Mikiko Yamamoto

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.

SYNTHESIS AND STRUCTURE OF A THREE-DIMENSIONAL LANTHANUM(III) COORDINATION POLYMER WITH MELLITATE, {La2[C6(COO)6](H2O)9} · 2H2O

Abstract The crystal and molecular structure of a lanthanum(III) mellitate, La2C12H22O23, has been determined by X-ray structural analysis using a combination of direct and heavy atom methods. The complex crystallizes in the monoclinic space group P21/n with unit-cell dimensions of a = 6.723(4), b = 11.368(5), c = 29.813(4) A and β = 95.851(3)°. Block-diagonal least-squares refinement using automated diffractometer-collected data resulted in R = 2.5 and Rw = 3.4. The crystal structure consists of layers perpendicular to the a axis. Each layer is formed by an extended network of lanthanum ions coordinated with mellitate anions and water molecules, and linked through a complex three-dimensional hydrogen-bonding network. Among the six carboxylate groups of the mellitate anion, five form coordination bonds to six lanthanum atoms. The two independent lanthanum ions are both nine-coordinate and the configuration around lanthanum is a tricapped trigonal prism with the La-O bond distances ranging from 2.457 A to ...

A UNIQUE COORDINATION POLYMER CONSISTING OF TWO PARALLEL C5H4S5 MOLECULES BRIDGING TWO SILVER(I) IONS (C5H4S5=4,5-ETHYLENEDITHIO-1,3-DITHIOLE-2-THIONE )

The silver(I) complex with 4,5-ethylenedithio-1,3-dithiole-2-thione (C 5 H 4 S 5 ), [Ag(C 5 H 4 S 5 ) 2 NO 3 ] ∞ , was synthesized and the molecular structure and packing were characterized crystallographically. The Ag atom is coordinated with four ligands through two thiocarbonyl sulfur atoms (CS) and two thioether sulfur atoms of the six-membered ring (–S–), respectively, forming an extremely distorted tetrahedral geometry. This is the first metal complex of TTF or BEDT–TTF analogs, in which the sulfur atom in a five- or six-membered ring directly coordinates to the silver(I) ion. Two parallel C 5 H 4 S 5 molecules are connected by two Ag(I) ions to give a unique infinite chain. The S⋯S contacts of 3.41 A are very strong between two nearby chains along the b axis, generating a two-dimensional network. The crystal of the complex is monoclinic with space group P 2/ n , a =8.701(1), b =8.955(1), c =11.811(1) A, β =91.438(8)°, V =920.0 A 3 , Z =2, R =0.031, R w =0.045. Although the iodine-doped free ligand is an insulator, the iodine-doped complex is a semiconductor ( σ =3×10 −5 S cm −1 ) at room temperature.

Synthesis and crystal structure of two ternary dicopper(I) complexes having the unsymmetrical coordination arrangement bridged by 1,8-naphthyridine (napy). [Cu2(napy)2(Me2CO)](PF6)2·2Me2CO and [Cu2(napy)2(dppm)(CH3CN)](PF6)2

Abstract Two novel ternary dicopper(I) complexes bridged by 1,8-naphthyridine (napy), [Cu2(napy)2(Me2CO)](PF6)2·2Me2CO (1) and [Cu2(napy)2(dppm)(CH3CN)](PF6)2(2), have been prepared and their structures have been determined crystallographically. Complex 1: space group P2 1 la, a=12.281(4), b=21.154(3), c=13.891(3) A , β=112.74(2)°, Z=4, R=0.079 and R w =0.093 . Complex 2: space group Cc, a=19.572(7), b=13.708(7), c=18.457(3) A , β=108.56(2)°, Z=4, R=0.064 and R w =0.066 . On complex 1 two Cu atoms are doubly bridged by two napy ligands to provide a dinuclear structure, which has a close Cu(I)…Cu(I) separation of 2.533(2)A. Two Cu atoms on 2 are also triply bridged by two napy and one dppm ligands to give a dinuclear structure with a close Cu(I)…Cu(I) separation of 2.607(3) A. On these dicopper(I) complexes the most remarkably structural feature is that the coordination environment around each Cu atom is different: complexes 1 has one linear and one T-shaped copper, and 2 has one distorted trigonal and one distortd tetrahedral copper. It was structurally found that the Cu(I)…Cu(I) separation greatly depends on the coordination arrangement around each Cu atom: the Cu(I)…Cu(I) distance should be longer in the order of the coordination arrangements of [two linear coppers]. one linear and one T-shaped copper, two trigonal coppers, one trigonal and one tetrahedral copper, and two tetrahedral coppers.

Synthesis, structure and properties of a linear copper(I) coordination polymer with tetrakis(ethylthio)tetrathiafulvalene

Abstract A new linear coorination polymer composed of copper(I) cations and tetrakis(ethylthio)tetrathiafulvalene (TTC 2 -TTF) molecules has been synthesized by the reaction of copper(I) perchlorate and TTC 2 -TTF in acetone under argon. The compound, [Cu(TTC 2 -TTF)]ClO 4 , was characterized by spectroscopic and X-ray crystallographic methods. It is a 1:1 metal-ligand complex in which each of the copper(I) ions is tetrahedrally coordinated by four sulphur atoms from the bridging TTC 2 -TTF molecules to form coordination polymeric chains which are separated from each other by the perchlorate anions in the crystal. The complex was doped with iodine to afford [Cu(TTC 2 -TTF)] ClO 4 I, which exhibits a conductivity of 6 × 10 −4 S cm −1 at 25°C for a compacted pellet.

Preparation, characterization and X-ray crystal structures of I2 and copper(II) complexes of 2,11-dithia[3.3]paracyclophane

Abstract The crystal structures of dtpcpI4, [CuCl2(dtpcp)(EtPH)] (2) and [CuBr2(dtpcp)(MeOH)] (3), where dtpcp=2,11-dithia[3.3]-paracyclophane, have been determined by X-ray crystallography. Complex 1 contains two crystallographically independent I2dtpcpI2 molecules in the unit cell, each having crystallographical −1(C1) symmetry. The structures of both 2 and 3 consist of a one-dimensional array of copper(II) ions linked via dithia-bridged paracyclophane. While 1 is an electric insulator at room temperature, the iodine oxidation of 2 and 3 produced charge-transfer complexes which gave conductivities 10−5.5 and 10−6.9 S cm−1, respectively. Both 2 and 3 show the typical ESR signals and normal magnetic moments fo a dilute copper(II) ion at room temperature, but exhibit an antiferromagnetic coupling at low temperature through the conjugated π system of the bridging ligand.

Syntheses, structures and properties of linear copper(I) coordination polymers with tetrakis(ethylthio)tetrathiafulvalene and tetrakis(propylthio)tetrathiafulvalene

Two-linear coordination polymers composed of copper(I) cations and tetrakis(ethylthio)tetrathiafulvalene (TTC 2 -TTF) and tetrakis(propylthio)tetrathiafulvalene (TTC 3 -TTF) molecules have been synthesized by the reaction of copper(I) tetrafluoroborate with TTC 2 -TTF and copper(I) perchlorate with TTC 3 -TTF, respectively, in acetone under argon. The compounds, [Cu(TTC 2 -TTF)]BF 4 ( 1 ) and [Cu(TTC 3 -TTF)]ClO 4 ( 2 ), were characterized by spectroscopic and X-ray crystallographic methods. They are 1:1 metal-ligand complexes in which each of the copper(I) ions is tetrahedrally coordinated by four sulfur atoms from the bridging TTC 2 -TTF or TTC 3 -TTF molecules to form coordination polymeric chains. 1 and 2 were doped with iodine to to afford {[Cu(TTC 2 -TTF)]BF 4 }(I 3 ) 0.33 and {[Cu(TTC 3 -TTF)]ClO 4 }(I 3 ) 0.33 , which exhibit conductivities of 2 × 10 −5 and 4 × 10 −5 S cm −1 , respectively, at 25°C for compacted pellets.

Assembly of a mixed-valence Cu(I/II) system coupled by multiple hydrogen bonding through tetrahydroxybenzoquinone

Abstract The synthesis and characterization of a mixed-valence copper complex [CuII(bpy)2Cl]2[CuICl2]2(C6O6H4), where bpy = 2,2′-bipyridine, is described. The structure contains discrete copper(II) cation and copper(I) anion groups. In the cation each divalent copper is linked to two bpy molecules and one chloride ion in a trigonal bipyramidal fashion, whereas in the anion each monovalent copper is linearly bound to two chlorine atoms. The mixed-valence Cu(I/II) system is associated by multiple hydrogen bonding through tetrahydroxybenzoquinone, leading to an infinite chain structure of the complex. The complex was also characterized by spectroscopic studies.

Co-ordinative versatility of 3,5-bis(2-pyridyl)pyrazole in silver and copper compounds

Two silver(I) and one copper(II) complex with 3,5-bis(2-pyridyl)pyrazole (Hbpypz) have been synthesized and their molecular structures determined by X-ray crystallography. In the dinuclear complex [Ag2(Hbpypz)4][CIO4]2·2Me2CO there are two crystallographically independent monomeric units linked by intramolecular hydrogen bonds. In each unit Hbpypz only uses two of its four nitrogen atoms, acting as a typical bidentate chelate ligand. In the polymeric complex {[Ag(Hbpypz)]CIO4}∞ each silver(I) ion is co-ordinated to three nitrogen atoms of two different Hbpypz molecules and each ligand in turn bridges two spearate Ag atoms forming an infinite-chain structure of macrocations with non-interacting CIO4– anions. The tetranuclear complex [Cu4(bpypz)4(CIO4)4]·2H2O consists of two weakly associated dimeric units coupled via intramolecular stacking between the pyridine and pyrazole rings with an average spacing of 3.50 A, which gives rise to charge-transfer absorption bands in the near-UV region. The temperature dependence of the ESR spectrum and magnetic susceptibility indicates the presence of an antiferromagnetic interaction in the system. While Hbpypz is strictly planar in the copper(II) complex, a non-coplanar conformation is observed in both silver(I) complexes, indicative of the unique co-ordinative versatility of the pyrazole derivative.

Synthesis and structural characterization of crown thioether complexes of silver(I) and copper(II)

The crown thioether silver(I) complexes {[Ag{(OH)2[16]aneS4}]NO3}∞1 and {[Ag{(OH)2[16]aneS4}][O2CMe]}∞2 and the copper(II) complex [Cu{(OH)2[16]aneS4}][ClO4]23, where (OH)2[16]aneS4= 1,5,9,13-tetrathiacyclohexadecane-3,11-diol, have been prepared by reaction of (OH)2[16]aneS4 with the appropriate metal salt. The two silver structures are not isomorphous. Complex 1 crystallizes in the monoclinic space group C2 with a= 13.500(4), b= 9.178(2), c= 8.695(4)A, β= 121.99(2)° and Z= 2. Silver(I) is tetrahedrally bound with four thioether group from four symmetry-related macrocycles and each ligand molecule in turn co-ordinates to four separate silver(I) ions in an exodentate fashion to yield a three-dimensional tetrahedral polymeric network. Complex 2 crystallizes in the orthorhombic space group Pccn with a= 14.121(9), b= 17.203(8), c= 15.940(3)A and Z= 8. It contains two types of crystallographically different silver(I) ions, both of which are co-ordinated by four sulfur atoms from four symmetry-related macrocycles in a rather distorted-tetrahedral fashion. The silver atoms are in a two-dimensional sheet arrangement interconnected by the macrocycle. Complex 3 crystallizes in the monoclinic space group P21/c with a= 7.820(2), b= 13.853(2), c= 9.627(2)A, β= 90.85(2)° and Z= 2. The molecule is a discrete monomer in which the tetradentate macrocycle is in the endodentate conformation with four thioether donors in a precisely square-planar arrangement around the copper.