Protonated Bis(quinuclidine) Included in a Novel “Bichannel” (Urea)–Chloride Host: a Very Large Urea Channel

The synthesis, crystal structure and properties of a novel ternary inclusion compound formed by protonated bis(quinuclidine) inserted in a urea–chloride anionic host, urea⁵[quinuclidine²H]⁺Cl^- (1), are reported. In the host structure each urea molecule interacts with adjacent urea molecules via N-H ?O hydrogen bonds forming a channel arrangement. Each hexagonal channel is linked through halide ions by N-H ?Cl hydrogen bonds forming a bichannel-like structure. The channel width of the host (14.32?Å) is one of the largest known for a urea host derivative. The compound may be described as a commensurate species, c ^g/c ^h=0.98. Conductivity determined for 1 at room temperature is 4.00?×?10^-6 (Ω?cm)^-1, and it increases with temperature to 3.33?×?10^-4 (Ω?cm)^-1 at 77°C. Aspects of the thermal stability of the product are discussed.     

Alkyne‐Linked Poly(1,8‐carbazole)s: A Novel Class of Conjugated Carbazole Polymers

Novel conjugated carbazole polymers based on the alkyne‐linked 1,8‐carbazole structure are synthesized in high yield by the Sonogashira cross‐coupling reaction and acetylenic oxidative coupling reaction. The polymers are thermally stable and highly soluble in common organic solvents such as CHCl₃, CH₂Cl₂, and THF. As compared to ethynylene‐linked polymer, the butadiynylene‐linked polymer display a bathochromic shift in the absorption maximum and end absorption position. In addition, the fluorescence behaviors in CH₂Cl₂ are almost identical for both polymers. Electrochemical measurements indicate that the ethynylene‐linked polymer possesses a lower first oxidation potential than the butadiynylene‐linked one.

     

The Role of Chloro Substituents in Solid Inclusion Formation. Crystal Structures Formed by a Bulky Hydroxy Host with Ethyl Acetate (2:1) and Cyclohexylamine (1:2) as Guest

Abstract

Two inclusion compounds of the 11-[bis(p‐chlorophenyl)hydroxymethyl]-9,10-dihydro-9,10-ethanoanthracene host (1) have been studied by X-ray diffraction in order to find an explanation of the exceptional clathrate formation ability of the present chloro-containing host as compared with that of closely related chlorine-free host analogues. Crystal data: 1·ethyl acetate (2:1), C₂₇H₂₂OCl₂·½(C₄H₈O₂), M_w = 501.45, P2_1/c, a = 8.9060(5), b = 11.1109(6), c = 25.642(1) Å, β = 99.03(1)°, Z = 4, R = 0.047 for 2029 F values with I>2σ(I); 1·cyclohexylamine (1:2), 2[C₂₉H₂₂OCI₂·2(C₆H₁₃N)], M_w = 1311.50, Pc, a = 12.144(2), b = 12.689(3), c =23.119(8) Å, β = 91.68(1)°, Z = 2, R = 0.054 for 3073 F values with I>2σ(I). Although the two solid inclusion compounds differ in host‐guest stoichiometry, space group symmetry and also in host‐guest recognition mode, both co-crystals are held together by numerous C?H…X (X = O, N or Cl) interactions, in which the chloro-substituents of 1 play a very active role. The observed frequent participation of chlorine in intermolecular interactions in these compounds suggests an ability of the (C?)Cl substituents to effectively enhance the crystal formation in the absence of more dominant forces.     

一类新型嘧啶苯氧(硫)醚的合成及生物活性

一类新型嘧啶苯氧(硫)醚的合成及生物活性;双乙烯酮; 氯硝基嘧啶; 苯氧（硫）醚; 嘧啶肼; 生物活性     

A Five‐layer π‐Aromatic Structure Formed through Self‐assembly of a Porphyrin Trimer and Two Aromatic Guests

In this study we synthesized two‐ and four‐armed porphyrins – bearing two carboxyl and four 2‐aminoquinolino functionalities, respectively, at their meso positions – as a complementary hydrogen bonding pair for the self‐assembly of a D₂‐symmetric porphyrin trimer host. Two units of the two‐armed porphyrin and one unit of the four‐armed porphyrin self‐assembled quantitatively into the D₂‐symmetric porphyrin trimer, stabilized through ammidinium‐carboxylate salt bridge formation, in CH₂Cl₂ and CHCl₃. The porphyrin trimer host gradually bound two units of 1,3,5‐trinitrobenzene between the pair of porphyrin units, forming a five‐layer aromatic structure. At temperatures below ?40 °C, the rates of association and dissociation of the complexes were slow on the NMR spectroscopic time scale, allowing the 1 : 1 and 1 : 2 complexes of the trimer host and trinitrobenzene guest(s) to be detected independently when using less than 2 eq of trinitrobenzene. Vis titration experiments revealed the values of K₁ (2.1±0.4×10⁵ M^?1) and K₂ (2.2±0.06×10⁴ M^?1) in CHCl₃ at room temperature.     

Synthesis of Novel Bis(pyrido[2,1‐a]isoquinolines) Linked to Aliphatic or Aromatic Core via Ether Linkage

A synthesis of novel bis(pyrido[2,1‐a]isoquinoline‐1,3‐dicarbonitriles) by the multicomponent reaction of 2‐(6,7‐dimethoxy‐3,4‐dihydroisoquinolin‐1‐yl)acetonitrile with the corresponding bis(aldehydes) and malononitrile in the presence of basic catalysts was reported.     

A New Clathrate Featuring a Spiro-Type Ammonium Host. X-Ray Structure of the Inclusion Compound with Chloroform

A new onium salt host molecule 1 featuring a spiro-type ammonium backbone was synthesized and shown to form a crystalline inclusion compound with chloroform, 1 · chloroform (1:2), the crystal structure of which is reported. The host molecular interactions including C–H···Br, Cl···Cl and aromatic stacking contacts are typical of the packing structure.Supplementary Data relevant to this publication have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication No. CCDC 229358.This revised version was published online in July 2005 with a corrected issue number.     

A Novel One-Dimensional Copper(II) Complex of a Carboxymethylated Tricyclic Azacrown Ether Derivative Linked by Hydrogen Bonding

The complex [CuL]·H₂O(H₂L=4,13-dioxa-1,7,10,16-tetraaza-1,16:7,10-bis(ethylene)-9,18-diacetic acid cyclooctadecane-8,17-dione) has been synthesized and structurally characterized. It crystallizes in the triclinic system, space group P1 with a=9.0111(7), b=9.4371(7), c=14.3092(11)Å, a=89.846(2), β=81.871(2), γ=65.616(2)°, V=1095.05(14)&Aringsup3;, and Z=1. The structure of the complex consists of two different CuL coordination moieties in which six-coordinated copper ions each have different coordination environments. In both CuL moieties, copper ions are coordinated to two tertiary nitrogen and four oxygen atoms, two from the crown ether ring and two from the pendant carboxylate groups. These two different CuL moieties are linked alternately by water molecules to form an infinite one-dimensional chain structure through hydrogen bonding between the water molecule and the uncoordinated oxygen atom of the carboxyl group.     

Exploring Clathrate Formation with an Optically Resolved Host. X-Ray Crystal Structure of the Inclusion Compound between (11S,12S)-(-)-9,10-Dihydro-9,10-ethanoanthracene-11,12-dicarboxylic Acid and n-Hexane (2 : 1)

The crystal structure of the inclusion compound formed between (11S,12S)-(-)-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid, (1), and n-hexane (2:1) has been studied by X-ray diffraction. It crystallizes in the tetragonal space group P41 and represents a less common type of inclusion compound, which has helical and chiral structural elements. Helical chains, formed by hydrogen-bonded host molecules, wind around the 21 screw axes and encircle the guest molecules. Crystal data: a=b=17.478(1); c=12.021(1)Å, Z=4 host–guest 2:1 units, R=0.043, Rw=0.061 for 2225 observations with I > 3 (I). The general shape and conformational flexibility of 1 with respect to the requirements of inclusion formation and crystal packing are discussed.     

Copper(I) Complexes with a Proximal Aromatic Ring: Novel Copper–Indole Bonding

A unique bonding of indole to a metal ion has been established. Two new tridentate N ligands with a pendent indole ring gave Cu^I complexes 1 and 2 , the latter of which exhibits the new form of bonding between the Cu^I ion in a distorted tetrahedral geometry and the indole C(2)−C(3) moiety. The bond is dependent upon the length of the side chain and therefore the accessibility of the ring to the metal center.     

A Bis-Chelating / Ligand for the Synthesis of Heterobimetallic Platinum(II)/Rhenium(I) Complexes: Tools for the Optimization of a New Class of Platinum(II) Anticancer Agents

The two independent and coordination sites of a newly synthesized bis[2-(hydroxyphenyl)-1,2,4-triazole] platform have been exploited to prepare four monometallic neutral ()Pt^II complexes carrying DMSO, pyridine, triphenylphosphine, or N-heterocyclic carbene as the fourth ligand. Then, the second coordination site was used to introduce an IR-active rhenium tricarbonyl entity, affording the four corresponding heterobimetallic neutral Pt^II/Re^I complexes, as well as a cationic Pt^II/Re^I derivative. X-ray crystallographic studies showed that distortion of the organic platform occurred to accommodate the coordination geometry of both metal centers. No ligand exchange or transchelation occurred upon incubation of the Pt^II complexes in aqueous environment or in the presence of Fe^III, respectively. The antiproliferative activity of the ligand and complexes was first screened on the triple-negative breast cancer cell line MDA-MB-231. Then, the IC₅₀ values of the most active candidates were determined on a wider panel of human cancer cells (MDA-MB-231, MCF-7, and A2780), as well as on a nontumorigenic cell line (MCF-10A). Low micromolar activities were reached for the complexes carrying a DMSO ligand, making them the first examples of highly active, but hydrolytically stable, Pt^II complexes. Finally, the characteristic mid-IR signature of the {Re(CO)₃} fragment in the Pt/Re heterobimetallic complexes was used to quantify their uptake in breast cancer cells.     

Synthesis and Crystal Structure of a Novel Tetranuclear Complex [Pb4（HQ）6（NO3）2]

Reaction of 8-hydroxyquinoline （HQ） with Pb（NO3）2 in water resulted in the formation of a tetranuclear complex [Pb4（HQ）6（NO3）2] 1. It has been characterized by IR, elemental analyses and X-ray diffraction. Crystal data for this complex： triclinic system, space group P1, a = 9.7399（6）, b = 11.6535（8）, c = 12.6806（8） A, α = 62.8050（10）, β = 78.4910（10）, γ = 80.5490（10）°, C54H36N8O12Pb4, Mr= 1817.67, Z = 1, V = 1250.04（14）A^3, Dc = 2.415 g/cm^3,μ = 13.503 mm^-1, -12≤h≤8, -14≤k≤13, -15≤1≤15, F（000） = 840, Rint = 0.0217, R= 0.0348 and wR = 0.0927. X-ray crystal structure analysis revealed that in 1 each Pb（ II ） contains a stereo- chemically active lone pair of electrons. The Pb…C interaction, C-H……O weak interaction and π…π stacking interactions are observed in the complex. In the solid state, the complex possesses strong photoluminescent emission at 485 and 528 nm.     

Bis(imino)carbazolate: A Master Key for Barium Chemistry

Reported here is a readily available bis(imino)carbazole‐based proligand that constitutes a convenient entry point into the challenging synthetic molecular chemistry of barium. It enables the preparation of rare or even, up to now, unknown, solution‐stable heteroleptic barium complexes. The syntheses and structural features for the first molecular barium fluoride and the first barium stannylide, with an unsupported Ba?Sn bond, are described, along with other carbazolate barium species: an amide (both a remarkably stable starting material and an excellent hydrophosphination precatalyst), iodide, and silanylide. DFT analysis of bonding patterns in the barium stannylide and barium silanylide highlights a prevailingly ionic barium–tetrelide bond with a small covalent contribution.     

A New Series of Charge-assisted Hydrogen-bonded Host Frameworks Based on [Co（en）_3]~（3＋）and Dicarboxylates

A new series of metal complex carboxylates(MCC)made of [Co(en)3]3+(MC)and either 2,6-naphthalenedicarboxylic(NDC)or 4,4-biphenyldicarboxylic(BPDC)were synthesized and structurally characterized.The four new compounds have a general formula(MC)2(C)3·n(guest)with the guests of dimethylformamide(DMF)and dimethyl sulfoxide(DMSO)and water.All the structures represent a pillared-layer type,where the layer consists of MC cations,carboxylate anions or water molecules via a large number of hydrogen bonds.The layers are pillared by the organic residues of NDC or BPDC,resulting in the inclusion cavities where the guest molecules reside.Although their topological structures are similar,they crystallize in different crystal structures due to the rearrangement of pillars and hydrogen-bonded layers.     

Potassium Salts of 2,5-Bis(trimethylsilyl)-Germolide: Switching between Aromatic and Non-Aromatic States

The reduction of a 1-mesityl-2,5-bis-trimethylsilylchlorogermole 8 with KC₈ is reported. While the reaction with one equivalent of KC₈ gave the dimer with a Ge−Ge bond 10 , excess of KC₈ (four equivalents) resulted in the formation of the potassium salt of the germole dianion, 11 with reductive cleavage of the Ge−C bond. Careful reduction with two equivalents of KC₈ in THF provided the potassium salt of the planar germolide 5 . Its solid-state structure revealed contact ion pairs with the potassium ion η⁵-coordinated to the germacyclopentadienide ring. The molecular structure of the anion indicates a high degree of cyclic electron delocalization, in agreement with results from DFT calculations. Separation of the ion pair by complexation of the potassium ions with 18-crown-6 triggers the isomerization to germolide 6 , which is characterized by a pyramidal coordination sphere of the germanium atom and a localized diene structure. The isomers 5 and 6 represent a rare example for a structurally manifested switch between a non-aromatic and an aromatic state induced by an external stimulus, in this case the complexation of the counter cation.     

New chloro- and trifluoroacetato tricarbonylrhenium(I) complexes with a N,N′-bis(benzophenone)-1,2-diiminoethane Schiff base ligand: Spectral and structural studies

The reaction of Re(CO)₅Cl with the chelating ligand N,N′-bis(benzophenone)-1,2-diiminoethane (bz₂en) afforded the neutral fac-[Re(CO)₃(bz₂en)Cl]. The subsequent reaction with AgOCOCF₃ gave fac-[Re(CO)₃(bz₂en)OCOCF₃]. Their pseudooctahedral fac structures have been established by FTIR, UV–Vis, ¹H, ¹³C NMR and have been confirmed by X-ray diffraction analysis. The electrochemical behaviour of the investigated complexes has been studied by cyclic voltammetry.     

Studies on Synthesis and Photochromism of a Novel Class of Fulgimide： （Z）-4-Oxazolylfulgimide

A novel class of fulgimide, (Z)-4-oxazolylfulgimide ((Z)-1-benzyl-4-isopropylidene-3-[1-(2-aryl-5-methyloxazolyl)ethylidene]tetrahydropyrrole-2,5-dione), was synthesized by the reaction of (Z)-4-oxazolyl fulgide (4-isopropylidene-3-[1-(2-aryl-5-methyloxazolyl) ethylidene]tetrahydrofuran-2,5-dione) with benzyl amine. Photochromic property of (Z)-4-oxazolylfulgimide was studied. Compared with (Z)-4-oxazolylfulgide, the absorption maximum of the colored form of (Z)-4-oxazolylfulgimide is bathochromic-shifted. Substituents on the aryl ring affect the absorption maximum of the open form and the colored form of (Z)-4-oxazolylfulgimide.