Caged phosphite complexes of copper(I) halides

The coordination chemistry of the caged phosphites 4-2,6,7-trioxa-1-phosphabicyclo [2.2.2]octane (MeCage) and 4-nitro-t2,6,7-trioxa-1t-phosphabicyclo[2.2.2]octane (NO₂Caget) with copper(I) halides is reported. Reactions of CuX = CuCl, CuBr, and CuI with the phosphite ligands afford complexes of the type [CuX(MeCage)]₄, [CuX(NO₂Cage)]₄, [CuX(MeCage)₂]₂, [CuX(NO₂Cage)₂]₂, and [CuX(MeCage)₃]. Recrystallization of [CuBr(NO₂Cage)₂]₂ in MeCN produced [CuBr(NO₂Cage)(NCMe)]₂. Three X-ray crystal structures are reported: [CuCl(MeCage)]₄ (I – 4, a = 13.4292(5) Å, b = 13.4292(5) Å, c = 9.4641(5) Å, V = 1706.79(13) ų, Z = 2), [CuBr(MeCage)₂]₂ (I4₁/a, a = 19.5751(17) Å, b = 19.5751(17) Å, c = 16.4513(15) Å, V = 6303.9(10) ų, Z = 8), and [CuBr(NO₂Cage)(NCMe)]₂ (P2₁/c, a = 9.0506(4) Å, b = 15.2428(7) Å, c = 8.8673(4) Å, = 109.7640(10), V = 1151.24(9) ų, Z = 2).     

Crystal and molecular structures of several tetrakis (nitrile)copper(I) complexes

The crystal structures of several [Cu(RCN)₄]X salts (R = Me, X = SO₃CF₃ ^–; R = Ph, X = BF₄ ^–, ClO₄ ^–, and PF₆ ^–) were determined using single crystal X-ray diffraction. All of the compounds contain distorted tetrahedral Cu(I) centers and noncoordinating anions, with the acetonitrile and benzonitrile structures containing three and one unique CuL₄ ⁺ complex in their respective asymmetric units. One important distortion is observed in the benzonitrile-Cu bonds, which are bent up to 23° away from linearity. The result is a flattened complex that maximizes the – tacking of the aromatic rings and is the dominant packing interactions between the complexes.     

Crystal structures of thetrans-cyclooctene complexes of copper(I) chloride and silver nitrate

The crystal and molecular structures of the title compounds CuCl·C₈H₁₄ and AgNO₃·C₈H₁₄, have been determined by single-crystal X-ray diffraction techniques, and refined by full-matrix least squares. Both compounds crystallize in the orthorhombic space groupPbca witha=6.191(7),b=12.456(2),c=23.272(4) Å for CuCl·C₈H₁₄, anda=7.383(2),b=9.825(2),c=26.980(5) Å for AgNO₃·C₈H₁₄;Z=8 in both cases. FinalR factors are 0.047 and 0.029 respectively. The cyclooctene ring has the twist chair-chair (TCC) conformation, with approximateD ₂ symmetry, in both compounds, and the torsion angles around the double bonds are –134.2(4) and –137.0(4)° respectively. Slight lengthening of the metal-complexed double bond is attributed to enhanced olefin metal -donation of thetrans bond.     

Synthesis and crystal structure of three mixed-ligand copper(II) complexes with nitrilotriacetic acid

The synthesis and X-ray diffraction study of three Ca[CuX(Nta)] · 2H₂O complexes, where X = Cl (I) or Br (II and III are the monoclinic and orthorhombic modifications, respectively), are performed. Structures I–III are built of [CuX(Nta)]^2? anionic complexes and hydrated Ca²⁺ cations, which are linked by Ca-O bonds into a three-dimensional framework. In I–III, the coordination of the Cu atom includes the N atom and three O atoms of the tetradentate chelate Nta ^3? ligand and the X ^? anion in the trans position with respect to N. The Cu-O bond lengths vary in the ranges 1.971–2.268 Å in I, 1.958–2.289 Å in II, and 2.040–2.110 Å in III. The Cu-X bond lengths are 2.223, 2.364, and 2.354 Å in I, II, and III, respectively. In I and II, the coordination polyhedron of the Cu atom is approximated by a distorted square pyramid with an O atom at the apical vertex, whereas in III, the polyhedron is described as a distorted trigonal bipyramid with the N and Br atoms at the axial sites. The structures are additionally stabilized by O(w)-H…O and O(w)-H…X hydrogen bonds.     

Crystal structures of four complexes produced by reaction of copper(I) cyanide with imidazoles

Four complexes of CuCN with imidazoles have been prepared by adding the ligand to a solution of CuCN in aqueous sodium thiosulfate. The imidazole ligands used were 2-methylimidazole (mim), 1,2-dimethylimidazole (dmim), 5-chloro-1-methylimidazole (clmim), and 2-phenylimidazole (phim). Complex 1, (CuCN)(mim) is monoclinic, C2/c, a = 9.565(3), b = 7.764(5), c = 8.983(8) Å, = 96.76(3)°, Z, = 4, Complex 2, (CuCN)(dmim) is monoclinic, P2₁/c, a = 8.120(2), b = 11.796(4), c = 16.375(9) Å, , = 100.87(4)°, Z = 8. Complex 3, (CuCN) (clmim) is monoclinic, C2/c, a = 24.907(4), b = 6.894(5), c = 18.259(4) Å, = 102.79(2)°, Z = 16. Complex 4, (CuCN)(phim) is orthorhombic, Pca2₁, a = 9.204(4), b = 8.125(2), c = 26.304(6) Å, Z, = 8. Complexes 1, 2, and 4 have one-dimensional chains –Cu–CN–Cu– with an imidazole bonded to each Cu. Complex 3 has a two-dimensional sheet of CuCN, again with an imidazole bonded to each Cu. In 1 the imidazole group is disordered by a two-fold rotation approximately around the N···N direction in the imidazole group. In 3 one of the imidazole groups has a disorder involving exchange of the Cl and CH₃.     

Crystal structures of copper(II) nitrate,copper(II) chloride,and copper(II) perchlorate complexes with 2-formylpyridine semicarbazone

Compounds dinitrato(2-formylpyridinesemicarbazone)copper (I), dichloro(2-formylpyridinesemicarbazone) copper hemihydrate (II), and bis(2-formylpyridinesemicarbazone)copper(2+) perchlorate hydrate (III) are synthesized and their crystal structures are determined. In compounds I–III, the neutral 2-formylpyridine semicarbazone molecule (L) is tridentately attached to the copper atom via the N,N,O set of donor atoms. In compounds I and II, the Cu: L ratio is equal to 1: 1, whereas, in III, it is 1: 2. In complex I, the coordination sphere of the copper atom includes two nitrate ions with different structural functions in addition to the L ligand. The structure is built as a one-dimensional polymer in which the NO₃ bidentate group fulfills a bridging function. The coordination polyhedron of the copper(2+) atom can be considered a distorted tetragonal bipyramid (4 + 1 + 1). Compound II has an ionic structure in which the main element is the [CuLCl₂ · Cu(H₂O)LCl]⁺ dimer. In the dimer, the copper atoms are linked via one of the μ₂-bridging chlorine atoms. The coordination polyhedra of the central atoms of the Cu(H₂)LCl and CuLCl₂ complex fragments are tetragonal bipyramid and tetragonal pyramid, respectively. In compound III, the copper atom is octahedrally surrounded by two L ligands in the mer configuration.     

The conformation of pentaazamacrocyclics. I. Crystal structures of nickel (II) and copper (II) complexes of 1,4,7,11,14-pentaazacycloheptadecane

The crystal structures of [Ni(17-aneN₅)H₂O]Br₂·3H₂O (17-aneN₅=1,4,7,11,14-pentaazacycloheptadecane) and of [Cu(17-aneN₅)]CuBr₄ are reported. Diffraction data using MoK radiation were measured with a CAD-4 diffractometer and the structures refined by full-matrix least squares. The nickel compound has regular octahedral coordination with coordinated water completing the octahedron. The copper is approximately square-pyramidal with an apical Cu-N bond of 2.29(4) Å, compared to a mean bond length of 2.06(2) Å in the basal plane. As a result, the folding of the 17-membered macrocyclic rings is completely different in the two compounds.     

Crystal structures of copper(II) chloride,copper(II) bromide,and copper(II) nitrate complexes with pyridine-2-carbaldehyde thiosemicarbazone

The crystal structures of chloro-(2-formylpyridinethiosemicarbazono)copper dimethyl sulfoxide solvate (I), bromo-(2-formylpyridinethiosemicarbazono)copper (II), and (2-formylpyridinethiosemicarbazono)copper(II) nitrate dimethyl sulfoxide solvate (III) are determined using X-ray diffraction. In the crystals, complexes I and II form centrosymmetric dimers in which the thiosemicarbazone sulfur atom serves as a bridge and occupies the fifth coordination site of the copper atom of the neighboring complex related to the initial complex through the center of symmetry. In both cases, the coordination polyhedron of the complexing ion is a distorted tetragonal bipyramid. Complex III in the crystal structure forms polymer chains in which the copper atom of one complex forms the coordination bond with the thicarbamide nitrogen atom of the neighboring complex. In this structure, the coordination polyhedron of the central atom is an elongated tetragonal bipyramid. It is established that complexes I–III at a concentration of 10^?5 mol/l selectively inhibit the growth of 60 to 90 percent of the cancer tumor cells of the human myeloid leukemia (HL-60).     

Coordination complexes of 2,6-diarylpyrazines with copper(II) acetate

The coordination chemistry of a series of 2,6- and 2,3-diarylpyrazines with copper(II) acetate is reported. The 2:2 coordination complexes formed between two 2,6-diarylpyrazines and copper(II) acetate are characterized by X-ray crystallography. The structure (2,6-bis(3,5-dimethylphenyl)pyrazine)copper(II) acetate acetonitrile solvate, (C₄₈H₅₂Cu₂N₄O₈) (C₂H₃N) is triclinic, P 1, with a = 7.9685(10), b = 13.1893(16), c = 13.8267(17) Å, = 107.585(3)°, = 103.921(3)° and = 96.759(3)°. The structure of (2-(2,6-dimethylphenyl)-6-(3,5-dimethylphenyl)pyrazine)copper(II) acetate, C₄₈H₅₂Cu₂N₄O₈, is monoclinic, P2₁/c, with a = 8.2196(7), b = 12.5174(11), c = 21.7325(19) Å and = 96.201(2)°.     

Crystal structure of 1,4,8,12-tetraazacyclopentadecane copper(II) tribromocuprate(I)

The title compound is a mixed valence compound obtained as one of the products of the reaction of Cu(15-ane N₄)Br₂ with CoBr₂·6H₂O in water/acetone solvent (15-ane N₄=1,4,8,12-tetraazacyclopentadecane). The compound is tetragonal, space group P4₂/mbc witha=16.675(2)Å,c=13.185(3)Å,V=3666(1)ų, withZ=8, for p_calc=2.106 g/cc. Refinement of 674 unique observed reflection yielded final values ofR=0.088 andR _w=0.083. The compound contains chains of alternating Cu(15-ane N₄)²⁺ cations and CuBr ₃ ^2– anions. The chains run perpendicular to thec axis, and are arranged in alternate layers running parallel toa andb. The chains lie athwart the mirror planes atz=0 andz=1/2, with disorder observed for both the (15-ane N₄) rings and the CuBr ₃ ^2– anions. The Cu(II) ion is coordinated by the tetradentate macrocycle to yield an approximate square planar coordination. The CuBr ₃ ^2– anions are nearly planar with Cu–Br(ave.)=2.37Å. Long semi-coordinate Cu(II)...Br bonds of 3.0Å link the cations and anions.     

Crystal structures and magnetic properties of bipyridine copper(II) complexes

The synthesis, structure and magnetic properties of [Cu(diMe-bipy)Br₂] are reported (diMe-bipy=4,4-dimethyl 2,2-bipyridine). The complex has a polymeric structure composed of [Cu(diMebipy)Br₂] subunits linked via bridging bromine atoms. Each copper atom is hexacoordinated in a distorted octahedral coordination environment. Crystallographic data: monoclinic, space groupC2/c,Z=4, unit cell of dimensionsa=18.312(7),b=9.818(2),c=7.486(2)Å,=107.750(0)° at 293 K. The best fit of the magnetic susceptibility data by the uniform Heisenberg chain model forS=1/2 ions yields values for the exchange coupling constant of –0.46 cm^–1. The magnetic susceptibility of the dimeric [Cu(diMe-bipy)Cl₂]₂·0.5H₂O exhibits a maximum near 12 K that is indicative of an antiferromagnetic interaction between the two metal centers. The best fit of the experimental data by the Bleaney-Bowers equation was obtained withg=1.95 andJ=–6.99 cm^–1.     

Structural and spectroscopic properties of N-benzenesulphonylglycine complexes with copper (II)

In this paper are reported structural and spectroscopic properties of (N-benzenesulphonylglycinato) triaquacopper (II) (complex I) and dipotassium bis (N-benzenesulphonylglycinato) cuprate (II) (complex II). The crystals of (I) are monoclinic, space groupP2₁/c,Z=4, with=12.736(4),b=10.292(3),c=10.402(3) Å,=109.41(2)° while those of complex (II) are orthorhombic, space groupPbca, witha=23.333(8),b=10.508(4),c=16.989(5) Å. In both complexes the aminoacid molecules act as bidentatevia carboxylic oxygen and the amide nitrogen atom; in (I) three water molecules complete the coordination to tetragonal pyramidal, while in (II) coordination is square planar, tetrahedrally distorted involving two ligand molecules. The structure (I) was refined to a finalR index of 0.0596 and (II) toR=0.0466.     

Synthesis and crystal structure of thiosemicarbazide complexes of nickel(II) and copper(II)

Thiosemicarbazide complexes of nickel(II) [Ni(TSC)₂](HSal)₂ (I) and copper(II) [Cu(TSC)₂](HSal)₂ (Ia) (TSC is thiosemicarbazide and HSal is a salycilate anion), as well as complexes [Ni(TSC)₂](SO₄) · 2H₂O (II) and [Ni(TSC)₃]Cl₂ · H₂O (III), are synthesized and characterized by IR spectroscopy and X-ray diffraction. Monoclinic crystals I and Ia are isostructural; space group P2₁/n, Z = 2. Crystals II are monoclinic, space group P2₁/m, Z = 2. Crystals III are orthorhombic, space group Pbca, Z = 8. In I and Ia, two planar salycilate anions sandwich a planar centrosymmetric [Ni(TSC)₂]²⁺ cation to form a supermolecule. The cation and anions are additionally bound by hydrogen bonds. Other hydrogen bonds connect supermolecules into planar layers. In structure II, centrosymmetric [Ni(TSC)₂]²⁺ cations are connected by ??-stacking interactions into supramolecular ensembles of a specific type. The ensembles, water molecules, and (SO₄)^2? anions are bound in the crystal via hydrogen bonds. In the [Ni(TSC)₃]²⁺ cation of structure III, ligands coordinate the Ni atom by the bidentate chelate pattern with the formation of five-membered metallocycles. These metallocycles have an envelope conformation unlike those in I and II, which are planar. In III (unlike in analogous complexes), a meridional isomer of the coordination octahedron of the Ni atom is formed. Together with Cl1^? and Cl2^? anions, cations form supermolecules, which are packed into planar layers with a square-cellular structure. The layers are linked by hydrogen bonds formed by crystallization water molecules that are located between the layers.     

Crystal structures of salicylideneguanylhydrazinium chloride and its copper(II) and cobalt(III) chloride complexes

The crystal structures of salicylideneguanylhydrazinium chloride hydrate hemiethanol solvate (I), salicylideneguanylhydrazinium trichloroaquacuprate(II) (II), and bis(salicylideneguanylhydrazino)cobalt(III) chloride trihydrate (III) are determined using X-ray diffraction. The structures of compounds I, II, and III are solved by direct methods and refined using the least-squares procedure in the anisotropic approximation for the non-hydrogen atoms to the final factors R = 0.0597, 0.0212, and 0.0283, respectively. In the structure of compound I, the monoprotonated molecules and chlorine ions linked by hydrogen bonds form layers aligned parallel to the (010) plane. In the structure of compound II, the salicylaldehyde guanylhydrazone cations and polymer chains consisting of trichloroaquacuprate(II) anions are joined by an extended three-dimensional network of hydrogen bonds. In the structure of compound III, the [Co(LH)₂]⁺ cations, chloride ions, and molecules of crystallization water are linked together by a similar network.     

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.     

Crystal structures of three methylmercury(II) complexes with thiazolidine-2-thione

The crystal structures of three CH₃Hg⁺ complexes with 1,3-thiazolidine-2-thione (HT) are reported. The cationic [(CH₃Hg)HT]NO₃ complex is monoclinic, space group P2₁/c,a=7.158(14),b=10.156(7),c=13.472(12) Å,=108.21(4)°,Z=4. The structure was refined toR=0.045. The [(CH₃Hg)HT]⁺ cation contains a CH₃Hg⁺ group bonded to the exocyclic S atom of the ligand retaining its N-H proton. This proton is lost and the CH₃Hg⁺ group remains bonded to sulfur in the neutral [(CH₃Hg)T] compound (hexagonal, P6₃,a=13.502(8),c=6.984(7) Å,Z=6,R=0.027). The [(CH₃Hg)₂T]NO₃ compound (monoclinic, C2/c,a=25.200(10),b=7.029(6),c=17.946(8),=128.99(3)°,Z=8,R=0.047) contains complex cations in which the CH3Hg⁺ groups are bonded to N and the exocyclic S atom. This series of compounds shows that the exocyclic S atom is always the first target for the CH₃Hg⁺ group, which is also found to bind to nitrogen in the 2:1 compound. No coordination is observed with the endocyclic S site, which does not even participate in intermolecular H-bonding or HgS contacts in the solids.     

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.     

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.