Synthesis and crystal structure of tetraiminediphenolate diiron(II) macrocyclic complex

The crystal structure of the binuclear tetraiminediphenolate diiron(II) macrocyclic complex [Fe₂(tidf)(CH₃OH)₄](ClO₄)₂ (tidf = tetraiminediphenolate ligand) is presented. The molecular structure (monoclinic, space group C2/c, Z = 4, a = 20.6903(14)Å, b = 11.0827(11) Å, c = 16.0494(15) Å, = 99.911(6) shows two iron(II) cores occupying distorted octahedral geometries with four methanol molecules bound axially. Main equatorial bond distances are 2.050(3) Å for Fe—O1 and 2.067(4) Å for Fe—N1 with a Fe Fe distance of 3.108(1) Å. Contrasting to the monoiron complex the macrocycle does not adopt a bent conformation being nearly coplanar with the maximum deviation from the least-squares plane of 0.18 Å.     

Crystal structure,physical and photophysical properties of a platinum(II) complex coordinated to the biphenyl dianion and cyclooctadiene

The complex, Pt(bph)(COD), where bph is the biphenyl dianion and COD is 1,5-cyclooctadiene, crystallizes in the orthorhombic space groupPbca witha=12.178(4) Å,b=9.693(3) Å andc=25.344(9) Å andZ=8. The Pt–C distances to the olefinic carbon atoms that result from the electron donation of the COD ligand are in the range 2.20(3)–2.27(3) Å and the Pt–C distances to the bonded bph ligand are shorter at 2.01(3)–2.03(2) Å. The lowest energy absorption of the complex is at 383 nm (=1.2×10³). The emission spectrum is structured in fluid solution at room temperature with the emission energy maximum at 537 nm, _cm, and =1.93 s. Temperature dependent emission lifetime measurements result in ak _o value of 2.69×10⁴, a preexponential factor of 2.47×10⁶ and a E₁ value of 324 cm^–1.     

Coordination properties of sulfonyl-N-aminoacids: Crystal and molecular structure of the [Zn(II) (N-(p-toluenesulfonyl)-L-glutaminate)2(H2O)2] complex

The coordination behavior of N-tosyl-L-glutamine (hereafter abbreviated as tsglnH, tosyl =toluenesulfonyl group) toward the Zn(II) ion is investigated by means of structural and spectroscopic techniques. From aqueous solution, at acidic pH the Zn(II) ion separates a compound of empirical formula Zn(tsgln)₂·2H₂O whose crystal structure is determined. The crystal is monoclinic, space group C2, with cell dimensions:a=19.775(5),b=5.3146(3),c=16.543(8) Å, =119.93(3)°,Z=2. The Zn(II) is tetrahedrally coordinated by two symmetry-related tsgln monoanions acting as monodentate carboxylate ligands and two symmetry related water molecules. The Zn–O bond distances are similar while the angles at Zn(II) ion differ significantly from those of regular tetrahedron. The side chain amide group does not participate in metal coordination and forms intermolecular hydrogen bonds.     

The crystal structure of a magnesium(II) ethyl diglyme complex

Dibromo[1,1-oxybix[2-ethoxyethane]-O,O,O]-(tetrahydrofuran-O) magnesium, C₁₂H₂₆O₄MgBr₂, crystallizes in space group Pbca witha=7.402(1),b=16.726(2),c=29.248(3) Å,V=3620.9(12) ų,Z=8. The structure was refined toR=0.083 andR _w =0.055 for 1880 observed reflections. Magnesium is octahedrally coordinated by twocis bromine atoms and four oxygen atoms, three from the meridional ethyl diglyme and one from tetrahydrofuran. The Mg–Br distances are 2.614(3)trans to thf and 2.529(3) Åtrans to the central O of the diglyme. The Br–Mg–Br angle is 97.9(1)° and the Mg–O(thf) distance is 2.196(6) Å. The O–Mg–O bite angles subtended by the diglyme are 75.3(2) and 75.7(2)°. The Mg–O(ethyl diglyme) distances are 2.127(6), 2.136(6), and 2.090(6) Å.     

Preparation and crystal structure of tris(γ-aminobutanoic acid) dioxouranium(VI) diperchlorate

The title compound has been prepared and its crystal structure determined by X-ray crystallography. The compound is monoclinic,P2₁/m,Z=2, witha=9.842(5),b=22.136(6),c=5.939(4) Å, and =108.71(3)°. The complex is ionic and hasC _s symmetry. The uranyl group is equatorially bonded to three bidentate acid molecules in a distorted hexagonal bipyramidal coordination geometry. Bond distances are: U-O(uranyl) 1.76(1) Å, U-O(equatorial) 2.47–2.48 Å, C-O 1.25–1.28 Å, Cl-O 1.40–1.43 Å. The amino acid is zwitterionic with the ionized carboxyl chelate to uranium and the amino terminus protonated. The structure is stabilized by hydrogen bonding.     

Self-assembly in transition metal complexes: structural characterization of a copper histamine nitrate [Cu(II)(him)2(NO3)2]

A new monomeric copper (II) complex with histamine (him), [Cu(II)(him)₂(No₃)₂], has been prepared by the reaction of Cu(NO₃)₂ with histaminium dichloride and its structure was determined by x-ray crystallography. The complex crystallizes in the triclinic system, space group with a = 5.7238(4), b = 8.7094(7), c = 9.2481(11) Å, = 69.693(8), = 73.242(7), = 71.050(7)°, V = 400.84(6) ų, and Z = 1. The structure consists of discrete [Cu(II)(him)₂(NO₃)₂] molecules in which the metal atom is centrosymmetrically coordinated by two histamine ligands forming an equatorial plane with Cu–N(imidazole ring) being 2.032(2) and Cu–N(NH₂ group) being 2.023(2) Å. Two O atoms from nitrate anions coordinate on the elongated axial positions with Cu–O being 2.549(2) Å. In the crystal structure, the molecules are organized by hydrogen bonds forming a two-dimensional network.     

Crystal structure and two-stage hydrolysis of dimethoxo (meso-tetra(4-methoxyphenylporphyrinato))tin(IV), Sn(tmpp)(OMe)2

In this work, we determine the crystal structure of dimethoxo(meso-tetra(4-methoxyphenylporphyrinato))tin(IV), Sn(tmpp)(OMe)₂ (1). Experimental results indicate that the tin atom has an octahedral geometry. The geometry around the tin center has Sn(1)–O(5) = 2.020(6), Sn(1)–O(6) = 2.003(7) Å and an average Sn(1)–N = 2.10(1) Å. The two methoxo groups are unidentately coordinated to the tin(IV) atom. Two-stage hydrolysis of Sn(tmpp)(OMe)₂ in CDCl₃ was observed by ¹H and ¹³C NMR spectroscopy. Compound (1) crystallizes in the space group P2₁/n with a = 14.7492(1), b = 19.2022(3), c = 16.0806(2) Å, = 94.104(1)°, and Z = 4.     

Crystal structure of [Mn2(III)(salpa)2Cl2(H2O)2] (H2salpa = 1-(salicylaldeneamino)-3-hydroxypropane)

The manganese complex, (Mn₂(III)(salpa)₂Cl₂(H₂O)₂], has been prepared and its structure determined using x-ray crystallography. The dimer is a di-₂-alkoxo complex which is a six-coordinate manganese dimer with unsupported alkoxide bridges and a rare example of a chloride- and water-containing manganese dimer. The complex crystallizes in the monoclinic space group P2₁/c with a = 9.315(5), b = 11.130(4), c = 11.637(5) Å, = 104.33(3)°, V = 1169.0(9) ų, and Z = 2. The structure comprises discrete binuclear clusters in which the metal atoms are bridged by two alkoxo oxygens of the salpa^2– ligands. The Mn—O and Mn—N distances are in good agreement with those found for other manganese(III) Schiff base complexes. The Mn—Cl and Mn—O3 distances are 2.585(2) and 2.371(2) Å, respectively, and the Mn ··· Mn distance is 3.001(1) Å. In the crystal, there are two types of hydrogen bonding between the H₂O molecule and the Cl atom with Cl ··· H(H₂O) distance of 2.33(6) (intramolecule: –1 + x, y, –1 + z) and 2.68(6) Å (intermolecule: –1 + x, 0.5–y, –0.5 + z).     

Structure of acetato(meso-5,10,15,20-tetraphenylporphyrinato)gallium(III): Ga(tpp)(OAc)

The title compound, Ga(tpp)(OAc), crystallizes in the space group P2₁/n witha=10.628(2),b=16.176(2),c=20.750(2), Å, =92.64(2)°, andZ=4. The gallium atom has a squarepyramidal coordination geometry formed by the four nitrogen atoms of the porphyrinato group (Np) and the acetate ion. The geometry around the gallium center of the Ga(tpp)(OAc) molecule has Ga–O(1)=1.874(4) Å and average Ga–Np(porphyrin nitrogen)=2.056(4) Å. The acetate group is unidentately coordinated to the gallium (III) atom. Ga-71 NMR spectroscopy provides a complementary method for investigation of the acetate ligand. Combining the calculated value of _c, 29.0 ps, with the measured Ga-71 quadrupolar relaxation time, T_1Q=11.1 s, the quadrupole coupling constant of Ga-71 is 28.1 MHz. This further supports that Ga is covalently coordinated to the acetate and tpp in Ga(tpp)(OAc). The methyl and carbonyl carbons of the acetate group are separately located at 20.4 and 168.8 ppm at 24°C for the Ga(tpp)(OAc).     

A dinuclear cyano-bridged complex based on hexacyanoferrate(III) and samarium(III) nitrate: synthesis and crystal structure

A new complex, [Sm(DMF)₄(H₂O)₄Fe(CN)₆]·H₂O (DMF = N, N-dimethylformamide), has been synthesized and characterized by X-ray single crystal structure and thermogravimetric analyses. The complex crystallizes in the P2₁/n space group, with lattice parameters a = 17.583(4) Å, b = 8.870(2) Å, c = 19.845(6) Å, = 95.98(3)°, V = 3078(1) ų, D _x = 1.679 Mg m^–3, D _m = 1.65(1) Mg m^–3, Z = 4. The molecular structure shows that a cyano-bridged bimetallic structure is obtained. The Sm atom is coordinated by eight oxygen atoms of four water molecules and four DMF molecules and one nitrogen atom of the bridging cyanide ligand. The iron atom assumes approximately an octahedral environment surrounded by six CN ligands. The hydrate water molecule is hydrogen-bonded to one of the O atoms bound to Sm. Each terminal CN ligand of the Fe(CN) ₆ ^3– entity is hydrogen-bonded to some O atoms of water molecules. An infrared spectrum is also reported.     

Synthesis and structure of bis(2,6-dimethylpyrazine)(THF)copper(II) nitrate

Attempts to crystallize Cu(2,6-dmpz)(NO₃)₂ (2,6-dmpz = 2,6-dimethylpyrazine) by reaction of 2,6-dmpz with Cu(NO₃)₂·3H₂O in THF resulted in the synthesis of Cu(2,6-dmpz)₂(NO₃)₂·THF. The compound crystallized in the monoclinic space group C2/c and exists as isolated molecules with distorted square pyramidal geometry: a = 11.609(4) Å, b = 10.415(3) Å, c = 18.256(6) Å, = 108.332(4)°. The 2,6-dmpz molecules coordinate to the Cu ions through the distal (remote from the methyl) nitrogens. The molecules are arrayed in stacks parallel to the b-axis.     

Synthesis,structure and IR characterization of disodium tetra(9,10-dihydro-9-oxo-10-acridineacetato)zincate(II) bis(ethanol) heptahydrate

The synthesis, crystal structure and IR data are reported for Na₂[Zn(CMA)₄]·2EtOH·7H₂O, where CMA^– is the 9,10-dihydro-9-oxo-10-acridinacetate ion. The complex crystallizes in the monoclinic space group P2/n, with cell dimensionsa=17.335(9),b=8.440(5),c=21.875(12) Å, =91.94(5)°,Z=2. The structure was solved by direct methods and refined to a finalR value of 0.0363 for 3022 non-zero reflections. The Zn²⁺ ion occupies twofold axis and is coordinated to four carboxylate ligands, the ZnO₄ tetrahedron is considerably distorted with Zn–O distances of 1.978(3) and 1.961(3)Å. Each Na⁺ cation interacts with two water, one ethanol, and three carboxylate O atoms comprising distorted octahedron. The Zn²⁺ and Na⁺ cations are linked through monooxygen and syn-syn carboxylate bridges forming a trinuclear, mixed-metal cluster. The Zn...Na separation is 3.267(2)Å and Na...Na distance equals 3.520(2)Å. All oxygen bonded H-atoms are utilized in hydrogen bonds. The acridone rings overlap in the crystal with the 3.5 Å interlayer separations. The compound has been characterized by IR spectroscopy.     

Synthesis and crystal structure of a new two-dimensional chromium(III) network through hydrogen bonds

A new chromium(III) complex, [Cr(ox)(bdmpza)(H₂O)], (ox = oxalate dianion and bdmpza = bis(3,5-dimethylpyrazol-1-yl)acetate, respectively), has been synthesized and characterized by X-ray crystallography. This compound crystallizes in the monoclinic space group P2₁/c, with a = 7.008(3) Å, b = 14.229(5) Å, c = 16.497(7) Å, = 101.588(7)°, V = 1611.5(11) ų, Z = 4. The chromium atom has a distorted octahedral environment with different coordination atoms. Bis(3,5-dimethylpyrazol-1-yl)acetate anion is a tridentate ligand, and the oxalate group acts as a chelating bidentate ligand. This compound also forms an infinite two-dimensional network through O–H O hydrogen bonds. The lengths of the hydrogen bonds are 2.765(5) and 2.733(5) Å, respectively.     

Synthesis and structure of tris(N-methylaminoethanoldithiocarbamato)arsenic(III)

The title compound was synthesized by the interaction of arsenic(III)chloride with freshly prepared N-methylaminoethanoldithiocarbamic acid in methanol. The compound crystallized in the triclinic system, space groupP with two molecules per unit cell, the dimensions area=6.509(10)Å,b=14.077(3)Å,c=14.195(3)Å, =64.16(2)^o, =84.67(2)^o and =84.00(2)^o. The molecule is monomeric with three short (mean 2.320(3)Å) and three long (mean 2.927(2)Å) As-S bonds. Asymmetry in the As-S bonds is due to the presence of stereochemically active lone pair on arsenic and the coordination polyhedron deviates from the usual D₃ symmetry to C₃ symmetry. Disorder exists in one of the dithiocarbamate ligands probably due to the O...O interaction arising from the water molecule. The anisobidenticity of the As-S bond distances is as a consequence of stereochemical requirement of the ligand and the lone pair of electrons on arsenic.     

The crystal structure of tris(4-methylpyridine) tricarbonylmolybdenum(0)

The title compound, Mo(4-CH₃C₅H₄N)₃(CO)₃, is monoclinic, P2₁/c, with cell dimensionsa=10.385(1),b=13.572(2),c=15.522(2) Å, =105.08(1)°,Z=4. The complex isfac-octahedral with approximate three-fold symmetry. The Mo–C bond lengths are 1.901–1.904(7) Å, distinctly shorter than in the parent Mo(CO)₆, and the Mo–N bond lengths are 2.297–2.331(5) Å.     

Crystal structure of triaquamaleatostrontium(II) monohydrate, [Sr(C4H2O4)(OH2)3]·H2O

[Sr(C₄H₂O₄)(OH₂)₃]·H₂O is monoclinic, P2₁/n, witha=11.476(2),b=7.027(1),c=12.344(2) Å, =115.74(3)°,V=896.67 ų,Z=4. The Sr atom is surrounded by nine oxygen atoms which come from four different maleate anions and three water molecules. The Sr–O distances range from 2.546(2) to 2.808(2) Å. The C–O distances are equal within the standard deviation 1.263(3) to 1.258(3) Å). In the maleate anion, the planes that contain the carboxylate groups form an angle of 74.44(9)°. Both carboxylate groups deviate significantly from planarity. The different coordination modes of the carboxylate group and the extensive hydrogen bonding present are responsible for the polymeric nature of the structure.     

Synthesis and crystal structure of two vanadium(V) hydroxylamido complexes with amino acid ligands

Two vanadium(V) hydroxylamido complexes with amino acid ligands including Alanine, [VO(NH₂O)₂(Ala)]·2H₂O, and Threonine, VO(NH₂O)₂(Thr), were synthesized and characterized by elemental analyses, IR spectrum, and single crystal X-ray diffraction. The two complexes are seven-coordinated with four nitrogen atoms and three oxygen atoms in pentagonal bipyramidal geometry. The different hydrogen bonds (N–H···O, O–H···O) observed in the two complexes result in the two-dimensional network structure. [VO(NH₂O)₂(Ala)]·2H₂O belongs to monoclinic: space group P2(1)/c, with a = 21.874(13) Å, b = 8.874(5) Å, c = 15.865(9) Å, = 100.423(8)°, V = 3029(3) ų, Z = 12, D _c = 1.678 g/cm³, (MoK) = 1.002 mm^–1, F (000) = 1584, and final R ₁ = 0.0375, wR ₂ = 0.0886 for observed reflections 1189 (IT > I> 2(I)). VO(NH₂O)₂(Thr) is rhombohedral: space group R-3, with a = 21.460(16) Å, b = 21.460(16) Å, c = 11.184(12) Å, = 120°, V = 4461(7) ų, Z = 18, D _c = 1.669 g/cm³, (MoK) = 1.012 mm^–1, F(000) = 2304, and final R ₁ = 0.0356, wR ₂ = 0.0924 for observed reflections 1306 (I > 2(I)).     

Crystal and molecular structure of benzophenone azine: evidence for an Fe(II) carbene intermediate

Benzophenone azine crystallizes in the monoclinic space groupA2/a (No. 15) witha=16.303(3) Å,b=5.4864(2) Å,c=21.973(5) Å, =85.52(2)°,V=1959.4(8) ų, andD _calc=1.22 g cm^–3 forZ=4. The structure was solved by direct methods and refined againstF to a finalR value of 0.047. The unit cell contains four molecules of the title compound; the asymmetric unit consists of half a molecule. Despite the high crystallographic symmetry, the two halves of the molecule arenot related by a center of symmetry; instead, the molecule adopts C₂ symmetry; the molecular C₂ axis is coincident with the crystallographic twofold axis. The formation of benzophenone azine from the reaction of the iron-containing Lewis acid complex [(⁵-C₅H₅)Fe(CO)₂(THF)]⁺ [BF₄]^– and diphenyldiazomethane provides strong evidence for an Fe(II) carbene intermediate.     

Crystal and molecular structure of bis(imazapyr)diaqua copper(II)

The imidazolinone herbicide imazapyr, 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid (H₂imz) interacts with Cu(II) leading to [Cu(Himz)₂(H₂O)₂] which crystallizes in the space group Pbca, with a = 12.5370(3) Å, b = 19.8500(5) Å, c = 22.7720(9) Å, and Z = 8. The Cu(II) atom is octahedrally surrounded by four nitrogen atoms of two Himz^– anions and two water molecules. Each Himz^– acts as a chelating ligand by means of N pyridine and N lactam atoms leading to five-membered chelate rings. The Cu N distances vary from 1.948(4) to 2.299(5) Å while the Cu O are 2.114(5) and 2.256(6) Å. The imidazol N-H are involved in short intramolecular hydrogen bonds with the carboxylate groups. The structure is stabilized by an intermolecular hydrogen-bonded network involving the water molecules and the carboxylate groups.     

Synthesis and structures of two chiral bis(pyrazolyl)borate complexes, [{H<Subscript>2</Subscript>B(4-Mepz)(3,5-Me<Subscript>2</Subscript>pz)}<Subscript>2</Subscript>M], M = Co,Zn

The title compounds are chiral and have similar molecular geometries. The Co complex crystallizes in space group P2₁/c with a = 8.475(4) Å, b = 7.706(8) Å, c = 35.778(9) Å, = 95.779(18) and Z = 4, while the Zn complex crystallizes in space group P2₁/n with a = 8.353(3) Å, b = 20.768(4) Å, c = 13.818(3) Å, = 100.96(2) and Z = 4. The metal atoms are tetrahedrally coordinated to two bidentate ligands with M–N distances in the ranges 1.985(2)–2.018(2) Å (Co) and 1.985(2)–2.008(2) Å (Zn), and N–M–N angles in the ranges 96.07(7)–128.23(7) (Co) and 98.50(8)–125.63(8) (Zn). No agostic bonds are formed. The molecules display C₁ symmetry; geometric considerations indicate that the formation of the other two possible conformers, with C₂ symmetry, is sterically less favorable.