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.     

Crystal structures of copper(II) and nickel(II) nitrate and chloride complexes with 4-bromo-2-[(2-hydroxyethylimino)-methyl]phenol

The crystal structures of {4-bromo-2-[(2-hydroxyethylimino)-methyl]phenolo}aquacopper(II) nitrate hemihydrate (I), chloro-{4-bromo-2-[(2-hydroxyethylimino)-methyl]phenolo}copper hemihydrate (II), and chloro-{4-bromo-2-[(2-hydroxyethylimino)-methyl]phenolo}aquanickel (III) are determined using X-ray diffraction. Crystals of compound I are formed by cationic complexes, nitrate ions, and solvate water molecules. In the cation, the copper atom coordinates the singly deprotonated molecule of tridentate azomethine and the water molecule. The copper complexes are joined into centrosymmetric dimers by the O _w -H···O hydrogen bonds. The crystal structure of compound II is composed of binuclear copper complexes and solvate water molecules. The copper atom coordinates the O,N,O ligand molecule and the chlorine ion, which fulfills a bridging function. The coordination polyhedron of the metal atom is a distorted tetragonal bipyramid in which the vertex is occupied by the chlorine atom of the neighboring complex in the dimer. Compound III is a centrosymmetric dimer complex. The coordination polyhedra of two nickel atoms related via the inversion center are distorted octahedra shared by the edge.     

Crystal structures of bis-ligand complexes of copper(II) with 2-[(2-hydroxyethylamino)-methyl]-4,6-dinitrophenol, 2,4-dichloro-6-[(2-hydroxyethylamino)-methyl]phenol, and 2,4-dibromo-6-[(2-hydroxyethylamino)-methyl]phenol

The crystal structures of bis{2,4-dibromo-6-[(2-hydroxyethylamino)-methyl]phenolato}copper (I), bis{2,4-dichloro-6-[(2-hydroxyethylamino)-methyl]phenolato}copper (II), and bis{2-[(2-hydroxyethylamino)-methyl]-4,6-dinitrophenolato}copper (III) in which the metal atom is located at the center of symmetry are determined using X-ray diffraction. Crystals of compounds I and II are isostructural. The copper atom in the structures of compounds I and I coordinates two singly deprotonated bidentate molecules of the ligand through the phenol oxygen atoms and the azomethine nitrogen atoms with the formation of a distorted planar square. In the crystals, complexes I and II form one-dimensional infinite chains along the b axis. In the structure of compound III, the coordination polyhedron of the central atom is an elongated tetragonal bipyramid with the base formed by the azomethine nitrogen atoms and the phenol oxygen atoms. Both vertices of the bipyramid are occupied by the oxygen atoms of the amino alcohol groups of the neighboring complexes, which are related to the initial complex through the center of symmetry. In turn, the oxygen atoms of the alcohol groups of the initial complex are located at the vertices of the coordination bipyramids of the metal atoms of the neighboring centrosymmetric complexes, thus forming infinite polymer chains along the a axis.     

Crystal structures of 6-[(2-hydroxy-1,1-bishydroxymethylethylamino)methylene]-2,4-dinitrocyclohexa-2,4-dienone hydrate and complexes of copper(II) chloride and copper(II) nitrate with this ligand

The crystal structures of 6-[(2-hydroxy-1,1-bishydroxymethylethylamino)methylene]-2,4-dinitrocyclohexa-2,4-dienone hydrate L · H₂O (I), chloro-(2-hydroxymethyl-2-methylpropane-1,3-diol-2-iminomethyl-4,6-dinitrophenolo)aquacopper hydrate [Cu(H₂O)(L-H)Cl] · H₂O (II), and (2-hydroxymethyl-2-methylpropane-1,3-diol-2-iminomethyl-4,6-dinitrophenolo)aquacopper nitrate [Cu(H₂O)(L-H)]NO₃ (III) are determined using X-ray diffraction. It is established that the salicylidene fragment of azomethine L in the structure of compound I is in a quinoid tautomeric form. In the crystal, molecules L and water molecules are joined together by hydrogen bonds into two-dimensional layers aligned parallel to the (010) plane. The copper atom in the structure of compound II coordinates the singly deprotonated tridentate molecule L (whose salicylidene fragment is in a benzenoid form), the chlorine ion, and the water molecule. The coordination polyhedron of the central copper atom is a distorted tetragonal pyramid. In the structure of compound III, the polymer chains are formed through the coordination bonds of the copper atom with two oxygen atoms of the amino alcohol fragment of azomethine L of the neighboring complex, which is related to the initial complex by the translation along the x axis. The coordination polyhedron of the central atom is an elongated tetragonal bipyramid. Polymers and nitro groups form a three-dimensional framework through hydrogen bonds.     

Crystal structures of bis{4-bromo-2-[(2-hydroxyethylimino)methyl]phenolato}copper and bis{4-chloro-2-[(2-hydroxyethylimino)methyl]phenolato}copper

The crystal structures of bis{4-bromo-2-[(2-hydroxyethylimino)methyl]phenolato}copper (I) and bis{4-chloro-2-[(2-hydroxyethylimino)methyl]phenolato}copper (II) are determined. Crystals I are monoclinic, space group P2₁/c, Z = 2, and R = 0.0732 (for all reflections). Crystals II are likewise monoclinic, space group P2₁/n, Z = 2, and R = 0.1106. In the structures of compounds I and II, the metal atom is situated at the center of symmetry and coordinated by two singly deprotonated bidentate 4-bromo-or 4-chloro-2-[(2-hydroxyethylimino)methylphenol molecules, respectively, through phenol oxygen and azomethine nitrogen atoms, which form a distorted planar square. In the structures of compound II, the coordination polyhedron of the central atom is completed to an elongated tetragonal bipyramid by the amino alcohol oxygen atoms of the adjacent complexes.     

Crystal structures of copper(II) nitrate complexes containing 4,4’-bipyridyl and halogen-substituted 2-[(2-hydroxyethylimino)methyl]phenols

The crystal structures of (μ-4,4’-bipyridyl)-di{nitrato-2,4-dibromo-6-[(2-hydroxyethylimino)methyl]phenolo (1-)copper} (I), (μ-4,4’-bipyridyl)-di{nitrato-2,4-dichloro-6-[(2-hydroxyethylimino)methyl]phenolo(1-)copper} (II), and (μ-4,4’-bipyridyl)-{4-chloro-2-[(2-hydroxyethylimino)methyl]phenolo(2-)copper-nitrato-4-chloro-2-[(2-hydroxyethylimino)methyl]phenolo(1-)copper} tetrahydrate (III) are determined. The crystal structures of compounds I and II contain binuclear complexes, in which each copper atom is coordinated by the singly deprotonated tridentate molecule of the corresponding azomethine, the monodentate nitrate ion, and bipyridyl that plays the role of a bridge between the central atoms. In the structures of compounds I and II, the coordination polyhedra of the copper atoms are slightly distorted tetragonal pyramids. The pyramid base is formed by the imine and bipyridyl nitrogen atoms and the phenol and alcohol oxygen atoms. The axial vertices of the pyramids are occupied by the oxygen atoms of the monodentate nitrato groups. The crystal structure of compound III involves tetranuclear complexes in which the coordination polyhedra of the central copper atoms are (4 + 1 + 1) bipyramids. The base of these bipyramids is formed by the imine and bipyridyl nitrogen atoms and the phenol and alcohol oxygen atoms. One apical vertex is occupied by the bridging phenol oxygen atom of the nearest complex. The sixth coordination site of the first copper atom is occupied by the chlorine atom of the salicylidene fragment of the neighboring complex related to the initial complex through the center of symmetry. In turn, the sixth coordination site of the second copper atom is occupied by the oxygen atom of the monodentate nitrato group.     

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.     

Synthesis and crystal structures of nitratocobaltates Na2[Co(NO3)4], K2[Co(NO3)4], and Ag[Co(NO3)3] and potassium nitratonickelate K2[Ni(NO3)4]

The cobalt(II) and nickel(II) nitrate complexes with an island structure (Na₂[Co(NO₃)₄] (I) and K₂[Co(NO₃)₄] (II)] and a chain structure [Ag[Co(NO₃)₃] (III) and K₂[Ni(NO₃)₄] (IV)] are synthesized and investigated using X-ray diffraction. In the anionic complex [Co(NO₃)₄]^2? of the crystal structure of compound I, the Co coordination polyhedron is a twisted tetragonal prism formed by the O atoms of four asymmetric bidentate nitrate groups. In the anion [Co(NO₃)₄]^2? of the crystal structure of compound II, one of the four NO₃ groups is monodentate and the other NO₃ groups are bidentate (the coordination number of the cobalt atom is equal to seven, and the cobalt coordination polyhedron is a monocapped trigonal prism). The crystal structures of compounds III and IV contain infinite chains of the compositions [Co(NO₃)₂(NO₃)_2/2]^? and [Ni(NO₃)₃(NO₃)_2/2]^2?, respectively. In the crystal structure of compound III, seven oxygen atoms of one monodentate and three bidentate nitrate groups form a dodecahedron with an unoccupied vertex of the A type around the Co atom. In the crystal structure of compound IV, the octahedral polyhedron of the Ni atom is formed by five nitrate groups, one of which is terminal bidentate. The data on the structure of Co(II) coordination polyhedra in the known nitratocobaltates are generalized.     

Synthesis and crystal structure of <Emphasis Type="Italic">catena</Emphasis>-bis(nicotinamide)aqua(μ-phthalato)copper(II) hemihydrate

The copper(II) phthalate complex with nicotinamide [CuL ₂(μ-Pht)(H₂O)] · 0.5H₂O(I) (where L is nicotinamide and Pht ^2? is an anion of phthalic acid) is synthesized and investigated using IR spectroscopy and X-ray diffraction. The crystals of compound I are monoclinic, a = 13.368(2) Å, b = 7.891(3) Å, c = 20.480(2) Å, β = 108.69(2)°, Z = 4, and space group P2₁/c. The structural units of crystal I are linear chains formed by bridging phthalate anions and crystallization water molecules. The copper atom is coordinated by two pyridine nitrogen atoms of two nicotinamide ligands (Cu-N, 2.001 and 2.045 Å), two oxygen atoms of different phthalate anions (Cu-O, 1.964 and 2.235 Å), and the oxygen atom of the H₂ O molecule (Cu-O, 2.014 Å). The coordination polyhedron of the copper atom is completed to an elongated (4 + 1 + 1) tetragonal bipyramid by the second (chelating) oxygen atom of the carboxyl group (Cu-O, 2.587 Å), which is one of the anions of phthalic acid. The linear polymer molecules are joined into complex macromolecular dimers with the closest internal contacts of the specific type. The macromolecular dimers are the main supramolecular ensembles of the crystal structure.     

Specific stereochemical features of metallochelate complexes with tridentate <Emphasis Type="Italic">N,N,N</Emphasis>(<Emphasis Type="Italic">N,N</Emphasis>,O)-donating ligands

Earlier X-ray diffraction studies of a series of 12 adducts (I–XII) between metallochelate complexes [M = Co(II), Ni(II), and Cu(II)] with tridentate N,N,N(N,N,O)-donating Schiff bases (L) and monodentate or bidentate ligands (L′) revealed a similarity in the stereochemistry of these compounds. The coordination polyhedron of metal atoms in compounds I–XII is a tetragonal pyramid (bipyramid) with two vertices occupied competitively. The L ligand occupies three coordination sites in the base of the pyramid. The L′ ligand approaches the metal atom, as a rule, in a direction perpendicular to the basal plane. The fourth site in the base of the pyramid and the apical vertex are occupied competitively. Different patterns of occupation of these positions are observed: they include the donor atoms of both the L and L′ ligands.     

Crystal and molecular structure of 2-(2-pyridyl)-indandione-1,3 and a zinc(II) complex with this ligand

The crystal structures of 2-(2-pyridyl)-indandione-1,3 C₁₄H₉NO₂ (HL, I) and the zinc complex ZnL ₂(Dmso) (II) (where Dmso is dimethyl sulfoxide) with this ligand are determined. The specific features of the crystal structures of both compounds are considered. A comparative analysis of the supramolecular aggregates in crystals of these compounds is performed. It is demonstrated that the supramolecular dimers retain their structure in the crystals of compounds I and II. These dimers are involved in weak secondary interactions (usually of one type) with the formation of spatially more complex supramolecular associates, such as chains, ribbons, and layers.     

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 and molecular structure of four adamantyl-substituted tetrazoles

Four adamantyltetrazoles—1-(1-adamantyl)tetrazole (I), 2-(1-adamantyl)tetrazole (II), 2-(3-aminoadamantyl-1)tetrazole (III), and 2-(3-aminoadamantyl-1)-5-methyltetrazole (IV)—are synthesized, and their crystal structures are studied. It is found that the tetrazole rings in the 1-substituted molecule I and 2-substituted molecules II–IV have close linear parameters but differ significantly in endocyclic angles. The degree of delocalization of double bonds in I is somewhat smaller than that in II–IV. The identical relative orientation of the tetrazole ring and adamantyl fragment in I–IV is stabilized by intramolecular C-H...N interactions (H...N, 2.57(2)–2.76(2) Å). The molecular packings of crystals I–IV are determined by weak intermolecular C-H...N interactions; in III and IV, the packings are in addition affected by N-H...N interactions that involve NH₂ groups. In the series of compounds I–IV, a qualitative dependence of the lengths of intermolecular H...N contacts and antiviral activity on the basicity of nitrogen atoms in the molecules is revealed.     

Crystal and molecular structures of dimethyl 4-phenylthiosemicarbazidediacetate and its adduct with rhodium(II) acetate

The crystal structures of dimethyl 4-phenylthiosemicarbazidediacetate C₁₃H₁₇N₃O₄S (I) and its adduct [C₈H₁₂O₈Rh₂ (C₁₃H₁₇N₃O₄S)₂] (II) with rhodium(II) acetate are determined by X-ray diffraction analysis. The unit cell parameters of crystals I are as follows: a = 8.066(6) Å, b = 15.812(6) Å, c = 24.977(8) Å, β = 94.88(3)°, space group P2₁/n, and Z = 8. The unit cell parameters of crystals II are a = 8.513(1) Å, b = 16.055(1) Å, c = 16.071(3) Å, β = 104.99(1)°, space group P2₁/c, and Z = 2. In structure I, two crystallographically independent molecules considerably differ from each other in the mutual orientation of the structural fragments containing the ester groups. In the centrosymmetric dimeric complex II, the organic molecule I acts as a monodentate thio ligand and adopts only one conformation.     

Crystal structures of complexes of the <Emphasis Type="Italic">cys-syn-cys</Emphasis> isomer of dicyclohexano-18-crown-6 with oxonium hexafluorotantalate and oxonium hexafluoroniobate

The crystal structures of [(cys-syn-cys-dicyclohexano-18-crown-6 · H₃O)][TaF₆] and [(cys-syn-cys-dicyclohexano-18-crown-6 · H₃O)][NbF₆] complex compounds are determined using X-ray diffraction analysis. The tantalum complex has two polymorphic modifications, namely, the monoclinic (I) and triclinic (II) modifications. The unit cell parameters of these compounds are as follows: a = 8.507(4) Å, b = 11.947(5) Å, c = 27.392(12) Å, β = 93.11(1)°, Z = 4, and space group P2₁/n for modification I; and a = 10.828(1) Å, b = 11.204(1) Å, c = 12.378(1) Å, α = 72.12(1)°, β = 79.40(1)°, γ = 73.70(1)°, Z = 2, and space group P-1 for modification II. The triclinic niobium complex [(cys-syn-cys-dicyclohexano-18-crown-6 · H₃O)][NbF₆] (III) with the unit cell parameters a = 10.796(3) Å, b = 11.183(3) Å, c = 12.352(3) Å, α = 72.364(5)°, β = 79.577(5)°, γ = 73.773(4)°, Z = 2, and space group P-1 is isostructural with tantalum complex II. The structures of all three complexes are ionic in character. The oxonium cation in complexes I–III is encapsulated by the crown ether and thus forms one ordinary and two bifurcated hydrogen bonds with the oxygen atoms of the crown ether. This macrocyclic cation is bound to the anions through the C-H...F contacts (H...F, 2.48–2.58 Å). The conformation of the macrocycle in complex I differs substantially from that in complex II (III).     

Molecular, crystal, and electronic structure of the cobalt(II) complex with 10-(2-benzothiazolylazo)-9-phenanthrol

The reaction of 10-(2-benzothiazolylazo)-9-phenanthrol (HL) with cobalt(II) acetate gives the coordination compound [CoL ₂] · CHCl₃ (I). The molecular and crystal structure of I is determined by X-ray diffraction. The coordination polyhedron of the Co atom in complex I is an octahedron. The anion L acts as a tridentate chelating ligand and is coordinated to the Co atom through the phenanthrenequinone O1 atom and the benzothiazole N1 atom of the moieties L and the N3 atom of the azo group to form two five-membered metallocycles. The molecular and electronic structures of the compounds HL, L, and CoL ₂ are studied at the density functional theory level. The results of the quantum-chemical calculations are in good agreement with the values determined by X-ray diffraction.     

Five-coordinate Co(II) complexes with nitrilotriacetic acid: Crystal structures of Ca[Co(Nta)X] · nH2O (X − = Cl, Br, or NCS)

The synthesis and X-ray diffraction study of three Ca[Co(Nta)X] · nH₂O complexes [X ^? = Cl, n = 2.3 (I); X ^? = Br, n = 2 (II); and X ^? = NCS, n = 2 (III)] are performed. The main structural units of crystals I–III are the [CoX(Nta)]^2? anionic complexes and hydrated Ca²⁺ cations. The anionic complexes have similar structures. The coordination of the Co²⁺ atom in the shape of a trigonal bipyramid is formed by N + 3O atoms of the Nta ^3? ligand and the X ^? anion in the trans position with respect to N. In structures I–III, the Co-O and Co-N bond lengths lie in the ranges 1.998–2.032 and 2.186–2.201 Å, respectively. The Co-X bond lengths are 2.294 (I), 2.436 and 2.445 (II), and 1.982 Å (III). The environments of the Ca²⁺ cations include oxygen atoms of one or two water molecules and six or seven O(Nta) atoms with the coordination number of 9 in I or 8 in II and III. The Ca-O(Nta) bonds form a three-dimensional framework in I or layers in II and III. Water molecules are involved in the hydrogen bonds O(w)-H···O(Nta), O(w)-H···X, and O(w)-H···O(w). Structural data for crystals I–III are deposited with the Cambridge Structural Database (CCDC nos. 287 814–287 816).     

Crystal structure of [<Emphasis Type="Italic">N</Emphasis>-(2-aminoethyl)iminodiacetato](1,10-phenanthroline)copper(II) tetrahydrate, [Cu(<Emphasis Type="Italic">Aeida</Emphasis>)(<Emphasis Type="Italic">Phen</Emphasis>)] · 4H<Subscript>2</Subscript>O

Crystals of [N-(2-aminoethyl)iminodiacetato](1,10-phenanthroline)copper(II) tetrahydrate, [Cu(Aeida)(Phen)] · 4H₂O (I), are obtained, and their structure is determined. Crystals I are triclinic, and the unit cell parameters are as follows: a = 8.341(1) Å, b = 9.424(1) Å, c = 13.864(2) Å, α = 74.23(1)°, β = 79.25(1)°, γ = 82.67(1)°, Z = 2, and space group P1. The structural units of the crystal are [Cu(Aeida)(Phen)] molecular complexes and crystallization water molecules. The coordination polyhedron of the copper atom is a tetragonal bipyramid with four nitrogen atoms in the equatorial plane (mean Cu-N, 2.05 Å) and two oxygen atoms of the acetate groups in axial positions (Cu-O, 2.264 and 2.426 Å; O-Cu-O angle, 148.8°). The Aeida and Phen ligands fulfill the tetradentate (2N + 2O) chelate and bidentate (2N) chelate functions, respectively. The complexes are joined into dimer associates in which the interplanar spacing between Phen molecules is equal to 3.54 Å and the Cu?Cu distance is 7.02 Å.     

Supramolecular architecture of two charge-transfer complexes based on 2,7-(X, X)-4,5-dinitro-9-dicyanomethylenefluorenes (X = NO2 or CN) and tetrathiafulvalene

The crystal packings of two charge-transfer complexes based on tetrathiafulvalene and substituted fluorenes-2,4,5,7-tetranitro-9-dicyanomethylenefluorene (in complex I) or 2,7-dicyano-4,5-dinitro-9-dicyanomethylenefluorene (in complex II)— are analyzed. Crystals of complex II involve a third component, namely, C₆H₅Cl solvate molecules. Crystals of both complexes are characterized by the formation of stacks composed of alternating donor and acceptor molecules and sheets in which the molecules are linked through different-type weak interactions. In structure II, chlorobenzene molecules occupy cavities that are formed in stacks in the vicinity of the tetrathiafulvalene molecules due to the larger difference in size of the donor and acceptor molecules in complex II as compared to that in complex I. The chlorobenzene molecules provide a close packing. These molecules are involved in the system of weak interactions to form the Cl?N and C-H?N secondary bonds with the CN groups of the acceptor molecules in the sheets.     

Structures of nitrato-(2-hydroxybenzaldehydo) (2,2′-bipyridyl)copper and nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2′-bipyridyl)copper

Nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2′-bipyridyl)copper (I) and nitrato-(2-hydroxybenzaldehydo)(2,2′-bipyridyl)copper (II) were synthesized and characterized by X-ray diffraction. The coordination polyhedron of the central copper atom in complex I can be described as a distorted tetragonal pyramid whose base is formed by the phenol and carbonyl oxygen atoms of the monodeprotonated 2-hydroxy-5nitrobenzaldehyde molecule and the nitrogen atoms of the 2,2′-bipyridyl ligand and whose apex is occupied by the oxygen atom of the nitrato group. In the crystal structure, complexes I are linked by the acido ligands and the NO₂ groups of the aldehyde molecule into infinite chains. In complex II, the central copper atom is coordinated by 2-hydroxybenzaldehyde, 2,2′-bipyridyl, and the nitrato group, resulting in the formation of centrosymmetric dimers. The coordination polyhedron of the central copper atom can be described as a bipyramid (4 + 1 + 1) with the same base as in complex I. The axial vertices of the bipyramid are occupied by the oxygen atom of the nitrato group and the bridging phenol oxygen atom of the adjacent complex related to the initial complex by a center of symmetry. In the crystal structure, complexes II are hydrogen bonded into infinite chains.