Low-Temperature Heat Capacities and Thermodynamic Properties of Hydrated Nickel L-Threonate Ni（C4H7O5）2·2H2O（S）

Low-temperature heat capacities of the compound Ni（C4H7O5）2·2H2O（S） have been measured with an auto- mated adiabatic calorimeter. A thermal decomposition or dehydration occurred in 350--369 K. The temperature, the enthalpy and entropy of the dehydration were determined to be （368.141 ±0.095） K, （18.809±0.088） kJ·mol ^-1 and （51.093±0.239） J·K^-1·mol^-1 respertively. The experimental values of the molar heat capacities in the temperature regions of 78-350 and 368-390 K were fitted to two polynomial equations of heat capacities （Cp,m） with the reduced temperatures （X）, [X=f（T）], by a least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated on the basis of the fitted polynomials. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated with an interval of 5 K.     

Crystal Structure, Lattice Energy, and Standard Molar Enthalpy of Formation of the Complex (C11H18NO)2CuCl4(s)

The complex (C₁₁H₁₈NO)₂CuCl₄ (s), which may be a potential effective drug, was synthesized. X‐ray crystallography, elemental analysis, and chemical analysis were used to characterize the structure and composition of the complex. Lattice energy and ionic radius of the anion of the complex were derived from the crystal data of the title compound. In addition, a reasonable thermochemical cycle was designed, and standard molar enthalpies of dissolution for reactants and products of the synthesis reaction of the complex were measured by an isoperibol solution‐reaction calorimeter. The enthalpy change of the reaction was calculated to be Δ_rH^?_m=(2.69±0.02) kJ·mol^?1 from the data of the above standard molar enthalpies of dissolution. Finally, the standard molar enthalpy of formation of the title compound was determined to be Δ_rH^?_m[(C₁₁ H₁₈NO)₂CuCl₄, s]= ? (1822.96±6.80) kJ·mol^?1 in accordance with Hess law.     

对氨基苯甲酸热力学性质的量热和热分析研究

在80～400 K温区,用高精度全自动绝热量热仪测定了对氨基苯甲酸摩尔热容,得到摩尔热容随温度的变化的关系式为：     

Synthesis and magnetic properties of μ-phenolato copper (Ⅱ) binuclear complexes with different exogenous bridges

The syntheses and magnetic properties are reported for a series of copper(Ⅱ) complexes prepared from a pentadentate binucleating ligand 2,6-diformyl-4-methylphenol di(benzoyl-hydrazone) (H3L). These complexes incorporate different exogenous ions (X-) into a bridging position to form copper(Ⅱ) binuclear complexes of the formula [Cu2(H2L)X]2+, where X-= Br-(1), Cl-(2), HO-(3), C2H5O-(4) and C3H3N2- (5). The complexes have been characterized with variable temperature magnetic susceptibility (4.2-300 K) and the observed data were fit to those from a modified Bleaney-Bowers equation by least-squares method, giving the exchange integral 2J = -6.2 cm-1 for 1, -76.4 cm-1 for 2, -241.9 cm-1 for 3, -231.1 cm-1 for 4 and -343.8 cm-1 for 5. This suggested that there is an antiferromagnetic interaction between the Cu(Ⅱ) ions and the sequence of the effect of some exogenous bridging ligands on magnetic coupling is corresponding to that in spectrochemical series.     

Synthesis,crystal structure and properties of a novel copper(II) complex with tripod ligand tris(1H-benzimidazol- 2-ylmethyl)amine

A five-coordinate copper complex with the tripod ligand tris(1H-benzimidazol-2-ylmethyl)amine (ntb), of composition [Cu(ntb)(H₂O)] (C1O₄)₂?·?C₅H₄N₂O₃?·?H₂O (C₅H₄N₂O₃?=?4-nitropyridine-N-oxide), was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and U.V. The crystal structure of the copper complex has been determined by single-crystal X-ray diffraction, and shows that the Cu^II is bonded to a tris(1H-benzimidazol-2-ylmethyl)amine (ntb) ligand and a water molecule through four N atoms and one O atom, giving a distorted trigonal–bipyramidal coordination geometry with approximate C ₃ molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasi-reversible Cu⁺²/Cu⁺ couple. Electron spin resonance data confirm a trigonal-bipyramidal structure and with g ₂?<?g _ζ and a very small value of A ₂ (20?×?10^?4?cm^?1).     

Die Kristallstrukturen von [Cu2Cl2(AA · H+)2](NO3)2 und [AA · H+]Pikr− (AA · H+ = Allylammonium; Pikr− = Pikrat)

The Crystal Structures of [Cu₂Cl₂(AA · H⁺)₂](NO₃)₂ and [AA · H⁺]Picr^? (AA · H⁺ = Allylammonium; Picr^? = Picrat) By an alternating current electro synthesis the crystal-line π-complex [Cu₂Cl₂(AA · H⁺)₂](NO₃)₂ has been obtained from CuCl₂ · 2H₂O, allylamine (AA), and HNO₃ in ethanolic solution. X-ray structure analysis revealed that the compound crystallized in the monoclinic system, space group P2₁/a, a = 7.229(3), b = 7.824(3), c = 26.098(6) Å, γ = 94.46(5)°, Z = 4, R = 0.025 for 2 023 reflections. The crystal structure is built up of Cu_nCl_n chains which are connected by π-bonding bidentate AA · H⁺ …? ON(O)O …? H⁺ · AA units. For comparision with the above complex the structure of [AA · H⁺]Picr^? (Picr^? = picrate anion) is also reported.     

Crystal Structure, Phase Transition, and Thermodynamic Properties of Bis-dodecylammonium Tetrachlorozincate (C12H25NH3)2ZnCl4(s)

The crystal structure and composition of (C₁₂H₂₅NH₃)₂ZnCl₄(s) were characterized by chemical and elemental analysis, X‐ray powder diffraction technique and X‐ray crystallography. The lattice energy of the title compound was calculated to be U_POT=888.82 kJ·mol^?1. Low temperature heat capacities of the title compound have been measured by a precision automated adiabatic calorimeter over the temperature range from 80 to 403 K. An obvious solid to solid phase transition occurred in the heat capacity curve, and the peak temperature, molar enthalpy and molar entropy of the phase transition of the compound were determined to be T_trs= (364.02±0.03) K, (_trsH_m= (77.567±0.341) kJ·mol^?1, and (_trsS_m= (213.77±1.17) J·K^?1·mol^?1, respectively. Experimental molar heat capacities before and after the phase transition were respectively fitted to two polynomial equations. The smoothed molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were calculated and tabulated at an interval of 5 K.     

Bis(1‐methyl­guanidinium) tetra­chloro­cuprate(II) and 4‐(2‐pyrimidin‐1‐io)­piperazinium tetra­chloro­cuprate(II)

The crystal structures of the title compounds, (C₂N₃H₈)₂[CuCl₄], (I), and (C₈H₁₄N₄)[CuCl₄], (II), have been studied by X‐ray diffraction. The structures consist of discrete [CuCl₄]^2? anions with two monoprotonated (C₂N₃H₈)⁺ cations for (I) and a diprotonated (C₈N₄H₁₄)²⁺ cation for (II). The [CuCl₄]^2? anions of both compounds have flattened tetrahedral geometries. There are several N—H?Cl weak bonds that join the [CuCl₄]^2? anions and the organic cations helping retain the pseudo‐tetrahedral geometries of the anions.     

Interaction of the Benzenium Ion with Inert Ligands: IR Spectra of C6H7+?Ln Cluster Cations (L=Ar,N2, CH4, H2O)

IR photodissociation spectra of mass‐selected clusters composed of protonated benzene (C₆H₇⁺) and several ligands L are analyzed in the range of the C? H stretch fundamentals. The investigated systems include C₆H₇⁺? Ar, C₆H₇⁺? (N₂)_n (n=1–4), C₆H₇⁺? (CH₄)_n (n=1–4), and C₆H₇⁺? H₂O. The complexes are produced in a supersonic plasma expansion using chemical ionization. The IR spectra display absorptions near 2800 and 3100 cm^?1, which are attributed to the aliphatic and aromatic C? H stretch vibrations, respectively, of the benzenium ion, that is, the σ complex of C₆H₇⁺. The C₆H₇⁺? (CH₄)_n clusters show additional C? H stretch bands of the CH₄ ligands. Both the frequencies and the relative intensities of the C₆H₇⁺ absorptions are nearly independent of the choice and number of ligands, suggesting that the benzenium ion in the detected C₆H₇⁺? L_n clusters is only weakly perturbed by the microsolvation process. Analysis of photofragmentation branching ratios yield estimated ligand binding energies of the order of 800 and 950 cm^?1 (≈9.5 and 11.5 kJ mol^?1) for N₂ and CH₄, respectively. The interpretation of the experimental data is supported by ab initio calculations for C₆H₇⁺? Ar and C₆H₇⁺? N₂ at the MP 2/6‐311 G(2df,2pd) level. Both the calculations and the spectra are consistent with weak intermolecular π bonds of Ar and N₂ to the C₆H₇⁺ ring. The astrophysical implications of the deduced IR spectrum of C₆H₇⁺ are briefly discussed.     

Reversible SO2 Uptake by Tetraalkylammonium Halides: Energetics and Structural Aspects of Adduct Formation Between SO2 and Halide Ions

Contact with SO₂ causes almost immediate dissolution of tetraalkylammonium halides, R₄NX, (R = CH₃ (Me), X = I; R = C₂H₅ (Et), X = Cl, Br, I; R = C₄H₉ (nBu), X = Cl, Br), with the formation of an adduct, [R₄N]⁺[(SO₂)_nX]^– (n = 1–4). Vapor pressure measurements indicate the proclivity for SO₂ uptake follows the order N(CH₃)₄⁺ < N(C₂H₅)₄⁺ < N(C₄H₉)₄⁺. This trend is in accord with the Jenkins–Passmore volume‐based thermodynamic model. Born–Haber cycles, incorporating the lattice energy and gas phase energy terms, are used to evaluate the energetic feasibility of reactions. Density functional theory calculations (B3PW91; 6‐311+G(3df)) have been used to calculate the energetics of (SO₂)_nX^– (X = Cl and Br) anions in the gas phase. The experimental studies show that tetraalkylammonium halides are feasible sorbents for SO₂. In order to correlate the theoretical model, experimental enthalpy, Δ_rH° and entropy, Δ_rS° changes have been determined by the van't Hoff method for the binding of one SO₂ molecule to (C₂H₅)₄NCl, resulting in the liquid adduct (C₂H₅)₄NCl · SO₂. The structure of the analogous 1:1 bromide adduct, (C₂H₅)₄NBr · SO₂, has been determined by single‐crystal X‐ray diffraction (monoclinic, P2₁/c, a = 9.1409(14) Å, b = 12.3790(19) Å, c = 11.3851(17) Å, β = 107.952(2)°, V = 1225.6(3) ų). The structure consists of discrete alkylammonium cations, bromide anions and SO₂ molecules with short contacts between the anion and SO₂ molecules. The (C₂H₅)₄N⁺ cationadopts a transoid conformation with D_2d symmetry, and represents a rare example of a well‐ordered (C₂H₅)₄N⁺ cation in a crystal structure. The Br^– anions and SO₂ molecules forms a chain, (SO₂Br^–)_n, with bifurcated contacts. Non‐bonding electron pairs on the halide anions engage in electrostatic interactions with the sulfur atoms and charge‐transfer interactions with the antibonding S–O orbitals of the bound SO₂ moiety. Raman and ¹⁷O NMR spectra provide compelling evidence for a charge‐transfer interaction between SO₂ molecules and the halide ions.     

Structures of Mn(II) complexes of bis(2-pyridylmethyl)amine (bpa) and (2-pyridylmethyl)(6-methyl-2-pyridylmethyl)amine (Mebpa): geometric isomerism in the solid state

The crystal structures of [Mn(bpa)₂](ClO₄)₂ (1), [bpa?=?bis(2-pyridylmethyl)amine], and Mn(6-Mebpa)₂(ClO₄)₂ (2), [6-Mebpa?=?(6-methyl-2-pyridylmethyl)(2-pyridylmethyl)amine] have been determined. In 1, two facial [Mn(bpa)₂]²⁺ isomers are observed in the same unit cell, one with C _i (1a) and the other with C₂ (1b) symmetries. In 2, only the isomer with C₂ symmetry is observed. The structure of [Mn(bpa)₂]²⁺ with only C₂ symmetry has been reported previously (Inorg. Chem., 31, 4611 (1992)). The bond length order Mn–N_amine?>?Mn–N_pyridyl, observed in the C₂ and the C _i isomers in the crystals of 1, is the reverse of the order observed in the structure of [Mn(bpa)₂](ClO₄)₂ which contains only the C₂ isomer in the unit cell. The structure of 2 in which only the C₂ isomer is found, also shows the bond length order Mn–N_pyridyl?>?Mn–N_amine. In cyclic voltammetric experiments in acetonitrile solutions, 1 and 2 show irreversible anodic peaks at E _p?=?1.60 and 1.90?V respectively, (vs. Ag/AgCl), assigned to the oxidation of Mn(II) to Mn(III). The substantially higher oxidation potential of 2 is attributable to a higher rearrangement energy in complex 2 due to the steric effect of the methyl substituent.     

Syntheses,spectroscopic characterizations and crystal structures of diorganotin(IV)-oxo-carboxylates with 2-pyrazinecarboxylic acid or (2-pyrimidylthio)acetic acid

Eight diorganotin(IV)-oxo-carboxylates {[R₂Sn(O(O)CR′)]₂O}₂?·?Y (R′?=?C₄H₃N₂Y?= H₂OR?=?ⁿBu 1, Y?=?0 R?=?Me 2, Y?=?0 R?=?C₆H₅ 3, Y?=?0 R?=?C₆H₅CH₂ 4; R′?=?CH₂SC₄H₃N₂-2,6Y?=?0 R?=?ⁿBu 5, Y?=?CH₂Cl₂R?=?Me 6, Y?=?0 R?=?C₆H₅ 7, Y?=?0 R?= C₆H₅CH₂ 8) have been prepared in 1?:?1 molar ratios by reactions of diorganotin(IV) oxide with 2-pyrazinecarboxylic acid or (2-pyrimidylthio)acetic acid, respectively. All the complexes are characterized by elemental analysis, IR, ¹H NMR and ¹³C NMR spectra. Except for 2, 4 and 7, the complexes are also characterized by X-ray crystallography diffraction analyses, which reveal that the complexes adopt the familiar dicarboxylato tetraorganodistannoxane structural mode. Among them, the evident difference is that weak intramolecular interactions between Sn and N atoms are recognized in complexes 1 and 3. However, for complex 5 two different coordination modes are found in the same lattice.     

Hexachlorocuprate(II) Anion: Vibration Spectra and Structure

For the complexes (CH₈N₄)₂[CuCl₆], (C₂H₉N₅)₂[CuCl₆] · 2H₂O, and (CH₈N₄O)₄[CuCl₆]Cl₄, where (CH₈N₄)²⁺, (C₂H₉N₅)²⁺, and (CH₈N₄O)²⁺ are the aminoguanidinium, biguanidium, and carbohydrazidium cations, respectively, IR and Raman spectra were taken and analyzed in the region of Cu—Cl vibrations. Polarization measurements of the Raman spectra of (CH₈N₄O)₄[CuCl₆]Cl₄ single crystals were performed with the purpose of assigning the vibrations to symmetry types. Vibration spectra were calculated for the hexachlorocuprate ion in the given series of compounds, and the spectra of the examined complexes were compared with spectra of the previously known compounds incorporating the hexachlorocuprate(II) ion.     

NUCLEOPHILIC ADDITION OF WATER AND ETHANOL TO COORDINATED DI-(2-PYRIDYL)KETONE IN RHENIUM(V) AND TECHNETIUM(V) COMPLEXES. THE CRYSTAL STRUCTURE OF DICHLORO(HYDROXY-DI-(2-PYRIDYL)METHOXIDE)OXORHENIUM(V)

Abstract

Complexes of general formula MOCl₂[(C₅H₄N)₂C(O)(OR)] (M = Re, Tc; R = H, Et) were prepared by the reaction of trans-ReOCl₃(PPh₃)₂ and (n-Bu₄N)[TcOCl₄] with di-(2-pyridyl)ketone (DPK) in ethanol (R = Et) under nitrogen and in benzene, containing trace amounts of water, in air (R = H). The compounds were characterized by elemental analysis, vibrational, optical and proton nuclear magnetic resonance spectroscopy. The evidence suggests that the coordinated DPK ligand has undergone addition of water and ethanol at the carbonylic carbon atom, and that the (C₅H₄N)₂C(o)(OR) moiety acts as a uninegative, terdentate N,O,N-donor ligand. The X-ray crystal structure of the complex ReOCl₂[(C₅H₄N)₂C(O)(OH)] is also reported. Crystal data: C₁₁H₉N₂O₃Cl₂Re, orthorhombic, space group Pcca; a = 14.935(5), b = 11.896(8), c = 14.937(11)Å, and U = 2653.8 (2.7)ų to give Z = 8 for D _calc = 2.37 g cm_?3. The structure was solved by Patterson and Fourier methods and refined by least-squares methods to R = 0.076. The complex has an Re = O bond distance of 1.67(2)Å, and a deprotonated diolate oxygen of the ligand is coordinated in the position trans to the oxo group.     

Crystal Structures and Magnetic Properties of Charge-Transfer Salts: Cobaltocenium Bis(cis 1,2-diphenylethene-1,2-dithiolato)metalates (Metal = Ni,Pd, Pt)

Charge-transfer salts [Co(C₅H₅)₂][M(dpt)₂] (M = Ni and Pt; dpt = cis-1,2-diphenylethene-1,2-dithiolate) were synthesized and crystallographically characterized. [Co(C₅H₅)₂][Ni(dpt)2] crystallizes in the monoclinic space group C2/c with a = 25, 607(3) Å, b = 9.4151(11) Å, c = 14.407(4) Å, β = 101.373(22)°, V = 3405.3(10) Å₃ and Z = 4. [Co(C₅H₅)₂][Pt(dpt)₂] belongs to the triclinic space group $ {\rm P}\bar 1 $ with a = 9.4666(11) Å, b = 13.9869(12) Å, c = 14.2652(9) Å, α = 99.983(6)°, β = 90.034(7)°, γ = 109.751(7)°, V = 1747.2(3) ų and Z = 2. Both structures consist of ··· D⁺A^?D⁺A^?D⁺A^? ··· linear chains with the local C₅ axis of the eclipsed [Co(C₅H₅)₂]⁺ cation parallel to the best MS₄ plane of the [M(dpt)₂]^? anion. Magnetic susceptibility measurements show that χ_M T values of the complexes [Co(C₅H₅)₂][M(dpt)₂] (M = Ni, Pd, and Pt) remain nearly constant in the temperature range 15–300 K, but decrease rapidly with further decreasing of temperature, indicating weak antiferromagnetic interactions at low temperatures.     

In‐house and synchrotron X‐ray diffraction studies of 2‐phenyl‐1,10‐phenanthroline,protonated salts,complexes with gold(III) and copper(II), and an orthometallation product with palladium(II)

Different salts of the 2‐phenyl‐1,10‐phenanthrolin‐1‐ium cation, (pnpH)⁺, are obtained by reacting 2‐phenyl‐1,10‐phenanthroline (pnp), C₁₈H₁₂N₂, (I), with a variety of anions, such as hexafluoridophosphate, C₁₈H₁₃N₂⁺·PF₆⁻, (II), trifluoromethanesulfonate, C₁₈H₁₃N₂⁺·CF₃SO₃⁻, (III), tetrachloridoaurate, (C₁₈H₁₃N₂)[AuCl₄], (IV), and bromide (as the dihydrate), C₁₈H₁₃N₂⁺·Br⁻·2H₂O, (V). Compound (I) crystallizes with Z′ = 2, with both independent molecules adopting a coplanar conformation. In (II)–(IV), a hydrogen bond exists between the cation and anion, while one of the lattice water molecules serves as a hydrogen‐bonded bridge between the cation and anion in (V). Reaction of (I) with HAuCl₄ gives the salt complex (IV); however, reaction with KAuCl₄ produces the monodentate complex trichlorido(2‐phenyl‐1,10‐phenanthroline‐κN¹⁰)gold(III), [AuCl₃(C₁₈H₁₂N₂)], (VI). Dichlorido(2‐phenyl‐1,10‐phenanthroline‐κ²N,N′)copper(II), [CuCl₂(C₁₈H₁₂N₂)], (VII), results from the reaction of CuCl₂·2H₂O and (I), in which the Cu^II center adopts a tetrahedrally distorted square‐planar geometry. The pendent phenyl ring twists to a bisecting position relative to the phenanthroline plane. The square‐planar Pd^II complex, bromido[2‐(phenanthrolin‐2‐yl)phenyl‐κ³C¹,N,N′]palladium(II), [PdBr(C₁₈H₁₁N₂)], (VIII), is obtained from the reaction of (I) with [PdCl₂(cycloocta‐1,5‐diene)], followed by addition of bromine. A coplanar geometry for the pendent ring is adopted as a result of the tridentate bonding motif.     

2-甲基-2-丁醇的低温热容和热力学性质

本文用精密自动绝热量热仪测定了2-甲基-2-丁醇在80～305 K温区的热容,从热容曲线(Cp-T) 发现三个固－固相变和一个固－液相变, 其相变温度分别为T = 146.355, 149.929, 214.395, 262.706 K。从实验热容数据用最小二乘法得到以下四个温区的热容拟合方程。在80～140K温区, Cp,m = 39.208 + 8.0724X - 1.9583X2 + 10.06X3 + 1.799X4 - 7.2778X5 + 1.4919X6, 折合温度X = (T –110) / 30; 在 155 ～ 210 K温区, Cp,m = 70.701 + 10.631X + 12.767X2 + 0.3583X3 - 22.272X4 - 0.417X5 + 12.055X6, X = (T –182.5) /27.5; 在220 ～ 250 K温区, Cp,m = 99.176 + 7.7199X - 26.138X2 + 28.949X3 + 0.7599X4 - 25.823X5 + 21.131X6, X = (T – 235)/15; 在 270～305 K温区, Cp,m =121.73 + 16.53 X- 1.0732X2 - 34.937X3 - 19.865X4 + 24.324X5 + 18.544X6, X = (T –287.5)/17.5。从实验热容计算出相变焓分别为0.9392, 1.541, 0.6646, 2.239 kJ×mol-1; 相变熵分别为6.417, 10.28, 3.100, 8.527 J×K-1×mol-1。根据热力学函数关系式计算出80～305 K温区每隔5 K的热力学函数值 [HT –H298.15]和 [ST –S298.15]。     

Counter‐anion role in the formation of two supramolecular complexes: [Ag2(DPP)2](ClO4)2·CH3CN and [Ag2(DPP)2(NO3)2] {DPP is N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine}

The title compounds, bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ²N¹:P}disilver bis(perchlorate) acetonitrile monosolvate, [Ag₂(C₁₈H₁₇N₂P)₂](ClO₄)₂·CH₃CN, (1), and bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ²N¹:P}bis[(nitrato‐κ²O,O)silver], [Ag₂(C₁₈H₁₇N₂P)₂(NO₃)₂], (2), each contain disilver macrocyclic [Ag₂(C₁₈H₁₇N₂P)₂]²⁺ cations lying about inversion centres. The cations are constructed by two N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine (DPP) ligands linking two Ag⁺ cations in a head‐to‐tail fashion. In (1), the unique Ag⁺ cation has a near‐linear coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands. Two ClO₄⁻ anions doubly bridge two metallomacrocycles through Ag...O and N—H...O weak interactions to form a chain extending in the c direction. The half‐occupancy acetonitrile molecule lies with its methyl C atom on a twofold axis and makes a weak N...Ag contact. In (2), there are two independent [Ag(C₁₈H₁₇N₂P)]⁺ cations. The nitrate anions weakly chelate to each Ag⁺ cation, leading to each Ag⁺ cation having a distorted tetrahedral coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands, and two chelating nitrate O atoms. Each dinuclear [Ag₂(C₁₈H₁₇N₂P)₂(NO₃)₂] molecule acts as a four‐node to bridge four adjacent equivalent molecules through N—H...O interactions, forming a two‐dimensional sheet parallel to the bc plane. Each sheet contains dinuclear molecules involving just Ag1 or Ag2 and these two types of sheet are stacked in an alternating fashion. The sheets containing Ag1 all lie near x = , , etc, while those containing Ag2 all lie near x = 0, 1, 2 etc. Thus, the two independent sheets are arranged in an alternating sequence at x = 0, , 1, etc. These two different supramolecular structures result from the different geometric conformations of the templating anions which direct the self‐assembly of the cations and anions.     

Ni(II) and Co(II) complexes with 2,4-dichlorophenoxyacetic acid and 2-(2,4-dichlorophenoxy)-propionic acid

Nickel(II) and cobalt(II) complexes with the commercial herbicides 2,4-dichlorophenoxyacetic acid (2,4D; C₈H₆O₃Cl₂) and 2-(2,4-dichlorophenoxy)-propionic acid (2,4DP; C₉H₈O₃Cl₂) were prepared and characterized. On the basis of the results of elemental analysis and Ni and Co determination, the following molecular formulae were proposed for the obtained compounds: Ni(C₈H₅O₃Cl₂)₂·6H₂O, Co(C₈H₅O₃Cl₂)₂·6H₂O, Ni(C₉H₇O₃Cl₂)₂·2H₂O and Co(C₉H₇O₃Cl₂)₂·2H₂O. X-ray powder analysis was carried out. The IR, electronic (VIS) spectra and conductivity data were discussed. Water solubility of the synthesized complexes at room temperature was examined. Thermal decomposition of the compounds was studied. Dehydration processes occur during heating in air. The anhydrous compounds decompose via different intermediate products to oxides. TG/MS studies indicate formation of gaseous mass fragments of decomposition including H₂O⁺, OH⁺, CO₂ ⁺, HCl⁺, Cl₂ ⁺, CH₃Cl⁺, CH₂O⁺, C₆H₆ ⁺ and other. This revised version was published online in August 2006 with corrections to the Cover Date.     

Asymmetrische Hg(II)-Komplexe mit Organothiolato- bzw. Organoselenolato-und Triazenato-Liganden

The mixed mercury complexes (2XC₆H₄)₂N₃HgY (X=CH₃, F, Cl, Br, I;Y=SC₂H₅, SC₆H₅, SeC₆H₅) have been prepared. Both the Hg–S and Hg–Se bonds and, in contrast to other mixed triazenato-mercury compounds, the triazenato-mercury bonds have been shown to be kinetically labile on the NMR time scale by means of⁷⁷Se and¹⁹⁹Hg NMR spectroscopy. Evidence has been obtained for the presence of (2XC₆H₄)₂N₃HgY together with HgY ₂ and [(2XC₆H₄)₂N₃]₂Hg in solution.