Synthesis and Crystal Structure of Three New Metal-Organic Frameworks in the Ln(III)/2,6-Pyridinedicarboxylate System

Abstract  

In this paper, three new metal-organic frameworks, synthesized by hydrothermal technique, are described. The compounds crystallize in triclinic space group P − 1 with cell parameters, respectively equal to (1) [La(H₂O)₃(dipic)]₂(C₂O₄) · 2H₂O a = 7.9990(1) ?, b = 8.3380(4) ?, c = 9.6180(5) ?, α = 98.194(5)°, β = 100.438(3)°, γ = 102.437(3)°, (2) [Eu(H₂O)₂(C₂O₄)]₂(dipic) · 3H₂O a = 8.2170(6) ?, b = 10.5900(8) ?, c = 13.0670(3) ?, α = 93.951(3)°, β = 103.393(5)°, γ = 107.797(6)°, and (3) [Ce₃(dipic)₃(Hdipic)(SO₄)(H₂O)₃] · 4H₂O a = 11.655(1) ?, b = 12.886(1) ?, c = 16.139(2) ?, α = 106.369(8)°, β = 92.90(1)°, γ = 115.787(7)°. They differ by their dimensionality mono-dimensional for (1), tri-dimensional for (2) and bi-dimensional for (3).     

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.      

Synthesis,Characterization and Fluorescent Property of Two Mixed Ligand Coordination Polymers Constructed from 4-Cyclohexene-1,2-dicarboxylate and Nitrogen-Containing Ligands

Abstract  

Two new coordination polymers [Cd(1,2′-cy)(btx)_0.5H₂O]_n 1 and {[Ni(1,2-cy)(2,2′-bipy)(H₂O)₂]·3H₂O}_n 2 (1,2′-cy=4-cyclohexene-1,2-dicarboxylate, btx=1,4-bis(triazol-1-ylmethyl)benzene, 2,2′-bipy=2,2′-bipyridine) had been synthesized. Their structures were characterized by elemental analysis, IR, TG and X-ray single-crystal diffraction analysis. Crystal data for complex 1: Triclinic, space group P-1, a = 6.4303(13) ?, b = 10.399(2) ?, c = 11.713(2), α = 83.04(3)°, β = 81.87(3)°, γ = 83.84(3)°, and Z = 2. For complex 2: Orthorhombic, space group Pbcn, a = 15.613(3) ?, b = 13.970(3) ?, c = 21.290(4) ?, and Z = 4. Complex 1 exhibits an interesting two-dimensional wavelike covalent layer structure. When Ni salt was replaced by Cd salt, and reacts with 1,2′-cy and 2,2′-bipy, one-dimensional chain-like complex 2 was obtained. Furthermore, the fluorescent property of complex 1 was reported.     

Two Metal Complexes Supported by {VO<Subscript>3</Subscript>}<Subscript>n</Subscript><Superscript>n−</Superscript> Chains: Hydrothermal Syntheses and Crystal Structures of [M(dpa)V<Subscript>2</Subscript>O<Subscript>6</Subscript>] (M = Zn(II) and Cu(II); dpa = 2,2′-dipyridylamine)

Abstract  

Two new metal complexes supported by {VO₃}_n ⁿ⁻ chains, [M(dpa)V₂O₆] (1, M = Zn²⁺; 2·H₂O, M = Cu²⁺; dpa = 2,2′-dipyridylamine), have been synthesized hydrothermally and characterized by elemental analysis, TG analysis, IR spectroscopy and single-crystal X-ray diffraction. Crystal data: [Zn(dpa)V₂O₆] 1, Triclinic, P-1, a = 9.663(7) ?, b = 10.617(7) ?, c = 15.114(10) ?, α = 105.678(10)°, β = 104.772(9)°, γ = 94.021(10)°, Z = 2; [Cu(dpa)V₂O₆]·H₂O 2·H₂O, Monoclinic, C2, a = 20.543(3) ?, b = 7.2460(9) ?, c = 10.4853(13) ?, β = 111.318(2)°, Z = 4. Complex 1 is constructed from sinusoidal {VO₃}_n ⁿ⁻ chains with {Zn(dpa)}²⁺ fragments spanning the adjacent troughs and crests into an 1D ribbon-like structure. Complex 2 is built up by linking {VO₃}_n ⁿ⁻ chains via pairs of symmetrical {Cu(dpa)}²⁺ fragments into a 2D layered structure. The Zn(II) and Cu(II) ions exhibit tetrahedral and square pyramidal coordination environments, respectively. The formation of the two isomers is attributed to the flexibility of {VO₃}_n ⁿ⁻ chains and the different coordination configurations of the two metal ions. There exist significant π–π stacking and hydrogen bonding interactions in complexes 1 and 2.     

Structural Modulation in Lanthanide Tetracyanoplatinates Incorporating Terpyridine: Synthesis and Structures of Four Distinct One-Dimensional Variants

Abstract  

The synthesis of four different lanthanide tetracyanoplatinates all incorporating 2,2′:6′,2″-terpyridine have been carried out in acetonitrile/water mixtures by reaction of an appropriate Ln³⁺ salt with 2,2′:6′,2″-terpyridine and potassium tetracyanoplatinate. The use of different Ln³⁺ salts as reactants results in the isolation of {La(tpy)(H₂O)₃}₂[Pt(CN)₄]₃·2CH₃CN·2H₂O (La-1) space group P[`1] P\bar{1} , a = 9.3862(15) ?, b = 12.186(1) ?, c = 13.493(1) ?, α = 88.082(7)°, β = 80.22(1)°, γ = 74.88(1)°, {Pr(tpy)(H<sub>2</sub>O)<sub>3</sub>}<sub>2</sub>[Pt(CN)<sub>4</sub>]<sub>3</sub>·2H<sub>2</sub>O (Pr-2) space group P[`1] P\bar{1} , a = 9.2458(15) ?, b = 10.8068(9) ?, c = 13.6178(14) ?, α = 84.554(8)°, β = 74.905(10)°, γ = 79.490(9)°, Ho(tpy)(H₂O)₂(NO₃)[Pt(CN)₄] · CH₃CN (Ho-3) space group P2₁/c, a = 12.867(1) ?, b = 15.1046(15) ?, c = 13.651(4) ?, β = 105.39(1)°, or Yb(tpy)(H₂O)₂(NO₃)[Pt(CN)₄]·0.5CH₃CN·1.5H₂O (Yb-4) space group Pbcn, a = 13.226(7) ?, b = 15.870(2) ?, c = 24.276(3) ? under quite similar reaction conditions. All four of these compounds have been isolated as single crystals and X-ray diffraction has been used to investigate their structural features. None of these compounds are isostructural with one another, but all contain one-dimensional, polymeric structures that contain tris chelation of the Ln³⁺ cations by terpyridine and bridging of the Ln³⁺ ions by tetracyanoplatinate. La-1 and Pr-2 contain both cis- and trans-bridging of Ln³⁺ cations by tetracyanoplatinate resulting in double chains with a ladder-type structure. Ho-3 and Yb-4 are similar in that they contain chelation of Ln³⁺ by both terpyridine and a nitrate anion and both structure types only contain cis-bridging by tetracyanoplatinate. All four structures contain Pt–Pt interactions in the form of dimeric units.     

Synthesis and Crystal Structures of Two New Schiff Base Hydrazones Derived from Biphenyl-4-Carbohydrazide

Abstract  

The crystal structures of two novel Schiff base hydrazones have been determined by means of the X-ray diffraction. These compounds: N′-[(E)-(2,5-dimethoxyphenyl)methylidene]biphenyl-4-carbohydrazide, C₂₂H₂₀N₂O₃ (1) and N′-[(E)-(4-fluorophenyl)methylidene]biphenyl-4-carbohydrazide, C₂₀H₁₅FN₂O (2), are the first structurally characterized biphenyl derivatives of phenylmethylidene-carbohydrazide. Both compounds crystallize in the monoclinic space groups, 1 in P2₁/c space group with a = 13.987(2) ?, b = 16.426(3) ?, c = 8.214(2) ?, β = 98.12(2)°, and 2 in C2/c with a = 37.163(5) ?, b = 10.696(2) ?, c = 8.098(2) ?, β = 101.18(2)°. Both molecules have very similar bond lengths and angles pattern, even in the differently substituted phenyl ring. However, the conformations of the molecules differ significantly, the more crowded molecule 1 is much more folded than 2. The dihedral angle between the terminal ring planes is 56.17(6)° in 1 while in 2 it is as small as 2.83(14)°. In both structures relatively short and linear N–H···O hydrogen bonds (created by the best available hydrogen bond donor and acceptor) connect molecules into the chains along the unit cell parameter of ca. 8 ? in length. The next stage of the crystal architecture determination, the secondary interactions, are however quite different: in 1 there are almost solely dispersion van der Waals interactions while in 2 some more specific C–H···F and C–H···π interactions are also involved in the crystal packing.     

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.      

Hydrogen-Bonded Molecular Ladders and Interlaced Networks in Complexes Built of V-Shaped Molecules 4,4′-Isopropylidenediphenol or 4,4′-Oxydibenzoic Acid with 4,4′-Bipyridine

Abstract  

The title compounds, C₁₀H₈N₂·C₁₅H₁₆O₂ (1) and C₁₀H₈N₂·C₁₄H₁₀O₅ (2), were synthesized by 4,4′-bipyridyl and two similar V-shaped molecules. The two complexes both crystallized in the same space group P2₁/n with the crystal cell parameters: a = 16.0536(3) ?, b = 6.42730(1) ?, c = 21.2717(4) ?, β = 102.330°, V = 2144.21(7) ?³, Z = 4 in compound 1 and a = 7.45020(10) ?, b = 10.0784(2) ?, c = 26.9430(5) ?, β = 92.1140(10)°, V = 2021.67(6) ?³, Z = 4 in compound 2. Compound 1 forms regular molecular chains containing alternative 4,4′-bipyridyl and 4,4′-isopropylidenediphenol units; the molecular components are linked by two types of O–H···N hydrogen bonds. Additionally, every two neighboring chains are connected to be a ladder structure by means of weak C–H···O interactions. In compound 2, 4,4′-bipyridyl and 4,4′-oxydibenzoic acid first construct one-dimensional architecture by strong O–H···N hydrogen bonds, which are similar with the interactions in compound 1. Secondly, two types of weak C–H···O contacts formed between 4,4′-bipyridyl and the acid link one-dimensional chains to be interlaced three-dimensional hydrogen-bonded networks.     

Crystal and Molecular Structures of 2-Amino-4-Nitrobenzoic Acid and Its Cocrystals with 2,2′-Bipyridine (2/1) and Bis(pyridin-2-yl)ketone (1/1)

Abstract  

The eight-membered {···HOC=O}₂ synthon featured in the crystal structure of 2-amino-4-nitrobenzoic acid (1) is replaced by carboxylic acid···N-pyridine hydrogen bonds in its cocrystals with 2,2′-bipyridine (2/1; 2) and bis(pyridin-2-yl)ketone (1/1; 3) indicating the robust nature of the latter synthon. Disruption of the three-dimensional architecture based on O–H···O and N–H···O(nitro) hydrogen bonds in (1) is evident in the cocrystals which form supramolecular tubes (2) and chains (3) based on O–H···N and N–H···O hydrogen bonding. Compound (1) crystallizes in the monoclinic space group P2₁/n with a = 3.6291(1) ?, b = 7.7339(3) ?, c = 26.561(1) ?, β = 91.385(2)°, and Z = 4. Compound (2) crystallizes in the monoclinic space group C2/c with a = 27.562(3) ?, b = 6.8300(6) ?, c = 12.923(1) ?, β = 110.593(5)°, and Z = 4. Compound (3) crystallizes in the monoclinic space group P2₁/c with a = 3.795(3) ?, b = 12.024(8) ?, c = 35.65(2) ?, β = 92.131(6)°, and Z = 4 (determined from synchrotron data).     

Synthesis,Crystal Structure and Luminescent Property of a Ternary Complex [Cd(sfdb)(3-pytpy)]<Subscript>2</Subscript>·2H<Subscript>2</Subscript>O (H<Subscript>2</Subscript>sfdb = 4,4′-Sulfonyldibenzoic Acid, 3-pytpy = 4′-(3-Pyridyl)-2,2′:6′,2″-Terpyridine)

Abstract  

A new ternary complex [Cd(sfdb)(3-pytpy)]₂·2H₂O (H₂sfdb = 4,4′-Sulfonyldibenzoic acid, 3-pytpy = 4′-(3-pyridyl)-2,2′:6′,2″-terpyridine) 1 has been hydrothermally synthesized and characterized by the elemental analysis, IR spectroscopy and single crystal X-ray diffraction. X-ray diffraction analysis reveals that 1 (C₃₄H₂₄CdN₄O₇S) crystallizes in triclinic space group P-1, features an interesting 1D channel-containing supramolecular structure constructed from grid-like dimers via π–π stacking interactions. Unit cell parameters for 1: a = 8.866(2) ?, b = 11.083(3) ?, c = 15.790(4) ?, α = 103.612(4)°, β = 95.044(3)°, γ = 101.083(4)° and Z = 2. The luminescent spectrum shows the emission peak of complex 1 is at 392 nm which is attributed to the intraligand transition.     

Hydrogen-bonded Three-dimensional Supramolecular Network Constructed by Dinuclear Ni(II) Macrocyclic Complex and 1,2,4,5-Benzenetetracarboxylate

Abstract  

A new coordination polymer [Ni₂(L)(H₂btec)]_n, (1) was obtained from the reaction of NiSO₄·6H₂O, macrocyclic ligand 3,6,9,17,20,23-hexaaza-29,30-dihydroxy-13,27-di-tert-butyl-tricyclo[23,3,1,1^11,15]triaconta-1(28),11,13,15(30),25,26-hexaene (H₂L), and 1,2,4,5-benzenetetracarboxylic acid (H₄btec) in methanol. Its structure was determined by X-ray diffraction analysis. The crystal is monoclinic C2/c space group with cell parameters a = 20.4923(3) ?, b = 14.2389(3) ?, c = 14.5130(2) ?, β = 97.441(2)°, V = 4199.05(12) ?³, and Z = 8. The X-ray analysis shows that each Ni (II) cation is six-coordinated by an O₃N₃ donor set. The macrocyclic complex [Ni₂L] ²⁺ are bridged by H₂btec²⁻ anions to form 1D chains, which are further joined via N–H···O hydrogen bonds to yield a 3D supramolecular structure. Thermogravimetric analysis (TGA) for the complex is discussed.     

The Zolmitriptan-Pyridine (1:1) and Zolmitriptan-Propiophenone (3:2) Inclusion Complex

Abstract  

The crystal structures of zolmitriptan with pyridine (I) and propiophenone (II) solvates have been determined by single crystal X-ray diffraction studies. Compound (I) crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 8.5610(5) ?, b = 12.2709(7) ?, c = 19.6201(12) ?, V = 2061.1(2) ?³, and Z = 4, while compound (II) crystallizes in the monoclinic space group P2₁ with a = 15.085(1) ?, b = 19.656(12) ?, c = 21.0860(13) ?, β = 92.068(1)°, V = 6248(4) ?³ and Z = 4. The asymmetric unit of (I), C₁₆H₂₁N₃O₂·C₅H₅N, contains one zolmitriptan molecule and one pyridine solvate, while the asymmetric unit of (II), 3(C₁₆H₂₁N₃O₂)·2(C₉H₁₀O) comprises six zolmitriptan molecules and four propiophenone solvates. In both structures, the N–H···N hydrogen bonds, form an infinite helical chain and generate a C(11)-type motif in (I) and a D₂²(13)-type motif in (II). Both the complexes have layer structures, the layers being constructed from rings (cavity) of four zolmitriptan molecules, hydrogen bonded through N–H···N and N–H···O bonds, where the pyridine (I) and propiophenone (II) solvates are included in an R₄⁴(33) ring.     

Synthesis and Crystal Structures of Dioxomolybdenum(VI) Complexes with ONS-Donor Ligands

Abstract  

Three dioxomolybdenum complexes namely dioxo(5-chlorosalicylaldehyde thiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C1), dioxo(5-chlorosalicylaldehyde 2-ethylthiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C2) and dioxo(5-chlorosalicylaldehyde N-phenylthiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C3) were prepared. The compounds all crystallize in the triclinic space group P-1 with a = 7.3184(3) ?, b = 7.5035(3) ?, c = 14.9713(6) ?, α = 85.005(2)°, β = 85.616(2)°, γ = 66.987(2)° for C1, a = 8.2339(1) ?, b = 10.1739(1) ?, c = 10.4017(1) ?, α = 78.486(1)°, β = 89.312(1)°, γ = 81.730(1)° for C2, a = 7.0591(1) ?, b = 9.5603(1) ?, c = 14.5762(2) ?, α = 76.280(1)°, β = 81.351(1)°, γ = 81.985(1)° for C3. In general, the overall geometry of these complexes can be regarded as a distorted octahedron with the tridentate thiosemicarbazonato ligands (L²⁻) bonded to the MoO₂ ²⁺ core, with the imine nitrogen, phenoxyl oxygen, sulfur atom and one of the terminal oxygen atoms of the dioxomolybdenum occupying the equatorial position. The sixth coordination site is occupied by the dimethylsulfoxide (DMSO) solvent molecules. The adjacent molecules of C1 are linked by N–H···N intermolecular hydrogen bonding, forming polymeric chains that run parallel to the bc plane. On the other hand, C2 is a discrete molecule while the molecules of C3 associate via weak N–H···O hydrogen bonding interaction to form a polymeric chain that runs along the a-axis.     

Synthesis and Structure of a One-Dimensional Copper(II)–Potassium(I) Complex of (<Emphasis Type="Italic">S</Emphasis>)-2-Hydroxy-3-Phenylpropanoic acid

Abstract  

Evaporation of the mixture solution of Cu(ClO₄)₂·6H₂O, KOH and (S)-2-hydroxy-3-phenylpropanoic acid affords a Cu(II)–K(I) coordination compound 1. Single-crystal X-ray diffraction analysis reveals that 1 is a one-dimensional comb-like coordination polymer in the P2₁2₁2₁ space group with crystal cell parameters a = 10.989(2) ?, b = 15.939(3) ?, c = 22.511(5) ?, V = 3943(1) ?³ and Z = 4.     

Structure and Antibacterial Activity of 3-(3,4-Dimethoxyphenyl)furan-2(5<Emphasis Type="Italic">H</Emphasis>)-ones

Abstract  

Crystalline hydrate of the title compound (5), C₁₉H₂₆N₂O₅·2(H₂O), was structurally characterized by single crystal X-ray diffraction. It crystallizes in monoclinic system space group P 21/c with a = 7.3987(7) ?, b = 17.8691(16) ?, c = 17.0022(13) ?, β = 112.944(3)°, V = 2070.0(3) ?³, Z = 4, R ₁ = 0.0592, wR ₂ = 0.1016, and T = 298(2) K. The X-ray structure determination revealed that the center furanone ring is nearly coplanar with 3,4-dimethoxybenzene ring, making a dihedral angle of 0.860(69)°. Two kinds of centrosymmetric tetramers characterized by graph-set motifs of R ₇⁸(36) and R ₄⁶(32) are formed through O–H···O, O–H···N and C–H···O hydrogen bonding interactions, which generate a sheet of edge-fused rings parallel to the (011) plane. These sheets are further linked into a three dimensional network by C–H···π interactions. Nine 3-(3,4-dimethoxyphenyl)furan-2(5H)-ones were synthesized and fully characterized by elemental analysis, MS and ¹H NMR. All of them were evaluated for antimicrobial activities against three Gram-positive organisms and a Gram-negative organism, and compound 5 was the most active against Staphylococcus aureus ATCC 25923.     

Absence of Platinophilic Interactions in a Series of Tetracyanoplatinates Incorporating Cyclic Amines

Abstract  

Three novel compounds have been synthesized and structurally characterized: [1,10-Hphen]₂Pt(CN)₄·2H₂O (1a) space group P2₁/n, a = 8.73070(17) ?, b = 15.4609(2) ?, c = 9.82661(19) ?, β = 103.252(2)°; [2,2′-Hbipy]₂Pt(CN)₄·2H₂O (1b) space group P2₁/n, a = 7.0859(14) ?, b = 12.940(2) ?, c = 13.7486(19) ?, β = 100.708(16)°; K₂[Pt(CN)₄]·2phen (phen = 1,10-phenanthroline) (2) space group P2₁/c, a = 8.1393(4) ?, b = 20.4050(9) ?, c = 8.4085(4) ?, β = 105.284°. All three structures contain isolated [Pt(CN)₄]²⁻ ions and they all illustrate the absence of Pt⋯Pt interactions due to the presence of bulky cyclic amines or ammoniums. The structures of 1a and 1b contain large organic cations, 2,2′-bipyridinium and 1,10-phenanthrolinium, respectively while compound 2 contains neutral 1,10-phenanthroline molecules co-crystallized between the potassium tetracyanoplatinate framework.     

Synthesis, Structure and Characterization of Two 1D Chain-like Cadmium Terephthalate Complexes: [Cd(tp)(H2O)3]?·?4H2O and [Ph4P][Cd(tp)0.5Cl2]?·?H2O

Abstract  Two new compounds, [Cd(tp)(H₂O)₃] · 4H₂O (1) and [Ph₄P][Cd (tp)_0.5Cl₂] · H₂O (2) (tp = terephthalate, [Ph₄P] = tetraphenylphosphonium), are metal-polycarboxylate coordination polymers prepared by similar hydrothermal synthesis techniques. Both compounds crystallize in the 1D chain-like architectures. 1 (C₈H₁₈CdO₁₁) is orthorhombic Pcca, Z = 4 (a = 7.3018(1) ?, b = 9.9975(3) ?, c = 19.9695(5) ?, V = 1457.77(6) ?³). 2 (C₂₈H₂₄CdCl₂O₃P) is triclinic P−1, Z = 2 (a = 9.5028(4) ?, b = 12.3130(5) ?, c = 12.7343(6) ?, α = 68.380(1)°, β = 73.723(1)°, γ = 89.624(1)°, V = 1321.8(1) ?³). Transition metal cadmium centers bridged by rigid linear tp ligands give rise to a 1D infinite zigzag chain polymer for 1 and a simple 1D infinite stepped chain polymer for 2. 1 presents an interesting plywood-like packing network while 2 shows a simple parallel rod-like stacking network. An intense fluorescent emission at 412 nm (λ_exc = 338 nm) for 1 in the solid state at room temperature is observed. Index Abstract  Polymeric compounds [Cd(tp)(H₂O)₃] · 4H₂O (1) and [Ph₄P][Cd (tp)_0.5Cl₂] · H₂O (2) crystallize in two remarkable 1D chain-like architectures prepared by similar hydrothermal synthesis techniques, showing an interesting plywood-like packing network in 1 and a simple parallel rod-like stacking network in 2, respectively. An intense fluorescent emission at 412 nm (λ_exc = 338 nm) for 1 in the solid state at room temperature is observed.      

Characterization of Molecular Complexes of 1,4-Naphthoquinone Derivatives

Abstract  

The structures of sulphur atom tethered quinone containing flexible carboxylic acid (3-methyl-1,4-dioxo-1,4-dihydronaphthalen-2-ylsulfanyl)acetic acid (1) and its molecular complex with 4,4′-bipyridine (3) are determined. The compound 1 crystallizes in P-1 (triclinic, a = 7.5378(6) ?, b = 7.6413(7) ?, c = 10.3101(9) ?; α = 89.779 (7)°, β = 81.042 (5)°, γ = 89.101(7)°) and the molecular complex 3 crystallises in P2(1)/n (monoclinic, a = 9.3383(7) ?, b = 3.970(3) ?, c = 42.130(3) ?, β = 91.056(5)°) space groups, respectively. The R₂²(8) type hydrogen bonding between dicarboxylic acid groups present in the parent compound 1 is lost on interaction with 4, 4′-bipyridine; in the molecular complex 3 R₂²(7) type of O···H–C and O–H···N interactions are present between the pyridine rings and carboxylic acid groups. The molecular complex (4) derived from 3-carboxymethylsulfanyl-1,4-dihydroxynaphthalen-2-yl-sulfanyl) acetic acid (2) with triphenylphosphine oxide in 1:2 ratio, crystallises in C2/c space group have monoclinic, a = 26.0494(13) ?, b = 10.5402(5) ?, c = 17.1023(8) ?, β = 108.719 (5)°). The triphenylphosphine oxide molecules are preferentially held by O–H···O interactions between carboxylic acid and P=O bond.     

Synthesis and Structural Characterization of Substituted Salicylate Titanocene Complexes: Three Supramolecular Frameworks Determined by Weak Interactions

Abstract  Based on the reaction between Cp₂TiCl₂ and substituted salicylic acids in the presence of β-cyclodextrin polymer (β-CDP), three four-coordinated titanocene complexes [(η⁵-C₅H₅)₂Ti(S,O′)(OCC₆H₄)·(C₆H₆)_0.5] (1), [(η⁵-C₅H₅)₂Ti{(O,O′)(3,5-Cl₂-OCC₆H₂)}] (2) and [(η⁵-C₅H₅)₂Ti{(O,O′)(3,5-(NO₂)₂-OCC₆H₂)}] (3) were synthesized in high yields and their crystal structures have been determined by single-crystal X-ray diffraction. The structure of 1 has a Monoclinic space group P2₁/c with a = 8.313(3) ?, b = 9.960(4) ?, c = 22.330(8) ?, β = 111.856(11)° and Z = 4. The structure of 2 has a Monoclinic space group P2₁/c with a = 8.0577(13) ?, b = 8.9022(14) ?, c = 21.977(4) ?, β = 96.298(3)° and Z = 4. The structure of 3 has a Triclinic space group P-1 with a = 8.1687(11) ?, b = 8.3027(11) ?, c = 12.7164(17) ?, α = 102.930(2)°, β = 100.479(2)°, γ = 95.458(2)° and Z = 2. Each of the complexes exhibits a three-dimensional framework constructed through weak interactions, which are hydrogen bonding, π–π stacking and C–H···π interactions. It was found that the variation of the substituted salicylate ligands affect the weak interactions as well as the specific framework structure that forms. Graphical Abstract  Three four-coordinated titanocene complexes [(η⁵-C₅H₅)₂Ti(S,O′)(OCC₆H₄)·(C₆H₆)_0.5] (1), [(η⁵-C₅H₅)₂Ti{(O,O′)(3,5-Cl₂-OCC₆H₂)}] (2) and [(η⁵-C₅H₅)₂Ti{(O,O′)(3,5-(NO₂)₂-OCC₆H₂)}] (3) were synthesized in high yields, each of the complexes exhibits a three-dimensional framework constructed through weak interactions. It was found that simple variation of the substituted salicylate ligands affect the weak interactions as well as the specific framework structure that forms. .