N,N′-methylenedipyridinium Pt(II) and Pt(IV) hybrid salts: synthesis, crystal and molecular structures of [(C5H5N)2CH2] · [PtCl4] and [(C5H5N)2CH2] · [PtCl6]

The highly insoluble organic-inorganic hybrid ionic compounds N,N??-methylenedipyridinium tetrachloroplatinate(II) [(C₅H₅N)₂CH₂] · [PtCl₄] and N,N??-methylenedipyridinium hexachloroplatinate(IV) [(C₅H₅N)₂CH₂] · [PtCl₆] were obtained by the treatment of N,N??-methylenedipyridinium dichloride monohydrate [(C₅H₅N)₂CH₂]Cl₂ · H₂O with K₂[PtCl₄] or (NH₄)₂[PtCl₆], respectively, in an aqueous solution. Both complexes were isolated, purified, characterised by elemental analysis, and their molecular structures were confirmed by powder X-ray diffraction. The crystal structure of both compounds consists of separated discrete dications [(C₅H₅N)₂CH₂]²⁺ and anions [PtCl _n ]^2? (n = 4 or 6). As anticipated, the dications formed a butterfly shape consisting of two pyridine rings bound to the methylene group via their N atoms, while the Pt centre had a square planar geometry in [(C₅H₅N)₂CH₂] · [PtCl₄] and an octahedral coordination in [(C₅H₅N)₂CH₂] · [PtCl₆]. Interestingly, both crystal structures are stabilised by intermolecular C-H??Cl non-standard hydrogen bonds, ??-?? ring interactions between two pyridine rings of adjacent dications, and also by Cl-?? interactions.     

Thermal decomposition reaction kinetics of complexes of [Sm(o-MOBA)3bipy]2·H2O and [Sm(m-MOBA)3bipy]2·H2O

The complexes of [Sm(o-MOBA)₃bipy]₂·H₂O and [Sm(m-MOBA)₃bipy]₂·H₂O (o(m)-MOBA = o(m)-methoxybenzoic acid, bipy-2,2′-bipyridine) have been synthesized and characterized by elemental analysis, IR, UV, XRD and molar conductance, respectively. The thermal decomposition processes of the two complexes were studied by means of TG–DTG and IR techniques. The thermal decomposition kinetics of them were investigated from analysis of the TG and DTG curves by jointly using advanced double equal-double steps method and Starink method. The kinetic parameters (activation energy E and pre-exponential factor A) and thermodynamic parameters (ΔH ^≠ , ΔG ^≠ and ΔS ^≠) of the second-step decomposition process for the two complexes were obtained, respectively.     

Synthesis and structure of bismuth-containing complexes [(Ph4BiO)2{2,5-(CH3)2C6H3S(O)}] 2 + [Ph2Bi2I6]2−,[(Ph4Bi]+[PhBi(C5H5N)I3]−, [Ph4Sb] 4 + [Bi4I16]4−⋅2(CH3)2 C=O, and [Ph4Sb] 3 + [Bi5I18]3−

The reactions of tetraphenylbismuthonium and -stibonium salts Ph₄EX (E = Bi, Sb; X = I, OSO₂ (C₆H₃(CH₃)₂-2,5), OSO₂C₆H₃(OH-4)(COOH-3)) with bismuth triiodide in acetone afford complexes [Ph₄Bi]⁺[PhBi(C₅H₅N)I₃]^-, [(Ph₄BiO)₂S(O){2,5-(CH₃)₂C₆H₃S(O)} [Ph₂Bi₂I₆]^2–, [Ph₄Sb [Bi₄I₁₆]^4-·2(CH₃)²C=O, and [Ph₄Sb] ₃₊ ⁺ [Bi₅I₁₈]^3-, whose structural units, according to the X-ray diffraction data, are tetraphenylbismuthonium (-stibonium) cations and mono-, di-, tetra-, and pentanuclear anions, respectively.     

Electronic absorption and circular dichroism spectra of Δ-[Os(bipy)2(bipy−)]+, Δ-[Os(bipy)(bipy−)2]0 and Δ-[Os(bipy−)3]−

The electronic absorption and circular dichroism spectra of the complexes produced by the one-, two- and three-electron reduction of Δ-[Os(bipy)₃]²⁺ are reported for the first time. The spectra confirm that, as in the cases of the Fe^II and Ru^II analogues, the electrons are localised on the bipyridine ligand and the complexes are correctly formulated [Os(bipy)₂(bipy⁻)]⁺, [Os(bipy)(bipy⁻)₂]⁰ and [Os(bipy⁻)₃]⁻. The absorption spectra of the series of fully reduced complexes [M(bipy⁻)₃]⁻: M  Fe, Ru, Os are compared.     

Orbital imaging of the “lone pair” electrons in N(CH3)3, NH3and NF3 by electron momentum spectroscopy

The electron density in each of the outermost MOs of N(CH₃)₃and NF₃, as measured by electron momentum spectroscopy, is found to exhibit a very much higher degree of s character than the corresponding orbital in NH₃. This behaviour is clearly predicted by MO calculations which indicate appreciable delocalization of electron density away from the nitrogen in N(CH₃)₃ and NF₃. The observed results for N(CH₃)₃ are contrary to predictions based on commonly used intuitive arguments involving lone pairs, molecular geometry and hybridized orbitals. The present work is supportive of the view that CH₃ groups are intrinsically more electron attracting than H when bonded to N.     

Synthesis and structure of bismuth-containing complexes [Ph3PMe] 2 + [BiI5]2− and [Ph3PMe] 2 + [BiI5 · C5H5N]2− · C5H5N

The complexes [Ph₃PMe] ₂ ⁺ [BiI₅]^2? (I) and [Ph₃PMe] ₂ ⁺ [BiI₅ · C ₅H₅N]^2? · C ₅H₅N (II) were synthesized by the reaction of bismuth triiodide with triphenylmethylphosphonium iodide, and their structures were determined by X-ray diffraction analysis. The P atom in cation I has slightly distorted tetragonal coordination polyhedron (the CPC angles 109.42(4)° and 109.52(4)°, the bond lengths P-C_Ph 1.779(2), P-C_Me 1.793(1) Å. The Bi atom in the anion of complex I has an ideal trigonal-bipyramidal coordination polyhedron (Bi-I_eq 3.0031(4), Bi-I_eq 3.0485(5) Å). The crystal of complex II consists of the anions [BiI₅ · C ₅H₅N]^2?, solvated pyridine molecules, and two types of crystallographically independent tetrahedral triphenylmethylphosphonium cations (the angles CPC 106.9(1)°–111.7(1)°, the distances P-C_Ph 1.785(3)–1.792(3), P-C_Me 1.793(3), 1.786(3) Å). The Bi atoms in the anion of complex II have a distorted octahedral coordination polyhedron (Bi-I 3.0878(4)–3.1240(3), Bi-N(1) 2.628(3) Å).     

Formation and Crystal Structure of [(F5TeOXe)+·SO2ClF][Sb(OTeF5)6-]

Xe(OTeF₅)₂ reacts with Sb(OTeF₅)₃ under the formation of [Xe₂(OTeF₅)₃]⁺[Sb(OTeF₅)₆]^-. From SO₂ClF solution a yellow solvate [F₅TeOXe]⁺·SO₂ClF· [Sb(OTeF₅)₆]^- is formed with the crystal data: a = 1028.1(1), b = 1040.9(1), c = 1780.2(3) pm, α = 98.07(1), β = 97.68(1), γ = 105.82(1)°, space group . The O-Xe···O fragment is essentially linear (176.1(2)°), and the two Xe-O distances are quite different 197.1(4) and 242.6(4) pm.     

Synthesis and structure of bismuth complexes [Ph3MeP] 2 + [BiI3.5Br1.5(C5H5N)]2− · C5H5N, [Ph4Bi] 4 + [Bi4I16]4− · 2Me2C=O, and [Ph3(iso-Am)P] 4 + [Bi8I28]4− · 2Me2C=O

Complexes [Ph₃MeP] ₂ ⁺ [BiI_3.5Br_1.5(C₅H₅N)]^2? · C₅H₅N(I), [Ph₄Bi] ₄ ⁺ [Bi₄I₁₆]^4? · 2Me₂C=O (II), and [Ph₃(iso-Am)P] ₄ ⁺ [Bi₈I₂₈]^4? · 2Me₂C=O (III) were synthesized by reactions of bismuth iodide with triphenylmethylphosphonium bromide, triphenylbismuthonium sulfosalicylate, and triphenylisoamylphosphonium iodide, respectively. The crystal structures of complexes I–III were determined by X-ray crystallography. The complexes contain, in addition to cations and solvent molecules, mono-, tetra-, and octanuclear anions, in which bismuth atoms are in octahedral coordination.     

Bi3GaS5]2[Ga3Cl10]2[GaCl4]2·S8 containing heterocubane-type [Bi3GaS5]2+, star-shaped [Ga3Cl10]-, monomeric [GaCl4]- and crown-like S8

By reaction of elemental bismuth, sulfur, bismuth(III) chloride and gallium(III) chloride in the ionic liquid (BMIm)Cl (BMIm: 1-butyl-3-methylimidazolium), [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is obtained as red transparent crystals. According to X-ray structure analysis based on single crystals, the title compound crystallizes with triclinic lattice symmetry and is composed of heterocubane-type [Bi(3)GaS(5)](2+) cations, trimeric star-shaped [Ga(3)Cl(10)](-) anions with three (GaCl(4)) tetrahedra sharing a single central chlorine atom, monomeric [GaCl(4)](-) tetrahedra and neutral, crown-shaped S(8)-rings. Here, the heterocubane [Bi(3)GaS(5)](2+) as well as the star-shaped [Ga(3)Cl(10)](-) are observed as building units for the first time. [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is further characterized by X-ray powder diffraction as well as by thermogravimetry/differential thermal analysis.     

Synthesis and structural studies of (1R,2R,5R)-chloro{o-[β-(2-hydroxy-2,6,6-trimethylbicyclo[3.1.1]hept-3-ylidenamino)ethyliminomethyl]phenoxy-O,N,N}palladium(II)

The reaction of (1R,2R,5R)-3-[{2-[(2-hydroxybenzylidene)amino]ethyl}imino]-2,6,6-trimethylbicyclo[3.1.1]heptan-2-ol with lithium tetrachloropalladate was studied. A chiral palladium(II) complex was thus obtained and its structure was confirmed by NMR spectroscopy and X-ray diffraction analysis.     

Synthesis and structure of antimony complexes [Ph3AmP] 2 + [Sb2I8 · 2DMSO]2−, [Ph3PrP] 2 + [Sb2I8 · C4H8O2]2−, and [(HOCH2CH2)3NH] 4 + [Sb4I16]4−

The reaction of equimolar amounts of triphenylamyl- and triphenylpropylphosphonium iodides and triethanolammonium iodide with antimony iodide in dimethyl sulfoxide, dioxane, or acetone gave complexes [Ph₃AmP] ₂ ⁺ [Sb₂I₈ · 2DMSO]^2?, [Ph₃PrP] ₂ ⁺ [Sb₂I₈ · C₄H₈O₂]^2?, and [(HOCH₂CH₂)₃NH] ₄ ⁺ [Sb₄I₁₆]^4?, the structure of which was established by X-ray diffraction analysis. The cations of all complexes have slightly distorted tetrahedral structure, and the antimony atoms in the anions are hexacoordinated. The crystals of the complexes have intra- and intermolecular contacts, which form the structure.     

Hydrothermal synthesis of a mixed-valence hexamolybdate cluster: crystal structure of [HN(CH2CH2)3N]2[HMoVMoVI5O19]·[N(CH2CH2)3N]

The hydrothermal reaction of MoO₃, V, Na₂WO₄· 2H₂O, [N(CH₂CH₂)₃N](1,4-diazabicyclo[2.2.2] octane), and H₂O at 160°C for 90h gave dark-brown crystals of [HN(CH₂CH₂)₃N]₂[HMo^VMo^VI ₅O¹⁹]·[N(CH₂CH₂)₃N], (1), in 40% yield. Complex (1) is the first one-electron reduced mixed-valence hexamolybdate to be crystallized and structurally characterized. The crystal structure of (1) consists of discrete [HMo^VMo^VI ₅O₁₉]^2– anions, [HN-(CH₂CH₂)₃N]⁺ cations, and neutral [N(CH₂CH₂)₃N] molecules of crystallization.     

Syntheses and(Crystal Structures of Two New One-dimensional Double Hydrogen-bonding-chain Complexes [Ni(bipy)2Cl]·ClO4 and [Zn(bipy)2Cl]·BF4

Two new transition metal complexes, [Ni(bipy)2Cl]·ClO4 (bipy = 2,2'-bipyridine) 1 and [Zn(bipy)2Cl]·BF4 2, have been synthesized and characterized by single-crystal X-ray diffraction analysis. Both 1 and 2 crystallize in monoclinic space group P21/n with Z = 4. For 1, a = 10.776(1), b = 12.067(1), c = 16.146(2)(A), β= 93.021(2)o, V = 2031.9(4)(A)3, Mr = 505.98, Dc = 1.654 g/cm3, μ = 1.255 mm-1, F(000) = 1032, the final R = 0.0406 and wR = 0.1002 for 3983 observed reflections with Ⅰ ＞ 2σ(I). For 2, a = 10.758(4), b = 12.058(4), c = 16.135(5) (A), β = 104.57(1)o, V = 2025.7(12) (A)3, Mr = 500.00, Dc = 1.639 g/cm3, μ = 1.396 mm-1, F(000) = 1008, the final R = 0.0470 and wR = 0.1237 for 3759 observed reflections with Ⅰ ＞ 2σ(I). The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. A one-dimen- sional zigzag double hydrogen-bonding-chain is generated by the intermolecular M-bipy …anion…bipy--M hydrogen bonding interactions between the chelating ligands of bipy and anion.     

Why are [P(C6H5)4](+)N3- and [As(C6H5)4](+)N3- ionic salts and Sb(C6H5)4N3 and Bi(C6H5)4N3 covalent solids? A theoretical study provides an unexpected answer

A recent crystallographic study has shown that, in the solid state, P(C(6)H(5))(4)N(3) and As(C(6)H(5))(4)N(3) have ionic [M(C(6)H(5))(4)](+)N(3)(-)-type structures, whereas Sb(C(6)H(5))(4)N(3) exists as a pentacoordinated covalent solid. Using the results from density functional theory, lattice energy (VBT) calculations, sublimation energy estimates, and Born-Fajans-Haber cycles, it is shown that the maximum coordination numbers of the central atom M, the lattice energies of the ionic solids, and the sublimation energies of the covalent solids have no or little influence on the nature of the solids. Unexpectedly, the main factor determining whether the covalent or ionic structures are energetically favored is the first ionization potential of [M(C(6)H(5))(4)]. The calculations show that at ambient temperature the ionic structure is favored for P(C(6)H(5))(4)N(3) and the covalent structures are favored for Sb(C(6)H(5))(4)N(3) and Bi(C(6)H(5))(4)N(3), while As(C(6)H(5))(4)N(3) presents a borderline case.     

Synthesis and structure of tetra-p-tolylantimony complexes [(4-MeC6H4)4Sb] 2 + [Hg2I6]2−, [(4-MeC6H4)4Sb] 2 + [HgI4]2−, [(4-MeC6H4)4Sb] 3 + [Sb3I12]2−, and [(4-MeC6H4)4Sb]+[ReO4]−

Complexes [(4-MeC₆H₄)₄Sb] ₂ ⁺ [Hg₂I₆]^2? (I), [(4-MeC₆H₄)₄Sb] ₂ ⁺ [HgI₄]^2? (II), [(4-MeC₆H₄)₄Sb] ₃ ⁺ [Sb₃I₁₂]^2? (III), were synthesized by reactions of tetra-p-tolylantimony iodide with mercury iodide and antimony iodide, respectively. Tetra-p-tolylantimony perrhenate [(4-MeC₆H₄)₄Sb]⁺[ReO₄]^? (IV) was prepared from tetra-p-tolylantimony chloride and sodium perrhenate in acetone. Crystal structures of complexes I, II, and IV were determined by X-ray crystallography. Mercury and rhenium atoms have tetrahedral coordinations in these complexes. The Hg-I and Re-O distances in the structures of I, II, and IV vary within 2.7719(13)–2.7908(12)Å, 2.7028(3)–2.9163(3) Å, and 1.693(3)–1.744(3) Å, respectively. Antimony atoms in two crystallographically independent trinuclear centrosymmetric [Sb₃I₁₂]^2? anions of complex III have an octahedral environment. Each terminal SbI₃ fragment (Sb-I_t, 2.8265(9)–2.8333(10)Å) is bound to the central atom through tree bridging iodine atoms (Sb(2)-I_br, 3.2275(9)–3.3620(10)Å). The distances between the central Sb atom and bridging iodine atoms are much shorter (Sb(1)-I_br, 3.0153(6)–3.0316(6) Å; Sb(3)-I_br, 2.9926(6)–3.0074(6) Å).     

Infrared investigations of the order–disorder ferroelectric phase transitions in imidazolium halogenobismuthates(III) and halogenoantimonates(III): (C3N2H5)5Bi2Cl11, (C3N2H5)5Bi2Br11 and (C3N2H5)5Sb2Br11

Infrared spectra of the powdered (C₃N₂H₅)₅Bi₂Cl₁₁, (C₃N₂H₅)₅Bi₂Br₁₁and (C₃N₂H₅)₅Sb₂Br₁₁ crystals in the region of internal vibrations of the imidazolium cations (3600 and 400 cm⁻¹) at the temperature intervals of 10–300 K, covering paraelectric–ferroelectric phase transitions, are presented and discussed in this paper. The research shows that the vibrational states of the imidazolium cations change markedly during the paraelectric–ferroelectric phase transition. The continuous nature of these transitions is well reflected in the infrared spectra, which is consistent with the previous X-ray and dielectric findings.     

Synthesis and structure of antimony iodide complexes: [Ph3MeP] + 2 [SbI5]2−, [Ph3MeP] + 3 [Sb3I12]3−·Me2C=O, [Ph3MeP] + 3 [Sb3I12]3−, and [Ph3MeP] + 3 [Sb2I9]3−

Complexes with antimony-containing anions, [Ph₃MeP] ₊ ² [SbI₅]^2? (I), [Ph₃MeP] ₊ ² [Sb₃I₁₂]^3? (II), [Ph₃MeP] ₊ ³ [Sb₃I₁₂]^3? · Me₂C=O (III), and [Ph₃MeP] ₊ ³ [Sb₂I₉]^3? (IV), were synthesized by reacting triphenylmethylphosphonium iodide with antimony iodide. The central atom in the cations of the complexes has a distorted tetrahedral coordination. In the trinuclear anions of complexes II and III, each of the terminal SbI₃ groups is bound to the central Sb atom through two μ₂- and one μ₃ iodine bridges (SbSbSb angles are 103.0° and 102.2°, respectively). In the binuclear anion of complex IV, antimony atoms are linked with each other via three bridging iodine atoms.     

Hydrothermal Syntheses, Crystal Structure and Thermal Behavior of [(CH_3)_2NH_2]_2[B_5O_6(OH)_4]_2·[HCON(CH_3)_2] and [NH_3CH_2CH_2NH_3]_2·[B_(14)O_(20)(OH)_6]

Two novel organic base templated nonmetal borates [(CH₃)₂NH₂]₂[B₅O₆(OH)₄]₂·[HCON(CH₃)₂] ( ? ) and [NH₃CH₂CH₂NH₃]₂[B₁₄O₂₀(OH)₆] ( II ) have been synthesized under hydrothermal conditions, and characterized by elemental analyses, FT‐IR spectroscopy, X‐ray diffraction, and TG‐DTA. Their crystal structures were determined from single crystal X‐ray diffraction. The crystal structure of compound I is characterized by forming a 3D supramolecular structure with large channels along axes b and c through O? H···O hydrogen‐bonding among the [B₅O₆(OH)₄]^? anions. The crystal structure of compound II is characterized by forming a 3D supramolecular structure with large channels along axis a and direction [111] through O? H···O hydrogen‐bonding among the [B₁₄O₂₀(OH)₆]^4? anions. The templating organic amine cations in I and II are both obtained through in situ hydrothermal reactions, and are both located in the channels of the 3D supramolecular structure, respectively. Their thermal behavior has been also investigated.