Crystal structure of [ethylenediamine-<Emphasis Type="Italic">N,N</Emphasis>′-di(3-propionato)copper(II)]-<Emphasis Type="Italic">tris</Emphasis>[dichloromercury(II)] [Cu(Eddp)·(HgCl<Subscript>2</Subscript>)<Subscript>3</Subscript>]<Subscript>n</Subscript>

Crystals of [Cu(Eddp)·(HgCl₂)₃]_n (monoclinic, a = 9.7547(7) Å, b = 18.3716(12) Å, c = 11.7811(9) Å, β = 94.828(9)°, Z = 4, space group P2₁/n) are made of infinite sheets involving dimeric complexes [Cu₂(Eddp)₂] interacting with quasi-molecules of HgCl₂ (Hg-Cl 2.29-2.36 Å). In the dimers, copper atoms are squarely surrounded by two N atoms and two O atoms of the ethylendiamine-N,N′-di(3-propionate) anion, and atom from a neighboring Eddp ion in the apical position; the second apical position is occupied by a Cl atom of one of HgCl₂ molecules. Weak Hg-Cl interactions (2.98-3.07 Å) join the molecules of HgCl₂ in almost planar centrosymmetrical Hg₆Cl₁₂ hexamers, and further (Hg-Cl 3.168(3) Å, 3.250(2) Å) in infinite chains of the hexamers. Finally, the dimeric copper complexes are linked to six Hg atoms of four adjacent hexamers by virtue of their oxygen atoms (Hg-O 2.322(8), 2.609(6) Å, 2.730(5) Å).     

Synthesis and structure of the cobalt(II) coordination compounds with <Emphasis Type="Italic">N,N</Emphasis>-dimethyl-<Emphasis Type="Italic">N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-dimethylthiocarbamoylsulfenamide

The CoLX₂ complexes were obtained by the reaction of N,N-dimethyl-N′,N′-dimethylthio-carbamoylsulfenamide (L) with CoX₂ (X = Cl, Br, I, NCS). The complexes were investigated by elemental and X-ray analysis, IR, ¹H NMR, and electron spectroscopy, conductometry, magnetochemistry, thermogravimetry. It is found that these compounds are high-spin complexes of pseudotetraedral structure with bidentate coordination of L through the thione sulfur atom and sulfenamide nitrogen atom.     

Isomerization reactions of RSNO (R=H,C<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript>H<Subscript>2<Emphasis Type="Italic">n</Emphasis>+1</Subscript><Emphasis Type="Italic">n</Emphasis>≤ 4)

We have applied various theoretical methods to gain detailed insights into the isomers as well as the transition states (TSs) along the corresponding reaction pathways for RSNO (R=H, C _n H_2n+1 n ≤ 4). On the basis of G2 and G2MP2 results, the relative order of stability for R=H is estimated to be trans-HSNO > cis-HSNO > HNSO > cis-HONS trans-HONS, while it is cis-CH₃SNO trans-CH₃SNO > CH₃NSO > trans-CH₃ONS > cis-CH₃ONS for R=CH₃. A similar trend is also obtained from the B3P86 method with considerably less computing effort if the nearly isoenergetic isomers cis-HONS and trans-HONS are ignored. Based on the results of B3P86, cis-RSNO is more stable than trans-RSNO when R=H is replaced by alkyl groups except for R=t-Bu. Natural bond orbital analyses allow us to explore whether the high reactivity of S-nitrosothiols is due to the strong negative hyperconjugation (). The mesomeric effect of S-nitrosothiols, although non-negligible, does not cause the breakage of N–O bond due to the compensation of columbic attraction between N and O.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.     

Copper(<Emphasis Type="SmallCaps">II</Emphasis>) complexes with <Emphasis Type="Italic">N</Emphasis>-(2-carboxyethyl)anthranilic acid H<Subscript>2</Subscript>CEAnt. Synthesis and crystal structure of [Cu(CEAnt)(H<Subscript>2</Subscript>O)] ⋅ H<Subscript>2</Subscript>O

Protolytic equilibria and complexation of N-(2-carboxyethyl)anthranilic acid (H₂CEAnt) with copper(II) ions in aqueous solutions were studied by UV spectroscopy and pH potentiometry. The H₂CEAnt compound has no zwitterionic structure, and the protons are localized on the carboxy groups. The acid ionization constants of H₃CEAnt⁺ (T = 25 °C, I = 0.1 M KNO₃) are pK ₀ = 1.3±0.2 (=NH₂ ⁺), pK ₁ = 3.88±0.02 (Alk-COOH), and pK ₂ = 5.28±0.02 (Ar-COOH). The model of complexation of H₂CEAnt with copper(II) ions involves two deprotonated complexes [Cu(CEAnt)] and [Cu(CEAnt)₂]²⁻ (logβ = 6.31±0.04 and 8.0±0.2, respectively). The [Cu(CEAnt)(H₂O)]⋅H₂O complex was synthesized by the reaction of H₂CEAnt with (CuOH)₂CO₃, and its structure was established by X-ray diffraction. The coordination polyhedron of Cu is intermediate between the tetragonal pyramid and trigonal bipyramid. The CEAnt²⁻ ligand serves as a tetradentate chelating bridging ligand (Cu-O, 1.944(3) and 1.950(3) Å; Cu-O', 2.195(4) Å; Cu-N, 2.016(5) Å), and the fifth position of the polyhedron is occupied by a water molecule (Cu-O_w, 1.976(4) Å). Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1518–1523, July, 2005.     

HNO(H<Subscript>2</Subscript>O)<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> (<Emphasis Type="Italic">n</Emphasis> = 1–4) clusters: a theoretical study

The geometrical structure, binding energy, and vibrational spectra of small clusters of nitrosyl hydride (HNO) and water molecules, HNO(H₂O) _n , where (n = 1–4), have been investigated at the MP2 level of theory, using 6-311++G(2d,2p) basis set. We located three dimers, six trimers, nine tetramers, and three pentamers at the MP2/6-311++G(2d,2p) computational level. Particular attention is given to existence and magnitude of NH···O blue-shifting hydrogen bonds. Blue shifts of the NH stretching frequency upon complex formation in the ranges between 28 and 151 cm⁻¹ is predicted. Cooperative effect in terms of stabilization energy along with the many-body interaction energies analysis was performed for the studied clusters. The Atoms in Molecules (AIM) theory was also applied to explain the nature of the complexes.     

Investigations of the EPR parameters for Cu<Superscript>2+</Superscript> in [Cu(ipt)(dap)H<Subscript>2</Subscript>O]<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript>•<Emphasis Type="Italic">n</Emphasis>H<Subscript>2</Subscript>O

The electron paramagnetic resonance (EPR) parameters (g factors and hyperfine structure constants) for Cu²⁺ in [Cu(ipt)(dap)H₂O] _n ?nH₂O (ipt is isophthalic acid, dap–1,3-diaminopropane) are theoretically investigated from the high order perturbation formulas of these parameters for a 3d ⁹ ion in a rhombically elongated octahedron. The ligand orbital and spin-orbit coupling contributions are included from the cluster approach because of strong covalency of the system. The nearly axial anisotropies of the g factors and hyperfine structure constants are correlated to the significant elongation distortion of the five-fold coordinated Cu²⁺ (in a distorted square pyramidal [CuN₂O₃] group). Nevertheless, the perpendicular anisotropies arising from the nonequivalent planar ligands are largely concealed by the experimental uncertainties. The theoretical analysis of the EPR behaviours for [Cu(ipt)(dap)H₂O] _n ?nH₂O would be helpful to understand the local structures and properties of this and relevant systems.     

Crystal structure of <Emphasis Type="Italic">N,N</Emphasis>′-Bis-(2,5-dimethoxybenzylidene)-1,3-diaminopropane

The Schiff-base compound N,N′-Bis-(2,5-dimethoxybenzylidene)-1,3-diaminopropan, (2,5-MeO-ba)₂pn, is synthesized and characterized by elemental analysis, FT-IR and ¹H NMR spectroscopy. The crystal structure of (2,5-MeO-ba)₂pn is determined by X-ray single crystal diffraction analysis. The X-ray diffraction analysis at 120 K reveals that (2,5-MeO-ba)₂pn crystallizes in the orthorhombic system, Fdd2 space group with a = 29.339(9) Å, b = 29.4073(11) Å, c = 4.4524(2) Å, V = 3840.8(3) ų, μ = 0.72 mm^?1, and Z = 8.     

The crystal structures of chiral (<Emphasis Type="Italic">R</Emphasis>/<Emphasis Type="Italic">S</Emphasis>) (C<Subscript>8</Subscript>H<Subscript>11</Subscript>N)<Subscript>2</Subscript>·CuCl<Subscript>2</Subscript>

Two opposite configuration (R/S) of chiral complexes (C₈H₁₁N)₂·CuCl₂ were obtained from the reaction of chiral d(+)/l(−)-α-ethylphenyl amine with copper chloride (II) in dry ethanol. The crystal structures of 1a and 1b were characterized by IR, elemental analysis and X-ray crystallography.     

Crystal structures of [<Emphasis Type="Italic">M</Emphasis>(Еn)<Subscript>3</Subscript>](ReO<Subscript>4</Subscript>)<Subscript>2</Subscript> (<Emphasis Type="Italic">M</Emphasis> = Ni,Zn)

The structures of two isostructural phases of [M(Еn)₃](ReO₄)₂ (M = Ni, Zn; Еn is ethylenediamine) are studied. The crystal structures belong to the triclinic system, but demonstrate a pseudohexagonal packing motif. It is shown that the product of thermal decomposition of [Zn(Еn)₃](ReO₄)₂ (hydrogen atmosphere, 400 °C) is a homogeneous mixture of nanocrystalline zinc and rhenium powders with coherent scattering regions of ~30 nm.     

Directed Aminomethylation of Pyrrole,Indole, and Carbazole with <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N′</Emphasis>,<Emphasis Type="Italic">N′</Emphasis>-Tetramethylmethanediamine

Catalytic aminomethylation of pyrrole and indole with N,N,N′,N′-tetramethylmethanediamine in the presence of 5 mol % of ZrOCl₂·8H₂O proceeds selectively at the positions 2, 5 of pyrrole and 1, 3 of indole. Carbazole under the same conditions affords 3-formyl-9-aminomethyl derivative. The reaction in the presence of 5 mol % of K₂CO₃ occurs as monoaminomethylation: for pyrrole at the position 2, for indole at the position 3, and for carbazole at the nitrogen atom of the substrate. Water-soluble 1,1′-(1H-pyrrole-2,5-diyl)bis(N,N-dimethylmethanamine) exhibits a fungistatic activity with respect to phytopathogenic fungi Rhizoctonia solani.     

Planar Four-Coordinate Carbon in Star-Like Perlithioannulenes C<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript>Li<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> (<Emphasis Type="Italic">n</Emphasis> = 3–6)

The structure and stability of perlithioannulenes C _n Li _n (n = 3–6) were examined ab initio [MP2(full)/6-311+G**] and in terms of the density functional theory (B3LYP/6-311+G**). The systems with n = 3, 5, and 6 may be stabilized as planar star-like structures with bridging lithium atoms and hypercoordinate carbon atoms. Star-like structures are the most stable isomers of odd-numbered annulenes (n = 3, 5), while the most stable isomers of even-numbered annulenes (n = 4, 6) have less symmetric nonplanar structures.     

Fast evaluation of molecular auxiliary functions <Emphasis Type="Italic">A</Emphasis><Subscript>α</Subscript> and <Emphasis Type="Italic">B</Emphasis><Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> by analytical relations

Analytical relations through the initial values are derived for the molecular auxiliary functions A _α (x) and B _n (x), where α =n+ɛ, 0⩽ ɛ < 1 and n=0,1,2,.... These relations are useful in the fast calculation of multicenter molecular integrals over integer and noninteger n Slater type orbitals. It is shown that the formulas obtained are numerically stable for all values of n,ɛ and x.PACS No: 31.15.+q, 31.20.EjAMS subject classification: 81-V55, 81-V45     

Magnetic properties of CuCr<Subscript>2–<Emphasis Type="Italic">х</Emphasis></Subscript>Sb<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Se<Subscript>4</Subscript> (<Emphasis Type="Italic">х</Emphasis> = 0–0.5) solid solutions

Magnetic properties of spinel solid solutions CuCr_2–х Sb _x Se₄ (х = 0–0.5) were measured in the temperature range 5–300 K in a constant (50 Oe and 10 kOe) magnetic field. The results are interpreted in terms of the ionic model suggested earlier for CuCr₂Х₄ compounds.     

Lanthanum(III) complex of uracil-1-acetic acid,a new 2D coordination polymer [La(Phen)(UA)<Subscript>3</Subscript>]<Subscript>n</Subscript> · <Emphasis Type="Italic">n</Emphasis>H<Subscript>2</Subscript>O (Phen = 1,10-phenanthroline and UA = uracil-1-acetate)

A new lanthanum(III) complex of uracil-1-acetate (UA) and 1,10-phenanthroline (Phen), [La(Phen)(UA)₃]_n · nH₂O, was synthesized and characterized by elemental analysis, IR spectroscopy, XRD powder diffraction, thermal analysis, and X-ray crystallography. The single crystal X-ray analysis shows that the compound is in the monoclinic system, space group P2₁/c with a = 14.645(6), b = 17.114(7), c = 14.141(6) Å, β = 117.206(6)°, V = 3152(2) ų, Z = 4, final R ₁ = 0.0455 and wR ₂ = 0.0909. Each La³⁺ ion is coordinated by two N atoms from Phen, seven carboxylate oxygen atoms, and one carbonyl oxygen atom from UA, which results in ten-coordinate geometry, LaN₂O₈. The structural studies indicate that the title compound is two-dimensional coordination polymer, and self-assembly of the compound in the solid state is likely to occur due to N-H…O and O-H…O hydrogen bonds.     

Transport and thermal characteristics of Cs<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Rb<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>H<Subscript>2</Subscript>PO<Subscript>4</Subscript>

The transport and thermal properties of Cs_{1 − x} Rb _x H₂PO₄ in a wide range of compositions were studied. The binary salts Cs_{1 − x} Rb _x H₂PO₄ (x = 0–0.9) contain solid solutions with a structure of CsH₂PO₄. The binary salts were synthesized by mechanically mixing the starting components and growing crystals by isothermal evaporation from aqueous solutions. The properties of Cs_{1 − x} Rb _x H₂PO₄ salts obtained by different procedures were found to differ considerably. At higher rubidium contents in compounds obtained by mechanical mixing, the superionic transition temperature rose insignificantly, the high-temperature phase conductivity decreased twofold, the low-temperature conductivity increased within the limits of the order of magnitude, and the system of hydrogen bonds was slightly weakened. In Cs_{1 − x} Rb _x H₂PO₄ crystals grown from solutions, the temperature of the superionic transition decreased along with its slowing down, and the low-temperature conductivity increased by more than three orders of magnitude because of the higher contents of residual acid aqueous centers in the structure of the salt. These systems are characterized by increased thermal stability.     

X-ray and computational structural study of neutral <Emphasis Type="Italic">bis</Emphasis>(<Emphasis Type="Italic">N,N,N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-tetramethylthiophosphoramidoyl)-methylamine

The structure of bis(N,N,N′,N′-tetramethylthiophosphoramidoyl)-methylamine 1 has been determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the monoclinic system, with a space group P2₁/c, a = 11.836(2) Å, b = 11.659(2) Å, c = 12.796(5) Å and β = 95.28(3)°, V = 1758.3(5) Å³ and Z = 4. The X-ray crystallographic data have been assessed by semi-empirical and ab-initio density functional theory and by Hartree–Fock molecular orbital methods. A comparative study of the results of the different methods is given.     

Synthesis of (Ni<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Co<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>)<Subscript>2</Subscript>P (0 ≤ <Emphasis Type="Italic">x</Emphasis> ≤ 0.65) substitution solid solution

The phosphides (Ni_{1 ? x} Co _x )₂P (0 ≤ x ≤ 0.65) crystallizing in the hexagonal system, space group P \(\bar 6\)2m, were synthesized in two steps starting from the continuous solid solution (Ni_{1 ? x} Co _x )₃(PO₄)₂ · 8H₂O. The initial phosphates were first completely dehydrated at 800°C and then reduced with hydrogen at 900–1000°C for 1–2 h.     

Thermodynamic investigation of the systems <Emphasis Type="Italic">Ln</Emphasis>Se<Subscript>2</Subscript>–<Emphasis Type="Italic">Ln</Emphasis>Se<Subscript>1.5</Subscript> (<Emphasis Type="Italic">Ln</Emphasis> = La,Nd)

A detailed thermodynamic study of the systems LnSe₂–LnSe_1.5 (Ln = La, Nd) was performed by static method of vapour pressure measurement using quartz membrane-gauge manometers within the temperature range 713–1,395 K. The p _Se–T–x dependences obtained in this study have shown that the phase regions in composition intervals studied consist of discrete phases: LnSe_1.95 LnSe_1.90, LnSe_1.85, LnSe_1.80 (Ln = La, Nd). The enthalpies and the entropies for the stepwise dissociation process were calculated from the experimental data. The standard enthalpies of formation and the absolute entropies were estimated for the compounds investigated using literature data.     

Storage performance of LiFe<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Mn<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>PO<Subscript>4</Subscript> nanoplates (<Emphasis Type="Italic">x </Emphasis>= 0, 0.5, and 1)

Although LiFePO₄ (LFP) is considered to be a potential cathode material for the lithium-ion batteries, its rate performance is significantly restricted by sluggish kinetics of electrons and lithium ions. Several attempts have been made so far to improve the performance of LiFePO₄ by reducing the grain size, doping with aliovalent atoms, and coating conductive materials such as carbon or RuO₂. We report here synthesis of LFP nanoplates by solvothermal method, tailoring the thickness as well as carbon coverage at surfaces to explore their influence on the storage performance. Due to the fact that Li⁺ ion diffuses along the b-axis, solvothermal method was aimed to control the thickness of nanoplates across the b-axis. We synthesized several nanoplates with various plate thicknesses along b-axis; among those, nanoplates of LFP with ～30-nm-thick b-axis having thin (2–5 nm) and uniform layer of carbon coating exhibits high storage capacity as well as high rate performances. Thus, a favorable morphology for LiFePO₄ has been achieved via solvothermal method for fast insertion/extraction of Li⁺ as compared to spherical nanoparticles of carbon-coated LFP. Galvanostatic cycling shows a capacity of 164?±?5 mAh g^?1 at 0.1 C rate, 100?±?5 mAh g^?1 at 10 C rate, and 46?±?5 mAh g^?1 at 30 C rate, with excellent capacity retention of up to 50 cycles. Further attempts have been made to synthesize LiMnPO₄ (LMP) as well as Li(Fe_1???x Mn _x )PO₄/C (x?=?0.5) nanoplates using solvothermal method. Although LiMnPO₄ does not exhibit high storage behavior comparable with that of LiFePO₄, the mixed systems have shown an impressive storage performance.     

5-Nitro-1,10-phenanthroline bis(<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylformamide-Κ′O)-bis(perchlorato) copper(II): synthesis,structural characterization,and DNA-binding study

The hexa-coordinated copper(II) complex [Cu(L)(DMF)₂(ClO₄)₂], where L = 5-nitro-1,10-phenanthroline, was synthesized and characterized. The X-ray crystal structure shows that the copper is coordinated by the two N-atoms of the 1,10-phenanthroline ligand plus four O-atoms, two from DMF ligands and two from the perchlorate anions. Thermal analysis showed that the complex was stable up to 285 °C. The interaction of the complex with calf thymus DNA was investigated using absorption and emission spectroscopic studies, and the binding constant (K _b) and linear Stern–Volmer quenching constant (K _sv) have been determined. Electrochemical characterization of the complex in acetonitrile showed a quasi-reversible one-electron exchange voltammogram for the Cu²⁺/Cu+ redox couple at ca. E _1/2 = −1.00 V (versus SCE) with ΔE = 200 mV and i _pc/i _pa ≈ 1.