trans-Bis(2-amino­pyridine-N)bis(O,O′-diiso­propyl di­thio­phosphato-S,S′)nickel(II)

In the title compound, [Ni(C₆H₁₄O₂PS₂)₂(C₅H₆N₂)₂], the coordination around the Ni atom, which lies on a crystallographic centre of symmetry, is octahedral with the S atoms from the di­thio­phosphate ligands occupying the equatorial positions, while the axial positions are occupied by the ring N atoms of the 2-amino­pyridine ligands. The mol­ecules form layers in the bc plane which are stacked in the direction of the a axis.     

cis-Di­chloro­bis­(triethyl­arsine)­platinum(II) and cis-di­chloro­bis­(triethyl­phosphine)­platinum(II)

The crystal structure of cis-[PtCl₂(C₆H₁₅As)₂], (I), is isostructural with a previously reported structure of cis-[PtCl₂(C₆H₁₅P)₂], (II). A new polymorph of (II) is also reported here. Selected geometrical parameters in the arsine complex are Pt—Cl 2.3412 (12) and 2.3498 (13), Pt—As 2.3563 (6) and 2.3630 (6) Å, Cl—Pt—Cl 88.74 (5), As—Pt—As 97.85 (2), and Cl—Pt—As 171.37 (4) and 177.45 (4)°. Corresponding parameters in the phosphine complex are Pt—Cl 2.364 (2) and 2.374 (2), Pt—P 2.264 (2) and 2.262 (2) Å, Cl—Pt—Cl 85.66 (9), P—Pt—P 98.39 (7), and Cl—Pt—P 170.26 (7) and 176.82 (8)°.     

Di­chloro­bis(4-methyl­pentan-2-onato-C4,O)­tin(IV) and bis(4-methyl­pentan-2-onato-C4,O)(2-thio­xo-1,3-di­thiole-4,5-di­thiol­ato-S,S′)­tin(IV) at 150 K

The structures of the ketotins determined here, [SnCl₂(C₆H₁₁O)₂] and [Sn(C₃S₅)(C₆H₁₁O)₂], respectively, along with that previously reported for [MeC(O)CH₂CMe₂]₂SnI₂, are compared with the structures of the analogous estertins [MeOC(O)CH₂CH₂]₂SnX₂. Pairwise comparison of the mean ketotin [estertin] Sn—X and Sn—O distances as Sn—X 2.4422 (4) [2.4054 (7) Å], 2.4970 (4) [2.471 (2) Å] and 2.8463 (4) [2.7788 (8) Å] and Sn—O 2.4926 (12) [2.528 (1) Å], 2.6110 (11) [2.629 (7) Å] and 2.435 (3) [2.525 (4) Å] (for X = Cl, S and I, respectively) clearly demonstrates the superior donor ability of the ketotin O atom in chelate formation.     

Aquabis(3,5-dimethyl-1H-pyrazole-κN2)(malonato-κ2O,O′)copper(II) ­dihydrate

In the neutral title complex, [Cu(C₃H₂O₄)(C₅H₈N₂)₂(H₂O)]·2H₂O or [Cu(mal)(dmp)₂(H₂O)]·2H₂O (mal is malon­ate and dmp is 3,5-di­methyl-1H-pyrazole), the Cu^II ion, in a slightly distorted square-pyramidal geometry, is coordinated by two O atoms of the bidentate malonate, the O atom of the water ligand and two N atoms from the two 3,5-di­methyl­pyrazole ligands. The mean Cu—N bond length is 2.007 (6) Å, longer than the Cu—O_mal bonds [1.950 (5) Å]. The apical position is occupied by a relatively strongly coordinated water mol­ecule [Cu—O_water 2.288 (5) Å]. The crystal structure is characterized by the layer motif of a hydrogen-bonded network.     

A linear cyclic oximate-bridged ­tetracopper(II) complex

The crystal structure of the title complex, tetrakis­[μ-6-amino-3-methyl-4-aza­hex-3-en-2-one oximato(1–)-κ⁴N,N′,N′′:O]tetracopper(II) tetraperchlorate 0.6-hydrate, [Cu₄(C₆H₁₂N₃O)₄](ClO₄)₄·0.6H₂O, shows the cation to be an oximate-bridged tetramer composed of four 6-amino-3-methyl-4-aza­hex-3-en-2-one oxime ligands and four copper(II) ions and to have crystallographically imposed symmetry. Each Cu^II atom is four-coordinated by the three N atoms of one oxime ligand and by the O atom of another oxime ligand in a distorted square-planar geometry.     

A nitronyl nitro­xide complex of ­nickel(II) with nitrate as a ligand

The complex cation in [4,5-di­hydro-4,4,5,5-tetra­methyl-2-(2-pyridyl-κN)­imidazol-1-oxyl 3-oxide-κO³](nitrato-κ²O,O′)(N,N,N′,N′-tetra­methyl-1,2-ethanedi­am­ine-κ²N,N′)­nickel(II) hexafluorophosphate dichloromethane solvate, [Ni(NO₃)(C₆H₁₆N₂)(C₁₂H₁₆N₃O₂)]PF₆·CH₂Cl₂, is the first example of a nitro­nyl nitro­xide complex of a transition metal ion having d electrons in which nitrate is coordinated as a bidentate ligand. Owing to the smaller steric requirement of NO₃⁻, the Ni—­O(nitro­xide) bond length [2.014 (2) Å] is remarkably shorter than that in the corresponding ­β-­diketonate complexes [2.052 (4)–2.056 (2) Å].     

Nitrogen-donor base adducts of bis(O,O′-di-isoamyldithiophosphato)nickel(II)

A series of Ni^II complexes with the O,O-di-isoamylester of dithiophosphoric acid and nitrogen-donor ligands of composition [Ni(i-Am₂dtp)₂(L)]; [dtp = O₂PS₂ ^–; L = 2,2-bipyridine (bpy); 1,10-phenanthroline (phen); 5-nitro-1,10-phenanthroline (nphen); 4,7-diphenyl-1,10-phenanthroline (baphen); 2,9-dimethyl-1,10-phenanthroline (neo), 2-aminomethylpyridine (amp), 2-(2-aminoethyl)pyridine (aep), 2,2-dipiridylamine (dpa), 1,2-diaminopropane (1,2-dap) or trans 1,2-diaminocyclohexane (dch)] have been prepared. The compounds have been characterized by elemental analyses (C,H,N,S), electronic and i.r. spectroscopy, magnetic and conductivity measurements and by cyclic voltammetry. The results show that all complexes behave as non-electrolytes in acetone. Electronic spectra and magnetic moments suggest a distorted cis-octahedral geometry around the Ni^II atom [_eff/_B <3.10, 3.40 >], except for [Ni(i-Am₂dtp)₂(aep)], where the measured temperature dependence of the magnetic susceptibility proved the tetrahedrally coordinated nickel [4.06 _eff/_B (298 K) – 3.20 _eff/_B (80 K)]. In the [Ni(i-Am₂dtp)₂(neo)] complex, the nickel atom is penta-coordinated. The X-ray crystal and molecular structure of [Ni(i-Am₂dtp)₂(1,2-dap)] has been determined.     

catena-Poly[[trans-di­chloro­copper(II)]-μ-1,4,7,10,13,16-hexa­thia­cyclo­octa­decane-S1:S10]

In the title complex, [CuCl₂(C₁₂H₂₄S₆)]_n, the CuCl₂ unit and the ligand lie on and about inversion centres, respectively. The coordination geometry at Cu^II is a tetragonally elongated octahedron with the equatorial positions occupied by two chlorides, Cu—Cl 2.2786 (12) Å, and two S donors, Cu—S 2.3710 (13) Å. The apical positions of the octahedron are defined by two S donors at distances of 2.8261 (14) Å from the metal. The macrocyclic ligand adopts a very puckered and distorted conformation. Eight of the 18 torsion angles are less than 90° and all S-donors are oriented exo to the ring.     

THE POLYMERIC COPPER(II) COMPLEX 1, 10-PHENANTHROLINE -N,N '-(μ-ISONICOTINATO-N,O) MONOAQUACOPPER(II) NITRATE DIHYDRATE

Abstract

The title complex has been prepared and its structure determined by X-ray diffraction. The complex crystallizes in space group C2/c with a = 26.892(5), b = 10.479(4), c = 14.179(2) Å, β = 98.59(2)°. Isonicotinate anions bridge adjacent Cu(II) atoms through the pyridine N atom and the carboxyl O atom to form zigzag polymeric chains along the b axis. The carboxyl group of the isonicotinate anion coordinates to the Cu(II) atom as a unidentate. Based on the molecular structure the infrared spectrum is discussed.     

Sodium thio­phenolate N,N,N′,N′-tetra­methyl­ethyl­enedi­amine

The title compound, Na⁺·C₆H₅S⁻·C₆H₁₆N₂, forms lipophilically wrapped infinite sodium chains along the a axis. Each sodium cation is coordinated by three thio­phenolate S atoms and two N centres of one tetra­methyl­ethyl­enedi­amine molecule.     

Bis(triethanolamine)cadmium(II) and -­mercury(II) saccharinates: seven-coordinate complexes containing both tri- and tetradentate triethanolamine ligands

The structures of the title triethanol­amine (tea) complexes of Cd^II and Hg^II saccharinates, bis­(triethanol­amine)-κ³O,N,O′;κ⁴O,N,O′,O′′-cadmium(II) 1,2-benziso­thia­zol-3(2H)-onate 1,1-dioxide, [Cd(C₆H₁₅NO₃)₂](C₇H₄NO₃S)₂, (I), and bis­(tri­ethanol­amine)-κ³O,N,O′;κ⁴O,N,O′,O′′-mercury(II) 1,2-benz­iso­thia­zol-3(2H)-onate 1,1-dioxide, [Hg(C₆H₁₅NO₃)₂](C₇H₄NO₃S)₂, (II), or [M(tea)₂](sac)₂, where M is Cd^II or Hg^II and sac is the saccharinate anion, reveal seven-coordinate metal ions in both complexes. Both complex cations, [M(tea)₂]²⁺, adopt a monocapped trigonal prism geometry in which the two tea ligands exhibit different coordination modes to achieve seven-coordination. One tea ligand acts as a tetradentate ligand using all its donor atoms, while the other behaves as a tridentate O,N,O′-donor ligand, with one of its ethanol groups remaining uncoordinated. The H atoms of the free and coordinated hydroxyl groups of the tea ligands are involved in hydrogen bonding with the amine N atom, and with the carbonyl and sulfonyl O atoms of neighbouring sac ions, forming an infinite three-dimensional network. A weak π–π interaction between the phenyl rings of the sac ions also occurs.     

Di­methyl (1R,8R)-1,11,11-tri­methyl-2,3-di­aza­tri­cyclo­[6.2.1.02,6]­undeca-3,5-diene-4,5-di­carboxyl­ate,a chiral mol­ecule with an approximate centrosymmetric crystal structure

The crystal structure of the title compound, C₁₆H₂₂N₂O₄, has two independent chiral mol­ecules related by a pseudo-inversion centre. 14 of the 22 non-H atoms have a centrosymmetric counterpart within a tolerance of 0.17 Å. A search of the Cambridge Structural Database [Spring 2000; Allen & Kennard (1993). Chem. Des. Autom. News, 8 , 1, 31–37] shows at least 10% of the crystal structures reported in the literature with space group P2₁ and Z = 4 to be chiral compounds with a pseudo-P2₁/c packing.     

5,6-Bis(2-pyridyl)-2,3-pyrazine­dicarbo­nitrile

The crystal structure of the title compound, C₁₆H₈N₆, contains two independent mol­ecules with no significant difference in their structures. The pyrazine ring makes dihedral angles of 36.7 (2) and 36.5 (3)° with the two pyridine rings in one mol­ecule, and 43.1 (2) and 38.4 (1)° in the other. The dihedral angles between the two pyridine rings are 58.2 (2) and 56.0 (2)°, respectively. The favoured orientation of the pyridine rings is such that their N atoms face each other.     

Two polymorphs of aqua[N,N′-ethyl­enebis(salicylideneaminato-N,O)]oxovanadium(V) nitrate

The title compound, aqua­[bis­(salicyl­idene)­ethyl­enediamin­ato-O,N,N′,O′]­oxovanadium(V) nitrate, [VO(C₁₆H₁₄N₂O₂)(H₂O)]NO₃, crystallizes as two polymorphs in the triclinic and monoclinic crystal systems. In both, the V atom has a distorted octahedral coordination geometry with a long V—O_water bond trans to V=O. The coordinated water mol­ecules are hydrogen bonded to the nitrate ions so that pairs of cations are linked to give neutral centrosymmetric dimers. The V=O and V—O_water distances are 1.598 (2) and 2.257 (2) Å, respectively, in the triclinic form, and 1.588 (3) and 2.230 (3) Å, respectively, in the monoclinic form. In the triclinic form, the dimers pack so that the salen [bis(salicyl­idene)ethylenediaminate] ligands are parallel to each other, whereas in the monoclinic form, which is the denser, there is a herring-bone arrangement.     

CRYSTAL STRUCTURE OF ADDUCT OF BIS(O,O''''-DIBUTYLDITHIOPHOSPHATO)-NICKEL (II) WITH BIPYRIDYL

<正> Ni[(C8H9O)2PS2]2 bipy, Mr=697.57, triclinic, Ci-Pl, a=9.469(1)A, b=14.638(3)A, c=14.637(2)A, α=69.64(1)° , β=71.16(1)°, r=89.99(1)°, V= 1785.6A3, Z=2, Dc=1.297g.cm-3, Mo kα radiation, λ=0.71073A, F(000)=736e, R=0.081 for 4986 independent reflections. Ni(II) is coordinated by four sulfur atoms and two nitrogen atoms to form a distorted octahedron. The angles between each two among planes N2Ni, NiS(11)S(12) and NiS(21)S(22) are nearly 90°.     

THE POLYMERIC COMPLEX 1, 10-PHENANTHROLINE-N,N'-(μ-NICOTINATO-N,O)DIAQUACOPPER(II) NITRATE DIHYDRATE

Abstract

The title complex has been prepared and its structure determined by X-ray diffraction methods. The complex crystallizes space group P2₁/a with a = 12.833(3), b = 10.443(2), c = 16.628(2)Å, β = 111.686(9)°. The nicotinate anions bridge adjacent Cu(II) atoms through both the pyridine N atom and the carboxyl O atom to form zigzag polymeric chains along the b axis. The carboxyl group of the nicotinate anion coordinates to the Cu(II) atom as a unidentate. Based on the molecular structure the infrared spectrum is discussed.     

Bis(μ3-barbiturato−O,O,O′)-(μ2-aqua)- aqua-barium(II): crystal structure,spectroscopic and thermal properties

A polymeric coordination compound, [Ba(H₂O) ₂(Hba)₂] (1) (H₂ba – barbituric acid, C₄H₄N₂O₃), was obtained. The structure of 1 was solved using powder X-ray diffraction methods. The Ba²⁺ ion in 1 formed a three-capped trigonal prism. The BaO₉ polyhedra, connected with each other by the edges and faces, formed a chain. Several 4- and 12-membered cycles due to the bridging μ₂-H₂O and bridging μ₃-Hba^– also formed implementing a 3-D polymer structure. The structures of 1 and other thiobarbiturate complexes were compared. The replacement of a S atom by an O atom in the heterocyclic ligand Htba^? (thiobarbiturate ion) of the compound Ba(H₂O)₂(Htba)₂ resulted in changes of the coordination number Ba(II) and supramolecular structure. The intermolecular hydrogen bonds O–H?O and N–H?O formed a 3-D net where pronounced 2-D layers of Hba^– ions could be found. A new topological net in 1 was observed. The IR and thermal stability were investigated.     

STRUCTURE AND CATALYTIC PROPERTIES OF PALLADIUM(II) (ACETYLACETONATO- κ2O,O′)BIS(TRIS(DIETHYLAMINO)PHOSPHINE) TETRAFLUOROBORATE

Journal of Structural Chemistry - The structure of complex [Pd(acac){P(NEt2)3}2]BF4 (I) is determined by XRD. In the crystal structure of I, the coordination sphere of palladium is characterized by...     

A NOVEL BINUCLEAR COPPER(II) COMPLEX: BIS[1,10-PHENANTHROLINE-N,N′-MALEATO- O,O′-COPPER(II)] DIMETHANOL TETRAHYDRATE

Abstract

A novel binuclear Cu(II) complex, [Cu₂(mal)₂(phen)₂]. 4H₂O. 2MeOH (phen= 1,10-phenanthroline, mal = maleato dianion), has been synthesized and characterized by elemental analysis, IR spectroscopy, solid-state ESR analysis and X-ray single crystal study. The complex consists of [Cu(mal)(phen)] subunits with two water and one methanol solvate molecules. The subunits show a distorted planar arrangement, existing in centrosymmetrically related pairs in the crystal packing. They have a distorted four-coordinate square-planar arrangement of N and O atoms about the central Cu atom; pairs of these [Cu(mal)(phen)] subunits form dimers by interaction of the fifth position on each Cu center with an O atom of a maleato ligand of the associated subunit with a Cu-Cu distance of 3.3425(9) å. The coordination around each Cu atom is best described as distorted square-pyramidal. The lattice water and methanol molecules are also confirmed by the TG study and IR spectra. The X-band solid-state ESR spectrum at room temperature exhibits an anisotropic feature with g′ = 2.24, g′ = 2.06.     

Nickel(II) and copper(II) – l-cysteine,l-methionine,l-tryptophan-nucleotide ternary complexes

Four new ternary complexes of Cu^II with l-methionine and the nucleotides 5AMP (adenosine 5-phosphate), 5GMP (guanosine 5-phosphate) and 5IMP (inosine 5-phosphate), and with l-tryptophan and 5AMP, were synthesized and characterized by elemental analysis and i.r. spectroscopy. One ternary complex of N^II with l-cysteine and 5IMP was also prepared and characterized. The study of the three ternary compounds of Cu^II, of general formulae Cu-5NMP-l-methionine, indicates coordination of the phosphate group and of N(7) of the purinic ring. l-Methionine is bound by the carboxylic and amino groups. The ternary complex obtained from a mixture of Cu-5AMP and l-tryptophan is a dimer in which the nucleotide bridges the two copper atoms. In the complex of Ni-5IMP and l-cysteine, the nucleotide seems to bind the metal through the N(7) of the heterocyclic ring, and the l-cysteine is coordinated as a bidentate chelate by the carboxyl and thiol groups. E.s.r. spectra of the copper complexes are in good agreement with the low symmetry structure proposed. The one-electron reduction potentials E_c(Fc⁺/Fc) (V) of Cu^II to Cu^I were established for the four copper complexes from cyclic voltammetry studies. The one-electron oxidation potential E_a(Fc⁺/Fc⁺) (V) of Ni^II to Ni^III was also measured for the nickel complex.