MOLECULAR RECOGNITION OF AN ORGANIC MOLECULE THROUGH FORMING A CO-CRYSTAL COMPLEX Synthesis and Crystal Structure of [Cdphen3](BF4)2-2CNA

Abstract

The co-crystal 1:2 adduct [Cdphen₃](BF₄)₂-2CNA (1) (phen = phenanthroline-N ¹, N ¹⁰ and CNA = 4-chloro-2-nitro-benzenamine) has been prepared by crystallization of bis (tetrafluoroborate)tri-s(phenanthroline)cadmium(II), [Cdphen₃](BF₄)₂, in the presence of 4-chloro-2-nitrobenzenamine. Single crystal X-ray analysis revealed that the cadmium(II) ion exhibits a distorted octahedral geometry with Cd-N bond distances of 2.337(3)-2.374(3)Å. The organic guest molecules are packed with the plane of the molecules parallel to the phenanthroline ligands. Both intra- and intermolecular hydrogen bonding is important in the complex.     

Syntheses and structures of two new uranyl complexes [UO2(DPDPU)2(NO3)2](C6H5CH3) and [UO2(PMBP)2(DPDPU)](CH3C6H4CH3)0.5

Two new uranyl complexes [UO₂(DPDPU)₂(NO₃)₂](C₆H₅CH₃) (1) and [UO₂(PMBP)₂ (DPDPU)](CH₃C₆H₄CH₃)_0.5 (2), (DPDPU?=?N,N′-dipropyl-N,N′-diphenylurea, HPMBP?= 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5) were synthesized and characterized. The coordination geometry of the uranyl atom in 1 is distorted hexagonal bipyramidal, coordinated by two oxygen atoms of two DPDPU molecules and four oxygen atoms of two bidentate nitrate groups. The coordination geometry of the uranyl atom in 2 is distorted pentagonal bipyramidal, coordinated by one oxygen atom of one DPDPU molecule and four oxygen atoms of two chelating PMBP molecules.     

Influence of hydrogen bonds on the molecular structure and conformations of two (C30H48O2) pentacyclic triterpene isomers

The structural study of two (C₃₀H₄₈O₂) pentacyclic triterpene (PCTT) isomers is presented. These terpenes, known as 30-hydroxy-lup-20(29)-en-3-one (1) and (11α)-11-hydroxy-lup-20(29)-en-3-one (2), were isolated from Maytenus imbricata Mart. Ex Reissek (Celastraceae). The molecular structure of 1 and 2 differs in the position of the hydroxyl group. Both compounds crystallize in non-centrosymmetric space groups with two molecules in the asymmetric unit. The crystal structure of 1 shows a triclinic P1 space group (a = 9.5518(1) ?, b = 9.7083(1) ?, c = 14.4696(2) ?, α = 93.832(1)°, β = 102.833(1)°, and γ = 103.307(1)°), while compound 2 crystallizes in a monoclinic P2₁ one (a = 13.4439(16) ?, b = 14.4463(14) ?, c = 13.5224(9) ? and β = 99.703(8)°). The two molecules independent by symmetry of 1 differ slightly due to the presence of static disorder in oxygen atoms. In addition, the intermolecular geometries of 1 and 2 were analysed, and in each isomer the crystal packing is stabilized by O-H…O intermolecular hydrogen bonds and van der Waals forces.     

Syntheses,structures and properties of two Cu complexes with 4-(1H-imidazol-4-ylmethyl)aminophthalic acid

Two temperature-dependent copper(II) complexes {[Cu(HL)][Cu(HL)(H₂O)]} _n (1) and {[Cu(HL)]·H₂O} _n (2) [H₃L = 4-(1H-imidazol-4-ylmethyl)aminophthalic acid] have been synthesised under hydrothermal conditions. X-ray diffraction analysis reveals that complex 1 displays two crystallographic independent units, 1D chain and binuclear unit, respectively. The 1D chains and binuclear molecules are staggered arrangements along the c-axis in an (…ABAB…) fashion. When increasing the reaction temperature, complex 2 was obtained with only 1D chains structure. In addition, the magnetic property of complex 2 was studied, which indicates antiferromagnetic interactions between the neighbouring Cu(II) centres. The electrochemical and electrocatalytic properties of complex 2 have also been studied by modified glassy carbon electrode of 2.     

Tridentate (NNO) Schiff-base copper(II) complex: synthesis,crystal structure,and magnetic study

A new azido adduct of a tridentate Schiff-base copper(II) complex has been synthesized and characterized structurally and magnetically. X-ray single crystal structure analysis reveals that the asymmetric unit of [Cu₂(L)₂(µ_1,1-N₃)₂][Cu(L)(N₃)] (1) [HL = 1-(N-ortho-hydroxyacetophenimine)-2,2-diethyl-aminoethane] has two independent moieties. One of these forms a dimer, containing end-on azido bridges, with its center of inversion related equivalents. The complex crystallizes in monoclinic space group P₂1/c with a = 10.112(2), b = 31.938(4), c = 9.718(2) Å and β = 95.00(2)°. Variable temperature magnetic susceptibility data show antiferromagnetic interactions between copper(II) centers.     

Syntheses, crystal structures and spectral properties of three chiral complexes [M((R, R)-et-pybox)Cl2] (M=Zn and Mn) and [Ni((R, R)-et-pybox)(H2O)2Cl]Cl

Three chiral complexes: [M((R, R)-et-pybox)Cl₂] (M=Zn, 1, and Mn, 2) and [Ni((R, R)-et-pybox)(H₂O)₂Cl]Cl (3) ((R, R)-et-pybox is C₂-symmetric 2,6-bis[4′-(R)-ethoxyoxazolin-2′-yl]pyridine) have been synthesized and characterized by elemental analysis, IR, UV, TG and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analyses show that 1 is isostructural to 2, the obtained complexes are of isolated mononuclear and the metal atoms of 1 and 2 have distorted trigonal bipyramidal coordination environment. A feature of interest is noted in the unit cell of 3, there exist two types of molecules, which similarly have a distorted octahedral geometry but only slightly differ in the orientation of the coordinated atoms to the central Ni atom. These two types of molecules interact with each other by O–H···Cl hydrogen bonds, giving rise to one-dimensional ribbon structure.     

Synthesis,structure, and thermal properties of benzene-solvated forms of bis(dimethyldithiocarbamato)piperidinezinc and -copper(II)

Solvated adducts of zinc and copper(II) dimethyldithiocarbamate complexes with piperidine of the general formula [M{NH(CH₂)₅}{S₂CN(CH₃)₂}₂] · C₆H₆ (M = Zn (I), ⁶³Cu (II)) were isolated on a preparative scale. According to X-ray diffraction data, compound I has a clathrate type structure: the benzene molecules located between the coordinated piperidine rings of neighboring adduct molecules are held by hydrogen bonds. Thermal destruction of I studied by simultaneous thermal analysis includes the desorption steps of benzene solvate molecules and inner-sphere piperidine molecules and thermolysis of the “dithiocarbamate part” of the adduct to give ZnS as the final product. The triaxial anisotropy pattern of EPR parameters of the isotope-substituted magnetically diluted adduct II indicates that the geometry of the copper coordination polyhedron is intermediate between a tetragonal pyramid (TP) and trigonal bipyramid (TBP). It was shown solvation of the adduct [⁶³Cu{NH(CH₂)₅}{S₂CN(CH₃)₂}₂] resulting a considerable increase in the contribution of the TBP component.     

Synthesis and crystal structure of a heterobinuclear complex [(PhPPy2)2PdCuCl2]ClO4 (PhPPy2=bis(2-pyridyl)phenylphosphine)

The mononuclear palladium(II) complex trans-[PdCl₂(PhPPy₂)₂] (1) reacts with [Cu(CH₃CN)₄]ClO₄ to afford the heterobinuclear [(PhPPy₂)₂PdCuCl₂]ClO₄·2CH₃CN (2), bridged by two PhPPy₂ ligands in a new mode. Complex 2 crystallizes in space group P2₁/c with a?=?12.947(1), b?=?9.142(1), c?=?33.454(2)?Å, β?=?99.698(1)°. The copper(I) and palladium(II) ions in 2 adopt distorted tetrahedral and square-planar geometry, respectively. At room temperature, the complex is photoluminescent in solution.     

Synthesis, characterization, and single crystal X-ray structures of [CoIII((BA)2en)(thiobenzamide)2]PF6 and [CoIII(acacen)(thiobenzamide)2]ClO4 and their solvatochromic properties

New cobalt(III) complexes of two tetradentate Schiff base ligands, acacen = bis(acetylacetone)ethylenediimine dianion and (BA)₂en = bis(benzoylacetone)-ethylenediimine dianion, with two axial thiobenzamide (tb) ligands have been synthesized by solid state methods and characterized by elemental analyses, IR, UV–Vis, and ¹H-NMR spectroscopy. Both complexes show solvatochromism in a variety of solvents. The crystal and molecular structures of (1) and (2) were determined by X-ray crystallography. The structure (1) contains two independent [Co^III((BA)₂en)(tb)₂]⁺ complexes, two independent PF₆ anions, and one well ordered ethyl acetate solvent molecule per asymmetric unit. In contrast, the structure (2) contains two independent [Co^III(acacen)(tb)₂]⁺ complexes of C₂ symmetry, a disordered ClO₄ group and disordered toluene molecules. The octahedral coordination of Co(III) is distorted and the Schiff base ligands (ONNO donors) coordinate the cobalt ion in four equatorial positions, and the two axial positions are occupied by S-bonded thiobenzamide molecules. Intramolecular N–H···O hydrogen bonds donated by the thiobenzamide molecules add to the stability of the complexes in the solid state. The IR, UV–Vis, and ¹H-NMR spectra of the two complexes and their solvatochromic properties are also discussed. The compounds exhibit LLCT mediated by the metal center. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis,Crystal Structure,and Characterization of a New Adduct 3-Ammoniumphenyl Sulfone Dihydrogenphosphate Phosphoric Acid [C12H14N2SO2](H2PO4)2H3PO4

Abstract

A new adduct 3-ammoniumphenyl sulfone dihydrogenphosphate phosphoric acid, [C₁₂H₁₄N₂O₂S](H₂PO₄)₂H₃PO₄, has been synthesized by slow evaporation at room temperature using 3-aminophenyl sulfone as the structure-directing agent. The structure, determined by single-crystal X-ray diffraction at 293 K, can be described as inorganic layers built by H₂PO₄ ^? groups and H₃PO₄ molecules, parallel to the (a, c) planes at y = 0.5, between which molecules of the organic group [C₁₂H₁₄N₂O₂S]²⁺ are inserted. In this atomic arrangement, hydrogen bonds and van der Waals interactions between the different species play an important role in the tri-dimensional network cohesion. Solid-state ¹³C and ³¹P MAS NMR spectroscopies are in agreement with the X-ray structure.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Tables S1 and S2. Figures S1 and S2.]

GRAPHICAL ABSTRACT      

Structural diversity in pseudohalide complexes of cadmium(II) with N-methylthiourea (Metu): Polymeric [Cd(Metu)2(NCS)2]n versus monomeric [Cd(Metu)2(CN)2]

Cadmium(II) complexes, catena-poly[bis(thiocyanato-κN)bis(N-methylthiourea)cadmium(II)], [Cd(Metu)₂(NCS)₂]_n (1) and dicyanidobis(N-methylthiourea)cadmium(II), [Cd(Metu)₂(CN)₂] (2) were prepared and their structures were determined by single crystal X-ray analysis. In 1, the cadmium(II) ion is bound to four sulfur atoms of bridging Metu ligands and two nitrogen atoms of thiocyanate adopting a distorted octahedral environment. In 2, the geometry around cadmium is distorted tetrahedral attained by two cyanide ions and two methylthiourea molecules bound through the sulfur atoms. The crystal structures of both complexes show intra and intermolecular hydrogen bonding interactions. The complexes were also characterized by IR and NMR spectroscopy and the spectroscopic data were discussed in terms of the nature of bonding.     

X-RAY STRUCTURES OF BIS[(2-AMINOPHENYL)DIPHENYLPHOSPHINE]BIS-(ETHANOL)SILVER(I) NITRATE AND TRIS[(2-AMINOPHENYL)DIPHENYLPHOSPHINE] SILVER(I) NITRATE MONOHYDRATE

Abstract

The crystal structures of two Ag(I) salts, [Ag(LH)₂(EtOH)₂](NO₃) (1) and [Ag(LH)₃](NO₃).H₂O (2) where LH is (2-aminophenyl)diphenylphosphine, have been determined at room temperature. In 1 the Ag atom is coordinated by two P atoms derived from the phosphine ligands (Ag-P(1) 2.433(3) and Ag-P(2) 2.439(3) Å and P(1)-Ag-P(2) 160.1(1)°) and two O atoms derived from two weakly coordinating ethanol molecules (Ag-O(1a) 2.49(1) and Ag-O(2a) 2.75(1) Å). In 2 the three phosphine ligands coordinate via the P atoms (Ag-P 2.455(2), 2.462(2) and 2.484(2) Å) which define a trigonal planar geometry about the Ag atom. In neither case was any evidence found for a bonding interaction between the amino-N atom and the Ag atom. Crystals of 1 are monoclinic, space group P2₁/n with unit cell dimensions: a=10.272(4), b=16.358(2), c=23.709(3) Å, β=101.01(2)° and Z=4 and crystals of 2 are triclinic, space group P 1 with a=11.857(2), b=21.285(2), c=11.190(4) Å, α=91.77(1), β=104.50(2), γ=97.93(1)° and Z=2. The structures were each refined by a full-matrix least-squares procedure to final R=0.058 using 2433 reflections for 1 and to R=0.069 using 4428 reflections for 2.     

Syntheses,characterizations and crystal structures of two new complexes, [Co2(CH2 =C(CH3)CO2)4(phen)2(H2O)2] and [Pb2(CH2 =C(CH3)CO2)4(phen)2]

Two new complexes, [Co₂(CH₂=C(CH₃)CO₂)₄(phen)₂(H₂O)₂] (1) and [Pb₂(CH₂=C(CH₃)CO₂)₄(phen)₂] (phen = 1,10-phenanthroline) (2), have been synthesized and structurally characterized by single crystal X-ray diffraction methods. There are two cocrystallized conformers of [Co(CH₂=C(CH₃)CO₂)₂(phen)(H₂O)] in the asymmetric unit of 1 with the Co atoms displaying similar coordination modes. In the asymmetric unit of 2, there exist two crystallographically independent [Pb(CH₂=C(CH₃)CO₂)₂(phen)] molecules with the Pb atoms showing completely different coordination geometries. Weak intermolecular interactions such as hydrogen bonding and π–π stacking are responsible for the supramolecular assembly and stabilization of the crystal structures of 1 and 2. The complexes are characterized by elemental analysis, IR spectra, and UV–Vis spectra. The fluorescent properties of 2 are also discussed.     

Copper(II) Halide Complexes of 2-Aminopyrimidines: Crystal Structures of [(2-aminopyrimidine) n CuCl2] (n=1,2) and (2-amino-5-bromopyrimidine)2CuBr2

The reaction of CuX₂(X=Cl, Br) with 2-aminopyrimidine in aqueous solution, or 2-amino-5-bromopyrimidine in aqueous acid yields compounds of the forms [LCuCl₂] _n (1), [L₂CuCl₂] (2) and [L'₂CuBr₂] (3) [L=2-aminopyrimidine; L'=2-amino-5-bromo-pyrimidine]. The three compounds all form layered structures in which each copper ion is coordinated to two 2-aminopyrimidine molecules and two halide ions. Common structural threads involve bridging ligation [either by monomeric (1) or hydrogen bonded ligand dimers (2 and 3)], N-H···X and N-H···N hydrogen bonding and π-π stacking interactions as well as semi-coordinate Cu···X bond formation (1 and 2) or Br···Br interactions (3). Compounds 1 and 2 crystallize as two-dimensional coordination polymers with asymmetrically bihalide bridged (CuX₂) _n chains cross-linked into sheets by the 2-aminopyrimidine molecules (1) or by hydrogen bonded L₂ dimers (2). The halide bibridged chains expand their primary copper coordination spheres to give 4 + 2 coordination spheres in 1 and 2. In 3, the layer structure involves coordination of the hydrogen bonded L'₂ dimers and C-Br···Br- interactions. Crystal data: (1): monoclinic, P2₁/m, a=3.929(1), b=12.373(2), c=7.050(1)å, β=91.206(4)°, V=342.7(1)&Aringsup3;, Z=2, D _calc= 2.225Mg/m³, μ=3.878 mm^-1, R=0.0269 for [|I|≥3σ(I)]. For (2): triclinic, P-1, a=4.095(4), b=7.309(5), c=10.123(6) å, α=86.28(6), β=78.44(6), γ=74.55(8)°, V=286.1(4) ų, Z=1, D _calc=1.884 Mg/m³, μ=2.360 mm^-1, R=0.0506 for [|I|≥2σ(I)]. For (3): triclinic, P-1, a=6.074(4), b=7.673(3), c=8.887(3) å, α=108.43(3) β=100.86(5), γ=106.96(4)°, V=357.0(3) ų, Z=1, D _calc=2.657 Mg/m³, μ=12.714mm^-1, R=0.0409 for [|I|≥2σ(I)].     

Synthesis and crystal structure of a 1 : 2 adduct of aquatrifluoroboron and triphenylphosphine oxide

A crystalline 1 : 2 adduct of aquatrifluoroboron and triphenylphosphine oxide 1/2[BF₃(H₂O)] · Ph₃PO(I) is synthesized and studied by X-ray diffraction analysis. The crystals are orthorhombic, space group Fdd2, a = 32.283 Å, b = 20.162 Å, c = 10.191 Å, Z = 16. The structure is solved by the direct method and refined by a full-matrix least-squares method in the anisotropic approximation to R = 0.054 against 2528 independent reflections (CAD4 automated diffractometer, MoK). A Ph₃PO molecule has a normal structure. A [BF₃(H₂O)] molecule is randomly disordered relative to axis 2; populations of positions of all its atoms are 0.5. The boron atom has a distorted tetrahedral coordination with a donor-acceptor B-O(w) bond. In crystal, strong hydrogen bonds of the P=OH-O-HO=P type are formed between the H₂O molecule and two Ph₃PO molecules.Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 1, 2005, pp. 12–16.Original Russian Text Copyright © 2005 by Chekhlov.     

Crystal and molecular structure of the copper(II) Schiff-base complex containing the azo group

From 3-allyl salicylaldehyde and 4-aminoazobenzene (HL), the Schiff-base complex of copper(II) is synthesized and structurally characterized. The crystallographic unit of a CuL₂ (1) single crystal contains two independent molecules of the complex. Coordination polyhedra of copper atoms are slightly distorted squares; azomethine ligands are in the trans-position. The neighboring molecules of the complex are bonded by intermolecular π stacking interactions.     

Studies on mono- and dinuclear bisoxime copper complexes with different coordination geometries

Two new mono- and dinuclear Cu(II) complexes, namely [CuL¹]·0.5H₂O (1) and [(Cu₂(L²)₂)(DMF)]·0.5DMF (2) (H₂L¹ = 1,2-bis{[(Z)-(3-methyl-5-oxo-1-phenyl-1H-pyrazolidin-4(4H)-yl)(phenyl)]methylene-aminooxy}ethane; H₂L² = 1,3-bis{[(Z)-(3-methyl-5-oxo-1-phenyl-1H-pyrazolidin-4(4H)-yl)(phenyl)] methyleneaminooxy}propane), have been synthesized and characterized by X-ray crystallography. The unit cell of complex 1 contains two crystallographically independent but chemically identical [CuL¹] molecules and one crystalline water molecule, showing a slightly distorted square-planar coordination geometry and forming a wave-like pattern running along the a-axis via hydrogen bonding and π···π stacking interactions. Complex 2 has a dinuclear structure, comprising two Cu(II) atoms, two completely deprotonated phenolate bisoxime (L²)²⁻ moieties (in the form of enol), and both coordinated and hemi-crystalline DMF molecules. Complex 2 has square-planar and square-pyramidal geometries around the two copper centers, whose basic coordination planes are almost perpendicular and form an infinite three-dimensional supramolecular network structure involving intermolecular C–H···N, C–H···O, and C–H···π(Ph) hydrogen bonding and π···π stacking interactions of neighboring pyrazole rings.     

Synthesis, Structure, and Nonrigidity of Os7(CO)20(CNBu t )

The cluster Os₇(CO)₂₀(CNBu ^t ) (1) has been prepared in 25% yield by the reaction of Os₆(CO)₁₈ with Me₃NO and Os(CO)₄(CNBu ^t ) at –78°C. The crystal structure of 1 reveals the expected capped octahedral arrangement of metal atoms with the noncarbonyl ligand attached to the capping Os atom. The OsOs lengths in the two independent molecules in the unit cell are in the range 2.823(1)–2.922(1) Å, with the longer bonds associated with the Os₃ triangle farthest from the capping Os atom. The ¹³C NMR spectrum of 1 in solution at room temperature has a 3:3:1 pattern that is consistent with rotation of the individual Os(CO)₂(L) (L=CO or CNBu ^t ) groups in the cluster. This in turn supports the idea that the capping Os(CO)₂(CNBu ^t ) unit binds to the central Os₆ via a centrally directed MO plus two tangential molecular orbitals.     

Synthesis and electrochemical study of 2-(2-pyridyl)benzothiazole complexes with transition metals (CoII, NiII, and CuII). Molecular structure of aquabis[2-(2-pyridyl)benzothiazole]copper(II) diperchlorate

The reactions of 2-(2-pyridyl)benzothiazole (1) with MX₂·nH₂O salts (M = Ni^II, Co^II, or Cu^II; X = Cl or ClO₄; n = 0–2) in EtOH afforded the corresponding complexes. Depending on the nature of the counterion in the starting metal salt, the reactions give compounds of composition M(1)Cl₂·nH₂O or Cu(1)₂(ClO₄)₂·H₂O. The molecular and crystal structure of the Cu^II(1)₂(ClO₄)₂·H₂O complex was established by X-ray diffraction. The copper atom in this complex has a distorted tetragonal-pyramidal ligand environment and is coordinated by four nitrogen atoms of two ligand molecules and one water molecule. Electrochemical study of the ligand and the resulting complexes by cyclic voltammetry and at a rotating disk electrode demonstrated that ligand 1 stabilizes reduced forms of complexes containing Ni, Co, or Cu atoms in the oxidation state +1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1738–1744, October, 2006.     

Two 1-D metal-organic polymers constructed from bis-benzimidazole-based ligands: syntheses,crystal structures,and luminescent properties

By combination of Mn(II) and Hg(II) salts with a flexible building unit 1,1′-(1, 5-pentanediyl)bis-1H-benzimidazole (pbbm), two 1-D chain metal-organic polymers [Mn(SCN)₂(pbbm)₂] _n (1) and {[HgCl₂(pbbm)] · DMF} _n (2) have been prepared. The polymeric 1-D chains in 1 consist of parallel ribbons of rings, whereas 2 possesses a 1-D zig-zag chain framework based on tetrahedral mercury atoms bridged by pbbm molecules and terminally coordinated by two chlorides. The significant differences of these metal-organic frameworks indicate that the flexible pbbm ligand adjusts its conformation to meet the requirement of the coordination preference of the metal center. The photoluminescent properties of these new materials have been studied in the solid state at room temperature.