Megumu Munakata

A new type of multilayer system–silver(I) complexes of polycyclic aromatic compounds

Abstract A new type of silver(I) coordination complex derived from silver(I) perchlorate (or triflate) and polycyclic aromatic compounds is reviewed. Structural studies by single-crystal X-ray diffraction have shown that all compounds contain extended one- to three-dimensional structures in which several metal atoms are sandwiched between two fused polycyclic systems. Special attention is paid to the combination of the plasticity of the metal ion, coordinative versatility of the aromatic ligand, solvent effect and the nature of the counteranions for designing metal complexes with a wide range of infinite frameworks.

Synthesis, crystal structures and magnetic behavior of polymeric lanthanide complexes with benzenehexacarboxylic acid (mellitic acid)

Abstract Three lanthanide complexes with mellitic acid [Ce2{C6(COO)6}(H2O)8]·H2O (1), [Eu2{C6(COO)6}(H2O)8]·H2O (2) and [Yb2{C6(COO)6}(H2O)10]·2H2O (3), have been synthesized and structurally characterized by X-ray crystallography and magnetic properties. The three compounds crystallize in the monoclinic space space P21/n, with unit cell dimensions of: a = 8.627(2), b = 13.218(2), c = 9.650(1) A , β = 95.93(1)° and Z = 2 for 1 ;a = 8.505(2), b = 13.145(1), c=9.536(2) A , β=94.73(2)° and Z=2 for 2 ; a = 8.420(1), b = 9.224(4), c = 16.229(1) A , β = 100.267(9)° and Z = 2 for 3. All three structures consist of an extended network of metal ions, coordinated to mellitate anions and water molecules linked by a complex hydrogen bonding. 1 and 2 are isomorphous with near isostructural [M2{C6(COO)6}(H2O)8] units in which the metal ion is coordinated by four water molecules and five oxygen atoms of the mellitate anions, and each mellitate group involves a tetrakis(bidentate) and bis(unidentate) coordination mode bridging six metal ions forming a three-dimensional framework. In 3 the ytterbium atom is bound with five water molecules and three oxygen atoms of the mellitate anion, and each mellitate moiety bridges four dodecahedral Yb(III) ions yielding a two-dimensional sheet structure. The magnetic susceptibility of 1 and 3 as a function of temperature (5.0–300 K) exhibits a sharp maximum at 6.0 K for both compounds.

Studies of copper(I) olefin complexes. Formation constants of copper olefin complexes with 2,2'-bipyridine, 1,10-phenanthroline, and their derivatives

Preparation de 25 nouveaux complexes [Cu(biL)(olefine)] + (biL=derive de bipy et phenanthroline; olefine=ethylene et derives). Constantes de stabilite

Synthesis, properties and crystal structures of dicopper(I) and disilver(I) complexes with 1,8-naphthyridine (napy): [Cu2(napy)2](ClO4)2 and [Ag2(napy)2](ClO4)2

Abstract Binuclear copper(I) and binuclear silver(I) complexes with 1,8-naphthyridine (napy) have been prepared. The crystal structures of [Cu 2 (napy) 2 ](ClO 4 ) 2 ( 1 ) and [Ag 2 (napy) 2 ](ClO 4 ) 2 ( 2 ) have been determined by using single crystal X-ray diffraction methods. Compound 1 crystallizes in space group P 1 , with a = 8.245(2), b = 10.376(2), c = 5.886(1) A, α = 84.06(2), β = 98.73(2), γ = 108.53(2) o and Z = 1; R = 0.047 for 1247 reflections. The cation of 1 , [Cu 2 (napy) 2 ] 2+ , is binuclear with two napy ligands bridging the two metals. The geometry of each Cu atom is nearly linear. Compound 1 , having a short Cu···Cu distance of 2.506(2) A, reversibly reacts with CO, acetylene and ethylene. Crystals of 2 are monoclinic space group P 2 1 / n with a = 16.017(7), b = 10.427(4), c = 5.752(2) A, β = 99.90(3) o and Z = 2; R = 0.088 for 1321 reflections. The structure of 2 is essentially the same as that of 1 . The Ag···Ag distance of 2.748(2) A is short compared with the corresponding distance in metallic silver 2.88 A.

Synthesis and crystal structure of hexanuclear copper(I) complexes of µ3-pyridine-2-thionate

1H-Pyridine-2-thione (C2H4NSH) reacts with [Cu(MeCN)4]PF6 in acetone to give an orange compound [Cu6(C5H4NS)6], which crystallized in the monoclinic space group P21/n, a= 12.257(2), b= 16.029(2), c= 9.581 (1)A, β= 108.859(9)°, and Z= 2. The single-crystal X-ray structure of the complex shows a distorted octahedral core of six copper atoms, with metal–metal distances ranging from 2.795(1) to 3.160(1)A. Each copper has a trigonal geometry constituted by the two thiolate sulphur and one pyridine nitrogen atoms, as distinct from the common copper–thione sulphur co-ordination in other copper(I)–C5H4NSH complexes. The copper atom deviates highly from the S2N co-ordination plane. The reaction solution was examined by 1H n.m.r. spectroscopy, which reveals the formation of several low-molecular-weight species in the early stages of the reaction.

An S⋯S contact assembled tetranuclear copper(I) complex with sulfur-rich ligand, 4,5-ethylenedithio-1,3-dithiole-2-thione

Abstract A copper(I) complex with 4,5-ethylenedithio-1,3-dithiole-2-thione (C 5 H 4 S 5 ), [Cu 4 I 4 (C 5 H 4 S 5 ) 4 ] ∞ , was synthesized and the molecular structure and packing were characterized crystallographically. The metal center is a stepped Cu 4 I 4 core coordinated by two ligands C 5 H 4 S 5 in different ways. One is bidentate coordinated through the thiocarbonyl group and the thioether group and the other is monodentate coordinated only through thiocarbonyl group. The Cu 4 I 4 clusters are bridged by bidentate C 5 H 4 S 5 molecules to form one-dimensional polymeric chains along the c -axis, and these chains form a three-dimensional network linked by interchain S⋯S contacts. The shortest S⋯S contact distance is 3.257 (2) A. A crystal of the complex is triclinic with space group P 1 , a=11.350(5) A , b=11.854(3) A , c=9.275(5) A , α=97.32(4)°, β=112.35(4)°, γ=67.67(2)°, V=1067.0(9) A 3 , Z=2, R=0.034, R w =0.051 .

Structural studies of copper(I) complexes with ethylene. Crystal structures of [Cu(2,2′-bipyridine)(ethylene)]ClO4 and [Cu(1,10-phenanthroline)(ethylene)]ClO4

Abstract The crystal structures of the complexes [Cu(2,2′-bipyridine)(ethylene)]ClO4 (I) and [Cu(1,10-phenanthroline)(ethylene)]ClO4 (II) have been determined from X-ray diffraction studies. Complex I crystallizes in the triclinic space group, P 1 , with four molecules in a unit cell of dimensions a 10.657(1), b 6.998(1), c 18.251(2) A, α 91.05(1), β 93.35(1), and γ 84.97(1)°. Complex II crystallizes in the monoclinic space group, P21/a, with four molecules in a unit cell of dimensions a 19.981(5), b 10.904(2), c 6.955(1) A, and β 103.90(2)°. Both structures were solved by heavy-atom methods, and refined by block-diagonal least-squares methods. The final R-values for I and II were 0.044 for 2225 observed reflections for I and 0.066 for 2005 observed reflections for II. In both crystals, the CuI ion is coordinated to two nitrogen atoms of 2,2′-bipyridine or 1,10-phenanthroline, and two carbon atoms of ethylene in an approximately planar form. The CC bond distances of the coordinated ethylene molecules, 1.360(13) and 1.346(18) A for I and 1.361(22) A for II, do not show marked lengthening compared with that for free ethylene, and may be explained by dπ(Cu) → dπ (ethylene) back-bonding between the Cu 3dπ orbital and the Rydberg 3dπ orbital of the ethylene molecule.

Syntheses, structures and properties of copper(I) co-ordination polymers with bridging phenazine: construction of one- and two-dimensional structures with π–π stacking of phenazine

Four novel copper(I) phenazine (phz) compounds, [{Cu(phz)(NO3)}∞]1, [{Cu(acr)2(NO3)}2(phz)(H2O)]2(acr = acridine), [{Cu2(phz)(PFO3)}∞]3 and [{[Cu(phz)(MeCN)]2(C16H10)(PF6)2}∞]4(C16H10= pyrene) have been synthesized and their molecular structures and packing have been determined by single-crystal X-ray diffraction methods. The copper atoms in 1 are bridged by phz forming an infinite one-dimensional zigzag chain. These bridging phz molecules have a π–π interaction between neighbouring chains forming an infinite columnar stack of phz molecules. The monomer complex, 2, has an infinite columnar stack of metal-free phz and metal-co-ordinated acr. Copper(I) atoms in 3 are bridged by phz and PFO32– alternately. The resulting one-dimensional chains are connected through a tetradentate, asymmetric PFO32– bridge, with π–π interaction between the phz molecules forming an infinite two-dimensional sheet structure. The backbone of compound 4 is almost the same as in 1 except that a pyrene molecule is intercalated into every other phz stack in a one-dimensional chain. The electrical conductivity of compound 3 and [{[Cu(phz)(MeCN)]2(C16H10)(PF6)2I1.3}∞]5, obtained by iodine doping of compound 4 were 1 × 10–7.6 and 1 × 10–4.7 S cm–1, respectively. The electronic absorption bands of compounds 1, 3 and 4 which appeared around 700 nm are characteristic of copper(I) co-ordination polymers with bridging phz.

Syntheses, crystal structures and autoreduction behavior of antiferromagnetically coupled dicopper(II) oximato complexes

Abstract Four dicopper(II) oximato complexes of 2-[2-(α-pyridyl)methyl]imino-3-butanone oxime (pmiboH) and 2-[2-(α-pyridyl)ethyl]imino-3-butanone oxime (peiboH), [Cu2(pmibo)2](ClO4)2 (1), [Cu2(pmibo)2](NO3)2·CH3OH (2), [Cu2(peibo)2](ClO4)2·CH3OH (3) and [Cu2(peibo)2(H2O)2](ClO4)2 (4), were prepared and characterized structurally and magnetically. All the dicopper(II) oximato complexes have a common cationic structure in which the two Cu atoms are bridged through two NO bridges of the oximato ligand to afford a dinuclear structure. The cation moieties of 1 and 2 consist of one six-membered Cu2N2O2 chelate ring and four five-membered (CuN2C2 and CuNC2N) chelate rings, providing a planar configuration. The cation moieties of 3 and 4 are also composed of three six-membered (Cu2N2O2 and CuNC3N) chelate rings and two five-membered CuN2C2 chelate rings, giving a twisted-boat configuration. The −2J values (H=−2JS1S2) are 835, 825, 550 and 510 cm−1 for 1, 2, 3 and 4, respectively, indicative of a strong antiferromagnetic interaction in the solid state. All the dicopper(II) oximato complexes show seven 1H NMR signals at 23°C in the range of −0.5 to 30 ppm with the linewidths at half-height, Δν1/2 of 60–1500 Hz, which is characteristic of antiferromagnetic species and indicates that the dinuclear structure is kept in solution. The −2J values reflect the degree of distortion from the planarity of the Cu2 framework. The −2J values roughly correlate with the 1H NMR parameters; the larger the −2J values, the smaller the chemical shifts and linewidths. Complexes 1 and 2 were found to undergo an autoreduction reaction in dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMA), and their behaviors were first monitored by UV–Vis and 1H NMR methods.

Crystal structure and magnetic properties of manganese (II) mellitate, [Mn2{C6(COO)6}(H2O)6][Mn(H2O)6]·2H2O with two-dimensional layered structure and three-dimensional hydrogen bonding networks

Abstract The crystal and molecular structure of manganese (II) mellitate, [Mn2{C6(COO)6}(H2O)6][Mn(H2O)6]·2H2O, has been determined by X-ray structure analysis. The complex crystallizes in the monoclinic system, space group C2/c, with cell constants a = 23.298(3), b = 6.456(3), c = 17.072(2) A , β = 101.01(1)° and Z = 4 . The structure was solved and refined to R = 0.029 (Rw = 0.036). There are two types of manganese ions in the structure. Mn(1) is situated on a crystallographic center of symmetry and bound to six water molecules while Mn(2) is coordinated octahedrally by three water molecules and three carboxylate oxygen atoms. The major structure feature is that the polyanion formed by Mn(2) ions and the mellitate hexanions with composition of [Mn2{C6(COO)6}(H2O)6]n2n− possesses a two-dimensional layered structure which is linked through a complex three-dimensional hydrogen bonding associated with the Mn(1) cation [Mn(H2O)6]2+ and the water of crystallization. Analysis of variable-temperature magnetic susceptibility data (5.0–300 K) shows that the complex displays antiferromagnetic exchange.