Structures of three halo(tetramethylethylenediamine)copper(I) complexes

The X-ray crystal structures of three halo(tetramethylethylenediamine)copper(I) complexes have been determined. (TMED)₂Cu⁺CuCl ₂ ^– (I) crystallizes in monoclinic space groupP2₁/n with lattice constantsa=9.332(9),b=15.126(7),c=14.49(1) Å,=96.95(7)°. (TMEDCuBr)₂ (II) crystallizes in monoclinic space groupP2₁/c with lattice constantsa=12.064(5),b=11.888(6),c=15.841(6) Å,=113.97(3)°. (TMED CuI)₂ (III) crystallizes in monoclinic space groupP2₁/c with lattice constantsa=12.401(6),b=12.159(6),c=15.412(9) Å,=109.12(4)°. Compound (I) is a molecule exhibiting two discrete environments for copper(I). The cation is a pseudotetrahedral monomer and the anion a linear monomer. Both (II) and (III) are dimers with asymmetrically bridging bromine and iodine atoms, respectively. Distortions from tetrahedral geometry are observed about the copper atoms in (II) and (III).     

The syntheses and crystal structures of two chromium(III) and molybdenum(III) coordination compounds with 4-ethylpyridine

The structures of trichlorotris(4-ethylpyridine)chromium(III), [CrCl₃(C₇H₉N)₃] (I), and trichlorotris(4-ethylpyridine)molybdenum(III), [MoCl₃(C₇H₉N)₃] (II), consist of neutral molecules where three 4-ethylpyridine and three chloro ligands coordinate to the metal with a meridional configuration. Compound I crystallizes in a trigonal space group P3₁ with a = 11.515(2) Å and c = 15.378(3) Å. Compound II crystallizes in a monoclinic space group C2/c with a = 24.200(3) Å, b = 18.089(3) Å, c = 22.6004(7) Å and = 106.7137(6)°.     

Group 6 metal carbonyl complexes of a bulky phosphine: The crystal structures of tris(trimethylsilyl)phosphine-M(0)pentacarbonyl, M = chromium, molybdenum, and tungsten

The crystal structures of M(P{Si(CH₃)₃}₃)(CO)₅, M = Cr (1), Mo (2), and W (3), have been determined. Crystal data for 1, trigonal crystal system, space group = P3₁, a, b = 9.2118(6) ?, c = 22.416(3) ?, V = 1647.3(2) ?³, Z = 3; for 2, trigonal crystal system, space group = P3₂, a, b = 9.3394(3) ?, c = 22.7375(12) ?, V = 1717.56(12) ?³, Z = 3; trigonal crystal system, space group = P3₂, a, b = 9.3147(5) ?, c = 22.6955(16) ?, V = 1705.33(18) ?³, Z = 3. All three structures show distorted octahedral coordination environments around the metal center and exhibit especially long M–P bond distances, illustrating the unique steric and electronic properties of this bulky phosphine ligand. The ³¹P{¹H} NMR spectra of the compounds are also reported.     

Influence of counter-anion on the coordination geometry of manganese(II) complexes with methyl-2-pyrazinecarboximidate ligand

Two new complexes of [Mn(2-MPyzCI)₂Cl₂].H²O (1) and [Mn(2-MPyzCI)₂(H₂O)₂](NO₃)₂ (2) were synthesized from the reaction of MnX₂.4H₂O (X=Cl^? and NO₃^?) with 2-cyanopyrazine in methanolic solution. The chelating methyl pyrazine-2-carboximidate (2-MPyzCI) ligand is formed via the methanolysis of 2-cyanopyrazine. Although coordination environment around manganes(II) ions is similar, but these complexes are different in geometrical position of 2-MPyzCI ligands. As both compounds are synthesized under the same reaction conditions, the only difference between these two complexes are counter ions and changing of geometrical position of ligands can be considered as a result of influence of the counter-anions on the molecular structures.     

Fluoro-containing complexes of chromium (III). II. Crystal structure oftrans-difluorodiaquo-ethylenediaminechromium(III) chloride

The results of an X-ray structure determination of one of the three possible chloride salts of [Cr(en) F₂(OH₂)₂]⁺ show the two fluoro ligands to betrans to each other. The purple crystals are monoclinic in the space groupC2/c-C _2h ⁶ , witha=11.409(3),b=9.319(2),c=10.260(3) Å,β=128.73(2)° andD _c =1.73 g cm^?3 forZ=4. Least-squares refinement based on 1341 independent observed reflections resulted in a finalR of 0.026. The molecule lies on a crystallographic two-fold axis, and the Cr-F, Cr-N, and Cr-O bond lengths are 1.885(1), 2.044(2), and 1.997(2) Å respectively. It is suggested that the ill-defined shoulder in the visible electronic spectrum of this complex is indicative of atrans dihalo geometry.     

Tris(triphenylphosphine)rhodium cyano and triphenylcyanoborate complexes: Structures and a DFT study

The structures of [Rh(CN)(PPh₃)₃](EtOH) (1), [Rh(NCBPh₃)(PPh₃)₃] (2), and [Rh(CNBPh₃)(PPh₃)₃] (3) are reported together with a density functional theory (DFT) study of the model compounds [Rh(NCBH₃)(PH₃)₃] and [Rh(CNBH₃)(PH₃)₃]. Compound 1 crystallizes in space group Pc with a = 10.4798(15) Å, b = 12.5410(18) Å, c = 19.974(3) Å and = 112.215(6)°; compound 2 crystallizes in space group with a = 12.929(2) Å, b = 14.362(2) Å, c = 17.575(3) Å and = 92.544(3)°, = 90.214(3)°, = 113.831(3)°; compound 3 crystallizes in space group with a = 12.915(2), b = 14.296(2), c = 17.664(3) Å and = 92.469(3)°, = 90.088(3)°, = 113.768(3)°. All three complexes show slight tetrahedral distortion from ideal square planar geometry (largest for 1). Differences in the reactivity and stability of 2 and 3 are interpreted according to the results of a density functional theory study.     

The effect of organic linkers on the supramolecular structures of two new Ni(II) cyclen complexes (cyclen = 1,4,7,10-tetraazadodecane)

Two new nickel(II)(cyclen) coordination polymers, {[Ni(cyclen)·(bipy)]·(ClO₄)₂}_n (1) and [Ni(cyclen)]₂·(squa)·(ClO₄)₂ (2) have been synthesized and characterized structurally, where cyclen is 1,4,7,10-tetraazadodecane. Compound 1 crystallizes in the monoclinic system, space group C2/c, with a = 10.5339(17) ?, b = 14.565(2) ?, c = 16.133(3) ?, β = 102.799(2)°, V = 2413.4(7) ?³. Compound 2 crystallizes in the orthorhombic system, space group P _{nm a} with a = 25.722(3) ?, b = 11.1168(12) ?, c = 11.4580(13) ?, V = 3276.3(6) ?³. In both compounds, each Ni^II center is in a distorted octahedral coordinated environment with four N_cyclen atoms and two N_pyridine atoms from 4,4′-bipyridine linker for 1 and two O_aqueou atoms from the coordinated water for 2, respectively. The complex 1 exhibits infinite zigzag 1D chains by linking of 4,4′-bipyridine coordinated. In complex 2, 2D sheet supramolecule generated through self-assembling by hydrogen bond.     

Structures of 355-1355-1355-1tricarbonyl: structural evidence for the near-electroneutrality of the dialkylacetal substituent

The structures of the (benzene dialkylacetal)tricarbonyl chromium complexes [⁶-C₆H₅-CH(OR)₂]Cr(CO)₆ (R=Me,1; Et,2), are reported. The compounds were examined as part of a study of the conformations of the tripodal tricarbonylchromium group. For [⁶-C₆H₅-CH(OMe)₂]Cr(CO)₃,1, monoclinic,P2₁/c (# 14),a=15.235(1) Å,b=6.5304(5) Å,c=12.702 Å, =103.197(1)^o,Z=4. For [⁶-C₆H₅-CH(OEt)₂]Cr(CO)₃,2, monoclinic,P2₁/c (# 14),a=9.859(3) Å,b=10.547(3) Å,c=15.138(3) Å, =108.42(2)^o,Z=4. The data show that the molecules adopt the expected three-legged piano stool structure. The carbonyl ligands in1 adopt an eclipsed arrangement with respect to the arene ring and its substituent, while those in2 are staggered. These conformations are consistent with the notion that the acetal substituent behaves largely as an electroneutral group, or at most as a weak electronic acceptor.     

Structural chemistry of peroxo compounds of group VI transition metals: I. Peroxo complexes of chromium (a review)

The specific features revealed in the structure of the d ³ Cr(III), d ² Cr(IV), d ¹Cr(V), and d ⁰ Cr(VI) peroxo complexes with the ratios M:O₂ = 1:1, 1:2, and 1:4 are considered. It is noted that, in eleven compounds of the general formula Cr(O₂)_nO_m A _p (n = 1, 2, 4; m = 0, 1; p = 0–4), the metal atoms can be in four oxidations states: +3 (d ³), +4 (d ⁴), +5 (d ¹), and +6 (d ⁰). This property distinguishes chromium peroxo compounds from molybdenum and tungsten dioxygen complexes, which, with one exception, are represented by the d ⁰ M(VI) compounds.     

Structures of bis(N-n-butylsalicylideneiminato)cobalt(II) and bis(N-tert-butylsalicylideneiminato)cobalt(II) complexes and reactivity towards oxygen and nitric oxide

The cobalt(II)-Schiff base complexes [Co(nbsal)₂] and [Co(tbsal)₂] [nbsal=N-n-butylsalicylideneiminate and tbsal=N-tert-butysalicylideneiminate,o-OC₆H₄CH=NR,R+Buⁿ and Bu^t, respectively] both have distorted tetrahedral structures, but the presence of thetert-butyl groups in [Co(tbsal)₂] causes much greater angular distortion, of the coordination tetrahedron. Although [Co(nbsal)₂] will react with nitric oxide and oxygen, [Co(tbsal)₂] reacts with neither and this appears to be due to the shielding of the cobalt by thetert-vutyl groups. The reactive complex [Co(nbsal)₂] crystallizes in the tetragonal system,a+14.244,c+5.395, Å,Z+2 and space group $P\bar 4$ . The structure was determined by the heavy-atom method, using MoKα diffractometer data, and refined by full matrix least-squares toR+0.035 for 777 reflections. The unreactive complex [Co(tbsal)₂] crystallizes in the orthorhombic systemPbc2₁,a+10.977,b+20.037,c+9.866 Å,Z+4. The structure was determined as above toR+0.051 for 1458 reflections.     

Two novel two-dimensional frameworks with channels built from hydrogen bonds: Structures and properties study on copper(II) and nickle (II) complexes of the macrocyclic ligand 1,4,7-triazacyclodecane (tacd)

Two novel supramolecular complexes [Cu(tacd)₂](C₄H₃O₄)₂ (1) and [Ni(tacd)₂]Cl₂·4H₂O (2) were synthesized and their structures were characterized by elemental analysis, IR spectrum, TGA and single-crystal X-ray analysis. The results indicated that the complexes 1 and 2 assemble into different 2D supramolecular net-work structures with channels via hydrogen bonds interaction. TGA curves showed the steps of weight-loss for 1 and 2.     

Direct and outer-sphere coordination of the magnesium ions in the crystal structures of complexes with 2-furancarboxylic acid (I) and 3-furancarboxylic acid (II)

(I) Mg₂C₂₀H₂₄O₁₈ monoclinic,PT,a=10.760(2) Å,b=11.052(2) Å,c=12.822(3) Å, α=105.31(3)^o, β=98.18(3)^o, γ=91.59(3)^o,Z=2. (II) MgC₁₀H₁₄O₁₀, monoclinic,C2/c,a=30.817(6)Å,b=10.499(2)Å,c=9.000(2)Å, β=91.31(3)^o,Z=8. Magnesium in complexes with furoic acids reveals two ways of coordination: direct, when furoic anions are bonded to Mg²⁺ in an ionic fashion and outer-sphere, when cations bind water in the first coordination sphere and furancarboxylic ligands are hydrogen bonded to the water molecules. This results in the formation of three bridging systems: ?Mg?O_carboxyl?C?O_carboxyl?Mg?, ?Mg?O_water ?O_carboxyl?C?O_carboxyl?C?O_carboxyl?Mg?, and ?Mg?O_water?O_carboxyl?C?O_carboxyl?O_water?Mg?. Magnesium 2-furancarboxylate (I) is dimeric, while magnesium 3-furancarboxylate (II) exhibits a polymeric structure.     

Structures of transition and alkaline earth metal salts of 5-aminonaphthalene-2-sulfonate and 6-aminonaphthalene-1, 3-disulfonate: Some unusual coordination behaviors

Salts of 5-aminonaphthalene-2-sulfonate with divalent Mg, Mn, Co, and Ni cations have been crystallized and their structures determined by single crystal X-ray methods. The Mg, Mn, and Co salts are isostructural. Crystal data for hexaaquamagnesium(II) 5-aminonaphthalene-2-sulfonate hexahydrate, [Mg(H₂O)₆](H₂NC₁₀H₆SO₃)₂·6H₂O: monoclinic, P2₁/c, Z=2, a=14.1329(18) ?, b=8.5789(11) ?, c=12.4880(17) ?, β=93.374(3)°, V=1511.5(3) ?³; hexaaquamanganese(II) 5-aminonaphthalene-2-sulfonate hexahydrate, [Mn(H₂O)₆](H₂NC₁₀H₆SO₃)₂·6H₂O: monoclinic, P2₁/c, Z=2, a=14.249(3) ?, b=8.5940(17) ?, c=12.505(3) ?, β=93.30(3)°, V=1528.8(6) ?³; hexaaquacobalt(II) 5-aminonaphthalene-2-sulfonate hexahydrate, [Co(H₂O)₆](H₂NC₁₀H₆SO₃)₂·6H₂O: monoclinic, P2₁/c, Z=2, a=14.1406(18) ?, b=8.5674(11) ?, c=12.4960(16) ?, β=93.297(2)°, V=1511.4(3) ?³. The structures are composed of alternating layers of octahedral metal–aqua complexes and sulfonate anions linked by hydrogen bonds. The three water molecules of crystallization are associated with the hexaaquametal cations and sulfonate O atoms. The repeat unit along the a-axis is a single layer. The Ni salt [crystal data for tetraaquabis(5-aminonaphthalene-2-sulfonato-N)nickel(II) dihydrate, [Ni(H₂O)₄(H₂NC₁₀H₆SO₃)₂]·2H₂O: triclinic, , Z=1, a=6.8524(10) ?, b=8.3094(12) ?, c=11.4832(17) ?, α=69.003(2)°, β=76.570(3)°, γ=83.952(2)°, V=593.56(15) ?³] has a very different structure with direct coordination of the amine N atom to Ni, a modified stacking pattern, and fewer free water molecules. Ag and Ni salts of an amine-substituted naphthalenedisulfonate have also been characterized. Crystal data for diaqua(6-ammonionaphthalene-1,3-disulfonato-O)silver(I) hydrate,[Ag(H₂O)₂(H₃NC₁₀H₅(SO₃)₂)]·0.42H₂O: monoclinic, P2₁/c, Z=2, a=9.099(3) ?, b=21.406(6) ?, c=7.629(2) ?, β=110.178(4)°, V=1394.9(7) ?³; tetraaquabis (6-ammonionaphthalene-1,3-disulfonato-O)nickel(II)tetrahydrate, [Ni(H₂O)₄(H₂NC₁₀H₅ (SO₃)₂)₂]·4H₂O: triclinic,, Z=1, a=6.7971(17) ?, b=10.661(3) ?, c=11.165(3) ?, α=68.308(4)°, β=88.292(5)°, γ=84.896(5)°, V=748.8(3) ?³. The silver salt contains six coordinate metal centers each of which bonds to four sulfonate O atoms from three different anions and two water molecules. The nickel salt contains octahedral cations with four water molecules and two trans sulfonate O atoms. Both structures are layered, but differently from each other and from those of the monofunctional naphthalenesulfonate salts.Unusual coordination of a sulfonate group to a transition metal and coordination of an amine group to nickel but not to cobalt or manganese have been observed in a series of metal aminonaphthalenesulfonate salts     

Photochemical synthesis and crystal structure of two potentially useful metal carbonyl complexes: pentacarbonyl(η2-cis-cyclooctene)-tungsten(0) and tetracarbonylbis(η2-cis-cyclooctene)tungsten(0)

W(CO)₅(C₈H₁₄) and W(CO)₄(C₈H₁₄)₂ were synthesized photochemically from W(CO)₆ andcis-cyclooctene with a respective yield of 71% and 18%. The compounds were characterized by NMR, IR and single X-ray crystallography. The IR spectra of the two compounds exhibited characteristic bands for the mono- and bis-substituted metal carbonyl complexes. In W(CO)₄(C₈H₁₄)₂, thecis-cyclooctene ligands are in atrans configuration with the double bonds perpendicular to each other. The two crystal structures were refined toR=0.040 for W(CO)₅(C₈H₁₄) and 0.025 for W(CO)₄(C₈H₁₄)₂. Although the tungsten-carbon (of the carbonyl groups) distances are very similar in both structures, the distances between the tungsten atom and the olefinic carbons are shorter in W(CO)₄(C₈H₁₄)₂, 2.36 Å, than in W(CO)₅(C₈H₁₄), 2.51 Å.     

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.     

Molecular gears: Structures of (9,10-triptyceno) crown ethers

The incorporation of 9,10-triptycene unit in a crown ether is examined from a structural perspective. Insertion of a triptycene group into 18-crown-6 stretches the crown into an ellipse, as seen in structures presented here of 9,10-triptyceno-22-crown-6 and its thallium complex. Symmetric addition of two triptycene groups into 18-crown-6 results in the sterically congested bis(9,10-triptyceno)-26-crown-6, whose crown cavity is filled with the -clouds of two arene groups. The larger bis(9,10-triptyceno)-32-crown-8 is more sterically relaxed. The structures of these bis(triptyceno)crown ether molecules are the first with two triptycene groups simultaneously linked through their 9 and 10 positions, thereby forming a simple molecular gearing mechanism. The compound 9,10-triptyceno-22-crown-6 (1) crystallizes in the orthorhombic space group Pbca with a = 10.7962(7), b = 15.826(3), c = 31.147(5) Å, V = 5321.8(12) ų, and Z = 8; its complex with TlNO₃ (Tl-1) crystallizes in the monoclinic space group P2₁/c with a = 8.1884(14), b = 19.552(2), c = 20.575(4) Å, = 97.062(8)°, V = 3269.2(9) ų, and Z = 4; bis(9,10-triptyceno)-26-crown-6 (2) crystallizes in the triclinic space group P with a = 8.6488(11), b = 10.7718(12), c = 12.3324(12) Å, = 111.58(1), = 100.55(1), = 106.43(1)°, V = 970.3(5) ų, and Z = 1; and bis(9,10-triptyceno)-32-crown-8 (3) crystallizes in the orthorhombic space group Pna2₁ with a = 20.186(3), b = 8.558(2), c = 25.623(2) Å, V = 4426.2(14) ų, and Z = 4.     

Crystal structure of a novel tertiary phosphine coordination complex: dichlorobis(tribenzylphosphine)nickel(II)

The title compound dichlorobis(tribenzylphosphine)nickel(II), Ni[P(CH₂C₆H₅)₃]₂Cl₂, belongs to a type of tertiary phosphine coordination complex, M(PR₃)₂X₂. There are two molecules in the unit cell which do not appear to interact chemically. Both molecules have a trans-square planar configuration with each nickel atom on a center of symmetry. Three benzyl groups are bonded to each phosphorus atom as rotors in a propeller, and the threefold axis is along the P—Ni bond, which has a mean length of 2.23(1) Å. Crystal data: C₄₂H₄₂Cl₂NiP₂, Triclinic, space group , a = 10.4892(15) b = 10.5249(12) c = 19.453(2) Å, = 83.872(8), = 76.839(9), = 62.241(8)°, V = 1850.5(4) ų, Z = 2. There is an intramolecular hydrogen bond between the C3 and C11 atoms.