Synthesis, spectral, and single crystal X-ray structural studies on (2,2′-bipyridyl)bis(dimethyldithiocarbamato) zinc(II) and (1,10-phenanthroline) bis(dimethyldithiocarbamato)zinc(II)

Synthesis, spectral, and single crystal X-ray structural studies on (2,2-bipyridyl)bis (dimethyldithiocarbamato)zinc(II) (1) and (l,10-phenanthroline)bis(dimethyldithiocarbamato)zinc(II) (2) complexes are reported in this paper. The complex (1) crystallizes in the orthorhombic lattice, space group Pcca, a = 18.456(3), b = 6.529(2), and c = 17.092(2) Å. The complex (2) crystallizes in the monoclinic space group C2/c, a = 13.372(2), b = 13.850(2), c = 24.680(3) Å, and = 102.71(4)°. IR spectra of the complexes (1) and (2) show the thioureide (C-N) bands at 1489 and 1510 cm^–1, respectively, which are lower than the value observed for the parent bisdithiocarbamate. Reduction in the thioureide stretching frequency is due to the increase in coordination around the zinc ion and the resultant increase in electron density. Thermal studies indicate that the 1,10-phenanthroline adduct is marginally more stable than the other complex. X-ray crystal structures of the two adducts show them to be octahedrally coordinated and monomeric in nature. The Zn-S distances are longer than those observed in the parent bisdithiocarbamate. The thioureide C-N bond distances in (1) and in (2) indicate the partial double bond character. The most important structural changes as a result of the adduct formation are observed in the Zn-S bond distances and S-Zn-S bond angles, in terms of very significant increases in Zn-S bond distances and reductions in S-Zn-S angles, compared to the parent bisdithiocarbamate. The observed changes are indicative of a strong steric force in operation in the adducts rather than electronic effects.     

Bis(2,2′-biimidazoline)bis(isothiocyanato)Metal(II) compounds. Synthesis,characterization and lattice hydrogen bonding for Metal = Mn(II) and Ni(II)

The synthesis, characterization and X-ray structures of two compounds with the general formula trans-M(biz)₂(NCS)₂ (in which biz = 2,2′-biimidazoline and M = Mn(II) for compound 1 and Ni(II) for compound 2) are reported. Both compounds crystallize in the triclinic space group P-1 with a = 8.393(5), b = 8.946(5), c = 7.659(5) Å, α = 104.440(5), β = 106.880(5), γ = 66.180(5)^∘, V = 497.7(5) ų, Z = 1 for compound 1 and a = 8.155(2), b = 8.8190(10), c = 7.480(2) Å, α = 102.259(15), β = 106.135(13), γ = 67.706(14)^∘, V = 474.7(2) ų, Z = 1 for compound 2.Both metal ions show octahedral coordination with the four nitrogen atoms of two biz ligands in the equatorial plane and the two nitrogen atoms of two isothiocyanate anions in the axial positions. The M–N≡C angles are 166.5(2) and 167.7(2) for compounds 1 and 2, respectively. These values are in the usually obtained range for trans-isothiocyanate coordinated compounds. The sulfur atom of each isothiocyanate anion acts as acceptor for the hydrogen bond with the NH group of the biz ligands. In the IR spectrum the vibrations of the thiocyanate anion are observed at 2090 and 776 cm⁻¹ for compound 1 and at 2108 and 778 cm⁻¹ for compound 2, and these values are typical for linear-bond isothiocyanate complexes of transition metals.     

Molecular structure of N-(2-phenylethyl)amide of α-(1,1-ethylenedioxy)-ethyl γ-hydroxybutyric acid (I) and1H NMR spectra of (I) and N-(p-methoxybenzyl)derivative (III)

The spectroscopic and X-ray investigation of the N-(2-phenylethyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are reported. The¹H NMR spectra for the title structure and for the N-(p-methoxybenzyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are given. The N-(2-phenylethyl)amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid, C₁₆H₂₃O₄N, crustallizes in the monoclinic space groupP2 ₁/c witha=21.547(5),b=6.333(2),c=11.822(3) Å and =101.01(2)°. The dioxolane ring has a half-chair conformation with C₂(O3)=2.4° and ||_av=18.2°. The inconsiderable deviations from planarity of the six atoms of the amide group are caused mainly by twist around the C4–N1 bond and out-of-plane bending at the N1 atom ((C4–N1)=4°, X_N =7°, X_c =0.4° ). The amide group plane is nearly coplanar with the phenyl ring. The molecules are connected by two intermolecular hydrogen bonds.     

Crystal and molecular structure,and infrared study of bis(2,2′-bipyridine) [N-(toluene-p-sulfonyl)glycinato-NO] cadmium(II) complex and related compounds

A series of complexes of formula [M(II)(bpy)₂(ArSO₂-N-aminoacidato-NO)]·3H₂O [bpy=2,2-bipyridine, M(II)=Zn(II), ArSO₂-N-aminoacidato-NO=N(toluene-p-sulfonyl)- and N(benzenesulfonyl)-glycinate-NO dianion, hereafter abbreviated as tsgly-NO and bsgly-NO, respectively, M(II)=Cd(II), ArSO₂-N-aminoacidato-NO=tsgly-NO] was separated and investigated by spectroscopic and X-ray methods. The crystal structure of [Cd(bpy)₂(tsgly-NO)]·3H₂O was determined. The compound crystallizes in the monoclinic space groupP2/n,Z=4,a=15.427(4),b=13.580(2),c=15.546(4)Å, =110.97(3),R=0.041,R _w =0.043. The structure consists of monomeric, approximately octahedral [Cd(bpy)₂(tsgly-NO)] units with a N₅O donor atom set, which gives rise to three almost orthogonal five-membered chelate rings. The IR spectra suggest similar environments for all the complexes.     

Synthesis and Structure of bis(β-Diketiminate) Chromium(II) Complexes

Abstract  

The new ligand 2,4-N,N′-bis(napthylamino)-pent-2-ene (L^napth) (1) has been synthesized and crystallizes in space group P2₁2₁2₁ with crystal cell parameters a = 8.196(3) ?, b = 9.119(3) ?, c = 25.746(10) ?, V = 1924.3(12) ?³ and Z = 4. The complexes bis[2,4-pentane-N,N′-bis(napthyl)ketiminato] chromium(II) (2), bis[2,4-pentane-N,N′-bis(isopropylphenyl)ketiminato] chromium(II) (3), and bis[2,4-pentane-N,N′-bis(tertbutylphenyl)ketiminato] chromium(II) (4) were synthesized and structurally characterized. Complex 2, the first complex reported with a bis(napthyl) β-diketiminate ligand, crystallizes in space group P − 1 with crystal cell parameters a = 12.0824(15) ?, b = 12.2462(16) ?, c = 14.8975(19) ?, α = 87.035(2)°, β = 80.615(2)°, γ = 62.756(2)°, V = 1932.9(4) ?³ and Z = 2. Complex 3 crystallizes in space group P2₁/n with crystal cell parameters a = 13.088(3) ?, b = 22.222(5) ?, c = 14.206(3) ?, β = 102.310(4)°, V = 4036.6(17) ?³ and Z = 4. Complex 4 crystallizes in space group P2₁/n with crystal cell parameters a = 20.831(6) ?, b = 11.575(4) ?, c = 21.373(7) ?, β = 107.241(5)°, V = 4922(3) ?³ and Z = 4. The degree of twist between the ligand planes is dependent on the steric bulk of the ligand.     

Crystal Structures and Properties of Bis(2-Aminopyrimidine-N-)-Bis(Thiocyanato-N)Zinc(II) and Catena-[2-Aminopyrimidine-N- (μ-Thiocynanto-S,N)(Thiocyanato-S)Cadmium(II)]

Abstract  

Complexes [Zn(NCS)₂(2-AMP)₂] (2-AMP = 2-aminopyrimidine) 1 and [Cd(SCN)₂(2-AMP)₂]_n 2 are prepared and characterized by X-ray crystallographic methods. 1 crystallizes in the monoclinic, space group C2/c, with a = 13.5761(14), b = 8.3330(10), c = 13.5962(15) ?, β = 99.5450(10)°, V = 1516.8(3) ?³, Z = 4. In 1, the zinc atom is coordinated by four N atoms from two AMP and two NCS⁻. 2 crystallizes in the monoclinic, space group C2/c, with a = 9.7259(11), b = 19.332(2), c = 8.2149(9) ?, β = 99.817(2)°, V = 1522.0(3) ?³, Z = 4. Complex 2 is made up of 1D chains along a-axis. Each Cd is attached to four NCS⁻ bridges and two pendant 2-AMP ligands.     

Synthesis and crystal structure of Nd(III)–Zn(II) complex

A novel heteronuclear complex, [NdZn₂L₆(NO ₃)(phen)₂] (HL = -methylacrylic acid, phen = 1,10-phenanthroline), was synthesized and characterized by elemental analysis, infrared absorption spectra (IR) and its molecular structure was also determined by X-ray structure analysis. The title complex contains a discrete trinuclear ZnNdZn molecule bridged by carboxylate groups between Zn and Nd ions and crystallizes in space group P¯1 with the cell dimensions: a = 13.601(3) Å, b = 16.859(2) Å, c = 12.575(2) Å, = 110.09(1), = 112.21(1), = 81.10(2).     

Crystal and molecular structure of aqua(2,2′-bipyridine)bis(betaine)copper(II) perchlorate monohydrate

A new monomeric copper(II) complex with 2,2-bipyridine (bpy) and betaine (bet), [Cu(byy)(bet)₂(H₂O)](ClO₄)₂ · H₂O, has been prepared and characterized by X-ray crystallography. The complex crystallizes in the triclinic space groupP-1 witha=8.859(2),b=11.191(2),c=14.850(3) Å, =91.41(1), =97.19(1), =91.97(1)°,V=1459.2(7) ų, andZ=2. The structure comprises discrete cations [Cu(bpy)(bet)₂(H₂O)]²⁺ in which the metal atom is coordinated in a distorted square-pyramidal environment by two oxygen atoms from a pair of monodentate carboxylato ligands [Cu–O=1.950(2) Å] and two nitrogen atoms of a bidentate bpy ligand [Cu–N=1.997(3)–2.005(3) Å] on the basal plane, and one aqua [Cu–O=2.267(3) Å] ligand at the apical position.     

Syntheses and Crystal Structures of Two New Cadmium(II) and Nickel(II) Complexes with 1,4-Phenylenediacetate and 2,2′-Bipyridyl-Like Ligands

Abstract  

Two new complexes, namely [Cd(PDA)_0.5(2,2′-bpy)Cl](H₂PDA) (1) and [Ni(PDA)(phen)(H₂O)]₂ (2) (H₂PDA = 1,4-phenylenediacetic acid, 2,2′-bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline), have been synthesized and characterized by elemental analysis, IR spectra and X-ray crystal diffraction. Single-crystal X-ray diffraction analysis shows that complex 1 crystallizes in the triclinic space group P-1 with unit cell dimensions a = 8.760 (4) ?, b = 11.190 (5) ?, c = 13.917 (7) ?, α = 110.383 (5)°, β = 101.736 (5)°, γ = 100.612 (5)°, V = 1202.8 (10) ?³, Z = 2, R ₁ = 0.0314 and wR ₂ = 0.0898. Complex 2 crystallizes in the monoclinic space group P2(1)/n with unit cell dimensions a = 9.911 (3) ?, b = 17.924 (6) ?, c = 10.638 (4) ?, β = 94.998 (5)°, V = 1882.7 (11) ?³, Z = 2, R ₁ = 0.0397 and wR ₂ = 0.1150. In complex 1, Cd(II) ions are alternately bridged by PDA ligands and chloride ions into 1D chains and the PDA ligands display trans-configuration. Complex 2 is a dimer and two Ni(II) ions are linked by two PDA ligands with cis-configuration, resulting in a cyclic structure. In spite of these differences, both in complexes 1 and 2 there are π–π stacking interactions and hydrogen bonding to make them 3D supramolecular frameworks.     

The X-ray crystal structures of bis(l-α-alaninehydroxamato)nickel(II) and bis(l-α-alaninehydroxamato)copper(II)

The structure of twol--alaninehydroxamato (-Alaha) complexes of Ni(II) and Cu(II) have been determined by single-crystal X-ray diffraction methods. The crystals of Ni(-Alaha)₂·2H₂O (I) are monoclinic witha=12.267(4),b=4.798(2),c=10.017(4)Å,=95.48(3)°,Z=2, and space groupP2₁. The crystals of Cu(-Alaha)₂·2H₂O (II) are monoclinic witha=5.073(2),b=11.463(3),c=20.198(5) Å,Z=4 and space groupP2₁2₁2₁. The values of the final residualsR for Ni(-Alaha)₂·2H₂O and Cu(-Alaha)₂·2H₂O are 0.06 and 0.03, respectively. The molecular structures of Ni(-Alaha)₂ and Cu(-Alaha)₂ consist of a square planar and a pentanuclear piramidal, respectively, with the-alaninehydroxamato, (CH₃CH₂(NH₂)CONOH^–), ligands coordinating to metal ion via the N(amino) and the hydroxamic N^– donors.     

Synthesis and Study of New Mesogens II: p-(p′-n-Alkoxycinnamoyloxy)-benzylidene p″ -anisidines (1) and p-(p′-n-Alkoxycinnamoyloxy)- benzylidene anilines (2)

Two new homologous series of liquid crystals viz. p-(p'-n-alkoxycinnamoyloxy) benzylidene p”-anisidines (1) and p-(p'-n-alkoxycinnamoyloxy) benzylidene anilines (2) comprising twenty four mesogens have been synthesized. Both are high melting series of mesomorphs. In the homologous series (1) the nematic mesophase is exhibited from the very first member; however, the first five compounds decompose at high temperatures before passing into isotropic liquid condition. Polymesomorphism is exhibited with the appearance of the smectic mesophase at the octyl derivative and remains up to the last viz. octadecyl homologue. Within polymesomorphic region the nematic mesophase is homeotropic; however, it shows a clear threaded texture where it is the only mesophase shown i. e. in the first seven members of the homologous series (1). The smectic mesophase shows focal conic fan shape texture belonging to smectic-A variety. The nematic-isotropic curve shows descending tendency as the series is ascended-a characteristic of high melting series. The smectic-nematic transition curve rises steeply and shows a levelling off tendency at the octadecyl derivative. In the homologous series (2), no decomposition occurs. The smectic mesophase commences a little early i. e. from hexyl derivative; while polymesomorphism is clearly exhibited up to the dodecyl derivative, the last two homologues are purely smectogens. The usual odd-even effect is observed in case of the nematic-isotropic curve for series (2). The smetic-nematic curve rises gradually and seems to be merging with the falling nematic-isotropic curve at the fifteenth homologue. The mesomorphic ranges in both series are quite wide; however, that of series (1) is wider than one obtained in series (2). Thermal stabilities are good and are in keeping with the molecular characteristics. The textures of the smectic and nematic mesophases are similar to that of the series (1). Both series are comparable with each other and other related series.     

Structure and spectral properties of (O-Cyclohexyldithiocarbonatio-S,S′) bis(triphesnylphosphine) copper(I) complex

The complex [(C₆H₁₁OCS₂)(PPh₃)₂Cu], was synthesized and characterized using IR, UV, and ¹H NMR. The crystal and molecular structure has been determined by X-ray diffraction. The yellow crystal of the complex is triclinic of space group , with parameters a=10.370(2)Å, b=13.530(3)Å, c=14.640(3)Å, =92.60(3)°, =108.00(3)°, =97.70(3)°, and Z=2. In the complex, the central Cu atom is in a distorted tetrahedral environment and chelated by two phosphorus atoms of the TRIPHOS and two sulfur atoms from the O-cyclohexyldithiocarbonate. The cyclohexane ring adopts a chair conformation. The thermal analytical data indicate that the complex begins to decompose at 101°C and stop at 360°C , leaving CuS. IR, UV, and NMR results supported the crystal structure.     

Optical band gap and Raman spectra in some (Bi2O3)x(WO3)y(TeO2)100−x−y and (PbO)x(WO3)y(TeO2)100−x−y glasses

The glasses representing (Bi₂O₃)_x(WO₃)_y(TeO₂)_100?x?y and (PbO)_x(WO₃)_y(TeO₂)_100?x?y systems were prepared. The dilatometric glass-transition temperatures of examined glass samples were found in the region 383–434 °C, the coefficient of thermal expansion varied from 12 to 16 ppm/°C and the density ranged from 6.30₂ to 6.80₈ g/cm³. From the optical transmission measurements of thin glassy bulk samples prepared by a glass blowing, the optical gap values were found in the narrow region 3.21–3.36 eV. For the temperature interval 300–480 K, the values of the temperature coefficient of the optical band gap varied from 3.7 × 10^?4 to 5.24 × 10^?4 eV/K. It is suggested that Raman feature observed at around 350 cm^?1 can be assigned to an overlap of Raman bands attributed to WO₆ corner shared octahedra and to the following three atomic linkages: Bi–O–Te, Pb–O–Te and W–O–Te.     

Crystal and Molecular Structures of 2-Amino-4-Nitrobenzoic Acid and Its Cocrystals with 2,2′-Bipyridine (2/1) and Bis(pyridin-2-yl)ketone (1/1)

Abstract  

The eight-membered {···HOC=O}₂ synthon featured in the crystal structure of 2-amino-4-nitrobenzoic acid (1) is replaced by carboxylic acid···N-pyridine hydrogen bonds in its cocrystals with 2,2′-bipyridine (2/1; 2) and bis(pyridin-2-yl)ketone (1/1; 3) indicating the robust nature of the latter synthon. Disruption of the three-dimensional architecture based on O–H···O and N–H···O(nitro) hydrogen bonds in (1) is evident in the cocrystals which form supramolecular tubes (2) and chains (3) based on O–H···N and N–H···O hydrogen bonding. Compound (1) crystallizes in the monoclinic space group P2₁/n with a = 3.6291(1) ?, b = 7.7339(3) ?, c = 26.561(1) ?, β = 91.385(2)°, and Z = 4. Compound (2) crystallizes in the monoclinic space group C2/c with a = 27.562(3) ?, b = 6.8300(6) ?, c = 12.923(1) ?, β = 110.593(5)°, and Z = 4. Compound (3) crystallizes in the monoclinic space group P2₁/c with a = 3.795(3) ?, b = 12.024(8) ?, c = 35.65(2) ?, β = 92.131(6)°, and Z = 4 (determined from synchrotron data).     

Structural comparisons between Cu(II) and Ni(II) diaza-coupled quasi-aromatic α-amineoxime complexes

Reaction of NioylH and CuoylH with the diazonium salt of sulfanilic acid quantitatively produces diaza complexes by coupling at the C-12 position. X-ray structural study: [Nioyl–N=N–C₆H₄SO₃H]·H₂O; C₁₉H₂₈O₆N₆S₁Ni₁ M _r = 527.23, monoclinic P2₁/c, a = 12.752(3), b = 10.795(3), c = 16.609(3) Å, = 92.46(3)°, V = 2284.2(9) ų, Z = 4, D _x = 1.533(2) mg m^–3 [Cuoyl–N=N–C₆H₄SO₃H]· HCl ·3H₂O; C₁₉H₃₃O₈N₆S₁Cu₁Cl₁, M _r = 604.56, triclinic, , a = 8.4019(8), b = 11.2266(99), c = 14.9370(20) Å, = 84.264(7), = 75.309(8), = 73.024(8)°, V = 1303.0(2) ų, Z = 2, D _x = 1.541(2) mg m^–3. The complexes were isolated from about 0.2 M HCl and had different formulas due to differing protonation. The sulfonic acid proton resides on the diaza nitrogen attached to the C₆H₄ ring and with the copper(II) analogue, protonation also occurs on the intramolecular hydrogen-bond oxygen. Bond distance and angle comparisons are made and related to potential electron delocalization between aromatic rings.     

Crystal and molecular structure of aquabis(2,2′-bipyridine)nitratomanganese(II) nitrate monohydrate

A new monomeric manganese(II) nitrate complex with 2,2-bipyridine (bpy), [Mn(bpy)₂(NO₃)(H₂O)](NO₃)·H₂O, has been prepared and characterized by X-ray crystallography. The complex crystallizes in the triclinic space group witha=9.721(3),b=14.691(5),c=8.578(3) Å, =106.79(3), =96.05(3), =82.55(3)°,V=1159.9 ų andZ=2. The structure comprises discrete cation [Mn(bpy)₂(NO₃)(H₂O)]⁺ in which the metal atom is coordinated by a pair of bidentate bpy ligands [Mn–N=2.261(4)–2.299(4) Å], a unidentate nitrato [Mn–O=2.284(4) Å] and aqua [Mn–O=2.160(3) Å] ligands in a highly distorted octahedral arrangement.     

Preparation and crystal structures of the Ce(IV) β-diketonates, [Ce(tmhd)4] and [Ce(pmhd)4] (tmhd =2,2,6,6-tetramethylheptane-3,5-dionate and pmhd = 1-phenyl-5-methylhexane-1,3-dionate)

The cerium(IV) -diketonate compounds [Ce(-diket)₄] [where -diket = tmhd (2,2,6,6-tetramethylheptane-3,5-dionate) 1, pmhd (1-phenyl-5-methylhexane-1,3-dionate) 2] were prepared by reacting cerium(IV) ammonium nitrate [CAN; Ce(NH₄)₂(NO₃)₆] with the respective Na(-diket) compound in ethanol, and structurally characterized by single crystal X-ray diffraction. Compound 1 crystallizes in the triclinic space group with a = 12.472(4), b = 19.972(5), c = 21.436(3) Å, = 97.05(7), = 90.16(2), = 106.55(3)°, V = 5076(2) ų, Z = 4, T = 150(2) K. Compound 2 crystallizes in the monoclinic space group P2₁/n. with a = 14.817(6), b = 17.123(6), c = 19.146(3) Å, = 105.46(4)°, V = 4682(3) ų, Z = 4, T = 150(2) K. Crystals of 1 contain two independent [Ce(tmhd)₄] molecules, with four chelating tmhd ligands bonded to each metal in a distorted dodecahedral arrangement; the cerium atom in 2 is also bonded to four chelating pmhd ligands but in this case the coordination geometry is closer to square antiprism. Both complexes are air and moisture stable. Sublimation studies reveal that 1 sublimes almost quantitatively, while 2 is comparatively involatile.     

Synthesis, crystal structure, and spectroscopy of (azido-N1)bis(2,2′-bi-imidazoline)copper(II) perchlorate

The compound [Cu(biz)₂(N₃)](ClO₄) (biz = 2,2-bi-imidazoline) has been synthesized and characterized by X-ray crystallography and infrared spectroscopy. In addition, EPR and magnetic measurements have been performed. The compound crystallizes in the monoclinic space group P2₁/c, with a = 9.2716(2), b = 27.6454(4), c = 7.4285(1) Å, = 102.1417(6)°, V = 1861.46(5) ų, and Z = 4. The coordination geometry around the Cu(II) ion is distorted square pyrimidal, with 4 nitrogen atoms of 2 bis-chelating ligand molecules in the basal plane and one nitrogen of the azide molecule in the apical position. The perchlorate ion is noncoordinating. In the infrared the vibrations of the coordinated azide anion are observed at 2050, 1286, and 620 cm^–1, while the vibrations of the free perchlorate anion are observed at 1071, 1035, and 919 cm^–1; Cu—N vibrations are observed at 418 and 336 cm^–1. The molecules are connected in the lattice via relatively strong hydrogen bonding between the N—H groups at the back of the biz ligand and the N1 and N3 atoms of the azide ligand forming layers. No intermolecular magnetic interaction was observed for this compound.     

Crystal structures of bis(cyanido)bis(N,N′-diethylthiourea-κS) mercury(II) and bis(cyanido)bis(N,N′-dipropylthiourea-κS) mercury(II)

Two mercury(II) complexes containing cyanide and, N,N′-diethylthiourea (detu) and N,N′-dipropylthiourea (dprtu) ligands, [(detu)₂Hg(CN)₂] (1) and [(dprtu)₂Hg(CN)₂] (2), respectively, have been prepared and characterized by X-ray crystallography. In the both complexes Hg atom lies on a 2-fold rotation axis, and is coordinated to the sulfur atoms of two thiourea ligands and to two cyanide carbon atoms. Both have a distorted tetrahedral environment with bond angles about the Hg atoms in the range of 93.41(4)°–146.75(19)°. In the crystal structures symmetry related molecules are linked via N-H-N hydrogen bonds resulting in the formation of a two-dimensional network in 1, while in 2 a double stranded one-dimensional chain is formed.     

Crystal and molecular structure of the photocatalyst tris(2,2′-bipyrazine)ruthenium(II) hexafluorophosphate

The X-ray structure determination of the complex tris(2,2-bipyrazine)ruthenium(II) hexafluorophosphate, [Ru(C₈N₄H₆)₃](PF₆)₂, has shown that the compound crystallizes in the monoclinic space group P2₁/c witha=13.459(5),b=23.486(8),c=17.913(10) Å,=139.85(1)°, andZ=4. Each asymmetric unit also contains one dimethylformamide and one water molecule. Least-squares refinement led to an R factor of 0.074 based on 3463 reflections for which I>2(I). The [Ru(C₈N₄H₆)₃]²⁺ cation has no crystallographic symmetry, but the requirements for point symmetry 32 are nearly met. The six Ru-N bond lengths agree within experimental error and have an average length of 2.05(1) Å.