Silver(I) Clusters Stabilized by the Carba-closo-dodecaboranylethynyl Ligand with O-Donor Coligands and Template Ions

Large silver(I) clusters stabilized by the dianionic carba-closo-dodecaboranylethynyl ligand were obtained. Crystallization of polymeric {Ag₂(12-C≡C-closo-1-CB₁₁H₁₁)}_n from dimethyl sulfoxide afforded [Ag₁₄(12-C≡C-closo-1-CB₁₁H₁₁)₇(DMSO)₁₂] · DMSO that contained an Ag^I₁₀ cage augmented by four Ag^I ions. Crystals of [Ag₁₆(12-C≡C-closo-1-CB₁₁H₁₁)₈(THF)₁₂] · 2THF were obtained from anhydrous THF and {Ag₂(12-C≡C-closo-1-CB₁₁H₁₁)}_n. In the presence of moisture the similar but water-containing complex [Ag₁₆(12-C≡C-closo-1-CB₁₁H₁₁)₈(THF)₁₂(H₂O)₂] · 2.5THF was identified. Both silver(I) clusters are composed of a central octahedral Ag^I₆ unit and ten further silver(I) ions bonded via argentophilic interactions. [Ag₁₄(12-C≡C-closo-1-CB₁₁H₁₁)₇(DMSO)₁₂] · DMSO and [Ag₁₆(12-C≡C-closo-1-CB₁₁H₁₁)₈(THF)₁₂] · 2THF were characterized by elemental analysis and vibrational (IR and Raman) as well as NMR spectroscopy. In addition, the crystal structures of [Ag₂₅(12-C≡C-closo-1-CB₁₁H₁₁)₁₂(CH₃CN)_13.5(OH)] · 0.5CH₃CN and [Ag₂₅(12-C≡C-closo-1-CB₁₁H₁₁)₁₂{(CH₃)₂CO}_13.5(H₂O)Cl] · 15(CH₃)₂CO were determined. Both compounds contain Ag^I₁₄ rhombic dodecahedrons augmented by eleven silver(I) ions. A hydroxide or a chloride template ion is present in the center of the rhombic dodecahedron, respectively.     

Syntheses and structural determinations of the nine-coordinate rare earth metal: Na4[DyIII(dtpa)(H2O)]2·16H2O,Na[DyIII(edta)(H2O)3]·3.25H2O and Na3[DyIII(nta)2(H2O)]·5.5H2O

Three complexes, Na₄[Dy^III(dtpa)(H₂O)]₂?·?16H₂O, Na[Dy^III(edta)(H₂O)₃]?·?3.25H₂O and Na₃[Dy^III (nta)₂(H₂O)]?·?5.5H₂O, have been synthesized in aqueous solution and characterized by FT–IR, elemental analyses, TG–DTA and single-crystal X-ray diffraction. Na₄[Dy^III(dtpa)(H₂O)]₂?·?16H₂O crystallizes in the monoclinic system with P2₁/n space group, a?=?18.158(10)?Å, b?=?14.968(9)?Å, c?=?20.769(12)?Å, β?=?108.552(9)°, V?=?5351(5)?ų, Z?=?4, M?=?1517.87?g?mol^?1, D _c?=?1.879?g?cm^?3, μ?=?2.914?mm^?1, F(000)?=?3032, and its structure is refined to R ₁(F)?=?0.0500 for 9384 observed reflections [I?>?2σ(I)]. Na[Dy^III(edta)(H₂O)₃]?·?3.25H₂O crystallizes in the orthorhombic system with Fdd2 space group, a?=?19.338(7)?Å, b?=?35.378(13)?Å, c?=?12.137(5)?Å, β?=?90°, V?=?8303(5)?ų, Z?=?16, M?=?586.31?g?mol^?1, D _c?=?1.876?g?cm^?3, μ?=?3.690?mm^?1, F(000)?=?4632, and its structure is refined to R ₁(F)?=?0.0307 for 4027 observed reflections [I?>?2σ(I)]. Na₃[Dy^III(nta)₂(H₂O)]?·?5.5H₂O crystallizes in the orthorhombic system with Pccn space group, a?=?15.964(12)?Å, b?=?19.665(15)?Å, c?=?14.552(11)?Å, β?=?90°, V?=?4568(6)?ų, Z?=?8, M?=?724.81?g?mol^?1, D _c?=?2.102?g?cm^?3, μ?=?3.422?mm^?1, F(000)?=?2848, and its structure is refined to R ₁(F)?=?0.0449 for 4033 observed reflections [I?>?2?σ(I)]. The coordination polyhedra are tricapped trigonal prism for Na₄[Dy^III(dtpa)(H₂O)]₂?·?16H₂O and Na₃[Dy^III(nta)₂(H₂O)]?·?5.5H₂O, but monocapped square antiprism for Na[Dy^III(edta)(H₂O)₃]?·?3.25H₂O. The crystal structures of these three complexes are completely different from one another. The three-dimensional geometries of three polymers are 3-D layer-shaped structure for Na₄[Dy^III(dtpa)(H₂O)]₂?·?16H₂O, 1-D zigzag type structure for Na[Dy^III(edta)(H₂O)₃]?·?3.25H₂O and a 2-D parallelogram for Na₃[Dy^III(nta)₂(H₂O)]?·?5.5H₂O. According to thermal analyses, the collapsing temperatures are 356°C for Na₄[Dy^III(dtpa)(H₂O)]₂?·?16H₂O, 371°C for Na[Dy^III(edta)(H₂O)₃]?·?3.25H₂O and 387°C for Na₃[Dy^III(nta)₂(H₂O)]?·?5.5H₂O, which indicates that their crystal structures are very stable.     

[BuN(CH2CH2)3NBu]3[Pb5I16] · 4 DMF – ein Iodoplumbat mit nahezu D5h‐symmetrischem Anion

[BuN(CH₂CH₂)₃NBu]₃[Pb₅I₁₆] · 4 DMF – an Iodoplumbate Anion with approximately D _5h Symmetry The star‐shaped anion of [BuN(CH₂CH₂)₃NBu]₃‐[Pb₅I₁₆] · 4 DMF ( 1 ) consists of a cyclic arrangement of five PbI₆ octahedra sharing one common I atom in the centre of an almost planar Pb₅ ring. Compound 1 crystallizes in space group P2₁ with a = 1657.2(1), b = 2029.2(1), c = 1773.6(1) pm, β = 113.238(8)°, Z = 2.     

The inner‐salt zwitterion,the dihydrochloride dihydrate and the dimethyl sulfoxide disolvate of 3,6‐bis(pyridin‐2‐yl)pyrazine‐2,5‐dicarboxylic acid

In the inner‐salt zwitterion of 3,6‐bis(pyridin‐2‐yl)pyrazine‐2,5‐dicarboxylic acid, (I), namely 5‐carboxy‐3‐(pyridin‐1‐ium‐2‐yl)‐6‐(pyridin‐2‐yl)pyrazine‐2‐carboxylate, [C₁₆H₁₀N₄O₄, (Ia)], the pyrazine ring has a twist–boat conformation. The opposing pyridine and pyridinium rings are almost perpendicular to one another, with a dihedral angle of 80.24 (18)°, and are inclined to the pyrazine mean plane by 36.83 (17) and 43.74 (17)°, respectively. The carboxy and carboxylate groups are inclined to the mean plane of the pyrazine ring by 43.60 (17) and 45.46 (17)°, respectively. In the crystal structure, the molecules are linked via N—H...O and O—H...O hydrogen bonds, leading to the formation of double‐stranded chains propagating in the [010] direction. On treating (Ia) with aqueous 1 M HCl, the diprotonated dihydrate form 2,2′‐(3,6‐dicarboxypyrazine‐2,5‐diyl)bis(pyridin‐1‐ium) dichloride dihydrate [C₁₆H₁₂N₄O₄²⁺·2Cl⁻·2H₂O, (Ib)] was obtained. The cation lies about an inversion centre. The pyridinium rings and carboxy groups are inclined to the planar pyrazine ring by 55.53 (9) and 19.8 (2)°, respectively. In the crystal structure, the molecules are involved in N—H...Cl, O—H...O_water and O_water—H...Cl hydrogen bonds, leading to the formation of chains propagating in the [010] direction. When (Ia) was recrystallized from dimethyl sulfoxide (DMSO), the DMSO disolvate 3,6‐bis(pyridin‐2‐yl)pyrazine‐2,5‐dicarboxylic acid dimethyl sulfoxide disolvate [C₁₆H₁₀N₄O₄·2C₂H₆OS, (Ic)] of (I) was obtained. Here, the molecule of (I) lies about an inversion centre and the pyridine rings are inclined to the planar pyrazine ring by only 23.59 (12)°. However, the carboxy groups are inclined to the pyrazine ring by 69.0 (3)°. In the crystal structure, the carboxy groups are linked to the DMSO molecules by O—H...O hydrogen bonds. In all three crystal structures, the presence of nonclassical hydrogen bonds gives rise to the formation of three‐dimensional supramolecular architectures.     

(Z)‐2‐Methylbuten‐1‐yl(aryl)iodonium trifluoromethanesulfonates containing electron‐withdrawing groups on the aryl moiety

The crystal structures of [(Z)‐2‐methyl­but‐1‐en‐1‐yl]­[4‐(tri­fluoro­methyl)­phenyl]­iodo­nium tri­fluoro­methane­sulfonate, C₁₂H₁₃F₃I⁺·CF₃O₃S^?, (I), (3,5‐di­chloro­phenyl)­[(Z)‐2‐methyl­but‐1‐en‐1‐yl]­iodo­nium tri­fluoro­methane­sulfonate, C₁₁H₁₂­Cl₂I⁺·CF₃O₃S^?, (II), and bis{[3,5‐bis­(tri­fluoro­methyl)­phenyl][(Z)‐2‐methyl­but‐1‐en‐1‐yl]­iodo­nium} bis­(tri­fluoro­methane­sulfonate) di­chloro­methane solvate, 2C₁₃H₁₂F₆I⁺·­2CF₃­O₃S^?·CH₂Cl₂, (III), are described. Neither simple acyclic β,β‐di­alkyl‐substituted alkenyl­(aryl)­idonium salts nor a series containing electron‐deficient aryl rings have been described prior to this work. Compounds (I)–(III) were found to have distorted square‐planar geometries, with each I atom interacting with two tri­fluoro­methane­sulfonate counter‐ions.     

Indole- and carbazole-substituted pyridinium iodide salts: a rare case of conformational isomerism in crystals

A series of indole- and carbazole-substituted pyridinium iodide salts has been synthesized and characterized. X-ray analysis revealed that the iodide salt of the indole-substituted cation (E)-4-(1H-indol-3-yl­vinyl)-N-methyl­pyridinium (IMPE⁺), C₁₆H₁₅N₂⁺·I⁻, (I), has two polymorphic modifications, (Ia) and (Ib), and a hemihydrate structure, C₁₆H₁₅N₂⁺·I⁻·0.5H₂O, (II). Until now, only one crystal modi­fication has been identified for the (E)-4-(9-ethyl-9H-carbazol-3-yl­vinyl)-N-methyl­pyridinium (ECMPE⁺) iodide salt, C₂₂H₂₁N₂⁺·I⁻, (III). Crystals of (Ia) and (Ib) comprise stacks of antiparallel cations with iodide anions located in the channels between the stacks. Due to the presence of the water mol­ecules, the packing in (II) is quite different to that found in (Ia) and (Ib), and positional disorder involving a statistical superposition of two rotamers of IMPE⁺, with different orientations of the indole fragment, was found. Crystals of (III) contain two independent ECMPE⁺ rotamers with different orientations of their carbazole substituents. The cations are packed in stacks, with the iodide anions located in the channels between the stacks. In (III), the iodide was found to be disordered over two sites, with occupancies of 0.83 and 0.17.     

Mass spectrometric determination of the configuration of 2-methyl-and 1,2-dimethyl-4-vinyl-ethinyl(n-butyl)-4-hydroxyperhydroquinolines

The configuration at C-2 and C-4 in the molecules of 2-methyl- and 1,2-dimethyl-4-vinylethinyl(n-butyl)-4-hydroxyperhydroquinolines was determined by mass spectrometry. The principal conclusions concerning the stereochemistry were made on the basis of differences in the values of the I_[M?15]⁺/I_[M]⁺·, I_[M?17]⁺/I_[M]⁺·, I[_M?43]⁺/I_[M]⁺· and I_[M?57]⁺/I_[M]⁺· ratios in the mass spectra of the epimeric vinylethinylic alcohols, and of the I_[M?15]⁺/I_[M]⁺· and I_[M?15]⁺/I_[M]⁺· ratios in the case of the n-butylic alcohols.     

Spectroscopic studies and X-ray crystal structures of charge-transfer complexes of 1,4,7-trithiacyclononane with diiodine

1,4,7-Trithiacyclononane ([9]aneS₃) reacts with molecular diiodine in CH₂Cl₂ to form a 1:1 adduct. The formation constant and the thermodynamic parameters of this adduct have been determined by UV-visible spectra of several solutions at the temperatures of 15, 20, 25, 30, and 35°C. The ¹³C NMR spectra show that adducts with higher ligand/diiodine molar ratios are formed. Two neutral charge-transfer molecular compounds having formula 2[9]aneS₃ · 4I₂ ( I ) and [9]aneS₃ · 3I₂ · ( II ) have been obtained as crystals. The crystals of I are triclinic (a = 8.498(2) Å, b = 13.984(4) Å, c = 14.898(6) Å, α = 65.57(2)°, γ = 89.19(2)°, γ = 81.26(2)°, Z = 2, space group P1; R = 0.025) and contain units formed by two [9]aneS₃ molecules connected by a diiodine molecule; one [9]aneS₃ binds two other diiodine molecules, while the second binds only one other diiodine molecule. The crystals of II are monoclinic (a = 13.810(2) Å, b = 9.829(4) Å, c = 16.198(6) Å, β = 113.41(2)°, Z = 4, space group P2₁/c; R = 0.019) and contain molecules of [9]aneS₃ binding three diiodine molecules. FT-Raman spectra in the characteristic v(I–I) region, carried out on the solid adducts, are discussed in comparison with the structural parameters.     

Crystal Structure of Tetrakis (phenacetin) Dihydrogentetraiodide Dihydrate {[H5C2OC6H4N (H)C(CH3)O]4·H2I4·2H2O}

(Phenacetin)₄·₂I₄·2H₂O is triclinic, a = 13.641 (7), b = 12.807 (6), c = 7.201 (3) Å, α = 99.8 (4), b? = 86.5 (4), γ = 104.0 (5)°, P1 , Z = 1. The ordered crystal structure has been refined to R_F = 0.050, using 4173 independent reflections measured on a four-circle diffractometer with MoKa (graphite monochromator) radiation. The crystals are composed of alternating positively and negatively charged slices; each positive slice contains a double layer of stacks of hemi-protonated phenacetin molecules which are H-bonded through their carbonyl groups (d(O - - - O) = 2.432 (4) Å) while each negative slice contains a single layer of I^2?₄-ions linked in chains along [100] through H-bonds to pairs of water molecules. The axes of the phenacetin stacks are parallel to the planes of the (I^2?₄·2H₂O)-layers. The I^2?₄-ion is centro-symmetric and can be approximately represented as I^?- - - I–I- - - I^? (d(I^? - - - I) = 3.404 (1) Å; d(I–I) = 2.774 (1) Å). The compound is a pseudo-type A basic salt.     

The NO- and NO2-catalyzed decomposition of I2 in shock waves

Measurements of the NO-catalyzed dissociation of I₂ in Ar in incident shock waves were carried out in the temperature range of 700°-1520°K and at total concentrations of 5 × 10^?6-6 × 10^?5 mol/cm³, using ultraviolet-visible absorption techniques to monitor the disappearance of I₂. It was shown that the main reaction responsible for the disappearance under these conditions is I₂ + NO → INO + I, for which a rate coefficient of (2.9 ± 0.5) × 10¹³ exp[-(18.0 ± 0.6 kcal/mol)/RT] cm²/mol·sec was determined. The INO formed dissociates rapidly in a subsequent reaction. The reaction, therefore, constitutes a “chemical model” for a “thermal collisional release mechanism.” Preliminary measurements of the rate coefficient for I₂ + NO₂ → INO₂ + I are also presented. Combined with information on the reverse reactions obtained in earlier room temperature experiments, these results lead to accurate values of ΔH°_f for INO and INO₂ equal to 29.7 ± 0.5 and 15.9 ± 1 kcal/mol, respectively.     

Die Aluminidiodide La24Al12I21 und La10Al5I8: Verbindungen mit intermetallischen La‐Al‐Bereichen und La‐Al‐Clustern

The Aluminide Iodides La₂₄Al₁₂I₂₁ and La₁₀Al₅I₈: Compounds with Intermetallic La‐Al Fractions and La‐Al Clusters Reacting pieces of La, LaI₃ and Al filings (molar ratio 22 : 8 : 15) at 800 °C–825 °C results in La₂₄Al₁₂I₂₁ (70 % yield) together with La₁₀Al₅I₈ (10 % yield), besides known La₃Al₂I₂ and La₂Al₂I. Both new compounds form golden coloured needles. La₁₀Al₅I₈ is brittle, whereas La₂₄Al₁₂I₂₁ is shaped as hair‐like easily deformable bundles. Both are monoclinic, space group C2/m, La₂₄Al₁₂I₂₁ with a = 35.753(7) Å, b = 4.327(1) Å, c = 27.442(6) Å, β = 116.62(3)° and La₁₀Al₅I₈ with a = 19.649(1) Å, b = 4.296(1) Å, c = 18.0290(1) Å and β = 96.67(3)°. The La atoms form trigonal prisms condensed into double chains along [010]. The La prisms are centered by Al atoms which form Al₆ rings connected into chains. The La‐Al strands are surrounded by I atoms in La₂₄Al₁₂I₂₁, whereas in La₁₀Al₅I₈ they are connected to form corrugated sheets separated by close packed layers of I atoms together with Al atoms. The octahedral voids around the Al atoms are occupied by La atoms, and such La₆Al clusters are connected via opposite edges to octahedra chains along [010].     

Theoretical investigation of the rates of electron transfer processes Q−I + QII → QI + Q−II and Q−I + Q−II → QI + Q2−II in photosynthesis

A theoretical investigation on the rates of electron-transfer processes Q⁻_I + Q_II → Q⁻_I + Q⁻_II and Q⁻_I + Q⁻_II → Q_I + Q²⁻_II was carried out by using the Marcus theory of long-range electron transfer in solution. The molecular reorganizational parameter λ, the free-energy change ΔG⁰ for the overall reaction, and the electronic matrix element H_DA for these two processes were calculated from the INDO-optimized geometries of molecules Q_I, Q_II, and histidine. Q_I and Q_II are plastoquinones (PQ) which are hydrogen-bonded to a histidine each, and the two histidines may or may not be coordinated to a Fe²⁺ ion. The plastoquinone representing Q_I is additionally flanked by two peptide fragments. Each of the species (Pep)₂Q_I · His and His · Q_II has been considered to be immersed in a dielectric continuum that represents the surrounding molecules and protein folds. INDO calculations confirm the standard reduction potential for the first process (calculated 0.127 V; observed 0.13 V) and predict a midpoint potential of 0.174 V for the second process at 300 K at pH 7 (experimental value remains uncertain but is known to be close to 0.13 V). The plastoquinone fragment carries almost all the net charge (about 95.7%) in [PQ · His]⁻ and the net charge in [PQH · His]⁻. The electron is transferred effectively from the plastoquinone part of [(Pep)₂Q_I · His]⁻ to the plastoquinone moiety of Q_II · His in the first step and to the plastoquinone fragment of HisH⁺ · Q⁻_II in the second step. Therefore, we made use of the formula for the rate of through-space electron transfer from Q_I to Q_II (and to Q⁻_II). The plastoquinones are, of course, electronically coupled to histidines, and the transfer is, in reality, through the molecular bridge consisting of histidines and also Fe²⁺. The through-bridge effect is inherent in our calculation of ΔG⁰, H_DA, and the reorganization parameter λ. We investigated the correlation between half-times for the transfer and (D⁻¹_op− D⁻¹_s), where D_op and D_s are, respectively, optical and static dielectric constants of the condensed phase in the vicinity of the plastoquinones. We found that with reasonable values of D_op (2.6) and D_s (8.5) the experimental rates are adequately explained in terms of transfers from the plastoquinone moiety of Q_I to that of Q_II. The t_1/2 values calculated for the two processes are 247 and 472 μs in the absence of Fe²⁺ and 134 and 181 μs in the presence of Fe²⁺. These are in good agreement with the observed values which are ≈ 100 and ≈ 200 μs when Fe²⁺ is present in the matrix and which are known to be almost twice as large when the Fe²⁺ is evicted from the matrix. The present work also shows that the Marcus-Hush theory of long-range electron transfers can be successfully applied to the investigation of processes occurring in a semirigid condensed phase like the thylakoid membrane region. © 1997 John Wiley & Sons, Inc.     

An insight into the disorder properties of the α-cyclodextrin polyiodide inclusion complex with Sr2+ ion: dielectric,DSC and FT-Raman spectroscopy studies

At T < 250 K, the polyiodide inclusion complex (α-cyclodextrin)₂·Sr_0.5·I₅·17H₂O displays two separate relaxation processes due to both the frozen-in proton motions in an otherwise ordered H-bonding network and the order–disorder transition of some normal H-bonds to flip-flop ones. At T>250 K, the AC-conductivity is dominated by the combinational contributions of the disordered water network, the mobile Sr²⁺ ions, the polyiodide charge-transfer interactions and the dehydration process. The evolution of the Raman spectroscopic data with temperature reveals the coexistence of four discrete pentaiodide forms. In form (I) (I^?  ₃·I₂ ? I₂·I^?  ₃), the occupancy ratio (x/y) of the central I^?  ion differs from 50/50. In form (IIa) (I₂·I^? ·I₂) x/y = 50/50, whereas in its equivalent form (IIb) (I₂·I^? ·I₂) ^* as well as in form (III) (I^?  ₃·I₂), x/y = 100/0 (indicative of full occupancy). Through slow cooling and heating, the inverse transformations (I) → (IIa) and (IIa) → (I) occur, respectively.

     

Chromium(III) Complexes with Quadridentate Amines. Crystal Structure of [cis-β-Cr(trien)(C2O4)] Cl·2H2O (I) and [Cr2(μ-OH)2(μ-tren)2] Br4·2H2O (II)

[cis-g-Cr(trien) C₂O₄)] Cl·2H₂O (I) (CrC₈H₂₂N₄O₆Cl) crystallizes at 22°C, from deionized water solution as a racemate in space group Pn (No. 7). Lattice constants are: a = 7.193(2), b = 9.1545(12), c = 11.469(2) Å; g = 100.994(13)°; V = 741.3(3) ų and D_calc = 1.603 gcm^-3 (MW = 357.75, Z = 2). A total of 2251 data were collected, using MoK f radiation ( u = 0.71703 Å), over the range 4 h 2 è h 60°; of these, 1441 (independent and with I S 2 σ (I)) were used in the structural analysis. Data were corrected for absorption ( w = 9.81 cm^-1) and the transmission coefficients ranged from 0.8676 to 0.9942. The final R (F) and R_w(F) residuals were 0.0338 and 0.0764, respectively. The cations of (II) exist in the lattice as enantiomeric pairs. [Cr₂( w -OH)₂( w -tren)₂]Br₄ ·2H₂O (II) (Cr₂C₁₂H₄₂N₈O₄Br₄) crystallizes in the monoclinic space group P2₁/n (No. 14) with a = 10.835(2) Å, b= 7.859(3) Å, c = 16.397(2) Å, g = 105.45(2)°, V = 1345.7(5) ų3 and D_calc = 1.940 g cm^-1 (MW = 786.18, Z = 4). A total of 2467 data were collected, using MoK f radiation ( u = 0.71703 Å), over the range 4 h 2 è h 50°; of these, 1450 (independent and with I S 2 σ ( I )) were used in the structural analysis. Data were corrected for absorption ( w =67.79 cm^-1) and the transmission coefficients ranged from 0.5589 to 0.9949. The final R(F) and R_w(F) residuals were 0.0481 and 0.1408, respectively for 2385 observed reflections with ( I S 2 σ ( I )). In the complex cation, the two Cr(III) centers are in a distorted octahedral environment and are bridged by two hydroxide groups and two ethylamine arms, one from each tren ligand, which spans over the binuclear core. Within the bridging moiety, the Cr···Cr separation is 3.005(2) Å, the ° Cr-OH-Cr = 101.3(2)° and ° O-Cr-O = 78.7(2)°, while the average Cr-N bond distance trans to the hydroxo groups (2.085(6) Å) is shorter than the corresponding cis Cr-N distance (2.104(5) Å).     

Formation and Crystal Structure of the Salt (IC(PPh3)2)2I[I3]·(I2)2 with a new Polyiodide Chain

The reaction of the carbodiphosphorane Ph₃P=C=PPh₃ ( 1 ) with MeI in the presence of iodine gives the oxidation product (IC(PPh₃)₂)₂I[I₃]·(I₂)₂ ( 2 ). In the solid state dimeric units linked by indefinite ···I^?···I₂···I₃^?···I₂···I^?··· chains are found. An additional I···I contact between the cation and the I₂ molecule is formed, amounting to 359.23(5) pm. 2 crystallizes in the monoclinic space group P2/c, with the unit cell dimensions a = 2053.9(1), b = 1011.4(1), c = 1889.8(1) pm; β = 105.21(1)° and Z = 4.     

A Low‐dimensional Viologen/Iodoargentate Hybrid [(BV)2­(Ag5I9)]n: Structure,Properties, and Theoretical Study

A new low‐dimensional benzyl viologen/iodoargentate hybrid, [(BV)₂(Ag₅I₉)]_n ( 1 ) (BV²⁺ = benzyl viologen) was prepared. In 1 , (Ag₆I₉)_n^2– chain exhibits a new type of one‐dimensional chain constructed from vertex‐sharing of Ag₅I₁₀ units, and its two‐dimensional layer structure was constructed from C–H ··· I hydrogen bonds. Strong luminescence at 404 nm can be detected in 1 . DFT calculation suggests that 1 displays a reduced bandgap, which is led by a more dispersed LUMO band of BV²⁺ compared with MV²⁺ in [MV(Ag₂I₄)]_n.     

Metal Derivatives of 1,3‐Imidazolidine‐2‐thione with Divalent d10 Metal Ions (Zn–Hg) : Synthesis and Structures

Reactions of divalent Zn‐Hg metal ions with 1,3‐imidazolidine‐2‐thione (imdtH₂) in 1 : 2 molar ratio have formed monomeric complexes, [Zn(η¹‐S‐imdtH₂)₂(OAc)₂] ( 1 ), [Cd((η¹‐SimdtH₂)₂I₂] ( 2 ), [Cd(η¹‐S‐imdtH₂)₂Br₂] ( 3 ), and [Hg(η¹‐S‐imdtH₂)₂I₂] ( 4 ). Complexes 1 – 4 , have been characterized by elemental analysis (C, H, N), spectroscopy (IR, ¹H, NMR) and x‐ray crystallography ( 1 ‐ 4 ). Hydrogen bonding between oxygen of acetate and imino hydrogen of ligand, {N(2)–H(2C)···O(2)^#} in 1 , ring CH and imino hydrogen, {C(2A)–H(2A)···Br(2)^#} in 3 have formed H‐bonded dimers. Similarly, the interactions between molecular units of complexes 2 and 4 have yielded 2D polymers. The polymerization occurs via intermolecular interactions between thione sulfur and imino hydrogen, {N(2)–H(2)···S(1)^#}, imino hydrogen and the iodine atom, {NH(1)···I(2)^#} in 2 and imino hydrogen – iodine atom {N(2A)–H(2A)···I(2)} and I···I interaction in 4 . Crystal data: [Zn(η¹‐S‐imdtH₂)₂(OAc)₂] ( 1 ), C₁₀H₁₈N₄O₄S₂Zn, orthorhombic, Pbcn, a = 9.3854(7) Å, b = 12.4647(10) Å, c = 13.2263(11) Å; V = 1547.3(2) ų, Z = 4, R = 0.0280 [Cd((η¹‐S‐imdtH₂)₂I₂] ( 2 ), C₆H₁₂CdI₂N₄S₂, orthorhombic, Pnma, a = 13.8487(10) Å, b = 14.4232(11) Å, c = 7.0659(5) Å; Z = 4, V = 1411.36(18) ų, R = 0.0186.     

Hydrogen‐bonding one‐dimensional chains containing the R42(8) motif in the ammonium salts 1‐naphthylammonium iodide and naphthalene‐1,8‐diyldiammonium diiodide

In 1‐naphthylammonium iodide, C₁₀H₁₀N⁺·I⁻, and naphthalene‐1,8‐diyldiammonium diiodide, C₁₀H₁₂N₂²⁺·2I⁻, the predominant hydrogen‐bonding pattern can be described using the graph‐set notation R₄²(8). This is the first report of a structure of a diprotonated naphthalene‐1,8‐diyldiammonium salt.     

Copper(II) Halide Complexes of 2-Aminopyrimidines: Crystal Structures of [(2-aminopyrimidine) n CuCl2] (n=1,2) and (2-amino-5-bromopyrimidine)2CuBr2

The reaction of CuX₂(X=Cl, Br) with 2-aminopyrimidine in aqueous solution, or 2-amino-5-bromopyrimidine in aqueous acid yields compounds of the forms [LCuCl₂] _n (1), [L₂CuCl₂] (2) and [L'₂CuBr₂] (3) [L=2-aminopyrimidine; L'=2-amino-5-bromo-pyrimidine]. The three compounds all form layered structures in which each copper ion is coordinated to two 2-aminopyrimidine molecules and two halide ions. Common structural threads involve bridging ligation [either by monomeric (1) or hydrogen bonded ligand dimers (2 and 3)], N-H···X and N-H···N hydrogen bonding and π-π stacking interactions as well as semi-coordinate Cu···X bond formation (1 and 2) or Br···Br interactions (3). Compounds 1 and 2 crystallize as two-dimensional coordination polymers with asymmetrically bihalide bridged (CuX₂) _n chains cross-linked into sheets by the 2-aminopyrimidine molecules (1) or by hydrogen bonded L₂ dimers (2). The halide bibridged chains expand their primary copper coordination spheres to give 4 + 2 coordination spheres in 1 and 2. In 3, the layer structure involves coordination of the hydrogen bonded L'₂ dimers and C-Br···Br- interactions. Crystal data: (1): monoclinic, P2₁/m, a=3.929(1), b=12.373(2), c=7.050(1)å, β=91.206(4)°, V=342.7(1)&Aringsup3;, Z=2, D _calc= 2.225Mg/m³, μ=3.878 mm^-1, R=0.0269 for [|I|≥3σ(I)]. For (2): triclinic, P-1, a=4.095(4), b=7.309(5), c=10.123(6) å, α=86.28(6), β=78.44(6), γ=74.55(8)°, V=286.1(4) ų, Z=1, D _calc=1.884 Mg/m³, μ=2.360 mm^-1, R=0.0506 for [|I|≥2σ(I)]. For (3): triclinic, P-1, a=6.074(4), b=7.673(3), c=8.887(3) å, α=108.43(3) β=100.86(5), γ=106.96(4)°, V=357.0(3) ų, Z=1, D _calc=2.657 Mg/m³, μ=12.714mm^-1, R=0.0409 for [|I|≥2σ(I)].     

A 3D interpenetrating supramolecular compound based on Cu ··· N weak coordination: synthesis,crystal structure and DFT investigation

A metal-organic hybrid compound, Cu[(pyc)₂(4,4′-bipy)] ·?H₂O (pyc =?pyridine-2-carboxylate, 4,4′-bipy =?4,4′-bipyridine), has been hydrothermally synthesized and characterized by X-ray determination, IR and elemental analysis. The compound crystallizes in tetragonal, space group I4₁/acd with a =?24.797(2) Å, b =?24.797(2) Å, c =?14.811(2) Å, β =?90°, V =?9106.7(18) ų, C₂₂ H₁₈N₄O₅Cu, Mr =?481.94, Dc =?1.406 g cm^?3, μ(Mo-Kα) =?0.999 mm^?3, F(000) =?3952, Z =?16, the final R =?0.0712 and wR =?0.1886 for 21727 observed reflections (I >?2σ). Compound 1 exhibits a three-dimensional interpenetrating network induced by weak Cu ··· N noncovalent interaction, C–H ··· π?and π–π interactions. Based on crystal data, quantum chemistry calculation at the DFT/B3LPY level was used to reveal the electronic structure of 1.