Bis(4‐picoline‐κN)gold(I) dibromidoaurate(I) and bis(4‐picoline‐κN)gold(I) dichloridoaurate(I): space‐group ambiguity?

Bis(4‐picoline‐κN)gold(I) dibromidoaurate(I), [Au(C₆H₇N)₂][AuBr₂], (I), crystallizes in the monoclinic space group P2₁/n, with two half cations and one general anion in the asymmetric unit. The cations, located on centres of inversion, assemble to form chains parallel to the a axis, but there are no significant contacts between the cations. Cohesion is provided by flanking anions, which are connected to the cations by short Au...Au contacts and C—H...Br hydrogen bonds, and to each other by Br...Br contacts. The corresponding chloride derivative, [Au(C₆H₇N)₂][AuCl₂], (II), is isotypic. A previous structure determination of (II), reported in the space group P with very similar axis lengths to those of (I) [Lin et al. (2008). Inorg. Chem. 47 , 2543–2551], might be identical to the structure presented here, except that its γ angle of 88.79 (7)° seems to rule out a monoclinic cell. No phase transformation of (II) could be detected on the basis of data sets recorded at 100, 200 and 295 K.     

Crystal structure and properties of (1,5-cyclooctadiene) (η<Superscript>5</Superscript>-pentamethylcyclopentadienyl) iridium(I) [Ir(cod)Cp*]

Volatile iridium(I) complexes [Ir(cod)Cp^x] (Cp^x = pentamethylcyclopentadienyl Cp*, ethylcyclopentadienyl Cp^Et, cod = 1,5-cyclooctadiene) are synthesized and characterized by IR and NMR spectroscopy. The [Ir(cod)Cp*] complex is a solid and the [Ir(cod)Cp^Et] complex is a liquid (SATP). The XRD method is used to determine the structure of the [Ir(cod)Cp*] complex: chemical formula C₁₈H₂₇Ir, space group P2₁/c, a = 8,4418(2) Å, b = 9,4764(3) Å, c = 19.2682(5) Å, β = 96.128(1) °, V = 1532.61(7) ų, Z = 4, d _calc = 1.888 g/cm³, μ = 8.697 mm^–1. The cyclopentadienyl ligand is η⁵-type coordinated; 1,5-cyclooctadiene have a cis-cis conformation and is η⁴-type coordinated. The thermal properties of the complexes are studied by thermogravimetry.     

Erbium(III) and lutecium(III) complexes [Ln(H<Subscript>2</Subscript>O)<Subscript>8</Subscript>][Cr(NCS)<Subscript>6</Subscript>] · 5H<Subscript>2</Subscript>O: Synthesis and crystal structure

[Ln(H₂O)₈][Cr(NCS)₆] · 5H₂O aqua complexes, where Ln = Er (1), Lu (2), have been found in an aqueous solution instead of binary complex salts with an organic ligand in their cation, when crystal products of the reaction between Ln(NO₃)₃ · 6H₂O (Ln = Er, Lu), K₃[Cr(NCS)₆] · 4H₂O, and 8-oxyquinoline (C₉H₇NO) were studied by X-ray diffraction. Crystals of complexes 1 and 2 are isostructural and crystallize in triclinic system, space group P\(\bar 1\), Z = 2. For complex 1: a = 9.0677(4) Å, b = 9.3115(4) Å, c = 16.9595 Å, α = 81.526(2)°, β = 86.153(2)°, γ = 83.879(2)°, V = 1406.33(10) ų, ρ_calc = 1.894 g/cm³; for complex 2: a = 9.0438(3) Å, b = 9.2880(3) Å, c = 16.9181(3) Å, α = 81.7250(10)°, β = 86.1600(10)°, γ = 83.8850(10)°, V = 1396.38(7) ų, ρ_calc = 1.926 g/cm³.     

Bis(Thiosemicarbazide)Copper(II) 1,5-Naphthalenedisulfonate Complex [Cu(Тsc)<Subscript>2</Subscript>](1,5-Nds): Synthesis and Crystal and Molecular Structures

The synthesis, analysis, and IR spectroscopic, thermogravimetric, and X-ray diffraction study of [Cu(Тsc)₂](Nds) (I), where Тsc is thiosemicarbazide NH₂NHС(=S)NH₂, and 1,5-Nds^2– is the doubly deprotonated 1,5-naphthalenedisulfoacid anion C₁₀H₆(SO₃) ₂ ^2– , have been performed. Crystal structure units in complex I are [Cu(Тsc)₂]²⁺ centrosymmetric complex cations and (Nds)^2– anions (including those in inversion centers). The copper atom is coordinated to the vertices of a square via the two sulfur and two nitrogen atoms of the two bidentate-chelate (S,N) ligands Тsc. Crystal structure units in complex I are linked together by a branched network of weak nonlinear N–Н···О hydrogen bonds with participation of donors (all the five independent hydrogen atoms of the two NH₂ groups and NH group of the [Cu(Tsc)]²⁺ complex cation) and acceptors (all the three independent oxygen atoms of the sulfato group of the 1,5-Nds^2– anion).     

(Vapour + liquid) equilibria for the binary mixtures (cis-pinane + α-pinene) and (cis-pinane + 1-butanol)

The isothermal and isobaric (vapour + liquid) equilibria for (cis-pinane + α-pinene) and (cis-pinane + 1-butanol) measured with an inclined ebulliometer are presented. The experimental results are analysed using the UNIQUAC equation with the temperature-dependence binary parameters with satisfactory results. Experimental vapour pressures of cis-pinane are also included.     

Hydrophilic Poly(ether‐ester)s and Poly(ether‐ester‐amide)s Derived from Poly(ε‐caprolactone) and ?COCl Terminated PEG Macromers

A series of poly(ε‐caprolactone) (PCL)‐based multiblock poly(ether‐ester)s (PEE)s and poly(ether‐ester‐amide)s (PEEA)s were obtained from α,ω‐dihydroxy‐PCL ( = 2–4 kDa) and ? COCl di‐terminated poly(ethylene oxide) (PEO) macromers (MAC) of different length ( = 150, 300, 600, 1 000 Da). 4,7,10‐Trioxa‐1,13‐tridecanediamine was used in the synthesis of PEEAs. Bulk polycondensation processes were accomplished by one step (PEE) and two step (PEEA) procedures. PEEAs with PCL/MAC/Trioxy molar ratios 1:2:1 and 1:3:2 were investigated. The multiblock copolymer architecture was proved by ¹H NMR and size exclusion chromatography (SEC) techniques. Unimodal molecular weight (MW) distributions and values in the range of 13.3–21.0 kDa (PEE) and 8.1–12.8 kDa (PEEA) were found. Crystalline PCL‐type phases were identified for both PEEAs and PEEs by X‐ray diffraction. The thermal transitions were investigated by differential scanning calorimetry (DSC). The T_m values (49.9–53.4 °C) reflect those of the PCL component while the T_g of PEEAs (?45 to ?52 °C) are higher than those of the PEEs (?58 to ?61 °C) or the macromers. The equilibrium water uptakes range from 1.0 to 18.4 wt.‐% (PEE) and from 4.4 to 8.8 wt.‐% (PEEA) depending on both the composition and length of the ethylene oxide sequences. A dependence of surface homogeneity on copolymer composition was found for PEEs by dynamic contact angle measurements.

The preparation of PEEAs and PEEs.     

A comparison of the structure and bonding in the aliphatic boronic R–B(OH)<Subscript>2</Subscript> and borinic R–BH(OH) acids (R=H; NH<Subscript>2</Subscript>, OH,and F): a computational investigation

Boronic acids, R–B(OH)₂, play an important role in synthetic, biological, medicinal, and materials chemistry. This investigation compares the structure and bonding surrounding the boron atoms in the simple aliphatic boronic acids, R–B(OH)₂ (R=H; NH₂, OH, and F), and the analogous borinic acids, R–BH(OH). Geometry optimizations were performed using second-order Møller–Plesset perturbation theory (MP2) with the Dunning–Woon aug-cc-pVTZ, aug-cc-pVQZ, and aug-cc-pV5Z basis sets; single-point CCSD(FC)/aug-cc-pVTZ//MP2(FC)/aug-cc-pVTZ level calculations were used to generate a QCI density for natural bond orbital analyses of the bonding. The optimized boron–oxygen bond lengths for the X–B–O_t–H trans-branch of the endo-exo form of the boronic acids and for the X–B–O–H cis-branch of the boronic and borinic acids (X=N, O, and F, respectively) decrease as the electronegativity of X increases. The boron–oxygen bond lengths are generally longer in the endo-exo or anti forms of the boronic acids than in the corresponding borinic acids. NBO analyses suggest the boron–oxygen bond in H₂BOH is a double bond; the boron–oxygen bonding in the remaining boronic and borinic acids in this study has a significant contribution from dative pπ–pπ bonding. Values for Δ\({\text{H}}_{298}^{0}\) for the highly balanced reaction, R–B(OH)₂ + R–BH₂ → 2 R–BH(OH), suggest that the bonding surrounding the boron atom is stronger in the borinic acid than in the corresponding boronic acid.     

Synthesis,characterization and thermochemistry of Cs(ASP) · nH2O (n = 0, 1)

New compounds of aspartic acid Cs(ASP) · nH₂O (n = 0, 1) have been synthesized and characterized by XRD, IR and Raman spectroscopy as well as TG. The structural formula of this new compound was Cs(ASP) · nH₂O (n = 0, 1). The enthalpy of solution of Cs(ASP) · nH₂O (n = 0, 1) in water were determined. With the incorporation of the standard molar enthalpies of formation of CsOH(aq) and ASP(s), the standard molar enthalpy of formation of −(1202.9 ± 0.2) kJ · mol⁻¹ of Cs(ASP) and −(1490.7 ± 0.2) kJ · mol⁻¹ of Cs(ASP) · H₂O were obtained.     

Synthesis,crystal structure and magnetic properties of a novel manganese(II)-nitronyl nitroxide-azido(μ<Subscript>1,1</Subscript> and μ<Subscript>1,3</Subscript>) one-dimensional complex

A novel one-dimensional manganese(II) complex containing nitronyl nitroxide radical [Mn₂(IM2-py)₂(Ac)₂(μ_1,1-N₃)(μ_1,3-N₃) · EtOH] _n was synthesized and characterized structurally and magnetically. It crystallizes in the monoclinic space group p2₁/n. Each Mn(II) ion is six-coordinated in a distorted octahedral environment. The two N atoms of the nitronyl nitroxide radical and the two O atoms of acetate ligands are in the equatorial plane, whereas the two different azido bridging ligands are in trans axial position. Mn(II) ions are linked by nitrogen atom of μ_1,1-azido and oxygen atoms of two carboxy groups to form a Mn-Mn unit. Mn-Mn units are linked by azido ligands through μ_1,3 bridging style to form a one-dimensional chain. The compound is connected by the coordination bonds, π-π interactions and hydrogen bonds as a three-dimensional structure. Magnetic susceptibility data support that there are stronger antiferromagnetic interactions between the radical and Mn(II) ion, weak antiferromagnetic interactions between the Mn-R units, and very weak antiferromagnetic interactions between the R-Mn-Mn-R units.     

A review on green Lewis acids: zirconium(IV) oxydichloride octahydrate (ZrOCl<Subscript>2</Subscript>·8H<Subscript>2</Subscript>O) and zirconium(IV) tetrachloride (ZrCl<Subscript>4</Subscript>) in organic chemistry

Lewis acids are important and interesting catalysts in most organic transformations. Among different Lewis acids, Zr(IV) species such as ZrCl₄ and ZrOCl₂·8H₂O are allocated special attention because of their low toxicity, availability and handling, moisture stability, and low cost in comparison to some of their corresponding compounds. During recent decades, Lewis acids have been used to promote different types of organic reactions because they naturally possess mild acidity properties and, as such, can catalyze reactions selectively. This means that in the presence of various functional groups, they can operate on a specific group to produce the objective product. In this review we have focused on the reactions which have been progressed in the presence of ZrCl₄ and ZrOCl₂·8H₂O. The study has been ordered based on the number of the reaction components and their solvent media.     

<Emphasis Type="Italic">catena</Emphasis>-(μ<Subscript>3</Subscript>-Bromo)di(μ<Subscript>2</Subscript>-bromo)bromo(18-crown-6)dilead(II): Synthesis and crystal structure

A new polymeric complex, catena-(μ₃-bromo)di(μ₂-bromo)bromo(18-crown-6)dilead(II), [Pb₂Br(μ₂-Br)₂(μ₃-Br)(18-crown-6)] _n (I), is synthesized, and its crystal structure is studied using X-ray diffraction analysis (space group P \(\bar 1\), a = 7.970, b = 16.048, c = 19.153 Å, α = 72.75°, β = 88.57°, γ = 87.92°, Z = 4, direct method, full-matrix least-squares method in the anisotropic approximation, R = 0.076 for 6093 independent reflections, CAD4 automated diffractometer, λMoK_α radiation). The crystal structure of complex I contains infinite chains of the PbBr₆ octahedra along the x axis with the bridging Br^? anions as common edges. The [PbBr(18-crown-6)]⁺ host-guest complex fragments are attached through weak Pb-Br bonds to these chains on the side. In two independent terminal fragments, the coordination polyhedra of the Pb²⁺ cations are distorted hexagonal bipyramids with bases of six O atoms of the crown ligand and two Br^? anions in the axial vertices. Two Pb²⁺ cations from the [PbBr₃] _n ^? infinite polymer chain have a distorted octahedral coordination.     

The phenomenon of conglomerate crystallization: XXXVII: The crystallization behavior of the Cr(III) and Co(III) amine carbonates [Cr(en)2CO3]I (I) and NH4{[cis-β-Co(trien)Co3]2}(PF6)3 (II)

[Cr(en)₂CO₃]I (I), ICoO₃N₄C₅H₁₆, crystallizes from water at 21°C in space groupP2₁/c (no. 14), with lattice constantsa=7.298(4),b=8.622(8),c=17.577(6)Å,=91.29(4)°;V=1105.59 ų andd(calc; MW=359.11, Z=4)=2.157 g cm^–3. A total of 2825 data points were collected over the range of 4°250°; of these, 1855 (independent and withI3(I)) were used in the structural analysis. Data were corrected for absorption (=37.657 cm^–1) and the transmission coefficients ranged from 0.4850 to 0.9991. The finalR(F) andR _w(F) residuals were, respectively 0.134 and 0.113. The cations exist in the lattice as the enantiomeric pair () and (). NH₄{[cis--Co(trien)CO₃]₂}(PF₆)₃ (II), Co₂P₃F₁₈O₆N₉C₁₄H₄₀, crystallizes from water at 21 °C in space groupP2₁/c (no. 14), with lattice constantsa=10.397(2),b=20.292(3),c= 27.082(4) Å,=100.30(3)°;V=3545.70 ų andd(calc; MW=983.29, Z=4)=1.842 g cm^–3. A total of 3724 data were collected over the range of 4°250°; of these, 2653 (independent and withI3(I)) were used in the structural analysis. Data were corrected for absorption (=12.031 cm^–1) and the transmission coefficients ranged from 0.8326 to 0.99985. The finalR(F) andR _w (F) residuals were, respectively 0.104 and 0.124. The cations exist in the asymmetric unit as() and()[cis--Co(trien)CO₃]⁺ pairs. The three independent PF₆ ^– anions exhibit the usual high thermal motion typical of these species and the NH₄ ⁺ cation is either disordered or exhibits high thermal motion also (its H atoms could not be found in difference maps).     

Neodymium(III) triaquatrihydroxo(1,3-diamino-2-propanoltetraacetato)germanium(IV) hydrate [Ge(OH)(μ-HHpdta)(μ-OH)Nd(OH)(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>] · H<Subscript>2</Subscript>O: Synthesis and crystal and molecular structure

The heteronuclear germanium(IV) and neodymium(III) complex with 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) [Ge(OH)(μ-HHpdta)(μ-OH)Nd(OH)(H₂O)₃] · H₂O has been synthesized for the first time and characterized by physicochemical methods (elemental analysis, X-ray powder diffraction, thermogravimetry, IR spectroscopy, X-ray crystallography). The crystals are monoclinic: a = 9.331(3) Å, b= 10.279(4) Å, c = 21.474(7) Å, β = 94.59(3)°, V = 2053.0(12) ų, Z = 4, space group P2₁/n, R1 = 0.0245 for 4060 reflections with I > 2σ(I). The compound is built of complex binuclear molecules [Ge(OH)(μ-HHpdta)(μ-OH)Nd(OH)(H₂O)₃] and water molecules of crystallization. The germanium and neodymium atoms are bridged by the oxygen atom of the hydroxo group (Ge-O, 1.798(2) Å; Nd-O, 2.539(2) Å) and the deprotonated oxygen atom of the isopropanol group of the HHpdta^4? ligand (Fe-O, 1.858(2)Å; Nd-O, 2.420(2) Å) to form a dimeric molecule. Each coordination sphere (of the Ge atom and of the Nd atom) contains one nitrogen atom (Ge-N, 2.096(3) Å; Nd-N, 2.807(2) Å) and two carboxylic oxygen atoms from four acetate branches of the octadentate HHpdta^4? ligand (av. Ge-O, 1.928(2) Å; Nd-O, 2.391(2) Å). The coordination polyhedron of the Ge atom is completed to a distorted octahedron by the oxygen atom of the terminal hydroxo group (Ge-O 1.811(2) Å), and the polyhedron of the Nd atom is completed to a nine-vertex polyhedron by the oxygen atoms of the terminal hydroxo group (Nd-O 2.494(3) Å) and three water molecules (Nd-O, 2.512(3), 2.520(3), and 2.723(3) Å). In the crystal structure, the complex molecules and the water molecules of crystallization are joined by a hydrogen bond system.     

Novel trialkylsilyl(germyl)-substituted thienyl- and furylbenzimidazoles and their N-substituted derivatives – synthesis,structure and cytotoxic activity

The reaction of 1,2-phenylenediamine with a variety of silicon- or germanium-containing 2-furaldehydes or 2-thienylcarbaldehydes in DMFA gave the corresponding benzimidazole derivatives in moderate yields (36–49%) in the presence of sodium hydrogen sulfite. As a result, a new series of silyl, germyl substituted hetarylbenzimidazoles were synthesized and their in vitro cytotoxicity was studied. The quaternisation of N-substituted benzimidazoles by heating with various alkyl, allyl and propargyl chlorides and bromides leads to the formation of benzimidazolinium salts. Potential cytotoxic activity of synthesized new benzimidazoles and benzimidazolinium salts was tested in vitro on two monolayer tumour cell lines: MG-22A (mouse hepatoma), HT-1080 (human fibrosarcoma) and normal mouse fibroblasts (NIH 3T3) and compared with corresponding benzimidazoles.     

Kinetic and thermodynamic studies on reactions of [PtCl(bpma)]<Superscript>+</Superscript> and [Pt(bpma)H<Subscript>2</Subscript>O]<Superscript>2+</Superscript> (bpma = <Emphasis Type="Italic">bis</Emphasis>-(2-pyridylmethyl)amine) with some azoles and diazines

Substitution reactions of the complexes [Pt(bpma)H₂O]²⁺ and [PtCl(bpma)]⁺, where bpma is bis-(2-pyridylmethyl)amine, with the nitrogen-donor ligands 1,2,4-triazole, pyrazole and pyridazine were studied in aqueous 0.1 M NaClO₄ using variable-temperature UV–VIS spectrophotometry. The reactions of the aqua complex were studied at pH 2.5, and those of the chloro complex were studied in the presence of 10 mM NaCl to prevent their hydrolysis. The values obtained for the second-order rate constants indicate that the complexes with bpma are more reactive than those with diethylenetriamine. In both cases, the aqua complexes are more reactive than the corresponding chloro complexes. The reactivity of the incoming ligands follows the order: 1,2,4-triazole > pyridazine > pyrazole. Activation parameters were determined for all the reactions, and the negative entropies of activation (∆S^≠) support an A or Ia mechanism.     

(Indenyl)iridacarborane (η<Superscript>5</Superscript>-indenyl)Ir(η-7,8-C<Subscript>2</Subscript>B<Subscript>9</Subscript>H<Subscript>11</Subscript>): synthesis,structure, and bonding

A reaction of iodide [(η⁵-indenyl)IrI₂]_n (1) with thallium dicarbollide Tl[Tl(η-7,8-C₂B₉H₁₁)] leads to (indenyl)iridacarborane (η⁵-indenyl)Ir(η-7,8-C₂B₉H₁₁) (2) in 32% yield. The X-ray diffraction study showed that in the structure of 2, the five-membered rings C₅ and C₂B₃ have a cisoid conformation, in which the bridgehead carbon atoms of the indenyl ligand are arranged opposite to the carborane cage carbon atoms. The DFT calculations showed that the Ir—indenyl bond in compound 2 is weaker than the Ir—Cp bond in the complex (η-7,8-C₂B₉H₁₁)IrCp.     

Preparation and shape control of β-Ni(OH)<Subscript>2</Subscript> nano-particle

A simple and convenient method for the preparation of needle-shape nanoparticles of β-Ni(OH)₂ has been developed. Results show that a needle-shaped β-Ni(OH)₂ can be easily obtained in the presence of ethylenediamine and sodium dodecylbenzene sulfonate within a size from 100 to 200 nm. The shape and structure of the product were characterized by XRD, TEM and FT-IR. It is noteworthy that the formation of needle-shape β-Ni(OH)₂ benefits from the addition of sodium dodecylbenzene sulfonate. The optimum preparation conditions and the possible mechanism are also discussed.      

Syntheses and structures of nickel–tungsten μ-tellurophenyl complexes CpNi(PPh<Subscript>3</Subscript>)(μ-TePh)W(CO)<Subscript>5</Subscript> and [CpNi(PPh<Subscript>3</Subscript>)(μ-TePh)]<Subscript>2</Subscript>W(CO)<Subscript>4</Subscript>

Syntheses and molecular structures of the heterometallic complexes of nickel cyclopentadienyl triphenylphosphine tellurophenolate with tungsten carbonyls (II and III) (CIF files CCDC nos. 1559733 and 1559734, respectively) are described.     

Synthesis and characterization of bis(<Emphasis Type="Italic">O,O</Emphasis>′-diisopropylmonothiophosphato)nickel(II) adducts and molecular structures of bis(pyridine)bis(<Emphasis Type="Italic">O,O</Emphasis>′-diisopropylmonothiophosphato)nickel(II) complex

The present work demonstrates the synthesis and characterization of adducts with bis(O,O′-diisopropylmonothiophosphato)nickel(II) complex, Ni{S(O)P(OⁱPr)₂}₂(L) _n (n = 2, L = pyridine, 2-picoline, 3-picoline; n = 1, L = 2,2′-bipyridyl and 1,10-phenanthroline). The crystallographic investigation of Ni{S(O)P(OⁱPr)₂}₂(C₅H₅N)₂ reveals distorted octahedral geometry around the central nickel(II) atom. The monothiophosphate moieties show anisobidentate coordination to the central metal, while the pyridine ligands are in cis positions. These nickel(II) adducts were characterized by elemental analysis, a range of spectroscopic techniques, and magnetic susceptibility measurement.     

Nickel(II) tetraaqua bis(benzoate) tris(phenylacethydrazide) complex [Ni(HL<Superscript>1</Superscript>)<Subscript>3</Subscript>](L<Superscript>2</Superscript>)<Subscript>2</Subscript> · 4H<Subscript>2</Subscript>O: Synthesis and crystal and molecular structure

The synthesis, IR and Raman spectroscopic study, and X-ray diffraction analysis of [Ni(HL¹)₃](L²)₂ · 4H₂O (I), where HL¹ is phenylacetic acid hydrazide and L² is the benzoate monoanion, have been performed. The structural units of a crystal of complex I are complex [Ni(HL¹)₃]²⁺ cations, (L²)^– anions, and crystallization water molecules. The nickel atom is coordinated to the three oxygen atoms at octahedron apices and the three nitrogen atoms of three bidentate chelate (О, N) ligands HL¹ in cis,trans-meredianal (fac) conformation. The structural units of a crystal of complex I are bonded by a branched network of О–Н···О and N–H···O hydrogen bonds.