Synthesis and Structural Characterization of <Emphasis Type="Italic">N</Emphasis>-(2-Pyridylmethyl)-3-Methoxysalicylaldiminato Copper(II) Chloride

Abstract  The copper(II) complex [Cu(C₅H₄NCH₂−N=CH–C₆H₃OCH₃–O)Cl], (1) containing a new tridentate Schiff base ligand (LH), which is the 1:1 condensation product of 2-(aminomethyl)pyridine and o-vaniline, has been synthesised and characterized by IR and UV–Vis spectra. Structural investigation shows that 1 crystallizes to a monoclinic system, having space group P2(1)/c, a = 6.9634(7), b = 18.1209(19), c = 10.3448(11) ?, α = 90°, β = 103.97(2)°, γ = 90° and Z = 4. The coordination geometry around the copper atom is slightly distorted square planar, formed by the N₂O donor set of the Schiff base and one Cl atom. The Cu–N(1), Cu–N(2), Cu–O(1) and Cu–Cl bond distances are 2.0114(14), 1.9414(14), 1.9147(12) and 2.2520(5) ?, respectively. Index Abstract  The copper(II) complex [Cu(C₅H₄NCH₂−N=CH–C₆H₃OCH₃–O)Cl], (1) containing a tridentate Schiff base ligand (LH), synthesised and characterized by IR and UV–Vis spectra. The central copper ion possesses a distorted square-planar geometry.      

Crystal and Molecular Structure of Dichloro(ethylenediamine)gold(III) Nitrate: [Au(NH<Subscript>2</Subscript>CH<Subscript>2</Subscript>CH<Subscript>2</Subscript>NH<Subscript>2</Subscript>)Cl<Subscript>2</Subscript>]NO<Subscript>3</Subscript>

Abstract  The gold(III) atom in [Au(NH₂CH₂CH₂NH₂)Cl₂]NO₃ is chelated by the ethylenediamine (en) ligand and the approximately square planar geometry is completed by two chloride atoms. Weak Au···O and Au···Cl contacts are noted above and below the square plane leading to a tetragonally distorted octahedron for the gold(III) center. Extensive charge-assisted hydrogen bonding of the type N–H···O leads to the formation of a 2-D array and layers are consolidated into a 3-D network via C–H···O and C–H···Cl contacts. The compound crystallizes in the orthorhombic space group Pbca with a = 10.3380(11) ?, b = 8.2105(7) ?, c = 19.625(2) ?, and Z = 8. Index Abstract  Square planar complex cations form additional Au···O and Au···Cl interactions to form a tetragonally distorted octahedron for gold. The ionic components are connected into a 2-D array via charge-assisted N–H···O hydrogen bonding interactions.      

Solvothermal Synthesis and Crystal Structure of a 18-Membered Macrocycle Schiff Base Dinuclear Copper(II) Complex: Cu2(NO3)4(APTY)4 (APTY = 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one)

Abstract  A new 18-membered macrocycle Schiff base dinuclear copper(II) complex: Cu₂(NO₃)₄(APTY)₄ (1) (APTY = 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one), has been successfully synthesized by solvothermal treatment of Cu(NO₃)₂ · 6H₂O with APTY. Compound 1 crystallizes in the triclinic space group P-1 with cell parameters: a = 10.556(2) ?, b = 12.075(2) ?, c = 15.230(3) ?, α = 74.75(3), β = 81.50(3), γ = 70.60(3)°, V = 1762.7(6) ?³, R1 = 0.0493, wR2 = 0.1400, Z = 1, D _calc = 1.455 g/cm³, F(000) = 798, S = 1.009. In the compound molecules, each of the six-coordinated Cu^II atoms are bridged by APTY ligands into 18-membered macrocycle, and each the Cu²⁺ atoms exhibits a significantly distorted octahedral geometry. The crystal packing is stabilized by C–H···O hydrogen-bonding interactions into a three-dimensional supramolecular framework. Index Abstract  A new 18-membered macrocycle Schiff base dinuclear copper(II) complex: Cu₂(NO₃)₄(APTY)₄ (1), has been successfully synthesized by solvothermal treatment (APTY = 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one). The six-coordinated Cu²⁺ atom exhibit significantly distorted octahedral geometry. The crystal packing is stabilized by C–H···O hydrogen-bonding interactions into a three-dimensional supramolecular framework.     

Supramolecular Aggregation in the 1:1 Co-crystal Formed Between Merocyanine Dye and 3-Nitrophenol,Characterized as a Hydrate

Abstract  The title organic salt comprises a (E)-4-[2-(4-hydroxyphenyl)vinyl]-1-methylpyridinium cation, a 3-nitro-phenoxide anion and a solvent water molecule of crystallisation. The anions and water molecules aggregate to form supramolecular chains facilitated by charge-assisted O–H···O hydrogen bonds and these form layers which are interspersed by layers of cations. Interactions between layers include O–H···O hydrogen bonding, as well as C–H···O and C–H···π contacts; π···π and C–H···O contacts are found within layers of cations. The compound crystallizes in the monoclinic space group P2₁/n with a = 15.018(7) ?, b = 7.328(2) ?, c = 17.571(7) ?, β = 112.342(15)°, and Z = 4. Index Abstract  A layer structure comprising alternating anions/water molecules and cations associated via charge-assisted O–H···O hydrogen bonding as well as C–H···O, C–H···π and π···π contacts is found in (II) .     

Synthesis and Crystal Structure of a Novel Double-Chain Coordination Polymer [Zn<Subscript>2</Subscript>(bipy)<Subscript>2</Subscript>(btec)(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>]<Subscript>n</Subscript> (bipy = 2,2′-bipyridine; btec = 1,2,4,5-benzenetetracarboxylate)

Abstract  A novel aromatic polycarboxylate polymer, [Zn₂(bipy)₂(btec)(H₂O)₂]_n (1), has been synthesized and structurally characterized by the single crystal X-ray diffraction. Compound 1 belongs to the triclinic crystal system, space group P-1; a = 7.7449(6) ?, b = 8.9286(8) ?, c = 10.7422(8) ?, α = 80.95(1)°, β = 70.21(1)°, γ = 78.14(1)°, V = 680.93(10) ?³, Z = 2. The coordination geometry of Zn(II) atom is distorted trigonal bipyramidal with two nitrogen atoms of one 2,2′-bipy group, two oxygen atoms from two different btec ligands, and one water. The 16-membered rings are alternately arranged forming an infinite 1-D double-chain structure. A 3-D network was constructed by interlayer C···H–O, O···H–O hydrogen bonds and π–π stacking interactions. Compound 1 exhibits fluorescence at room temperature in the solid state. Graphical Abstract  A 1-D double-chain aromatic polycarboxylate polymer, [Zn₂(bipy)₂(btec)(H₂O)₂]_n (1), has been synthesized and structurally characterized by the single crystal X-ray diffraction. A 3-D network was constructed by intermolecular C···H–O, O···H–O hydrogen bonds and π–π stacking interactions. Compound 1 exhibits fluorescence at room temperature in the solid state.      

Hydrogen Bonding in the Crystal Structures of New Imidazolium Triflimide Protic Ionic Liquids

Abstract  The synthesis and crystal structures of 1,3-diamino-2-methylimidazolium bis(trifluoromethylsulfonyl)imide (1), 1,3-dihydroxy-2-methylimidazolium bis(trifluoromethylsulfonyl)imide (2) and 1-(2-(diethylammonio)ethyl)-3-methylimidazolium bis(bis(trifluoromethylsulfonyl)imide) (4) are reported. The salts 1, 2 and 4 have melting points below 100 °C, the intermediate 1-(2-(diethylamino)ethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (3) is liquid at room temperature. Compound 1 is monoclinic, space group P2₁/n with a = 8.4979(4) ?, b = 12.2803(6) ?, c = 13.9400(7) ?, β = 93.086(4)°, and Z = 4. Compound 2 is monoclinic, space group P2₁/c with a = 7.6165(2) ?, b = 20.5323(8) ?, c = 9.7654(3) ?, β = 111.046(2)°, and Z = 4. Compound 4 is triclinic, space group with a = 8.5313(4) ?, b = 9.2157(4) ?, c = 20.5812(8) ?, α = 84.668(2)°, β = 83.738(2)°, γ = 63.096(2)°, and Z = 2. The ions in 1 build a network of N–H···O hydrogen bonds, in 2 they are linked to chains by O–H···N and bifurcated O–H···O hydrogen bonds, whereas in 4 they form pairs by N–H···O contacts. The triflimide anions adopt transoid conformations. Index Abstract  Short interionic contacts, conformational flexibility, and disorder phenomena were identified in the crystal structures of three new, low-melting, protic imidazolium triflimides.      

Syntheses and Crystal Structures of Two CuII Coordination Isomers [Cu(pmt)2] · 4H2O (1) and {[Cu(pmt)2] · 2H2O} n (2)

Abstract  A pair of Cu^II coordination isomers [Cu(pmt)₂] · 4H₂O (1) and {[Cu(pmt)₂] · 2H₂O} _n (2) [Hpmt = 2-(2-pyridylmethylamino) ethanesulfonic acid] have been prepared by reaction of the same proportion CuCl₂ · 2H₂O and Hpmt but with different experimental methods in water–methanol mixed solution, and were characterized by X-ray diffraction, elemental analysis, IR spectrum. X-ray analysis indicates that complex (1) is a mononuclear complex in which two deprotonated pmt ligands coordinate in a facial tridentate arrangement about the Cu^II atom. While complex (2) is a coordination polymer, in which four N atoms of pmt ligands coordinate to one Cu^II atom but its sulfonate O atoms bond to adjacent Cu^II atom. Thus 12-membered rings (–Cu–N–C–C–S–O–)₂ are obtained between two neighbouring Cu^II atoms and they connect one another to form this new polymer. Crystal data: [Cu(pmt)₂] · 4H₂O (1), Mr = 566.10, monoclinic, P2 ₁/c, a = 9.1950(8) ?, b = 11.5093(10) ?, c = 11.2304(10) ?, β  = 105.5550(10)°, Z = 2, V = 1144.96(17) ?³, R ₁  = 0.0407, wR ₂  = 0.1242 [I > 2σ (I)]; {[Cu(pmt)₂] · 2H₂O} _n (2), Mr = 530.07, triclinic, P-1, a = 7.6165(19) ?, b = 8.806(2) ?, c = 9.592(4) ?, α = 104.933(4)°, β = 106.732(4)°, γ = 109.503(3)°, Z = 1, V = 534.2(3) ?³, R ₁ = 0.0470, wR ₂ = 0.1082 [I > 2σ(I)]. Index Abstract  A pair of Cu^II coordination isomers [Cu(pmt)₂] · 4H₂O (1) and {[Cu(pmt)₂] · 2H₂O} _n (2) [Hpmt = 2-(2-pyridylmethylamino) ethanesulfonic acid] have been prepared by reaction of the same proportion CuCl₂ · 2H₂O and Hpmt but with different experimental methods in water–methanol mixed solution.      

Novel Complexes of Zinc(II) with Different Proton Transfer Ion Pairs Obtained from Dipicolinic Acid: Synthesis, Characterization and X-ray Crystal Structure

Abstract  Three new complexes of zinc(II) with three different proton transfer compounds, obtained from pyridine-2,6-dicarboxylic acid (dipicolinic acid) and different Lewis bases, were synthesized and characterized using IR, ¹H NMR and ¹³C NMR spectroscopy and single crystal X-ray diffraction. The chemical formulae and space groups of the complexes are (pipzH₂)[Zn(pydc)₂] · 4H₂O, P2₁/n (1), (EDGnH₂)[Zn(pydc)₂] · 3H₂O, P2₁/c (2) and (pdaH₂)[Zn(pydc)₂] · 4H₂O, (3) where pydc, pipz, EDGn and pda are standing for dipicolinic acid, piperazine, ethylenediguanidine and 1,3-propanediamine respectively. Cell parameters of the complexes are a = 7.9493(4) ?, b = 13.4386(7) ?, c = 21.0557(11) ?, β = 90.415(5)° for 1; a = 9.785(3) ?, b = 25.671(4) ?, c = 9.3402(16) ?, β = 90.790(17)° for 2 and a = 8.411(5) ?, b = 11.650(7) ?, c = 12.793(8) ?, α = 115.534(9)°, β = 92.791(10)°, γ = 97.778(10)° for 3. The three crystal structures illustrate that the metal ion is six-coordinated by two pydc’s. In all three compounds a large number of O–H⋯O, N–H⋯O and C–H⋯O hydrogen bonds are observed. These interactions as well as other noncovalent interactions such as ion–pairing and π–π stacking play an important role in the formation and stabilization of supramolecular systems in the crystal lattices. Index Abstract  The main purpose of this paper is to report and discuss about the synthesis, characterization, crystal structure and non-covalent interactions of three supramolecular frameworks of six-coordinated Zn(II) complexes, obtained by the reaction of different proton transfer compounds, i.e. (pipzH₂)(pydc), (EDGnH₂) (pydc) · 3H₂O and (pdaH₂)(pydc) · (pydcH₂) · 2.5H₂O with corresponding metallic salts.      

Crystal Structure of Antitubercular Complex: <Emphasis Type="Italic">cis</Emphasis>-(chloro)-[<Emphasis Type="Italic">N,N</Emphasis>′-<Emphasis Type="Italic">bis</Emphasis>-(diethyl-2,2′-bipyridine-3,3′-dicarboxylate)]ruthenium(II) Monohydrate

Abstract  Diethyl-2,2′-bipyridine-3,3′-dicarboxylate (3 or L) reacts with RuCl₃ · 3H₂O to give cis-(Cl)-[Ru(L)₂Cl₂] · H₂O (4) and structure of the complex was determined by spectral (IR, ¹H-NMR), and mass spectroscopic data, elemental analyses and X-ray crystallography. The structure is solved in triclinic, space group p-1 with a = 10.658 (2), b = 12.446 (3), c = 14.186 (5) ?, α = 104.856 (3), β = 108.704 (3), γ = 94.973 (2)°, V = 1693.2 (8) ?³, Z = 2 with final R = 0.012. The geometry of the complex is shown to be a distorted octahedral with four nitrogens of two 2,2′-bipyridyl ligands in two different planes with Ru–N distance as 2.021 (2)−2.071 (3) ?. The cis-position is occupied by two chloride atoms with Ru–Cl distance as 2.4156 (12) and 2.4167 (13) ?. The trans-axial Cl2–Ru1–N and Cl1–Ru1–N4 angles are respectively, 172.42 (7) and 174.12 (7)°. A weak hydrogen bonding is observed between the two chlorides and hydrogens of neighbouring molecule [C–H···Cl distance as 2.72, 2.77 (4) ?]. A second type of weak hydrogen bonding is also observed between the oxygens of carboxylate groups and hydrogens of a neighbouring molecule [C–H···O distance as 2.53, 2.56 and 2.34 (4) ?]. Graphical Abstract  The structure of anti-tubercular precursor complexes, cis-(chloro)-[N,N′-bis-(diethyl-2,2′-bipyridine-3,3′-dicarboxylate)]ruthenium(II) monohydrate is solved by single crystal X-ray diffraction analysis which reveals geometry of the complex to be a distorted octahedral with four nitrogens of two 2,2′-bipyridyl ligands in two different planes. The cis-position is occupied by two chloride atoms.      

Two Mononuclear Compounds with bis(Pyrimidin-2-yl)amine as a Ligand and as a Hydrogen-bonded Lattice Molecule. Synthesis, Structure and Spectroscopy of {[M(dipm)(H2O)(A)](dipm)(A)(H2O)} (M?=?Cd with A?=?ClO4; and Zn with A?=?BF4)

Abstract  Two isostructural mononuclear compounds with formula {[Cd(dipm)(H₂O)(ClO₄)](dipm)(ClO₄)(H₂O)} (1) {[Zn(dipm)(H₂O)(BF₄)](dipm)(BF₄)(H₂O)} (2) and (in which dipm = bis(pyrimidin-2-yl)amine) have been synthesised and characterised by X-ray crystallography and infrared spectroscopy. The structure of compound 1 has been solved in the space group P2₁/n with a = 18.860(4), b = 8.579(2), c = 20.917(4) ?, β = 101.33(3)°, V = 3318.4(12) ?³, Z = 4 with final R = 0.0454. The structure of compound 2 has also been solved in the space group P2₁/n with a = 19.026(4), b = 8.389(1), c = 20.720(4) ?, β = 101.37(3)°, V = 3242.2(10) ?³, Z = 4 with final R = 0.0689. The geometry around the metal ions is octahedral, and is constituted by four nitrogen atoms from two dipm molecules, an oxygen atom from a water molecule and a semi-coordinating anion atom ( for compound 1 and for compound 2). In the lattice are also present: a non-coordinating water molecule, an anion molecule and a dipm molecule. For compound 1, the Cd–N distances are between 2.296 and 2.328 ?. The distance is 2.310 ? and the is 2.477 ?. The Zn–N distances in compound 2 are between 2.121 and 2.164 ?. The distance is 2.147 ? and the distance is 2.373 ?. A hydrogen bond interaction of the Watson–Crick type is observed between the amine N atom of a dipm ligand to a pyrimidyl N atom and a non-coordinating dipm ligand with N···N distances, which vary from 3.066(5) to 3.109(5) ?. Furthermore medium to strong hydrogen bond interactions are present between oxygen atoms of the water molecules and the anions of the compounds. Index Abstract  Two isostructural mononuclear compounds with formula {[Cd(dipm)(H₂O)(ClO₄)](dipm)(ClO₄)(H₂O)} (1) {[Zn(dipm)(H₂O)(BF₄)](dipm)(BF₄)(H₂O)} (2) and (in which dipm = bis(pyrimidin-2-yl)amine) have been synthesised and characterised by X-ray crystallography and infrared spectroscopy. . Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Crystal Structure of 2-Thiophenecarboxamide: A One-dimensional Tubular Structure Formed by N–H···O Hydrogen Bonds

Abstract  The crystal structure of 2-thoiphenecarboxamide is described. The compound crystallizes in the orthorhombic Pna2₁ space group with unit cell parameters a = 10.044 (3) ?, b = 14.203 (4) ? and c = 15.941 (3) ?; V = 2,274.1 (10) ?³. The asymmetric unit contains four independent molecules which are linked by N–H···O hydrogen bonds. The asymmetric unit at (x, y, z) is connected with another one, produced by the a-glide plane at 0.75 along the b-axis, that lies at (x + 0.5, −y + 1.5, z) by two N–H···O hydrogen bonds and by a C–H···O weak hydrogen bond to form a one-dimensional tube. Adjacent tubes are linked by C–H···pi interactions to form a three-dimensional framework. Graphical Abstract  The crystal structure of 2-thiophenecarboxamide, contains four crystallographically independent molecular components in the asymmetric unit linked by four N–H···O hydrogen bonds and a weak C–H···O hydrogen bond and form a one-dimensional tube. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Crystal and Molecular Structure of the 1:2 Salt Formed Between 1,2-(4-Pyridyl)Ethane and 2-(4-Hydroxyphenylazo)Benzoic Acid

Abstract  Proton transfer occurred during co-crystallization of 1,2-(4-pyridyl)ethane with 2-(4-hydroxyphenylazo)benzoic acid to yield a salt comprising a 1:2 ratio of 1,2-bis(4-pyridinium)ethane dications and 2-(4-hydroxyphenylazo)benzoate anions. Centrosymmetrically related anions associate by charge-assisted O–H···O hydrogen bonds to form 24-membered {···OC₃N₂C₄OH}₂ synthons. These are connected into a supramolecular polymer via charge-assisted N–H···O hydrogen bonds involving the 1,2-bis(4-pyridinium)ethane dications. The compound crystallizes in the triclinic space group P−1 with a = 8.517(4) ?, b = 9.110(5) ?, c = 10.477(5) ?, α = 96.850(13)°, β = 94.446(12)°, γ = 104.946(10)° and Z = 1 {two anions and a dication}. Index Abstract  Supramolecular chains mediated by charge-assisted O–H···O and N–H···O hydrogen bonding are found in the salt containing a 1:2 ratio of 1,2-bis(4-pyridinium)ethane dications and 2-(4-hydroxyphenylazo)benzoate anions.      

Supramolecular Interactions in the Adduct of Di-triethylammonium,tetrachlorobenzene-1,4-dicarboxylate and tetrachlorobenzene-1,4-dicarboxylic acid

Abstract  The adduct of di-triethylammonium, tetrachlorobenzene-1,4-dicarboxylate and tetrachlorobenzene-1,4-dicarboxylic acid, i.e. {2(C₂H₅)₃NH⁺ C₈Cl₄O₄²⁻ H₂C₈Cl₄O₄}, crystallizes in triclinic, P-1 with cell dimensions of a = 8.5080(5) ?, b = 8.9789(6) ?, c = 12.5212(8) ?, α = 93.301(1)°, β = 109.107(1)°, γ = 103.565(1)°, V = 869.2(1) ?³ and Z = 2. The C₈Cl₄O₄²⁻ and H₂C₈Cl₄O₄ moieties link with each other by O–H···O along c axis, C–Cl···O=C along b axis and C–Cl···Cl–C along a axis to form the 3D framework of the crystal structure. The (C₂H₅)₃NH⁺ cations reside in the cavities of the 3D framework via various intermolecular interactions such as N–H···O, C–H···O and C–H···π. Index Abstract  In the title compound, tetrachlorobenzene-1,4-dicarboxylates and tetrachlorobenzene-1,4-dicarboxylic acids form 3D framework by hydrogen bonds and halogen bonds, and triethylammoniums reside in the voids of the framework via supramolecular interactions .     

Synthesis and Crystal Structure of a Polymorph of the DMF Solvate of the Dicoppertetracarboxylate Paddlewheel Complex Cu<Subscript>2</Subscript>(p-aminobenzoate)<Subscript>4</Subscript>(DMF)<Subscript>2</Subscript>

Abstract  Reaction between p-aminobenzoic acid (HpABA) and Cu(NO₃)₂ · 2.5H₂O in basic MeOH/DMF affords green crystals of the dicopper paddlewheel complex, Cu₂(pABA)₄(DMF)₂ · 2DMF, 1, identified by single crystal X-ray crystallography: triclinic P-1, with a = 10.3728(2) ?, b = 10.617(2) ?, c = 11.128(2) ?, α = 81.705(3)°, β = 79.984(2)°, γ = 65.965(2)° and Z = 2. The crystal structure of 1 reveals that it is the second polymorph of Cu₂(pABA)₄(DMF)₂ · 2DMF and experiments on the stability of 1 indicate that it can be converted to Form I through desolvation followed by exposure to DMF. Graphical Abstract  Crystal structure of a polymorphic discrete dicoppertetracarboxylate is investigated for the conversion between the two forms influenced by hydrogen bonds.      

Synthesis and Crystal Structure Analysis of Thiourea-Pendant Pyridines

Abstract  The crystal structures of pyridine containing thiourea moieties as substituents, (1) and (2), have been determined. The ortho-substituted pyridine (1) crystallized in monoclinic space group P2₁/c with a = 16.091(3) ?, b = 11.368(2) ?, c = 7.4364(14) ?, β = 100.489(4)o, V = 1337.5(4) ?³, z = 4. In this structure an intramolecular N–H···N hydrogen bond forms a pseudo-seven-membered ring. The meta-substituted pyridine (2) crystallized in monoclinic space group P2₁/c with a = 14.5408(15) ?, b = 8.8508(9) ?, c = 10.7959(11) ?, β = 106.435(2)o, V = 1332.6(2) ?³, z = 4. Crystal packing revealed that compounds (1) and (2) can form dimeric structures via intermolecular H-bonding using N–H···S and N–H···N interactions, respectively. Graphical Abstract  Varying the substituent position on the pyridine ring using thiourea moieties gave unique molecular aggregations in solid state structures.      

C–H···F Hydrogen-Bonded Assembly of Ni(II) and Cu(II) Complexes Generate 3D Supramolecular Frameworks

Abstract  Syntheses and X-ray structural characterizations of two new complexes [Ni(imi)₆](pfbz)₂ (1) and Cu(imi)₂(pfbz)₂ (2) (imi = imidazole, pfbz = pentafluorobenzoate) are reported. The first complex crystallizes in the triclinic space group P-1 with the crystal cell parameters a = 9.180(2) ?, b = 9.742(3) ?, c = 11.466(3) ?, α = 76.947(18)°, β = 80.629(18)°, γ = 78.043(19)°, V = 970.0(4) ?³ and Z = 1. The second complex crystallizes in the triclinic space group P-1 with the crystal cell parameters a = 7.3250(12) ?, b = 7.6685(10) ?, c = 10.888(4) ?, α = 92.80(2)°, β = 101.92(2)°, γ = 115.038(12)°, V = 535.7(2) ?³ and Z = 1. Examination of the structures shows that both complexes form three-dimensional hydrogen bonded networks in which C–H···F hydrogen bonds play significant roles. Index Abstract   C–H···F Hydrogen-Bonded Assembly of Ni(II) and Cu(II) Complexes Generate 3D Supramolecular Frameworks Chun-Hua Ge, Xiao-Yan Zhang, Fang Yu, Ya-Nan Guo, Xiang-Dong Zhang* and Qi-Tao Liu C–H···F interactions link simple complexes to form intricate three-dimensional supramolecular networks.      

Synthesis and Characterization of [(1-benzylpyrazole) [<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-bis(2-aminoethyl)-1,2-ethanediamine]copper(II)] Diperchlorate,a Structure with a Sterically Strained,Distorted-Trigonal-Bipyramidal Cation

Abstract  The synthesis, characterization, and molecular structure of the title compound, [(1-benzylpyrazole)[N,N-bis(2-aminoethyl)-1,2-ethanediamine]copper(II)] diperchlorate, [(nbp)(tren)Cu(II)](ClO₄)₂, 2  · 2ClO₄, is reported. The salt crystallized in the monoclinic space group P2₁/n with a = 10.1453(5) ?, b = 17.5250(8) ?, c = 13.6021(6) ?, β = 100.737(19)° and V = 2376.06(19) ?³ with Z = 4. The structure contains copper(II) (nbp)(tren) cations, each with a distorted-trigonal-bipyramidal CuN₅ coordination geometry, separated by perchlorate anions. The cations exhibit steric strain associated primarily with close contacts between the methylene protons of the nbp ligand and one of the amine groups of the tren ligand. The strain has a noticeable effect on the coordination geometry and certain physical properties of the complex. Graphical Abstract  In the title structure, steric strain in the (nbp)(tren)Cu(II) cations, associated with close contacts between protons of the nbp ligand and two of the amine groups of the tren ligand (dashed lines in the figure below) affects certain physical properties of the cation and is consistent with an anomalously long Cu(II)–N(pyrazole) distance (Cu–N41) and an unusually large axial–equatorial angle, N41–Cu–N12.      

Crystallographic and Conformational Analysis of [(<Emphasis Type="Italic">E</Emphasis>)-2-[(3-Chlorophenylimino)methy])-4-methoxyphenol]

Abstract  The crystal structure of C₁₄H₁₂ClNO₂ was determined by X-ray analysis. It crystallizes in the triclinic space group Pc with a = 12.5346(10) ?, b = 4.5101(3) ?, c = 12.0534(11) ?, α = 90.00o, β = 113.669(6)o, γ = 90.00o, Z = 2, Dx = 1.393 mg/m³, μ (MoK_α) = 0.298 mm⁻¹. The title compound is photochromic and molecule is non-planar. It adopts a phenol–imine tautomeric form with a strong intramolecular O–H···N hydrogen bond and a strong intermolecular C–H···O hydrogen bond. Minimum energy conformations AM1 were calculated as a function of the three torsion angles θ1(C10–C9–N1–C8), θ2(C9–N1–C8–C1) and θ3(N1–C8–C1–C6), varied every 10°. As in the X-ray experiment results, molecule has an angle that makes it non-planar between two aromatic rings in AM1 optimized geometry. Graphical Abstract  Molecular and crystal structure of [(E)-2-[(3-chlorophenylimino)methy])-4-methoxyphenol], C₁₄H₁₂ClNO₂, have been determined by single crystal X-ray diffraction study, and conformational analysis of the title molecule with respect to the selected torsion angle has been achieved by AM1 semi-empirical calculations.      

Synthesis and Crystal Structure of 2-(2,3,4-Trimethoxy-6-Methylbenzylideneamino)phenol

Abstract  The title compound 2-(2,3,4-trimethoxy-6-methylbenzylideneamino)phenol (C₁₇H₁₉NO₄, M _r = 301.33) was synthesised and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a = 10.4458(14), b = 8.3870(10), c = 17.780(2) ?, β = 91.102(2)^°, V = 1557.4(3) ?³, Z = 4, D _c = 1.285 g/cm³, λ = 0.71073 ?, μ(Mo Kα) = 0.092 mm⁻¹, F(000) = 640. The final refinement gave R = 0.0452, wR(F ²) = 0.1065 for 2,743 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the molecule adopts an E configuration at the C=N functional bond. The dihedral angle between the two phenyl rings is 38.3(3)°. The crystal structure is stabilized by C–H···O, O–H···O and O–H···N hydrogen bonds and π–π stacking interactions. Graphical Abstract  The title compound 2-(2,3,4-trimethoxy-6-methylbenzylideneamino)phenol (C₁₇H₁₉NO₄, M _r = 301.33) was synthesised and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a = 10.4458(14), b = 8.387(1), c = 17.780(2) ?, β = 91.102(2)°, V = 1557.4(3) ?³, Z = 4, D _c = 1.285 g/cm³, λ = 0.71073 ?, μ(Mo Kα) = 0.092 mm⁻¹, F(000) = 640. The final refinement gave R = 0.0452, wR(F ²) = 0.1065 for 2,743 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the molecule adopts an E configuration at the C=N functional bond. The dihedral angle between the two phenyl rings is 38.3(3)°. The crystal structure is stabilized by C–H···O and O–H···O hydrogen bonds and π–π stacking interactions.      

Synthesis and Crystal Structure of Pivalamidate-Bridged Trinuclear Platinum–Copper Complex with a Linear Pt–Cu–Pt Core

Abstract The heterotrimetallic complex [Cu{trans-Pt(NH₃)₂(NHCO^tBu)₂}₂](NO₃)₂ was synthesized and structurally characterized by X-ray crystallography. The cationic complex consists two trans-[Pt(NH₃)₂(NHCO^tBu)₂] units and one Cu²⁺ ion, which are linearly held together by four bridging pivalamidate ligands. The compound crystallizes in the monoclinic space group P2₁/c with a = 13.18(1) ?, b = 13.12(1) ?, c = 21.38(2) ?, β = 116.88(3)°?, V = 3674(5) ?³, and Z = 4. The trimeric Pt–Cu–Pt cation further aggregates into a dimer of trimer via a weak Pt···Pt interaction. Graphical abstract Synthesis and crystal structure of pivalamidate-bridged trinuclear platinum–copper complex with a linear Pt–Cu–Pt core Chao Chen, Huayu Qiu*, Fenghui Liu and Wanzhi Chen* A heterotrimetallic complex [Cu{trans-Pt(NH3)₂(NHCO^tBu)₂}₂](NO₃)₂ was synthesized and structurally characterized by X-ray crystallography.