Preparation and crystal structure of a copper(II) homobinuclear chelate

Summary The structure of the homobinuclear complex Cu₂(aapen)H₂O, where aapen is the tetraanionic ligand derived from the condensation of 1,2-diaminocthane witho-acetoacetylphenol, has been determined from diffractometer data and refined to R = 6.1%. The crystals are monoclinic,P2₁/c, witha = 12.991(5),b = 8.530(4),c = 18.546(6) Å, and = 104.10(4)°; Z = 4. The ligand employed has two different coordination sets of atoms, N₂O₂ and O₂O₂, two oxygen atoms being common to both donor sets. In the complex, one copper atom is retained in the plane of the inner N₂O₂ chamber whilst the other, which is incorporated in the outer O₂O₂ chamber, is five-coordinate, being axially bonded to a water molecule.     

Preparation and crystal structure of a nickel (II)-Uranyl(VI) binuclear chelate

Summary The structure of the heterobinuclear complex of Ni²⁺ and [U02₂]²⁺ with the tetraanionic ligand derived from the condensation of 1,2-diaminoethane with o-acetoacetylphenol has been determined from diffractometer data and refined to R = 7.2%. The crystals are monoclinic, P21 /a, with = 20.65(2), b = 8.58(1), c = 14.68(2) Å and = 97.78(5); Z = 4. The ligand employed has two different coordination sets of atoms, N₂O₂ and O₂O₂, two oxygen atoms being common to both donor sets. In the complex the nickel ion, which is four coordinate but not square planar, is retained in the inner N₂O₂ chamber, whilst the uranyl ion is incorporated in the outer O₂O₂ chamber. A molecule of solvent is retained to preserve the preferred seven coordination of uranium.     

N,N′-dialkylsubstituted Imidazolidine-2-thionecopper(I) complexes. X-ray analysis of chloro-bis(N,N′-dimethylimidazolidine-2-thione)copper(I)

Summary New complexes of copper(I) withN,N-dialkylsubstituted imidazolidine-2-thione ligands were prepared by reduction of CuX₂ (X = Cl or Br). The i.r. spectra show that in all the complexes the ligand coordinates through the sulphur atom. The crystal structure of chloro-bis(N,N-dimethylimidazolidine-2-thione)copper(I) has been determined from x-ray diffraction data. Crystals are monoclinic. space groupC ₂, with unit cell dimensions:a = 16.022(15),b = 9.942(10),c = 15.112(15) A, = 139.84(10)², Z = 4. The final R index is 5.2%. The copper coordination is trigonal, involving sulphur atoms of the two ligands and One chlorine atom. The steric effect of the two methyls imposes a rotation of the imidazolidine rings with respect to the coordination plane. The dihedral angle between the mean plane of thiourea moieties. parallel one with the other. and the coordination plane is 119.3°.This work was supported by the National Research Council (C.N.R.) of Rome.     

Crystal Structure of Diaqua(2.2.2-cryptand)strontium Bis(thiocyanate)

The crystal structure of the title compound, [Sr(C₁₈H₃₆N₂O₈)(H₂O)₂]²⁺·2SCN^– (I), was investigated by X-ray diffractometry: space group , a = 10.724(3), b = 15.512(3), c = 16.826(4) , = 97.96(3)°, Z = 4. The structure was solved by direct methods. The full-matrix least-squares anisotropic refinement converged to R = 0.038 for all 3837 independent measured reflections (CAD-4 automatic diffractometer, ). In the structure of I, the Sr²⁺ cation (c.n. 10) lies in the cavity of the cryptand ligand and is coordinated by all of its eight heteroatoms (6O+2N) and two O atoms of the two water molecules; its coordination polyhedron is a distorted two-base-centered bicapped trigonal prism. The cryptand ligand in I has an asymmetric conformation. The crystal structure of I has interionic hydrogen bonds (formed by the H atoms of the ligand water molecules) linking the complex cations and the SCN^– anions into complex infinite chains.     

Binding of calcium to amino acids (2)

Crystal structures ofN-acetyl-(DL)-methionine and its calcium adduct have been determined in order to examine possible calcium coordination through sulfur atom and conformation changes in the molecule upon calcium coordination. Crystals of the Ca adduct ofN-acetyl-(DL)-methionine are triclinic, space groupP¯1, a=11.356(2) Å,b=13.556(2) Å,c=15.035(3) Å,=95.42(1)°,=103.66(1)°, and=103.66(1)°, withZ=4 andd _o= 1.40 g cm^–3; 5834 reflections were collected at –125°C. TheN-acetyl-(DL)-methionine was also crystallized so that changes induced by the calcium coordination could be observed. TheN-acetyl-(DL)-methionine crystals are monoclinic, space groupP2₁/c,a=5.885(1) Å,b=9.290(1) Å,c=18.024(2) Å,=92.51 (1)°, withZ=4 andd _o=1.30 g cm^–3. Both structures were solved using direct methods and refined using full matrix least squares. The final values ofR andR _w were 0.051 and 0.053 for the Ca adduct and 0.048 and 0.039 for the free amino acid. All hydrogen atoms were located and included in the final calculations. Interatomic distances and angles of the four crystallographically independentN-acetylmethionine molecules in the Ca adduct are comparable to those of the free molecule, but the torsion angles change drastically. Calcium coordination through the sulfur atom is not found. The binding modes of all four independentN-acetylmethionine molecules in the Ca adduct are different. Of the two crystallographically independent calcium atoms one is 6 and the other is 7 coordinated. The calcium adduct shows several Ca-Ca bridges (with distances 4.722, 4.746, 5.503, and 6.265 Å) which can be described as a zigzag calcium chain or alternatively as slightly puckered sheets of calcium atoms parallel to theab plane atz O.     

The crystal and molecular structure of diaquadichlorotheophyllinecopper(II)

Summary The crystal structure of CuCl₂(C₇H₈N₄O₂)(H₂O)₂ has been determined from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares to R=0.067 for 2123 observed reflections. Unit cell constants are:a=9.930(8),b=9.987(8),c=7.483(6) Å,=123.2(1),=94.5(1),= 83.9(1)°. The space group is P¯1 withZ=2. The structure consists of diaquadichlorotheophyllinecopper(II) complexes linked by hydrogen bonds. The coordination polyhedron of copper is a square pyramid whose base, severely tetrahedrally distorted, is formed by a water molecule [Cu-Ow=2.025(7) Å], two chlorines [Cu-Cl=2.273(4), 2.296(4) Å] and an imidazole nitrogen [Cu-N=1.983(9) Å] from the theophylline ligand. A second water molecule is at the apex of the pyramid [Cu-Ow=2.292(7) Å]. Coordination is completed to a distorted octahedral one by a long Cu ... O=3.164(7) Å contact involving the exocyclic oxygen at C₆ of the theophylline ligand.     

The X‐ray Single Crystal Structures of an Acid‐functionalized Bis(2‐picolyl)amine (bpa) Ligand with Palladium(II) and Zinc(II) Display Different Intermoleclar Interactions around the Common (H2O)2(anion)2 Motif

This work reports structural investigations on two metal complexes of the functionalized (p‐carboxylatobenzyl)‐bis(2‐picolyl)amine ligand 1 (HL). The complex {[HLPdCl]Cl × H₂O}₂ ( 2_Pd ) has a square‐planar coordination around the Pd ion. It forms discrete dimers by intermolecular hydrogen bonding involving the protonated ligand HL. The coordination around the Zn²⁺ ion in {[(H₂O)LZn]CF₃SO₃ × 2 H₂O}_∞ ( 3_Zn ) is best described as distorted trigonal‐bipyramidal. The N₃O₂ ligand sphere is composed of three nitrogen atoms from the bpa ligand, one water molecule, and a carboxylate oxygen atom from a neighbouring molecule, thus forming infinite chains along the crystallographic a axis. Further intermolecular interactions are based on the same (H₂O)₂(anion)₂ motif as for 2_Pd , but whereas the former forms discrete dimers, 3_Zn forms a more complicated two‐dimensional coordination polymer with additional intermolecular hydrogen bonds.     

Reaction of early transition metal complexes with macrocycles. II. Synthesis and structure of TiCl3(H2O) · 18-crown-6, a compound with a unique bidentate bonding mode for the 18-crown-6 molecule

18-crown-6 reacts with TiCl₃ in CH₂Cl₂ to form a complex in which the crown ether functions as a tridentate ligand. Addition of moist hexane affords a molecular complex in which the crown ether functions as a bidentate ligand. A water molecule is bonded directly to the titanium atom and is further hydrogen bonded to three of the oxygen atoms of the crown. The deep blue crystals of the CH₂Cl₂ adduct belong to the monoclinic space groupP2₁/n witha=13.481(8),b=8.021(5),c=21.425(9) Å, =97.32(5)°, and _calc = 1.51 g cm^–3 forZ=4. Refinement led to a conventionalR value of 0.040 based on 873 observed reflections. The Ti–O bond distances for the crown oxygen atoms are 2.123(8) and 2.154(9) Å, while the oxygen atom of the water molecule is bonded at 2.072(8) Å. The octahedral coordination sphere of the titanium atom is completed by the three chlorine atoms at distances of 2.340(5), 2.352(4), and 2.373(4) Å. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82034 (10 pages).     

Mo2(O2CPh)6(PEt3)2, the second example of bridging Y11-02CR for dimolybdenum (III) compounds

From the reaction or Mo₂Cl₆(THF)₃ with excess of NaO₂CPh and PEt₃ in THF three types of crystals have been obtained and recrystallized in CH₂Cl₂. They are brown compound Mo₂(O₂CPh)₆(PEt₃)2·2CH₂Cl₂ (1), yellow-Mo₂(O₂CPb)₄ (2), and black Mo₄O₆(O₂CPh)₆(PEt₃)₂.CH₂Cl₂ (3). When a strict ratio of MO₂Cl₆(THF)₃:NaO₂CPh = 1:2 was applied, Mo₂(O₂CPh)₄(THF)₂, (4) was the only compound separated from the THF reaction mixture. Their structures have been determined by X-ray crystallography. There are three coordination modes of benzoate in 1: bridging ²-O₂CPh, bridging ¹-O₂CPh and terminal O₂CPh groups. Compound 2 is chemically well known, but was found to pack differently from the previously reported structure. Mo₄O₆(O₂CPh)₆(PEt₃)₂·CH₂C1₂ (3) is a mixed-valence Mo (IV, V) tetranuclear compound in a butterfly arrangement. A molecule of 4 is actually a MO₂(O₂CPh)₄ molecule with two THIF molecules axially coordinating to the molybdenum atoms. The crystallographic data for these compounds are as follows: 1, triclinicPl witha = 11.612(3) Å, b = 11.970(2) Å,c=12.135(3) Å,=95.55(2)°,=117.51(2)°,98.84(2)°,V=l450.8(7) ų,Z=1,R=0.0673, and R _w ,=0.0936; 2, monoclinicP2₁/n witha = 14,437(2) Å,b=5.6168(7) Å,c=15.979(3) Å,=93,93(l)°,V=1292.7(4) ų,Z=2,R=0.0217, and R_w=0.0352; 3, trigonal (hexagonal setting)R3¯ witha=28.83(4) Å,c=44.98(2) Å,V=323570(10) ų,Z=18,R=0.067, andwR2=0203; 4 monoclinicP2₁/c witha=9.456(4) Å,b=17.757(8) Å,c=10.887(3) Å,=109.63(2)°,V=1722(2)ų Z=2,R=0.0330, andR _w = 0.0451.     

Structure and thermal properties of a novel volatile bis(1,1,1-trifluoro-5,5-dimethyl-3-hexene-4-imino-2-onate) platinum(II) compound

A novel volatile Pt(II)β-iminoketonate complex is synthesized. β-Aminovinylketone H(i-ptac) = [CF₃–C(O)–CH=C(NH₂)–C(CH₃)₃] is used as a ligand. The XRD method is used to determine the structures of the ligand and the complex. The crystallographic data for C₁₆H₂₂F₆N₂O₂Pt are as follows: a = 10.0716(4) Å, b = 10.9572(4) Å, c = 9.6322(4) Å, β = 110.9010(10)°, space group С2/m, Z = 2, R = 0.011. The platinum atom has a square planar coordination with two oxygen and two nitrogen atoms of two bidentately linked ketoiminate ligands in trans-position; the PtO₂N₂ coordination site is formed.     

Crystal Structure of Diaqua(1,2-bis(2-(o-hydroxy-phenoxy)ethyloxy)ethane)(isothiocyanato)strontium Thiocyanate

The aqua complex of podand 1,2-bis(2-(o-hydroxyphenoxy)ethyloxy)ethane (L) with strontium thiocyanate of the composition [Sr(NCS)L(H₂O)₂]⁺ · SCN^– (I), was synthesized and studied by X-ray diffraction analysis: space group P 2₁/c, a = 17.730 Å, b = 8.558 Å, c = 18.169 Å, = 116.15°, Z = 4. The structure was solved by direct method and anisotropically refined by the full-matrix least-squares method to R = 0.039 for 4333 independent reflections (CAD4 autodiffractometer, MoK ). Structure I contains complex cation [Sr(NCS)L(H₂O)₂]⁺ of the host–guest type. The coordination polyhedron of Sr²⁺ cation (coordination number 9) is a distorted pentagonal bipyramid with four oxygen atoms at the benzene rings of the L podand and the oxygen atom of one water molecule in its base, the N atom of the SCN^– ligand at its single vertex, and with the remaining two O atoms of the L podand and O atom of another water molecule at a triple vertex. In a crystal, the complex cations and SCN^– anions are joined through the hydrogen bonds to form bulky layers parallel to the xy plane.     

Cobalt(II) and copper(II) complexes with chiral pyrazolylquinoline,a derivative of terpenoid (+)-3-carene. Catalytic activity in ethylene polymerization reaction

Coordination compounds [CoLCl₂] (I), [CuLCl(NO₃)] (II), CuL(NO₃)₂ (III), and CuLCl₂ (IV) (where L is a chiral pyrazolylquinoline—a derivative of terpenoid (+)-3-carene) were synthesized. X-ray diffraction data showed that crystal structures I and II are built of mononuclear acentric molecules. In the molecule of complex I, the Co₂₊ ion coordinates two N atoms of bidentate cycle-forming ligand L and two Cl atoms. The coordination polyhedron of Cl₂N₂ is a distorted tetrahedron. For complex I, μ_eff = 4.50 μ_B, which corresponds to a high-spin configuration d ⁷. In the molecules of II(1), II(2) (which are diastereoisomers of complex II), each Cu²⁺ ion coordinates two N atoms of bidentate cycle-forming ligand L, the Cl atom, and two O atoms of bidentate cyclic NO ₃ ^? ion. The ClN₂O₂ coordination polyhedra are tetragonal pyramids with different degrees of distortion. The structure of complex II consists of supramolecular clusters, i.e., isolated chains incorporating the molecules of II(1) and II(2). The values of μ_eff for II–IV correspond to the d ⁹ configuration. The results of EPR and IR study suggest that complex III contains the O₄N₂ polyhedron, whereas complex IV contains the Cl₂N₂ polyhedron. Complexes I and IV were found to show a high catalytic activity in ethylene polymerization reaction.     

A one‐dimensional nickel(II) coordination polymer containing 2,6‐dipicolinate and dipyrido[3,2‐a:2′,3′‐c]phenazine

A new coordination polymer, catena‐poly[[(dipyrido[3,2‐a:2′,3′‐c]phenazine‐κ²N,N′)nickel(II)]‐μ‐2,6‐dipicolinato‐κ⁴O²,N,O⁶:O^2′], [Ni(C₇H₃NO₄)(C₁₈H₁₀N₄)]_n, exhibits a one‐dimensional structure in which 2,6‐dipicolinate acts as a bridging ligand interconnecting adjacent nickel(II) centers to form a chain structure. The asymmetric unit contains one Ni^II center, one dipyrido[3,2‐a:2′,3′‐c]phenazine ligand and one 2,6‐dipicolinate ligand. Each Ni^II center is six‐coordinated and surrounded by three N atoms and three O atoms from one dipyrido[3,2‐a:2′,3′‐c]phenazine ligand and two different 2,6‐dipicolinate ligands, leading to a distorted octahedral geometry. Adjacent chains are linked by π–π stacking interactions and weak interactions to form a three‐dimensional supramolecular network.     

Poly[[aqua(μ7‐ethylenediaminetetraacetato)dicadmium(II)] monohydrate]

The title compound, {[Cd₂(C₁₀H₁₂N₂O₈)(H₂O)]·H₂O}_n, consists of two crystallographically independent Cd^II cations, one ethylenediaminetetraacetate (edta) tetraanion, one coordinated water molecule and one solvent water molecule. The coordination of one of the Cd atoms, Cd1, is composed of five O atoms and two N atoms from two tetraanionic edta ligands in a distorted pentagonal–bipyramidal coordination geometry. The other Cd atom, Cd2, is six‐coordinated by five carboxylate O atoms from five edta ligands and one water molecule in a distorted octahedral geometry. Two neighbouring Cd1 atoms are bridged by a pair of carboxylate O atoms to form a centrosymmetric [Cd₂(edta)₂]⁴⁻ unit located on the inversion centre, which is further extended into a two‐dimensional layered structure through Cd2—O bonds. There are hydrogen bonds between the coordinated water molecules and carboxylate O atoms within the layer. The solvent water molecules occupy the space between the layers and interact with the host layers through O—H...O and C—H...O interactions.     

The crystal structure of tetraethylammonium aquatetracyanooxorhenate(V)

Summary The crystal structure of the tetraethylammonium salt of [ReO(H₂O)(CN)₄]^– has been determined from threedimensional x-ray diffraction data. The light blue crystals are monoclinic, space group P2₁/m witha=8.760(1),b=9.518(5),c=11.718(1) Å, =102.63(1)^o with two molecules per unit cell. The final R value using 2009 observed reflections and anisotropic thermal parameters for all the non-hydrogen atoms was 0.038. The [ReO(H₂O)(CN)₄]^– ion has a distorted octahedral geometry with the rhenium atom displaced by 0.30 Å out of the plane formed by the four carbon atoms of the cyano ligands towards the oxo ligand. Bond distances: Re=O=1.667(8), Re–OH₂=2.142(7) and Re–C (average)=2.11(1) Å.     

(Benzoyl­acetonato)­chloro(1,10‐phen­anthroline)copper(II)

The crystal structure of the title compound, chloro(1,10‐phenanthroline‐N,N′)(1‐phenyl‐1,3‐butane­dion­ato‐O,O′)copper(II), [CuCl(C₁₀H₉O₂)(C₁₂H₈N₂)], has been determined. The Cu^II ion displays a distorted square‐pyramidal coordination, being linked to the two O atoms of the benzoyl­acetonate ligand and the two N atoms of the 1,10‐phenanthroline ligand in the basal plane, and the Cl atom in the apical site. TheCu—N, Cu—O and Cu—Cl bond lengths are 2.043 (2)/2.025 (2), 1.914 (2)/1.941 (2) and 2.485 (1) Å, respectively.     

Synthesis and structures of copper(II) and nickel(II) complexes of 1,8-diaza-4-thiaoctane. Characterization of a novel polymeric trigonal bipyramidal copper(II) complex containing both bridging and meridionally coordinated ligands

Summary The synthesis, x-ray structure determination, and spectroscopic properties of nickel(II) and copper(II) complexes of 1,8-diaza-4-thiaoctane (aeaps) are described. [Ni(aeaps)₂](ClO₄)₂ crystallizes in the orthorhombic space group Pbcn witha=10.943(2),b=13.209(2),c=14.798(2)Å, and Z=4. The complex crystallizes as the unsymmetrical facial isomer, with the sulfur atoms incis positions. The copper(II) complex crystallizes in the monoclinic space group Cc, witha=16.041(2),b=9.223(1),c=16.048(3) Å,a=118.65(2)⁰, and Z=4. The copper(II) ion has a trigonal bipyramidal coordination geometry, with one ligand coordinated meridionally, and two bridging ligands in which the thioether is not bound to a metal ion. The structures of these complexes are discussed in terms of the known solution chemistry of this ligand with copper(II) and nickel(II).     

Copper(II) bromide and copper(II) acetate complexes of 4,4′‐(p‐phenylene)bipyridazine

4,4′‐(p‐Phenylene)bipyridazine, C₁₄H₁₀N₄, (I), and the coordination compounds catena‐poly[[dibromidocopper(II)]‐μ‐4,4′‐(p‐phenylene)bipyridazine‐κ²N²:N^2′], [CuBr₂(C₁₄H₁₀N₄)]_n, (II), and catena‐poly[[[tetrakis(μ‐acetato‐κ²O:O′)dicopper(II)]‐μ‐4,4′‐(p‐phenylene)bipyridazine‐κ²N¹:N^1′] chloroform disolvate], {[Cu₂(C₂H₃O₂)₄(C₁₄H₁₀N₄)]·2CHCl₃}_n, (III), contain a new extended bitopic ligand. The combination of the p‐phenylene spacer and the electron‐deficient pyridazine rings precludes C—H...π interactions between the lengthy aromatic molecules, which could be suited for the synthesis of open‐framework coordination polymers. In (I), the molecules are situated across a center of inversion and display a set of very weak intermolecular C—H...N hydrogen bonds [3.399 (3) and 3.608 (2) Å]. In (II) and (III), the ligand molecules are situated across a center of inversion and act as N²,N^2′‐bidentate [in (II)] and N¹,N^1′‐bidentate [in (III)] long‐distance bridges between the metal ions, leading to the formation of coordination chains [Cu—N = 2.005 (3) Å in (II) and 2.199 (2) Å in (III)]. In (II), the copper ion lies on a center of inversion and adopts CuN₂Br₄ (4+2)‐coordination involving two long axial Cu—Br bonds [3.2421 (4) Å]. In (III), the copper ion has a tetragonal pyramidal CuO₄N environment. The uncoordinated pyridazine N atom and two acetate O atoms provide a multiple acceptor site for accommodation of a chloroform solvent molecule by trifurcated hydrogen bonding [C—H...O(N) = 3.298 (5)–3.541 (4) Å].     

Aqua(2,2′‐bi‐1H‐imidazole)chloro­copper(II) chloro­(imino­diacetato)copper(II) monohydrate

In the title compound, [CuCl(C₆H₆N₄)(H₂O)][Cu(C₄H₅NO₄)Cl]·H₂O, the Cu^II atom in the cation is coordinated by one Cl⁻ ion, two N atoms of the 2,2′‐biimidazole ligand and one aqua ligand. Within the anion, the Cu^II atom is bonded to one Cl⁻ ion, and one N and two O atoms of the imino­diacetate ligand. Neighbouring cations and anions are connected to each other by Cu·Cl semi‐coordination bonds of 2.830 (12) and 3.071 (12) Å, forming a Cu₂Cl₂ rectangular unit. The dinuclear units further link into a polymeric chain along the a axis through Cu·O_aqua interactions of 2.725 (3) Å. Including the long coordination bonds, the geometries around the Cu atoms in the cation and anion are square‐pyramidal and distorted octahedral, respectively.     

Acetato(N‐phenylpyridine‐2‐carboxamidato‐κ2N,N)(N‐phenylpyridine‐2‐carboxamide‐κ2N1,O)copper(II)

The title complex, [Cu(C₁₂H₉N₂O)(C₂H₃O₂)(C₁₂H₁₀N₂O)], is a neutral Cu^II complex with a primary N₃O₂ coordination sphere. The Cu centre coordinates to both a deprotonated and a neutral molecule of N‐phenylpyridine‐2‐carboxamide and also to an acetate anion. The coordination around the metal centre is asymmetric, the deprotonated ligand providing two N donor atoms [Cu—N = 1.995 (2) and 2.013 (2) Å] and the neutral ligand providing one N and one O donor atom to the coordination environment [Cu—N = 2.042 (2) Å and Cu—O = 2.2557 (19) Å], the fifth donor being an O atom of the acetate ion [Cu—O = 1.9534 (19) Å]. The remaining O atom from the acetate ion can be considered as a weak donor atom [Cu—O = 2.789 (2) Å], conferring to the Cu complex an asymmetric octahedral geometry. The crystal structure is stabilized by intermolecular N—H...O, C—H...O and C—H...π interactions.