In situ assembly of a host–guest linked,mixed valence copper(II)–copper(I) coordination polymer [Cu(1,2-en)2(μ3-I)2Cu2(μ2-I)2]n via partial reduction of copper(II) under ambient conditions

A 2-D coordination polymer, [Cu(1,2-en)₂(μ₃-I)₂Cu₂(μ₂-I)₂]_n (1), was formed at room temperature by in situ insertion of [Cu(1,2-en)₂]²⁺ guests into 1-D chains of a [Cu₂I₄]^2? host [1,2-en?=?1,2-diaminoethane]. The structure of the complex was confirmed by single-crystal X-ray diffraction study. The shortest copper(I)–copper(I) distance within the complex is 2.89?Å.     

Synthesis and Structure of Acetonitrile Solvates of Copper(II) Monofluoroacetate and Silver(I) Trifluoroacetate, [Cu2(CH2FCOO)4· 2CH3CN](CH3CN) and Ag3(CF3COO)3(CH3CN)2

Compounds [Cu₂(CH₂FCOO)₄· 2CH₃CN](CH₃CN) (I) and Ag₃(CF₃COO)₃(CH₃CN)₂(II) were synthesized and studied by X-ray structural analysis. Crystals Iare monoclinic, space group C2/c, a= 27.854(6), b= 8.286(2), c= 19.428(4) Å, = 106.82(3)°, V= 4292(2) ų, Z= 8, R ₁= 0.0426; crystals IIare triclinic, space group , a= 8.676(2), b= 9.819(2), c= 11.961(2) Å, = 95.27(3), = 109.59(3)°, = 104.60(3)°, V= 911.4(3) ų, Z= 2, R ₁= 0.0252. Structure Iis composed of the structural units (lanterns) typical of copper(II) carboxylates. The presence of an additional acetonitrile molecule noncoordinated by the copper atoms makes it possible to consider compound Ias a lattice clathrate. Structure IIhas no analogs among the silver carboxylates. It simultaneously contains silver atoms with coordination numbers varying from 2 to 4.     

Crystal structures of the selenium- and bromo-bridged copper(I) dimers [Cu2(μ2-Br)2(SePPh3)2 · (NCCH3)2] and [Cu2I2(μ3-dppm-Se,Se)2] · 2CH3CN

Reactions of copper(I) halides with Se-donor ligands, namely, triphenylphosphine selenide (Ph₃PSe) and bis(diphenylselenophosphinyl)methane (dppm-Se,Se) yielded bromo-bridged [Cu₂(μ₂-Br)₂(SePPh₃)₂(NCCH₃)₂] (1), and selenium-bridged, [Cu₂I₂(μ₃-dppm-Se,Se)₂]?· 2CH₃CN (2) dimers, whose crystal structures are described. Acetonitrile stabilizes 1 by coordinating and helps to stabilize the packing in crystals of 2.     

Synthesis and structure of a tetranuclear copper(II) 3,5-di-tert-butylcatecholate pyridine complex, [Cu(DTBC)Py]4 · 2CH3CN

The tetranuclear copper(II)-catecholate complex, [Cu(3,5-di-tert-butylcatecholate) (pyridine)]₄ · 2CH₃CN has been isolated from the reaction between Cu(0), pyridine and 3,5-di-tert-butyl-o-benzoquinone in acetonitrile solution in nearly quantitative yield. Brown crystals of C₈₀H₁₀₆N₆O₈Cu₄ are orthorhombic, space group P2₁2₁2₁, with a = 13.395(5), b = 24.287(11), c = 24.918(11) Å, Z = 4. The crystal structure determination allows for the cluster to be formulated as four square planar Cu(II) ions, each bonded to two oxygens of chelating catecholate, a pyridine nitrogen and a bridging oxygen from a neighbouring catecholate. The Cu Cu distances range from 3.152(1) to 3.572(1) Å. The tetranuclear complex exhibits an approximate parallel stacking of two pairs of coordination planes that is suggestive of a through-space pathway for antiferromagnetic interaction. It may also have a bearing on the observed catalytic oxidation by O₂ in solution.     

Synthesis,characterization and crystal structure determination of mononuclear and dinuclear copper(II) carboxylates: [Cu(Hdpa)2(en)] and [{Cu2(μ-na)4(CH3OH)2}·2CH3OH]

Two new copper complexes [Cu(Hdpa)₂(en)] (1) and [{Cu₂(μ-na)₄(CH₃OH)₂}·2CH₃OH] (2) (where en is ethylene diamine, Hdpa is 2′-carboxy-[1,10-biphenyl]-2-carboxylate anion and na is 1-naphtalenecarboxylate) have been synthesized and their crystal structures were determined by X-ray crystallography. Complex 1 was prepared from the reaction of Cu(NO₃)₂·3H₂O with ethylene diamine and 2,2′-biphenyldicarboxylic acid in a mixture of water and methanol and complex 2 was prepared from the reaction of CuSO₄·5H₂O with 1-naphtalenecarboxylic acid in methanol. The two complexes were characterized by IR, UV–vis, luminescence and elemental analysis. Moreover, complex 2 was characterized by EPR spectroscopy and thermogravimetric analysis. Complex 1 is a monomer and complex 2 is a dimer with a paddle-wheel structure; both structures are without precedent in the literature.     

Poly­[copper(II)-μ-pyrazine-μ3-squarato]

In the structure of the title compound, [Cu(C₄O₄)(C₄H₄N₂)]_n, each copper cation is surrounded by three squarate (3,4-di­hydroxy-3-cyclo­butene-1,2-dioate) anions and two pyrazine ligands, all of which are located in special positions. The copper cation and all atoms of the squarate anion are located on a mirror plane, whereas the pyrazine ligand is located around a mirror plane which is perpendicular to the ring plane. The cations are connected via the squarate anions and the pyrazine ligands, forming sheets parallel to (001).     

μ-phenoxo-bridged binuclear copper(II) complexes

Summary Two -phenoxo-bridged binuclear copper(II) complexes, [Fsal(GG)₂Cu₂Cl₃]·H₂O (1) containing an exogenous chloride-bridge and [Fsal(GG)₂Cu₂(OH)](ClO₄)₂·H₂O (2) containing an exogenous hydroxide-bridge, where {Fsal(GG)₂ = 2,6-bis[N-(acetylglycine)-imino-methylene]-4-methylphenol}, were synthesized. The complexes were characterized be several spectroscopic methods. According to variable temperature magnetic susceptibility measurements (4–300 K), the hydroxide-bridged complex (2) has a weak antiferromagnetic spin exchange integral (J =- 23.6 cm), while the chloride complex (1) has an unusual weak ferromagnetic spin exchange integral (J = + 30.9 cm); both complexes have similar optical spectra in the aqueous solutions.     

Synthesis, Structure and Properties of a Copper Complex Cu2(μ-PhCOO)2(μ-CH3COO)2(CH3OH)2

The title complex Cu2(μ-PhCOO)2(μ-CH3COO)2(CH3OH)2 1(C20H24Cu2O10, Mr=structure was determined by X-ray diffraction method. Complex 1 belongs to orthorhombic, space group Pbca with a = 13.083(6), b = 8.078(4), c = 21.566(2)(A), V = 2279(2) (A)3, Z = 4, Dc= 1.607g/cm3, F(000) = 1128,μ(MoKa) = 1.918 mm-1, the final R = 0.0506 and wR = 0.1382. Each Cu(Ⅱ)ion is coordinated by five oxygen atoms from two benzoic acids, two acetic acids and one methanol molecule in a slightly distorted square pyramidal environment. The title molecules construct a 2-D complex 1 displays strong emissions. IR and TG-DTA studies are also presented.     

Novel negatively charged cyanocuprate(I) host [Cu4(CN)7]3− built of tetrahedral Cu(I) coordination centers: Crystal structure of [{NH2(CH2CH2)2NCH2CH2NH2}2H][Cu4(CN)7]

The title inclusion compound [{NH₂(CH₂CH₂)₂NCH₂CH₂NH₂}₂H][Cu₄(CN)₇] was obtained as single crystals from an aqueous solution containing CuCN, KCN, andN-(2-aminoethyl)piperazine. It crystallizes in the monoclinic space groupP2/n,a = 12.3829(9),b = 8.5970(9),c = 12.6633(7) Å, = 109.984(5)°,z = 2,R = 0.035 for 2921 independent reflections. The inclusion structure is composed of the hydrogen-bonded dimeric onium guest [{NH₂(CH₂CH₂)₂NCH₂CH₂NH₂}₂H]³⁺ and the negatively-charged three-dimensional host [CU₄(CN)₇]^3– in which the CN-bridged framework Cu(I) atoms are all tetrahedral. A polyacene-like one-dimensional array of hexagons cornered by Cu(I) atoms and edged by -CN- linkages is arrayed in parallel to theb axis and stacked approximately along the c axis. The Cu(I) corner shared in the one-dimensional array extends an N-coordinate CN group along the c axis to a pair of unshared Cu(I) corners for which the C end behaves as a bifurcated ligand to build up the three-dimensional host structure. The cavity is composed of two networks of the hexagons at the top and bottom and pillared by six >CN- groups and accommodates a dimeric guest ofN-(2-aminoethyl)piperazinium cations protonated at each 4-N with the cations being hydrogen-bonded to each other through the 2-NH₂ groups sharing another H⁺.Presented at the Sixth International Seminar on Inclusion Compounds, Istanbul, Turkey, 27–31 August, 1995.     

1,2,4-Triphospholyl gold(I) and copper(I) complexes: synthesis,crystal and molecular structures of [Cu(PMe3)2(μ-P3C2tBu2)(μ-I)Cu(PMe3)2], [Cu(PMe3)2(μ-P3C2tBu2)2Cu(PMe3)2] and [Au(η1-P3C2tBu2)2][Au(PEt3)2]

Treatment of K(P₃C₂^tBu₂) with Cu₂I₂ and PMe₃ gave the binuclear complex [Cu(PMe₃)₂(μ-P₃C₂^tBu₂)₂Cu(PMe₃)₂] via the isolated intermediate compound [Cu(PMe₃)₂(μ-P₃C₂^tBu₂)(μ-I)Cu(PMe₃)₂]. The reaction of K(P₃C₂^tBu₂) with [AuCl(PEt₃)] on the otherhand gave the cation:anion complex [Au(PEt₃)₂][Au(η¹-P₃C₂^tBu₂)₂]. All complexes were fully characterised by multinuclear spectroscopy and single crystal X-ray diffraction studies.     

Tetranuclear azido-bridged copper(II) complex [Cu4(μ-salpn)2(μ1,1-N3)2(N3)2(H2O)2]: Synthesis,characterization and crystal structure

The reaction of salpnH₂ Schiff-base ligand (salpnH₂ = N,N′-bis(salicylidene)-1,3-propylenediamine) with Cu(NO₃)₂·3H₂O and a large excess of NaN₃ (1:2:8 molar ration), lead to the formation of [Cu₄(μ-salpn)₂(μ_1,1-N₃)₂(N₃)₂(H₂O)₂] (1), which has been successfully obtained and characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction. The strong absorption band at about 2000–2100 cm^?1 and at 1597 cm^?1 regions of the IR spectrum of 1 clearly proves the presence of the both end-on (EO) bridging and terminal azido ions and CN (azomethine) groups, respectively. Single-crystal X-ray analyses revealed that the copper atoms are bridged alternately by end-to-on (EO) azido and phenoxo-salpn ligands in the prepared tetranuclear copper(II) complex [Cu₄(μ-salpn)₂(μ_1,1-N₃)₂(N₃)₂(H₂O)₂] (1).     

Electronic state dependence of the ion-molecule reaction CH(3)CN(+) + CH(3)CN → CH(4)CN(+) + CH(2)CN: threshold electron-secondary ion coincidence (TESICO) and direct ab initio molecular dynamics study

The ion-molecule reaction, CH(3)CN(+) + CH(3)CN → CH(3)CNH(+) + CH(2)CN, has been investigated using the threshold electron-secondary ion coincidence (TESICO) technique. Relative reaction cross sections for two microscopic reaction mechanisms, i.e., proton transfer (PT) from the acetonitrile ion CH(3)CN(+) to neutral acetonitrile CH(3)CN and hydrogen atom abstraction (HA) by CH(3)CN(+) from CH(3)CN, have been determined for two low-lying electronic states, (2)E and (2)A(1) of the CH(3)CN(+) primary ion. The cross section for PT of the (2)A(1) state was smaller than that of the (2)E state, whereas that of HA are almost the same in the two states. Ab initio calculations showed that the dissociation of the C-H(+) bond of CH(3)CN(+) is easier in the (2)E state than that in the (2)A(1) state. The direct ab initio molecular dynamics (MD) calculations showed that two mechanisms, direct proton transfer and complex formation, contribute the reaction dynamics.     

STRUCTURAL STUDIES OF THE COPPER(II) ACETATE COMPLEXES Cu(o2CCH3)2(pyridine)3 AND Cu6(μ-O2CCH3)4(μ4-O2CCH3)2(μ-OCMe3)6

Abstract

[Cu(O₂CCH₃)₂]₂, 1, reacts with pyridine to form violet-blue Cu(O₂CCH₃)₂(pyridine)₃, 2, in > 90% yield. 2 crystallizes from pyridine with a distorted square-pyramidal geometry around copper with the monodentate acetate ligands located diagonally in the basal positions. 1 reacts with Bi(OCMe₃)₃ in THF to form blue Cu₆(μ-O₂CCH₃)₄(μ₄-O₂CCH₃)₂(μ-OCMe₃)₆, 3. 3 crystallizes from THF/hexanes with a hexagon of copper atoms linked by six doubly-bridging tert-butoxide ligands, four doubly-bridging bidentate acetates, and two quadruply-bridging bidentate acetate ligands.     

Synthesis, characterization and crystal structure of tetranuclear copper(II) complex [Cu4(μ-Salophen)2(μ1,1-N3)2(N3)2] with alternating μ1,1-azido and phenoxo bridges

Tetranuclear copper(II) complex [Cu₄(??-Salophen)₂(??_1,1-N₃)₂(N₃)₂] (I) has been synthesized from the reaction of Cu(NO₃)₂ · 3H₂O with the Schiff-base ligand salophen condensed from salicylaldehyde and 1,2-phenylenediamine at the presence of a large excess of NaN₃, which has been characterized by elemental analyses, FT-IR spectroscopy, and single-crystal X-ray diffraction. X-ray diffraction studies show that I is a tetranuclear Cu(II) complex with a pair of end-on (EO) azido ions bridging the copper(II) ions in a central Cu(??_1,1-N₃)₂Cu core and one phenoxo bridging the copper(II) ions in a Cu(??-Salophen)Cu core. All copper(II) ions in I are four coordinated and adopt approximate square planar coordination geometry.     

CRYSTAL AND MOLECULAR STRUCTURE OF (μ-SPh) (μ-SCH2CH2CN)Fe_2 (CO)_6

<正> The crystal and molecular structure of (μ-SPh)(μ-SCH2CH2CN)Fe2-(CO)5 has been determined by X-ray diffraction method. The crystals of this complex are triclinic, space group P1,with a=ll.175(1), b=ll.877(2), c= 15.640(2)1,α=106.20(1),β=103.15(1),γ=98.46(1)°; Z=4; Dc=1.67g/cm3. The final structure refinement converged with unweighted and weighted R factors of 0.028 and 0.034 for 2853 observed unique reflections.     

Study of allylic rearrangement in (μ-H)Os3(μ-O=CNRCH2CH=CH2)(CO)10 (R=H or CH3) clusters

The migration of the double bond in the allylcarboxamide ligands of (μ-H)Os₃(μ-O=CN RCH₂CH=CH₂) (CO)₁₀ (R=H (1) or CH₃ (2)), (μ-D)Os₃(μ-O=CNDCH₂CH=CH₂) (CO)₁₀, and (μ-H)Os₃(μ-O=CNHCD₂CH=CH₂)(CO)₁₀ clusters was studied by¹H,²H, and¹³C NMR spectroscopy. Neither μ-D nor ND groups in the deuterated complexes are directly involved in prototropic processes of allylic rearrangement. Initially, the deuterium atom of the CD₂ group migrates to the ψ-carbon atom of the allyl fragment to form the −CD=CH-CH₂D propenyl moiety, in which the deuterium and hydrogen atoms are gradually redistributed between the ψ-and β-carbon atoms. The triosmium cluster complexes containing the bridging carboxamide ligands O=CNRR' catalyze the allylic rearrangement ofN-allylacetamide. Based on the data obtained, the probable scheme of the allylic rearrangements in clusters1 and2 was proposed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2182–2186, November, 1999.     

Complexation of copper(II) with 2′,2′-dialkyl-para-tert-butylbenzohydrazides

The complexation of copper(II) with 2′,2′-dimethyl-, 2′,2′-dibutyl-, and 2′,2′-diisobutyl-para-tert-butylbenzohydrazide in water-ethanol media was studied. The reagents (HL) formed [Cu(HL)]²⁺ and [Cu(HL)₂]²⁺ cationic complexes in a weakly acidic medium and uncharged CuL₂ complexes in an alkaline medium. logK _st was calculated for these complexes. The effect of 2′,2′-alkyl radicals on the stability of the complexes was considered. The obtained results were compared with data on the complexation of copper(II) ions with 2′,2′-dialkylbenzohydrazides.     

Co-ordination of copper and silver by [Co2{μ-C2(CH2SCH2CH2)2S}(CO)6]

The thiamacrocycle [Co₂{μ-C₂(CH₂SCH₂CH₂)₂S}(CO)₆] reacts with Ag[BF₄] and PPh₃ to afford the fluxional compound [Co₂{μ-C₂(CH₂SCH₂)₂S}(CO)₆(AgPPh₃)][BF₄], the structure of which has been established by X-ray crystallography, and with [Cu(CH₃₋CN)₄][PF₆] to afford [Co₂{μ-C₂(CH₂SCH₂CH₂)₂S}(CO)₆(CuCH₃₋CN)][PF₆], which undergoes phosphine sustitution.