Synthesis, crystal structures, and properties of inorganic-organic hybrid complexes constructed from copper(II) macrocyclic fragment

Reaction of a macrocyclic copper(II) complex [Cu(L)](ClO₄)₂ · 3H₂O (I) (L = 1,3,10,12,16,19-hexaazatetracyclotetracosane) with a hexapod carboxylate ligand H₆TTHA (H₆TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetic acid) and a tripod carboxylate ligand H₃TATB (H₃TATB = 4,4′,4″-S-triazine-2,4,6-triyl-tribenzoic acid) yielded two mononuclear copper(II) complexes [Cu(L)][H₄TTHA] · 4H₂O (II) and [Cu(L)][HTATB] · 4H₂O (III). The complexes I–III have been structurally characterized. The crystal structures of complexes II and III show the copper(II) ion has a distorted pentacoordinate square-pyramidal geometry with two secondary and two tertiary amines from the macrocyclic complex [Cu(L)]²⁺ and one oxygen atom from the carboxylate ligand group at the axial position. The UV-Vis spectra are utilized to discuss the hydrolysis of the complex II.     

Synthesis, crystal structures and electrochemical properties of CoIII complexes with hexadentate ligand containing thioether-amidopyridyl donor set

Two new cobalt(III) complexes of the hexadentate ligand [1,4-bis[o-(pyridine-2-carboxamidophenyl)]-1,4-dithiobutane] (H₂bpctb) with N₄S₂ donor set atoms have been synthesized. A reaction of Co(CH₃COO)₂·4H₂O with (H₂bpctb) leads to the formation of [Co^III(bpctb)]PF₆ (1) having a CoN₂(pyridine)N′₂(amide)S₂(thioether) coordination by symmetric bpctb^2? ligand. A similar reaction under slightly different conditions, however, gives [Co^III(L ^a )(L ^b )] (2), resulting from a C–S bond cleavage reaction triggered by an acetate ion as a base, having CoN₂(pyridine)N′₂(amide)S(thioether)S′(thiolate) coordination. These two Co(III) complexes have been characterized by elemental analyses and spectroscopic methods, and the crystal and molecular structures of [Co^III(bpctb)]PF₆ (1) in the form of the solvate (1·MeOH·H₂O) and of [Co^III(L ^a )(L ^b )] (2) have been determined by X-ray crystallography. The Co atoms of both complexes exhibit distorted octahedral geometry. The electrochemical investigation of [Co(bpctb)]PF₆·MeOH·H₂O (1·MeOH·H₂O) and [Co^III(L ^a )(L ^b )] (2) by cyclic voltammetry reveals a reversible Co^III–Co^II redox process at E _1/2 = ?0.32 V (ΔE _p = 80 mV); for 1, and E _1/2 = ?0. 87 V (ΔE _p = 70 mV) for 2.     

Synthesis and structure of new copper(II) coordination compounds with 8-quinoline aldehyde semicarbazones and thiosemicarbazones

Copper(II) salts were reacted with various quinoline aldehyde chalcogensemicarbazones to yield compounds formulated as Cu(HL)X₂ · nH₂O (I: HL = quinoline aldehyde thiosemicarbazone (HL¹), X = ClO₄, n = 2; II: HL = quinoline aldehyde 4-C₂H₅-thiosemicarbazone (HL^1a), X = NO₃, n = 0; III: HL = quinoline aldehyde semicarbazone (HL²), X = ClO₄, n = 3 and IV: HL = quinoline aldehyde 4-Ph-semicarbazone (HL^2a), X = NO₃, n = 1). Regardless of the reagent ratio, the products were compounds having the metal: ligand ratio of 1: 1, where the organic ligand was coordinated tridentate in a molecular form. Single-crystal X-ray diffraction showed that, depending on the chalcogen atom in the organic ligand (S or O), the substituent in the 4th position (at the terminal nitrogen atom), and the specifics of the acido ligand, complexes I–IV had appreciably differing molecular structure organizations. The structures of I and III are formed by a 1D charged coordination polymer, ClO ₄ ^? anions, and water molecules and may be described by the formula [Cu(HL)(H₂O)(ClO₄)] _n (ClO₄) _n · nH₂O. Copper(II) coordination polyhedra in I and II are (4 + 2) and (4 + 1 + 1) tetragonal bipyramids, respectively. In II and IV, the structures are monomeric and can be described as [Cu(HL^1a)(NO₃)₂] with the metal coordination polyhedron shaped as a (4 + 1) tetragonal pyramid in II and as [Cu(HL^2a)(H₂O)(NO₃)](NO₃) with the metal coordination polyhedron shaped as a (3 + 2) trigonal bipyramid in IV. The structure of II is built of molecular complexes, each comprising, apart from ligand HL^1a, two monodentate coordinated NO ₃ ^? groups. The oxygen atom of one anion together with the NNS donor atom set of ligand HL^1a form the base, and the oxygen atom of the other anion is in the apex of the coordination polyhedron. In IV, the structure is ionic and built of NO ₃ ^? anions and [Cu(HL^2a)(H₂O)(NO₃)]⁺ complex cations, where a cationic coordination polyhedron has a trigonal-bipyramidal configuration with organic ligand HL^2a positioned along the long edge. The bipyramidal base is made up by the oxygen atoms of the coordinated water molecule and monodentate nitrato group and the nitrogen atom N2 of the azomethyne group.     

Ni(II) complexes with optically active bis(menthane), pinano-para-menthane ethylenediaminodioximes and pinano-para-menthane, bis(pinane) propylenediaminodioximes: Synthesis, structures, and properties

Reactions of Ni(NO₃)₂ · 6H₂O) in EtOH(iso-PrOH) with optically active bis(menthane) ethylene-diaminodioxime (H₂L¹), pinano-para-menthane ethylenediaminodioxime (H₂L²), pinano-para-menthane propylenediaminodioxime (H₂L³) and bis(pinane) propylenediaminodioxime (H₂L⁴) were used to synthesize [Ni(H₂L¹)NO₃[NO₃ · 2H₂O (I), [Ni(HL²)]NO₃ (II), [Ni(HL³)]NO₃ (III), and [Ni(HL⁴)]NO₃ (IV). X-ray diffraction study of paramagnetic complex I (μ_eff = 3.04 μB and diamagnetic complexes II and III revealed their ionic structures. A distorted octahedral polyhedron N₄O₂ in the cation of complex I is formed by the N atoms of tetradentate cycle-forming ligand, i.e., the H₂L¹ molecule, and the O atoms of the NO ₃ ^? anion acting as a bidentate cyclic ligand. In the cations of complexes II and III, containing a pinane fragment, the coordination core NiN₄ has the shape of a distorted square formed on coordination of tetradentate cycle-forming ligands, i.e., anions of the starting dioximes. The structure of diamagnetic complex IV is likely to be similar to the structures of complexes II and III.     

Synthesis and Characterisation of Diruthenium Paddlewheel Compounds Bearing 2,6-Di(p-tolyl)benzoate Ligands

The mixed carboxylate diruthenium complexes trans-[Ru ₂ ^II,III (O₂CCH₃)₂(O₂CAr)₂Cl] (I) and trans-[Ru ₂ ^II,II (O₂CCH₃)₂(O₂CAr)₂] (II) (O₂CAr = 2,6-di(p-tolyl)benzoate) have been synthesised along with [Ru ₂ ^II,III (O₂CAr)₄Cl] (III) and the homoleptic complex [Ru ₂ ^II,II (O₂CAr)₄] (IV). The structures trans-[Ru₂(O₂CCH₃)₂(O₂CAr)₂Cl(thf)]·(thf) and [Ru₂(O₂CAr)₄Cl(η ¹-CH₂Cl₂)] were determined by X-ray crystallography, and display the expected paddlewheel arrangement of the carboxylate ligands around the diruthenium core. The structure of III is a rare example of a structurally characterised dichloromethane complex, highlighting the Lewis acidic nature of the diruthenium axial position. The bulky ^?O₂CAr ligand protects the axial positions from intermolecular interactions in the absence of strong nucleophiles for III and IV, and the effect this has on the electronic structure of the diruthenium core in these complexes was investigated by cyclic voltammetry, electronic absorption spectroscopy and magnetic susceptibility studies.     

New binuclear ferrocenecarboxylates of rare-earth metals as precursors for ferrites: Syntheses,structures, and solid-phase thermolysis

New ferrocenecarboxylates of rare-earth metals, [Ln₂(μ-O,η²-OOCFc)₂(μ₂-O,O′-OOCFc)₂(η²-NO₃)₂(DMSO)₄] (Ln = Gd (I), Tb (II), and Y (III)) and [Gd₂(μ-O,η²-OOCFc)₂(η²-OOCFc)₄(DMSO)₂(H₂O)₂] · 2DMSO · 2CH₂Cl₂ (IV), are synthesized and characterized by X-ray diffraction analysis. Unlike all earlier known ferrocenecarboxylates of rare-earth metals, in isostructural compounds I–III the Ln atoms are linked by four bridging carboxyl residues, two of which are chelate-bridging (the coordination number of Ln is 9). Binuclear structure IV is formed by two chelate-bridging carboxylate ligands (the coordination number of Gd is 9). Weak antiferromagnetic and weak ferromagnetic interactions between the Gd atoms are observed in complexes I and IV, respectively. The thermal decomposition of the synthesized compounds is studied by differential scanning calorimetry and thermogravimetry. According to the X-ray diffraction data, the final thermolysis products of the complexes in air are garnets Ln₃Fe₅O₁₂.     

Syntheses,crystal structures,and magnetic properties of a series of double end-on azido-bridged dinuclear manganese(II) complexes

Four azido-bridged dinuclear Mn(II) complexes, [Mn₂(phen)₄ μ-₁,₁-N₃)₂][Fe^III(bpmb)(CN)₂]₂·H₂O (1), [Mn₂(phen)₄(μ-₁,₁-N₃)₂][Fe^III(bpClb)(CN)₂]₂·H₂O (2), and [Mn₂(phen)₄(μ-₁,₁-N₃)₂][M^III(bpdmb)(CN)₂]₂·3H₂O [M = Fe (3) or Cr (4); phen = 1,10-phenanthroline, bpmb^2– = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate, bpClb^2– = 1,2-bis(pyridine-2-carboxamido) 4-chloro-benzenate, bpdmb^2– = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate], have been synthesized using the synthetic strategy of large anion inducement. Single-crystal X-ray diffraction analysis reveals that all four complexes are doubly end-on (EO) azido-bridged binuclear Mn(II) complexes with two large [M(L)(CN)₂]^– (L = bpmb^2?, bpClb^2?, or bpdmb^2?) building blocks acting as charge-compensating anions. The magnetic properties of the complexes have been investigated, and the results indicate that the magnetic coupling between two Mn(II) centers through the EO azide bridges is ferromagnetic, with J = 0.64(1) cm^?1 for 1, 0.43(1) cm^?1 for 2, 0.50(1) cm^?1 for 3, and 0.66(2) cm^?1 for 4. The magneto-structural relationships of EO azido-bridged Mn(II) systems are discussed.     

Synthesis and structure of palladium complexes [Ph3PhCH2P]+[PdCl3(DMSO)]− · DMSO, [Ph4P]+[PdCl3(DMSO)]−, and [Ph4Sb(DMSO)]+[PdCl3(DMSO)]−

[Ph₃PhCH₂P]⁺[PdCl₃(DMSO)]^? · DMSO (I), [Ph₄P]⁺[PdCl₃(DMSO)]^? (II), and [Ph₄Sb(DMSO)]⁺[PdCl₃(DMSO)]^? (III) complexes have been synthesized via the reaction of palladium chloride with equimolar amounts of triphenylbenzylphosphonium chloride, tetraphenylphosphonium chloride, and tetraphenylstibonium chloride, respectively. According to X-ray diffraction data, the cations of complexes I (CPC = 104.90(8)°–111.61(9)°) and II (CPC = 105.12(10)°–111.46(10)°) have slightly distorted tetrahedral structures with P-C bond lengths of 1.786(2)–1.809(2) and 1.791(2)–1.799(2) Å, respectively. The antimony atom in the [Ph₄Sb(DMSO)]⁺ cation has a trigonal bipyramidal surrounding with the dimethyl sulfoxide (DMSO) oxygen atom in an axial position (Sb...O 2.567(2) Å). The palladium atoms in the square mononuclear anions of complexes I, II, and III are tetracoordinate, and Pd-Cl distances are 2.3101(5)–2.3104(5) Å, 2.2950(7)–2.2038(7) Å, and 2.2986(9)–2.3073(9) Å, respectively. The DMSO ligands are coordinated to the palladium atom through the sulfur atom (Pd-S, 2.2318(5) (I), 2.2383(6) (II), and 2.2410(9) Å (III)).     

Synthesis,structures and properties of three copper complexes created via in situ ligand cross-coupling reactions

Three copper complexes {[Cu₂(L¹)₂]·I₃} _n (1), [Cu(L²)₂] (2), and [Cu₂I₂(L³)₂(MBI)₂] (3) (MBI = 2-mercaptobenzimidazole, L¹ = N-(benzothiazol-2-yl)acetamidine anion, L² = N-(thiazol-2-yl) acetamidine anion, L³ = 3-methyl-[1,2,4]thiadiazolo[4,5-a]benzimidazole) have been synthesized solvothermally by the reactions of CuI with 2-benzothiazolamine, 2-aminothiazole and 2-mercaptobenzimidazole (MBI), respectively, in acetonitrile. In situ C–N (or C–S) cross-coupling ligand reactions were observed in all three complexes, and hypothetical reaction mechanisms are proposed for the formation of the ligands and their complexes. The single-crystal X-ray structural analysis reveals that both the Cu(II) and Cu(I) atoms are located in pseudo-tetrahedral environments in complex 1, and L¹ acts as a double bidentate ligand which coordinates with the Cu(I) and Cu(II) atoms to form a 1D coordination polymer. Unlike complex 1, the Cu(II) atom in complex 2 is in a square planar geometry, coordinated by two L² ligands with relatively small steric hindrance. In complex 3, the Cu(I) atoms have a distorted tetrahedral geometry, being coordinated by one nitrogen atom from L³, two sulfur atoms of MBI ligands, and one iodide. The sulfur atoms from MBI ligands bridge two Cu(I) atoms to form a binuclear complex. All three complexes exhibit relatively high thermal stabilities. Complex 1 displays intense fluorescence emission at 382 nm and complex 3 displays two intense fluorescence emissions at 401 and 555 nm.     

Crystal structures, magnetic, dielectric and ferroelectric properties of two copper(II) complexes with m-nitrobenzoic acid

Reactions of CuCl₂, m-nitrobenzoic acid (HNBA) and NaOH with 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) in aqueous ethanol afforded two Cu(II) complexes Cu(bpy)(NBA)₂, 1, and [Cu(phen)(H₂O)₂(NBA)](NBA), 2. The monomolecular Cu(bpy)(NBA)₂ moieties are both bridged by hydrogen bonding interactions and interlayer π ^*–π ^*stacking interactions to form a 3D (3,4,6)-connected supramolecular architecture with the Schäfli symbol of (4⁴·6²)(4⁴·6⁶·8⁵)(6³)₂. Complex 2 crystallizes in a noncentrosymmetric space group P2₁ where all molecules show the same orientation along the polar b axis. Preliminary investigations suggest that 2 exhibits ferroelectric hysteresis loops at room temperature with remanent polarization (P _r) of ca. 0.09 μC cm^?2 and coercive electric fields of 2.53 kV cm^?1, respectively. It may be a potential ferroelectric with a relatively large spontaneous polarization (P _s) of 0.22 μC cm^?2. Furthermore, permittivity property measurements reveal a dielectric constant (ε _r) of 6.36. Variable-temperature (2–300 K) magnetic susceptibility measurements showed the presence of weak ferromagnetic interactions between the Cu(II) ions for both 1 and 2.     

Xanthate complexes of {Nb2S4}4+

Alkyl xanthate complexes [Nb₂S₄(S₂COR)₄] (R = Et (I), iso-Pr (II), n-Bu (III), and iso-Am (IV)) are synthesized by the ligand exchange reaction in solutions from (Et₄N)₄[Nb₂S₄(NCS)₈] and the corresponding potassium salts in satisfactory yields. The X-ray diffraction analyses are carried out for the isopropyl xanthate (II) and butyl xanthate (III) complexes. From the view point of mutual arrangement of chelate cycles, complexes II and III exist in crystals as ΛΔ isomers. The niobium-niobium distances are 2.8789(4) Å in complex II and 2.8856(3) Å in complex III. The first example for the formation of short S...S contacts between the disulfide ligands of the {Nb₂S₄}⁴⁺ fragments in the crystal structure of III is found (3.146 Å).     

Further studies on the properties and effect of high energetic ionizing radiation on copper(II) complexes: 1H NMR,electronic absorption,ESR spectra and solid electrical conductivity

The effect of energetic γ-radiation on ¹H NMR, electronic absorption, ESR spectra, differential thermal analysis (DTA) and solid state dc electrical conductivity of the ligand N-phenyl-2-(2-(phenylamino)acetyl)hydrazine carbothioamide (H₂L) and its copper(II) complexes; Cu(HL)(OAc)H₂O, Cu(HL)BrH₂O and Cu(H₂L)₂(NO₃)₂?3H₂O before and after γ-irradiation (hereafter referred to as (B), (B ₁ ), (B ₂ ), (B ₃ ) and (A), (A ₁ ), (A ₂ ), (A ₃ ), respectively) has been studied. Electronic spectral bands of the complexes after irradiation exhibited some better resolved shapes with a remarkably higher absorbance, ESR spectrum of complex Cu(HL)BrH₂O (B ₂ ) before irradiation showed isotropic spectrum with g _iso = 2.075 however, after irradiation (A ₂ ) displayed axial ESR spectrum with g _∥ > g _⊥ > 2.0023 and d _(x2?y2) ground state. DTA of the compounds reveals that γ-irradiation induced generation of new peaks as well as changes in the peak intensities. Solid state dc electrical conductivity for complexes was investigated before and after γ-irradiation. Complexes were found to be semiconductors, the activation energies (E _a) were calculated for the complexes by using the Arrhenius plot.     

Synthesis,structure, and magnetic properties of heterotrimetallic tetranuclear complexes

Two novel heterotrimetallic tetranuclear complexes [Cu(H₂L)(CH₃OH)]₂Gd(DMF)Fe(CN)₆·2H₂O·DMF (1) and [Cu(H₂L)(CH₃OH)]₂Tb(H₂O)_0.57(DMF)_0.43Fe(CN)₆·5.5H₂O (2) are reported (H₄L = N,N′-ethylenebis(3-hydroxysalicylidene)). The central Ln(III) ion is surrounded by two neutral [Cu(H₂L)(CH₃OH)] moieties, forming a Cu₂Ln trinuclear unit. The [Fe(CN)₆]^3? anion is weakly coordinated to one Cu(II) ion of [Cu(H₂L)(CH₃OH)] through a cyanide nitrogen atom with the N–Cu distance of ca. 3.2 Å. Magnetic susceptibility measurements indicate the presence of overall ferromagnetic interactions in complexes 1 and 2. The magnetic coupling constant in complex 1 is J _Cu1Gd1 = 4.54 cm^?1 and J _Cu2Gd1 = 7.97 cm^?1 based on \( \hat{H} = - 2J_{\text{Cu1Gd1}} \hat{S}_{\text{Cu1Gd1}} - 2J_{\text{Cu2Gd1}} \hat{S}_{\text{Cu2Gd1}} \) . Dynamic AC magnetic susceptibility studies reveal that complex 2 shows frequency-dependent out-of-phase signals, typical of single molecule magnet behavior. The energy barrier for complex 2 under a 2 kOe applied DC magnetic field is 13 K.     

Tin(IV) complexes based on 2-hydroxy-3,6-di-tert-butyl-para-benzoquinone: Syntheses,structures, and electrochemical behavior in solution

A series of new tin(IV) complexes based on 2-hydroxy-3,6-di-tert-butyl-para-benzoquinone (LH) of the general formula L₂SnR₂ (R = Me (I), Et (II), Bu ⁿ (III), Ph (IV)) and LSnMe₃ (V) were synthesized. The obtained compounds were characterized by IR and ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy and elemental analysis. The X-ray diffraction analysis was carried out for complexes L₂Sn(Bu ⁿ )₂ (III) and LSnMe₃ (V). The low-frequency region of the IR spectra, which has not earlier been studied in detail, was interpreted for compounds I–V and previously described complex LSnPh₃ (VI). The electrochemical properties of LH and related tin complexes I–VI were studied. The nature of the hydrocarbon groups at the metal atom affects the stability of the intermediates formed in the electrochemical reactions.     

Synthesis, spectroscopic studies of new water-soluble Co(II) and Cu(II) macrocyclic complexes of 4,15-bis(2-hydroxyethyl)-2,4,6,13,15,17-hexaazatricyclodocosane: their interaction studies with calf thymus DNA and guanosine 5′ monophosphate

New water soluble Co(II) 1, Ni(II) 2 and Cu(II) 3 complexes of 4,15-bis(2-hydroxyethyl)-2,4,6,13,15,17-hexaazatricyclodocosane Co(II) were synthesized and characterized by various techniques, viz. elemental analysis, conductivity measurements, infrared, electronic, ESI-MS, ¹H and ¹³C NMR spectroscopy. Molar conductance measurements in aqueous solution showed that complexes 1, 2 and 3 are ionic in nature. On the basis of spectroscopic data, a square planar geometry was assigned to the complexes involving four N-atoms of the two cyclohexane moieties. Interaction studies of 1 and 3 with CT-DNA were carried using UV/Visible absorption spectroscopy, fluorescence spectrophotometry, cyclic voltammetry and viscosity measurements. Absorption spectral traces reveal 27.7 and 23.3% hyperchromism for complexes 1 and 3, respectively indicative of strong binding to CT-DNA. These results were authenticated by fluorescence quenching experiments and viscosity measurements. The intrinsic binding constants K _b of 1 and 3 are 2.94 × 10⁴ and 2.71 × 10⁴ M^?1, respectively. Early transition metals show preference for O6 position while later ones copper and cobalt prefer N7 position of DNA base guanine. To validate this hypothesis, interaction studies of copper (II) and cobalt (II) complexes were carried out with 5′GMP, which revealed electrostatic interactions are more favored along with hydrogen bonding than coordinate covalent interaction to N7 position of guanine.     

Copper complexes of two isomeric NS2-macrocycles

Two isomeric NS₂-macrocycles incorporating a xylyl group at ortho (o -L) and meta (m -L) positions were employed and their copper complexes (1?C5) were prepared and structurally characterized. The copper(II) nitrate complexes [Cu(L)(NO₃)₂] (1: L = o -L, 2: L = m -L) for both ligands were isolated. In each case, the copper center is five-coordinated with a distorted square pyramidal geometry. Despite the overall geometrical similarity, 1 and 2 show the different ligand conformation due to the discriminated packing pattern. Reaction of o -L with copper(II) perchlorate afforded complex 3 containing two independent complex cations [Cu(o -L)(H₂O)(DMF)(ClO₄)]⁺ and [Cu(o -L)(H₂O)(DMF)]²⁺; the coordination geometry of the former is a distorted octahedron while the latter shows a distorted square pyramidal arrangement. In the reactions of copper(I) halides (I or Br), o -L gave a mononuclear complex [Cu(o-L)I] (4) with a distorted tetrahedral geometry, while m -L afforded a unique exodentate 2:1 (ligand-to-metal) complex [trans-Br₂Cu(m-L)₂] (5) adopting a trans-type square-planar arrangement.     

Copper(I) halide complexes with ethylenediaminium L0(H+)2, N,N,N′,N′-tetraallylethylenediaminium L4(H+)2, and N,N,N,N′,N′-pentaallylethylenediaminium L5(H+). Synthesis and crystal structures of the complexes [L0(H+)2]0.5CuCl2, [L0(H+)2]0.5CuBr1.67Cl0.33, [{L4(H+)2}0.5Cu2Cl3], and [L5(H+)Cu4Br6]

Alkylation of ethylenediamine with allyl bromide in the presence of NaHCO₃ in benzene-ethanol and acetone-ethanol gave N,N,N′,N′-tetraallylethylenediamine L⁴ and N,N,N,N′,N′-pentaallylethylenediaminium bromide (L₅(H⁺)Br₂), respectively. The ac electrochemical synthesis at copper wire electrodes in solutions of copper(II) halide and an appropriate ligand yielded single crystals of Cu(I) complexes with ethylenediaminium ([L⁰(H⁺)₂]_0.5CuCl₂ (I) and [L⁰(H⁺)₂]_0.5CuBr_1.67Cl_0.33 (II)) and its N-allyl derivatives N,N,N′,N′-tetraallylethylenediaminium ([{L⁴(H⁺)₂}_0.5Cu₂Cl₃] (III)) and N,N,N,N′,N′-pentaallylethylenediaminium ([L⁵(H⁺)Cu₄Br₆] (IV)). The crystal structures of complexes I–IV were determined by X-ray diffraction. The isostructural crystals of complexes I and II are triclinic, space group P $ \bar 1 $ , Z = 2. For I: a = 5.936(3), b = 6.387(3), c = 7.126(4) Å, α = 67.82(4)°, β = 72.98(4)°, γ = 67.55(4)°, V = 227.7(2) ų. For II a = 6.110(3), b = 6.657(3), c = 7.309(3) Å, α = 68.40(3)°, β = 72.38(3)°, γ = 67.23(3)°, V = 250.4(2) ų. In structures I and II, the organic cations are between infinite anionic chains (Cu ₂ ^? ) _n . The crystals of π-complex III are triclinic, space group P $ \bar 1 $ , a = 6.851(4), b = 8.729(4), c = 9.960(4) Å, α = 98.25(3)°, β = 102.29(3)°, γ = 107.30(3)°, V = 541.8(5) ų, Z = 2. In structure III, all the four allyl groups are π-coordinated by the metal atoms of four discrete anions Cu₄Cl ₆ ^2? . The crystals of π-complex IV are monoclinic, space group C2/c, a = 15.228(5), b = 17.095(6), c = 20.182(6) Å, β = 92.43(4)°, V = 5249(3) ų, Z = 8. Only two of five allyl groups at the same N atom are coordinated by copper(I) atoms. Structure IV contains a complex inorganic fragment of the formula (Cu₄Br ₆ ^2? ) _n .     

3-(diallylamino)propanenitrile ((C3H5)2NC2H4CN, L) π-complexes with copper(I) ionic salts. Syntheses and crystal structures of compounds [Cu(H+L)ClO4]ClO4 · H2O, [Cu(H+L)BF4]BF4 · H2O, and [Cu(H+L)(H2O)]SiF6 · H2O

Qualitative single crystals of ??-complexes Cu(H⁺L)(ClO₄)]ClO₄ · H₂O (I), Cu(H⁺L)(BF₄)]BF₄ · H₂O (II), and [Cu(H⁺L)(H₂O)]SiF₆ · H₂O (III) are synthesized from solutions of 3-(diallylamino)propanenitrile (L) in propanol, ethanol, and methanol-water acidified with the corresponding acid to pH 3.5?C5 and from the copper(II) salts (Cu(ClO₄)₂ · 6H₂O, Cu(BF₄)₂ · 6H₂O, and CuSiF₆ · 4H₂O) using the alternating-current electrochemical method on copper wire electrodes. The crystal structures of the complexes are determined. All compounds crystallize in the monoclinic crystal system: complexes I and II are isostructural, space group P2₁/n, Z = 4. For compound III, space group P2₁/c, Z = 8. Unit cell parameters: for I a =7.8153(3), b = 16.7824(7), c = 12.4426(5) ?, ?? = 93.410(2)°, V = 1629.1(1) ?³; for II, a = 7.6755(4), b = 16.7119(7), c = 12.3784(6) ?, ?? = 94.354(2)°, V = 1583.2(1); and for III a = 9.826(2), b = 24.009(3), c = 12.061(2) ?, ?? = 91.820(6)°, V = 2843.9(7) ?³. The trigonal pyramidal coordination of the copper atom in complexes I-III is formed by two C=C bonds of the allyl groups of H⁺L, the nitrile N atom of the adjacent cation of the ligand, and the O or F atom of the ClO ₄ ^? or BF ₄ ^? anions. In structure III, the apical position of the pyramid is occupied by the O atom of the water molecule, since the SiF ₆ ^2? anion is considerably remote from the copper(I) atom. However, this anion is bound to the organic cation by hydrogen bonds F??H (2.05?C2.51 ?).     

Three one-dimensional chains with bulky backbone carboxylate ligands: Syntheses,crystal structures,and luminescent properties

To explore the influence of bulky backbone on complexes, three Co(II) and Zn(II) complexes with phenanthrene-9-carboxylate (L¹), 9H-fluorene-9-carboxylate (L²) or biphenyl-4-carboxylate (L³) together with incorporating auxiliary bridging ligad 4,4′-bipyridine (4Bipy), were synthesized and characterized: [Co(L¹)₂(4Bipy)(H₂O)₂]_∞ (I), [Zn(L²)₂(4Bipy)_0.5(4Bipy)_0.5]_∞ (II), and [Zn₃(L³)₄(4Bipy)_0.5(4Bipy)_0.5(4Bipy)_0.5(OH)₂]_∞ (III). X-ray single-crystal diffraction analyses show that complexes I–III both assume one-dimensional (1D) structures by incorporating the bridging 4Bipy (CIF file CCDC nos. 942729 (I), 942727 (II), and 942733 III). In I, mononuclear six-coordinated Co²⁺ ions are linked into a 1D linear chain by 4Bipy. While in II, mononuclear four-coordinated Zn²⁺ ions are linked into a 1D zigzag chain by 4Bipy. But in III, because of the existence of OH^?, hexanuclear Zn(II) can be regarded as a node, then bridge adjacent hexanuclear Zn(II) nodes by almost parallelled three 4Bipy ligands into a 1D linear chain. Finally the 1D chains of I–III are further assembled into an overall three-dimensional (3D) framework via intermolecular H-bonding, π…π stacking, and/or C-H…π supramolecular interactions, respectively. The results indicate that, besides different metal ions Co²⁺ and Zn²⁺ or OH^? anions, the steric hindrance of backbone ligands play an important role in the formation of I–III. Moreover, the luminescent properties of corresponding ligands and their complexes were briefly investigated.     

On the structure of Zn(II) and Cu(II) cyanin complexes in aqueous solution

B3LYP/6-31++G(d,p) optimizations on models for the metal cyanin, Cy, complexes [MCy(H₂O) _n ]⁺, (M = Zn(II), Cu(II); n = 2, 3, 4) in aqueous solution indicate that 4 is the most favoured coordination number in both cases. SP -4 and T -4 geometries are nearly isoenergetic for the former, while SP -4 is the only one obtained for the latter. Anionic cyanin displays higher affinity for Cu(II) than for Zn(II) or Mg(II). The electron density reorganization of cyanin model accompanying the complexation process was analyzed by means of the quantum theory of atoms in molecules. This analysis reveals that: (1) the O4′–M bond is stronger than O3′–M; (2) anionic cyanin displays a dual character between 4′-keto-quinoidal and 3′,4′-dienolate resonance forms; (3) Cu(II) takes more electron density than Zn(II) from Cy^? and water ligands; (4) when the coordination number increases, each ligand (Cy^? or water) transfers less electron density; (5) complex formation modifies the electron density in all the atoms of the ligands, but the largest modifications are displayed within the AC bicycle of Cy^?; and (6) a third part of density lost by the Cy^? ligand is removed from hydrogens.