may have in fact contaminated the results, the theoretical approach in RM78 requires corrections, and the rate calculations provided in RM78 are inconsistent. As the vibrational temperature of N2 remains relatively low in the initial stages of gas discharges in air, i.e., streamer formation, we conclude that if in fact vibrationally excited N2 is required for the O− + N2 → N2O + e reaction to proceed, the process will happen only in later stages of the discharge, e.g., during streamer to leader transition. Controlled experiments are required to reconcile the literature on the reaction of O− with ground state N2.

SYNTHESIS AND CRYSTAL STRUCTURE OF LiTb6O5(BO3)3

Single crystals of compound LiTb6O5(BO3)3 suitable for X-ray diffraction are prepared by the flux growth method. The compound crystallizes in the P21/n space group, a = 8.4350 A, b = 15.6232 A, c = 8.9025 A, β = 92.041°. The obtained compound belongs to the class of 3D-framework oxoborates. It has a similar structure to that of known LiGd6O5(BO3)3 but is not isostructural to the latter. Both structures are derivatives of fluorite, the predecessor compound in this structural series. The cationic part of the predecessor′s structural type is filled by Tb3+ and Li+ cations, while its anionic part is formed by oxide ions and oxygen atoms of borate anions. The melting point (1375±15 °C) and the band gap (4 eV) are determined for LiTb6O5(BO3)3.

Understanding the interactions between the bis(trifluoromethylsulfonyl)imide anion and absorbed CO2 using X-ray diffraction analysis of a soft crystal surrogate

The selective carbon dioxide (CO2) absorption properties of ionic liquids (ILs) are highly pertinent to the development of methods to capture CO2. Although it has been reported that fluorinated components give ILs enhanced CO2 solubilities, it has been challenging to gain a deep understanding of the interactions occurring between ILs and CO2. In this investigation, we have utilized the soft crystalline material [Cu(NTf2)2(bpp)2] (NTf2‒ = bis(trifluoromethylsulfonyl)imide, bpp = 1,3-bis-(4-pyridyl)propane) as a surrogate for single-crystal X-ray diffraction analysis to visualize interactions occurring between CO2 and NTf2‒, the fluorinated IL component that is responsible for high CO2 solubility. Analysis of the structure of a CO2-loaded crystal reveals that CO2 interacts with both fluorine and oxygen atoms of NTf2‒ anions in a trans rather than cis conformation about the S–N bond. Theoretical analysis of the structure of the CO2-loaded crystal indicates that dispersion and electrostatic interactions exist between CO2 and the framework. The overall results provide important insight into understanding and improving the CO2 absorption properties of ILs.

Layered calcium hydrogen selenite chlorides Ca(HSeO3)Cl and Ca(HSeO3)Cl(H2O), the first halides obtained in СaCl2–H2SeO3–H2O system

Abstract Synthesis, crystal structures and IR spectra of the first representatives of calcium hydrogen selenite halides are reported. Colourless prismatic crystals of calcium hydrogen selenite chloride Ca(HSeO3)Cl and corresponding hydrated analogue Ca(HSeO3)Cl(H2O) were produced upon evaporation of aqueous solutions. Ca(HSeO3)Cl is monoclinic, P21/c, a = 7.0031(11) Å, b = 7.7336(12) Å, c = 8.5024(13) Å, β = 109.889(3)°, V = 433.02(12) Å3, R 1 = 0.039. Ca(HSeO3)Cl(H2O) is orthorhombic, Pbca, a = 6.222(4) Å, b = 10.413(7) Å, c = 16.875(10) Å, V = 1093.3 (12) Å3, R 1 = 0.041. Ca(HSeO3)Cl and Ca(HSeO3)Cl(H2O) represent new structure types. In both structures, Ca2+ cations adopt mixed-ligand environments formed by oxygen atoms of hydrogen selenite anions (and water molecules for Ca(HSeO3)Cl(H2O)) and chloride ions. Both structures are layered. The crystal structure of Ca(HSeO3)Cl(H2O) demonstrates a rare phenomenon of hydrogen-bonded assembly of water and chloride in the interlayer space.

Experimental and DFT studies on surface properties of sulfonate-based surface active ionic liquids

Two anionic surface active ionic liquids (SAILs), 3-methyl-1-ethoxycarbonylimidazolium decanesulfonate ([Etmim][C10H21SO3]) and 3-methyl-1-ethoxycarbonylimidazolium dodecanesulfonate ([Etmim][C12H25SO3]) were synthesized and studied. The surface properties, aggregation properties and thermodynamic parameters of [Etmim][C10H21SO3] and [Etmim][C12H25SO3] aqueous solutions were determined using surface tension and electrical conductivity. Micelle formation of [Etmim][C10H21SO3] and [Etmim][C12H25SO3] was spontaneous and entropy-driven.Density functional theory (DFT) calculation was used to optimize the configuration of the anions (C10H21SO3, and C12H25SO3), imidazolium cation ([Etmim]+), and SAILs ([Etmim][C10H21SO3] or [Etmim][C12H25SO3]) with different number of water molecules (1–3) using Gaussian 16 at B3LYP/6-31G(d,p) level.Typical hydrogen bonds, bond length changes, bond angle changes, and charge changes of typical atoms in hydrated complexes were analyzed. For imidazolium cation hydrates, H2O formed two types of hydrogen bonds with cation ([Etmim]+). For sulfonate anion hydrates, H2O formed two types of hydrogen bonds with anions ([C10H21SO3]- or [C12H25SO3]-). Hydrogen atoms in H2O formed hydrogen bonds with oxygen atoms of polar sulfonate anions in three ways: 1:1, 2:1, and 2:1. The typical electron withdrawing atoms (N and O) in imidazolium cation was beneficial for the micelles formation. The electrostatic repulsion and electrostatic attractive interaction between polar groups of SAILs affected the CMC values of [Etmim][C10H21SO3] or [Etmim][C12H25SO3] aqueous solutions. Binding energy (D0), difference of binding energy (ΔD0) of sulfonate ion hydrates and SAIL hydrates confirmed the tendency of [Etmim][C12H25SO3] micelle formation was higher than that of [Etmim][C10H21SO3].

Structural and electronic properties of CuII, CoII, and NiII-containing chelate-based ionic liquids.

Potential applications of chelate-based ionic liquids depend on the structural and electronic properties of this class of liquid materials. Due to the large size of chelated metal anions, the high number of potential interaction sites could lead to complex intermolecular interactions, but metal-based anions have many degrees of freedom, and they have great potential in the structural modification of the physical properties of ionic liquids. To explore the influence of varying the metal center of anions and the length of carbon chains of cationic species, four single crystal structures of chelate-based ionic liquids, ([C10mim][M(F6-acac)3], M = Cu, Co, and Ni) and [C6mim][Cu(F6-acac)3] were obtained. Taking these as the initial configurations, theoretical efforts were made to understand the structural and electronic properties. The hydrogen bonding energies of the primary hydrogen bonding interaction, in the range of 17.7-20.9 kJ mol-1, follow the order of [C10mim][Ni(F6-acac)3] < [C10mim][Co(F6-acac)3] <[C10mim][Cu(F6-acac)3], and [Cnmim][Cu(F6-acac)3] (n≠ 10) < [C10mim][Cu(F6-acac)3], while the experimental viscosities exhibit an opposite trend. Furthermore, by NBO analysis, the more negative charge on the oxygen atoms of anions shows the stronger hydrogen bonding of imidazolium with C2H. The reliability of the theoretical method was supported by the comparison between the simulated and experimental infrared and UV/vis spectra. This work is useful in increasing the understanding of the structure-property relationship of chelate-based ionic liquids and furthering the rational design of novel ionic liquids.

Polynuclear Co(II) Myrtenates with 2,4-Lutidine

The reaction of cobalt(II) chloride with potassium myrtenate (KMyr) followed by addition of 2,3-lutidine in ethanol gives the trinuclear compound [Co3(Myr)6(2,4-Lut)2] (I). The central cobalt(II) atom is linked to each of the two other metal atoms by three myrtenic acid anions. The reaction of a solution of compound I with lithium myrtenate (LiMyr) results in the formation of tetranuclear heterometallic complex [Li2-Co2(Myr)6(2,4-Lut)2] (II). Compound II is composed of two binuclear {LiCo(Myr)3(2,4-Lut)} moieties, in which the lithium(I) atoms are linked to cobalt(II) atoms by bridging myrtenate anions. The lithium atoms are connected by two oxygen atoms of acid anions. Compounds I and II were characterized by X-ray diffraction (CIF files CCDC nos. 1898096 (I), 1898097 (II)).

Stereoselective formation and spectroscopic studies of [Cr(edda or eddp)(N[sbnd]N)]-type complexes (edda = ethylenediamine-N,N′-diacetate; eddp = ethylenediamine-N,N′-dipropionate)

[Cr(edda or eddp)(NN)]-type complexes (edda = ethylenediamine-N,N′-diacetate, eddp = ethylenediamine-N,N′-dipropionate; NN = 1,2-ethanediamine (en), 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen)) were formed with stereoselectivity. These complexes were characterized by UV–Vis and IR absorption spectra and X-ray crystal analysis. The chromium atom is coordinated to a bidentate N,N-ligand and a tetradentate −O,N,N,O−-ligand, producing a distorted CrN4O2 octahedral molecular geometry. The edda ligand coordinates to the chromium atom through two oxygen and two nitrogen atoms. The anionic oxygen atoms of the edda ligand occupy positions trans to each other. The crystal structures are stabilized by several intermolecular NH⋯O and/or OH⋯O hydrogen bonding interactions. In the tetrahydrate [Cr(edda)(bpy)] (1b), the solid-state structure has a notable feature of hydrogen bonding interactions among the water molecules, and the four water molecules form a (H2O)4 chain consisting of OH⋯O hydrogen bonds between complex cations. In the anhydride [Cr(edda)(en)] (1e), each complex cation is connected to two adjacent cations through N(edda)H⋯O(edda) hydrogen bonds and to two perchlorate anions through N(en)H⋯O hydrogen bonds to construct a two-dimensional sheet structure. The optically active [Cr(edda)(bpy)] (1b) and [Cr(edda)(phen)] (1p) could be isolated by fractional resolution using the [Sb2(d-tart)2]2− anion. However, both isomers were readily racemized, even in an acidic aqueous solution, within a period of 3 h. The eddp ligand in [Cr(eddp)(phen)] (2p) and [Cr(eddp)(bpy)] (2b) coordinates to the chromium atom through two oxygen and two nitrogen atoms. The anionic oxygen atoms of the eddp ligand occupy positions cis to each other. The NCrO angles of the β-alaninato (six-membered) ring in the eddp ligand are larger than those of the glycinato (five-membered) ring in the edda ligand. The formation of only the cis isomer in the eddp complex is caused by the relaxation of the strain on the β -alaninato ring.

Crystal structure of a one-dimensional coordination polymer of gadolinium dibromoacetate with 4,4'-bipyridine

A new gadolinium(III) complex with 4,4’-bipyridine (4-bpy) and dibromoacetate ligand of general formula [Gd(4-bpy)(CBr2HCOO)3(H2O)]n, has been synthesized, crystallized and characterized by a single-crystal X-ray diffraction analysis. The gadolinium atom has an unsymmetrical eight-coordinate geometry, being coordinated by six oxygen atoms of dibromoacetate anions, one nitrogen atom of 4-bpy and one water molecule. The complex is a one-dimensional polymer as a result of dibromoacetate ligand bridging with the repeating monomeric units. There are π...π stacking interactions between the 4-bpy rings as well as O–H...O and O–H...N hydrogen bonds. Crystal Data for C16H13Br6GdN2O7 (Mw = 981.99 g/mol): triclinic, space group P-1 (no. 2), a = 9.7368(4) Å, b = 11.5416(4) Å, c = 11.7634(4) Å, α = 104.2750(10)°, β = 94.060(2)°, γ = 92.6900(10)°, V = 1275.08(8) Å3, Z = 2, T = 90 K, μ(CuKα) = 28.190 mm-1, Dcalc = 2.558 g/cm3, 8399 reflections measured (7.782° ≤ 2Θ ≤ 133.18°), 4006 unique (Rint = 0.0409, Rsigma = 0.0639) which were used in all calculations. The final R1 was 0.0527 (I &gt; 2σ(I)) and wR2 was 0.1396 (all data).

Ab Initio Molecular Dynamics Simulation Study on the Stereo Reactions between Atomic Oxygen Anion and Methane.

Ion–molecule reaction between atomic oxygen anion (O−) and methane (CH4) has been systematically investigated employing the on-the-fly ab initio molecular dynamics simulations. Besides the major H-abstraction process as the exothermic reaction studied widely, an endothermic pathway to produce OCH3− and H is also observed in this study. Three typical O− attack modes with reference to the pyramid structure of CH4 fixed in space have been considered. It was found that the internal motions of the radical products are significantly dependent on the O− attack modes. As for the reaction between O− and the thermally vibrating CH4, the major pathway to produce OH− and CH3 is preferred by the direct H-abstraction and the minor pathway to produce H and OCH3− is the roaming reaction via the transient negative ion [HO-CH3]−.

Jahn–Teller Effect in the [CuEn3]CrO4 Structure

A change in the coordination of the copper atom in the crystal structure of [CuEn3]CrO4 (En is ethylenediamine) in studied in the range 150–300 K. According to the single crystal X-ray diffraction (XRD) data at 150 K, the single crystal has a complicated twining character based on the triclinic cell (a = 9.027(2) A, b = 13.335(3) A, c = 13.339(3) A, α = 71.77(3)°, β = 70.53(3)°, γ = 70.42(3)°) composed of two crystallographically independent [CuEn3]2+ complex cations. The coordination of copper atoms is a distorted square bipyramid; four short Cu–N distances lie in the range 2.049-2.082 A; two long ones are 2.415 A and 2.470 A. According to the differential scanning calorimetry (DSC) data, near 218 K there is a phase transition. The single crystal XRD experiment performed at 250 K (a = 15.6992(19) A, c = 9.7573(13) A, V = 2082.6(6) A3, space group P\(\bar 3\)c1 (No. 165), Z = 6) shows that chromate anions are disordered over three positions about the с axis, and Cu–N distances are 2.120-2.177 A. According to the DSC data, on further heating the structure undergoes yet another two alterations (260 K and 270 K) due to the disordering of oxygen atoms of chromate anions and the subsequent equalization of Cu–N distances. At 300 K in the structure (a = 9.0778(6) A, c = 9.7715(5) A, V = 697.4 A3, space group P\(\bar 3\)c (No. 163), Z = 2) all Cu–N distances are 2.155 A, and chromate anions are disordered over six positions about the с axis. A comparative crystal chemical analysis of the packing of the studied structures is carried out.

Structures of binary mixtures of ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide with primary alcohols: The role of hydrogen-bonding

The structure of ionic liquids (ILs) with shorter alkyl tail(s) of the constituent ions is predominantly governed by strong electrostatic interactions which are, in most cases, accompanied by specific interactions such as hydrogen bonding. Neat 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide Im1,4+/NTf2− IL possesses both of these interactions. However, in many conventional solvents such as short tail length primary alcohols, the structure is primarily determined by hydrogen bonding interactions. In this study, we aim to understand how the structure of Im1,4+/NTf2− changes with the addition of different amount of alcohol by employing atomistic molecular dynamics simulations. Specifically, we have chosen Im1,4+/NTf2− + 1-propanol and Im1,4+/NTf2− + 1-butanol mixtures as the pure components of both the mixtures possess complex interactions, including hydrogen bonding. The mixtures' composition-dependent structures were examined through simulated X-ray scattering structure functions (S(q)s), their partial components along with radial and spatial distribution functions. It is observed that there is significant hydrogen bonding between the anion and alcohols along with strong electrostatic interactions between the cation head and anion. For the entire composition of the mixtures studied, while alcohol's hydroxyl group is found near the cation head and the anion's oxygen atoms, the nonpolar tail of alcohol molecules tend to align with the tails of either the cation or other alcohol molecules. It is interesting to note that on adding even small amount of the IL (10%) to alcohol, the low q peak observed for the neat alcohols disappears. The X-ray scattering S(q)s reveal that the long-range charge ordering structure of the Im1,4+/NTf2− IL begin to build up at xIL = 0.3 but at larger length scales. The transitional structural changes in the both the mixtures take place for 0.3 ≤ xIL ≤ 0.8. The neat IL structure is virtually regained at and above xIL = 0.8.

Structure of A Coordination Polymer [Cu(En)2CrO4

The crystal structure of [Cu(En)2CrO4]n (En is ethylenediamine) is determined: a = 14.7359(4) A, b = 9.8083(3) A, c = 14.2664(4) A, V = 2061.98(10) A3, space group Cmce, Z = 8, dx = 1.931 g/cm3. It is demonstrated that the studied phase is isostructural with [Сu(Еn)2SO4]n. A pseudotetragonal copper atom coordination (Cu–N 2.0204 A and 2.0244 A, ∠N–Cu–N 84.73°) is completed to distorted octahedral by two oxygen atoms of chromate anions (Cu–O 2.433 A and 2.380 A).