Solvent extraction of Zr(IV) and Hf(IV) with <Emphasis Type="Italic">N,N,N′,N′</Emphasis>-tetraoctyldiglycolamide

N,N,N′,N′-tetraoctyldiglycolamide (TODGA) was synthesized and characterized with elemental analysis, infrared spectrometry and nuclear magnetic resonance spectrometry. The synthesized TODGA was applied for the extraction and separation of Zr(IV) and Hf(IV) from nitric acid solutions. The performed studies include the effects of TODGA, nitric acid, nitrate ion, hydrogen ion, and metal ion concentrations as well as time and temperature. TODGA shows effective extraction of Zr(IV) and Hf(IV) from HNO₃ ≥ 3 M. However, the maximum separation factor (D _Zr/D _Hf) obtained using TODGA is 2.8.     

Synthesis of <Emphasis Type="Italic">N,N′</Emphasis>-bis-[3-alkoxy-4-(hydroxy,alkoxy, acyloxy)-phenylmethylene- and -Phenylmethyl]-1,3-phenylenediamines

Starting with the vanillin series aldehydes, by reaction with 1,3-phenylenediamine in absolute methanol E,E-N,N′-bis-[3-alkoxy-4-(hydroxy-, alkoxy-, acyloxy)phenylme-thylene]-1,3-phenyl-enediamines (Shiff bases) are synthesized from reduction with Na[BH(OAc)₃] in benzene were prepared respective N,N′-bis-[3-alkoxy-4-(hydroxy-, alkoxy-, acyloxy)phenylmethyl]-1,3-phenyl-enediamines.     

Cu(bapen)M(CN)<Subscript>4</Subscript>·H<Subscript>2</Subscript>O complexes exhibiting chain-like structures (bapen = N,N′-bis(3-aminopropyl)-1,2-diaminoethane,M = Ni,Pd): preparations,crystal structures,spectroscopic and magnetic properties

Single crystals of Cu(bapen)Ni(CN)₄·H₂O and Cu(bapen)Pd(CN)₄·H₂O (bapen = N,N′-bis(3-aminopropyl)-1,2-diaminoethane) were isolated from the aqueous systems copper(II)—bapen—[M(CN)₄]^2? (M = Ni, Pd). Crystals of the two compounds are isostructural and are built up of two crystallographically independent quasi-linear chains [-Cu(bapen)-μ₂-NC-Ni(CN)₂-μ₂-CN-] _n and solvate water molecules. The copper(II) centers exhibit the usual distorted octahedral coordination with one tetradentate bapen ligand in the equatorial plane (mean Cu–N are 2.030 Å for Cu(bapen)Ni(CN)₄·H₂O and 2.018 Å for Cu(bapen)Pd(CN)₄·H₂O), while the axial positions are occupied by nitrogen atoms from μ₂-bridging cyanido ligands with longer Cu–N bonds (mean values are 2.544 Å for Cu(bapen)Ni(CN)₄·H₂O and 2.543 Å for Cu(bapen)Pd(CN)₄·H₂O). One of the two independent coordinated bapen ligands is disordered, as are the water molecules of crystallization. The Ni and Pd atoms in both studied compounds exhibit the usual square coordination with the bridging cyanido ligands trans to each other. Several OH···O, N–H···O and N–H···N hydrogen bonds enhance the stability of the structures. ESR spectra corroborated the presence of Jahn–Teller anisotropy at the copper(II) atoms. Magnetic studies in the temperature range 1.8–300 K reveal that both Cu(bapen)Ni(CN)₄·H₂O and Cu(bapen)Pd(CN)₄·H₂O follow Curie-Weiss laws with θ = ?0.51 K and θ = ?0.34 K, respectively, suggesting the presence of weak antiferromagnetic interactions.     

(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.     

Structure and stability of endohedral complexes <Superscript>4/2</Superscript>X@(HAlNH)<Subscript>2</Subscript> (X = N,P, As,C<Superscript>−</Superscript>, Si<Superscript>−</Superscript>)

The structures of a closo-hedral cluster (HAlNH)₁₂ and endohedral complexes ^4/2X@(HAlNH)₁₂ (X = N, P, As, C⁻, Si⁻) are studied by density functional theory (DFT) at the B3LYP/6-31G(d) level. The geometries, natural bond orbital (NBO), vibrational frequency (ν₁), energetic parameters, magnetic shielding constants (σ), and nucleus independent chemical shifts (NICSs) are discussed. It is found that all guest species are minima at the cage center. Inclusion energies (ΔE _inc) of all species are negative except those of ⁴N and ^4/2P. In all species, the endohedral quartet states (⁴X) are energetically less favorable than their doublet states (²X). The calculations predict that caged X states only donate <0.50 e to the cage and preserve their unencapsulated ground states.     

Geometric and electronic structure of an N,N′-ethylene-bis(salicylaldiminato) zinc(II) molecule,ZnO<Subscript>2</Subscript>N<Subscript>2</Subscript>C<Subscript>16</Subscript>H<Subscript>14</Subscript>

Gas electron diffraction at a temperature T of 641(5) K is used to study the structure of an N,N′-ethylenebis(salicylaldiminato) zinc(II) molecule, ZnO₂N₂C₁₆H₁₄, further Zn(salen). The structure of a gaseous Zn(salen) complex has C ₂ symmetry and is characterized by a substantial turn of two chelating fragments of the ligand with respect to each other, and also by a big difference in the length of coordination bonds: r _h1(Zn-O)=1.902(7) Å r _h1(Zn-N)= 2.027(7) Å. Results of the DFT/B3LYP calculation with 6-31G* and CEP,TZV basis sets of the molecule structure well agree with the experimental data. The electronic structure of Ni(salen), Cu(salen), Zn(salen), and Zn(acacen) molecules is considered.     

Synthesis,film-forming properties,and thermal and light sensitivity of <Emphasis Type="Italic">N,N′</Emphasis>-bis[4-hydroxy(alkoxy,acyloxy)-3-alkoxyphenylmethylidene]benzene-1,4-diamines

Previously unknown E,E-isomeric Schiff bases were synthesized by reaction of p-phenylenediamine with 4-hydroxy-3-methoxybenzaldehyde, 3-ethoxy-4-hydroxybenzaldehyde, and their O-alkyl and O-acyl derivatives in anhydrous methanol. Film-forming properties and thermal and light sensitivity of the products were studied.     

Synthesis and crystal and molecular structures of <Emphasis Type="Italic">N,N</Emphasis>′-methylenedipyridinium tetrachlorozincate(II) and <Emphasis Type="Italic">N,N</Emphasis>′-methylenedipyridinium tetrachlorocadmate(II)

Treatment of N,N′-methylenedipyridinium dichloride [C₅H₅N-CH₂-NC₅H₅]Cl₂ with MCl₂ (M = Zn or Cd) in aqueous solution gives the organic-inorganic hybrid ionic compounds [C₅H₅N-CH₂-NC₅H₅] · [MCl₄]. Both complex salts were fully characterised by multinuclear NMR spectroscopy, elemental analysis, and their molecular structures confirmed by powder X-ray diffraction studies. The most striking feature in both solid state structures was the presence of the C…Cl-M short contacts between the organic [C₅H₅N-CH₂-NC₅H₅] dication and inorganic [MCl₄] anion, which led to different crystal packing. For [C₅H₅N-CH₂-NC₅H₅]·[ZnCl₄], the C…Cl-Zn interactions led to the alternating arrangement of [C₅H₅N-CH₂-NC₅H₅]²⁺[ZnCl₄]²⁻ to form 1-D chains in the direction [010], and each individual chain had a two-fold rotational axis along the b axis, while for [C₅H₅N-CH₂-NC₅H₅] · [CdCl₄] the C…Cl-Cd associations gave 2-D network. In both solid state structures, the presence of Cl-ring centroid distances gave a strong indication of some form of Cl-π interactions.     

Two novel sandwich copper(II) complexes [CuLCl]<Subscript>2</Subscript>[CuCL<Subscript>4</Subscript>] and [CuLBr]<Subscript>2</Subscript>[CuBr<Subscript>4</Subscript>] (L = N,N′-bis(furaldehyde)diethylenetriamine)

The novel trinuclear copper(II) complexes [CuLCl]₂[CuCl₄](I) and [CuLBr]₂[CuBr₄] (II) (where L = N,N′-bis(furaldehyde) diethylenetriamine) were synthesized and structurally characterized by X-ray diffraction. They consist of sandwich units. Both I and II crystallize isomorphously in the monoclinic space group P2/n and feature cation/anion/cation geometry. The novel trinuclear copper(II) complexes I and II shown to be stabilized by a number of weak hydrogen bonds and intermolecular π-π stacking interactions. The article is published in the original.     

Syntheses and structural studies of the nickel(II) octahedral complexes Ni(N∩N)<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>L<Subscript>2</Subscript> with nitrogen-containing and carboxylate ligands

A series of new mononuclear octahedral nickel(II) complexes with the Ni(N∩N) _x L₂ framework (x = 2 or 3, N∩N = Рhen (1,10-phenanthroline), AMPy (2-(aminomethyl)pyridine), L is H₂O, anions of carboxylic acids (CF₃CO₂?, CCl₃CO₂?, HCO₂?), chloride ion, and water) is synthesized and described by IR spectroscopy, mass spectrometry, elemental analysis, and X-ray diffraction analysis: [Ni(Рhen)₂(OH₂)Cl]Cl · 2H₂O (I), [Ni(Рhen)₂(OH₂)(O₂CCF₃)](O₂CCF₃) (II, IIa), [Ni(Рhen)₂(HCOO)_1.618(H₂O)_0.382](HCOO)_0.382 · 4.618H₂O (III), ([Ni(Рhen)₂(OH₂)₂](O₂CCCl₃)₂ · 6.2H₂O (IV), [Ni(AMPy)₂(OH₂)₂](HCO₂)₂ · 6H₂O (V), and [Ni(Рhen)₃](CCl₃COO)₂ · 7H₂O (VI). The subunit containing two formate ligands in the inner sphere of the [Ni(Рhen)₂(HCO₂)₂] complex prevails in the crystal structure of complex III, which is not characteristic of the nickel carboxylate complexes of this type. In aqueous solutions complex IV undergoes decarboxylation to form [Ni(Рhen)₂(CO₃)] · 7H₂O. A change in the nature of the N-donor ligands in Ni(N∩N)₂L₂ leads to the change (cis or trans) in the configuration of the whole complex (СIF files CCDC no. 880414 (I), 842336 (II), 1430414 (IIa), 1478111 (III), 1430430 (IV), 1443133 (V), and 1430415 (VI)).     

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.     

Synthesis and crystal structure of the π copper(I) cyanide complex with N,N′-diallyl thiocarbamide 2CuCN · (C<Subscript>3</Subscript>H<Subscript>5</Subscript>NH)<Subscript>2</Subscript>CS

Crystals of the π copper(I) cyanide complex with N,N′-diallyl thiocarbamide, 2CuCN · (C₃H₅NH)₂CS (I), are synthesized from an aqueous-methanol solution of potassium nitroprusside, diallyl thiocarbamide on a copper electrode using the method of alternating-current electrochemical synthesis. The crystals are monoclinic: space group P2₁/n, a = 6.9440(5) Å, b = 13.760(1)) Å, c = 12.733(1) Å, β = 97.280(9)°, V = 1206.8(2) ų, Z = 4, R = 0.0361, R _w = 0.0362 for 2836 independent reflections with F ≥ 4σ(F). A unique polymeric structure is built due to the Cu(I)-(C=C) π bond and the bridging function of the thioamide S atom of the ligand molecule and one of the two independent cyano groups.     

Structure of a zinc(II) N,N’-ethylene-bis (acetylacetoniminate) molecule,ZnO<Subscript>2</Subscript>N<Subscript>2</Subscript>C<Subscript>12</Subscript>H<Subscript>18</Subscript>, according to gas electron diffraction data and quantum chemical calculations

Gas electron diffraction is used to study the structure of a zinc(II) N,N’-ethylene-bis(acetylacetoniminate) molecule, ZnO₂N₂C₁₂H₁₈, at a temperature T = 503(5) K. It is found that the molecule has the symmetry of the C₂ equilibrium configuration with a nonplanar structure of the ZnN₂O₂ coordination fragment and internuclear distances r_h1(Zn-O) of 1.958(13) ? and _h1(Zn-N) of 2.012(16) ?. Quantum chemical calculations by the DFT/B3LYP/CEP,TZV method gives the molecular structure consistent with that found in the experiment.     

Synthesis,characterization, and biological activities of oxovanadium(IV) and cadmium(II) complexes with reduced Schiff bases derived from <Emphasis Type="Italic">N,N′</Emphasis>-<Emphasis Type="Italic">o</Emphasis>-phenylenebis(salicylideneimine)

New oxovanadium(IV) and cadmium(II) complexes with reduced Schiff bases derived from N,N′-o-phenylenebis(salicylideneimine) have been synthesized and characterized using infrared and UV-visible spectra, ESR, and thermogravimetry. The complexes were identified as [ML] · (H₂O) species, where deprotonated ligands are coordinated to metal through N₂O₂ donor atoms. Antioxidant activity of the ligands and complexes was evaluated, revealing that the complexes exhibit a higher scavenging activity than the corresponding ligands. The prepared cadmium complexes showed slightly higher activity than the vanadium ones. Antifungal activity was tested against different human fungi including yeasts of the Candida genus (C. albicans and C. glabrata) and an opportunistic mould Aspergillus fumigatus. The oxovanadium complexes exhibited a very low activity toward C. albicans while the cadmium ones showed a significant growth inhibition of all the fungi tested; mainly of A. fumigatus though this mould is poorly susceptible to current antifungal agents like Itraconazole.     

Synthesis,structural and multinuclear natural abundance (<Superscript>13</Superscript>C, <Superscript>31</Superscript>P, <Superscript>195</Superscript>Pt) CP/MAS NMR studies of crystalline O,O′-dialkyldithiophosphate platinum(II) complexes

Platinum(II) O,O′-dicyclohexyl dithiophosphate [Pt{S₂P(O-cyclo-C₆H₁₁)₂}₂] (I) and platinum(II) O,O′-diisopropyl dithiophosphate [Pt{S₂P(O-iso-C₃H₇)₂}₂] (II) complexes were obtained and studied by solidstate ¹³C, ³¹P, and ¹⁹⁵Pt CP/MAS NMR spectroscopy. The dithiophosphate (Dtph) ligands in molecular structure I were found to be coordinated by platinum in S,S′-bidentate fashion to form the planar chromophore [PtS₄] (single-crystal X-ray diffraction data). For complex II, a new α-form (α-II) was obtained and identified by ³¹P MAS NMR spectroscopy. The ³¹P chemical shift anisotropy δ_aniso and the asymmetry parameter η of the ³¹P chemical shift tensor were calculated from the whole MAS spectra.     

Crystal structures of chiral (R/S) (C<Subscript>8</Subscript>H<Subscript>11</Subscript>N)<Subscript>2</Subscript> · Zn(OAc)<Subscript>2</Subscript>

Two opposite configuration (R/S) of chiral complexes (C₈H₁₁N)₂ · Zn(OAc)₂ (Ia and Ib—L-(−)-) and D-(+)-isomer) were synthesized by a simple one-pot method. The crystal structures of Ia and ib determined by X-ray crystallography.     

Chemical Bonding in the Complexes XeF<Stack><Subscript>5</Subscript><Superscript>+</Superscript></Stack>XF<Stack><Subscript>6</Subscript><Superscript>−</Superscript></Stack> (X = P,As, Sb,and Bi)

Ab initio quantum-chemical calculations of the complexes XeF ₅ ⁺ XF ₆ ^? (X = P, As, Sb, and Bi) were performed with the use of relativistic pseudopotentials for heavy atoms and full-electron basis sets. The chemical bonds were characterized by the parameters of critical points (electron density, its Laplacian, total electron energy, and its kinetic and potential components). It was demonstrated that the interaction between the XeF ₅ ⁺ cation and the XF ₆ ^? anion in XeF ₅ ⁺ XF ₆ ^? follows a key-lock scheme involving directed interactions of bridging fluorine atoms F_b → Xe and that the structuring function of the lone electron pair of the Xe atom is to compensate the destabilizing electrostatic interaction between the Xe and X atoms bearing excess positive charges.     

Synthesis,characterization, and X-ray crystal structure of the manganese(III) complex Mn(Sal<Subscript>2</Subscript>hn)(CH<Subscript>3</Subscript>OH)(N<Subscript>3</Subscript>) [Sal<Subscript>2</Subscript>hn = N,N′-bis(salicylidene)-1,2-hexanediamine]

The new manganese(III) complex, Mn(Sal₂hn)(CH₃OH)(N₃), where Sal₂hn = N,N′-bis(salicylidene)-1,2-hexanediamine, was prepared from a reaction mixture containing Sal₂hn, MnCl₂ · 2H₂O, and NaN₃ (2: 1: 8 molar ratio) in methanol and characterized using elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction. In the title complex, the Mn(III) center is in a distorted octahedral coordination geometry with the basal plane formed by the N₂O₂ donors of the tetradentate Schiff base dianion; the two phenolate O atoms and the two imine N atoms are each mutually in the cis position. The azide ion and the O atom of the methanol molecule occupy the other two positions of the octahedron. The hydrogen bond O(3)-H(3O)⋯N(5) links the mononuclear Mn(Sal₂hn)(CH₃OH)(N₃) units into a 1D chain extended along the x axis. The crystal structure is further stabilized by C(7)-H(7)⋯N(3) and C(16)-H(16)⋯N(5) hydrogen bonds.     

Synthesis and crystal structure of two {M(4,4′-dpdo)<Subscript>2</Subscript>[N(CN)<Subscript>2</Subscript>]<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>} complexes (M = Co(II), Mn(II); 4,4′-dpdo = 4,4′-bipyridyl-N,N′-dioxide)

The ligand 4,4′-bipyridyl-N,N′-dioxide (4,4′-dpdo) was used in the synthesis of two complexes, {Co(4,4′-dpdo)₂[N(CN)₂]₂(H₂O)₂} (1) and {Mn(4,4′-dpdo)₂[N(CN)₂]₂(H₂O)₂} (2). The complexes were found to be isostructural, triclinic, space group P-1 with Z = 1 and the following unit cell parameters: a = 8.158(8) Å, b = 8.865(8) Å, c = 9.477(9) Å; α = 70.988(13)°, β = 78.778(13)°, γ = 71.964(10)°; V = 612.8(10) ų for 1; a = 8.247(14) Å, b = 9.001(16) Å, c = 9.707(17) Å; α = 71.02(2)°, β = 78.63(2)°, γ = 72.62(2)°; V = 646(2) ų for 2. Final R-values were 0.075 and 0.083 for 1 and 2, respectively. In the molecules of the complexes, Co(II) or Mn(II) cation is coordinated by two O-atoms of two 4,4′-dpdo ligands, two terminal N-atoms of two dicyanamides, and two O-atoms of water molecules. The crystals are molecular, with adjacent complex molecules linked through a system of O-H...N and O-H...O hydrogen bonds.     

Synthesis,properties, and molecular and crystal structure of diantipyrylmethanium Bis(μ-tartrato)dihydroxydigermanate(IV) tetrahydrate (HDAm)<Subscript>2</Subscript>[Ge<Subscript>2</Subscript>(μ-L)<Subscript>2</Subscript>(OH)<Subscript>2</Subscript>] · 4H<Subscript>2</Subscript>O

The complex (HDam)₂[Ge₂(μ-L)₂(OH)₂] · 4H₂O (I) (H₄L is tartaric acid, Dam is diantipyrylmethane) was synthesized for the first time. The individual character and composition of I was established by elemental analysis and X-ray diffraction. The thermal stability of I was studied. The coordination sites of H₄L in the germanium complex were determined by IR spectroscopy. The structure of I was determined by X-ray crystallography. The crystals of I are triclinic: a = 9.3098(10) Å, b = 9.8088(10) Å, c = 17.6869(10) Å, α = 84.009(10)°, β = 77.926(10)°, γ = 67.088(5)°, V = 1454.3(2) ų, Z = 2, space group P \(\bar 1\), R = 0.0628 for 6343 reflections with I > 2σ(I). The compound is composed of the complex anions [Ge₂(μ-L)₂(OH)₂]^2?, the HDam⁺ cations, and crystal water molecules. In the dimeric anion, the metal atoms are bound to two completely deprotonated ligands L^4?. The latter are coordinated to the metal through the carboxyl (av. Ge-O, 1.911(6) Å) and hydroxyl (av. Ge-O, 1.768(6) Å) oxygen atoms. The coordination of each Ge atom is completed to trigonalbipyramidal by the O atom of the hydroxy ligand in the axial position (av. Ge-O, 1.748(7) Å). Both L^4? ligands are D isomers. In the crystal, the complex anions and crystal water molecules are combined by a system of hydrogen bonds.