Synthesis of novel palladium N‐heterocyclic‐carbene complexes as catalysts for Heck and Suzuki cross‐coupling reactions

Novel palladium‐1,3‐dialkylperhydrobenzimidazolin‐2‐ylidene (2a–c) and palladium‐1,3‐dialkylimidazolin‐2‐ylidene complexes (4a,b) have been prepared and characterized by C, H, N analysis, ¹H‐NMR and ¹³C‐NMR. Styrene or phenylboronic acid reacts with aryl halide derivatives in the presence of catalytic amounts of the new palladium‐carbene complexes, PdCl₂(1,3‐dialkylperhydrobenzimidazolin‐2‐ylidene) or PdCl₂(1,3‐dialkylimidazolin‐2‐ylidene) to give the corresponding C? C coupling products in good yields. Copyright © 2006 John Wiley & Sons, Ltd.     

Synthesis and Properties of a Novel 3D Europium Coordination Polymer with Helical Chain and (3,6)‐Connected rtl Net

The first coordination polymer of 2,2′‐((4‐carboxymethyl‐1,3‐phenylene)bis(oxy)) diacetic acid (H₃L) with europium(III) ion, [Eu(L)(H₂O)]·3H₂O ( 1 ), has been hydrothermally synthesized and structurally characterized. Complex 1 exhibits a 3D coordination polymer with helical chain and rtl topology of the point symbol (4·6²)₂(4²·6¹⁰·8³) based on [Eu₂(COO)₄] as secondary building unit (SBU). Furthermore, the luminescent and magnetic properties of complex 1 are studied.     

Regioselective Photochemical Cycloaddition Reactions of Diolefinic Ligands in Coordination Polymers

The pure diolefinic ligand 1,4‐bis(pyridin‐4‐yl)‐1,3‐butadiene (bpbde) is photostable in the crystalline state. With the assistance of coordination‐driven metal‐organic assemblies, the photoreactivity of this diolefinic ligand can be significantly enhanced. A hydrothermal reaction of bpbde with Cd(NO₃)₂?4 H₂O and the auxiliary ligand adipic acid resulted in the formation of a two‐dimensional photoreactive coordination polymer (CP), [Cd(adipate)(bpbde)]_n ( 1 ). When the aliphatic carboxylic acid was replaced by pimelic acid, another photoreactive CP [Cd(pimelate)(bpbde)]_n ( 2 ) with a three‐dimensional framework was obtained. With irradiation of 365 nm UV light, the bpbde ligands in crystalline 1 and 2 underwent a regioselective photochemical [2+2] cycloaddition reaction and converted to 3,4,7,8‐tetra(pyridin‐4‐yl)tricyclo[4.2.0.0^2,5]octane (tptco) and 1,3‐bis(pyridin‐4‐yl)‐2,4‐bis(2‐(pyridin‐4‐yl)vinyl)cyclobutane (bpbpvcb), respectively. The results provide an interesting insight into the rational design of highly regio‐ or stereoselective photocatalytic reactions for the formation of special organic molecules.     

Synthesis and Characterization of Triphenyltin(IV) Carboxylates with Isophthalic Acid and Benzoic Acid Derivatives: X‐ray Crystal Structures of 1D Supramolecular Chains

The reaction of triphenyltin(IV) hydroxide with the isophthalic acid and benzoic acid derivatives, 5‐(1,3‐dioxo‐1,3‐dihydro‐isoindol‐2‐yl)‐isophthalic acid (H₂L¹) and 4‐(1,3‐dioxo‐1,3‐dihydro‐isoindol‐2‐yl)‐benzoic acid (HL²) yielded the complexes [(SnPh₃)₂L¹] ( 1 ) and [(SnPh₃)L²] ( 2 ). All complexes were characterized by elemental analysis and FT‐IR and NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopy. Interestingly, the supramolecular structures of 1 and 2 are found to consist of 1D molecular chains built up by intermolecular C–H ··· O hydrogen bonds. Their thermal stabilities were also investigated.     

Copper(II) and Manganese(II) Coordination Polymers of 5‐Aminobenzene‐1,3‐dicarboxylic Acid (abdc) Ligand,Structural Studies of [Cu(μ4‐abdc) (DMF)]n and {[Mn(μ4‐abdc)(H2O)]·H2O}n

Two new two‐dimensional Cu^II and Mn^II coordination polymers of 5‐aminobenzene‐1,3‐dicarboxylic acid (abdc) ligand, [Cu(μ₄‐abdc)(DMF)]_n and {[Mn(μ₄‐abdc)(H₂O)]·H₂O}_n, have been synthesized and characterized by elemental analysis and IR‐ spectroscopy. The single crystal X‐ray analyses show that the coordination number in these complexes is six, CuO₅Cu and MnO₅N. The compounds are structurally diverse and the coordination polymer obtained from copper show significant copper–copper interaction while the manganese coordination polymer shows Mn–N_amino bond.     

Poly[[di­aqua­barium(II)]‐μ5‐m‐phenylenedioxydiacetato]: a three‐dimensional barium(II) coordination polymer

In the title coordination polymer, [Ba(1,3‐BDOA)(H₂O)₂]_n (where 1,3‐BDOA²⁻ is the m‐phenylenedioxydiacetate dianion, C₁₀H₈O₆), each Ba^II ion is ten‐coordinated by six carboxyl O atoms and two ether O atoms from different 1,3‐BDOA²⁻ ligands, as well as by two water mol­ecules, thus defining a dodeca­hedron. The Ba^II atoms are covalently linked by 1,3‐BDOA²⁻ ligands in different crystallographic directions, giving rise to a three‐dimensional open framework. The crystal structure is further stabilized by hydrogen bonds and π–π stacking inter­actions. In previously studied polymers of this type, the 1,3‐BDOA²⁻ ligand showed multiple bridging modes with metal ions, including bi‐, tri‐, tetra‐ and hexa­dentate. The title Ba^II complex represents a novel three‐dimensional coordination polymer constructed by octa­dentate bridging 1,3‐BDOA²⁻ ligands.     

A novel three‐dimensional zinc(II) coordination polymer based on 3,3′‐{[1,3‐phenylenebis(methylene)]bis(oxy)}dibenzoic acid and 1,4‐bis(pyridin‐4‐yl)benzene: synthesis,crystal structure and photocatalytic properties

A novel three‐dimensional (3D) Zn^II coordination polymer, namely, poly[[[1,4‐bis(pyridin‐4‐yl)benzene](μ₃‐3,3′‐{[1,3‐phenylenebis(methylene)]bis(oxy)}dibenzoato)zinc(II)] 1,4‐bis(pyridin‐4‐yl)benzene], {[Zn(C₂₂H₁₆O₆)(C₁₆H₁₂N₂)]·C₁₆H₁₂N₂}_n or {[Zn(PMBD)(DPB)]·DPB}_n, 1 , where H₂PMBD is 3,3′‐{[1,3‐phenylenebis(methylene)]bis(oxy)}dibenzoic acid and DPB is 1,4‐bis(pyridin‐4‐yl)benzene, has been synthesized by self‐assembly using zinc nitrate, a semi‐rigid dicarboxylic acid and a nitrogen‐containing ligand. The single‐crystal X‐ray structure determination indicates that 1 possesses an intriguing 3D architecture with a 4‐connected uninodal cds topology, which is constructed from dinuclear {Zn₂} clusters and V‐shaped PMBD^2? linkers. Compound 1 exhibits excellent photocatalytic activity on the degradation of the organic dyes Rhodamine B (RhB), Rhodamine 6G (Rh6G) and Methyl Red (MR).     

Cationic ring‐opening polymerization of novel 1,3‐dehydroadamantanes with various alkyl substituents: Synthesis of thermally stable poly(1,3‐adamantane)s

Cationic ring‐opening polymerizations of 5‐alkyl‐ or 5,7‐dialkyl‐1,3‐dehydroadamantanes, such as 5‐hexyl‐ ( 4 ), 5‐octyl‐ ( 5 ), 5‐butyl‐7‐isobutyl‐ ( 6 ), 5‐ethyl‐7‐hexyl‐ ( 7 ), and 5‐butyl‐7‐hexyl‐1,3‐dehydroadamantane ( 8 ), were carried out with super Brønsted acids, such as trifluoromethanesulfonic acid or trifluoromethanesulfonimide in CH₂Cl₂ or n‐heptane. The ring‐opening polymerizations of inverted carbon–carbon bonds in 4–8 proceeded to afford corresponding poly(1,3‐adamantane)s in good to quantitative yields. Poly( 4–8 )s possessing alkyl substituents were soluble in 1,2‐dichlorobenzene, although a nonsubstituted poly(1,3‐adamantane) was not soluble in any organic solvent. In particular, poly( 8 ) exhibited the highest molecular weight at around 7500 g mol^?1 and showed excellent solubility in common organic solvents, such as THF, CHCl₃, benzene, and hexane. The resulting poly( 4–8 )s containing adamantane‐1,3‐diyl linkages showed good thermal stability, and 10% weight loss temperatures (T₁₀) were observed over 400 °C. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4111–4124     

A new two‐dimensional ZnII coordination polymer based on 1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene and 5‐nitrobenzene‐1,3‐dicarboxylic acid: synthesis,crystal structure and physical properties

A novel two‐dimensional (2D) Zn^II coordination framework, poly[[μ‐1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene](μ‐5‐nitrobenzene‐1,3‐dicarboxylato)zinc(II)], [Zn(C₈H₃NO₆)(C₁₄H₁₄N₄)]_n or [Zn(NO₂‐BDC)(1,3‐BMIB)]_n [1,3‐BMIB is 1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene and NO₂‐H₂BDC is 5‐nitrobenzene‐1,3‐dicarboxylic acid], has been prepared and characterized by IR, elemental analysis, thermal analysis and single‐crystal X‐ray diffraction. Single‐crystal X‐ray diffraction analysis revealed that the compound is a new 2D polymer with a 6³ topology parallel to the (10) crystal planes based on left‐handed helices, right‐handed helical NO₂‐BDC–Zn chains and [Zn₂(1,3‐BMIB)₂]_n clusters. In the crystal, adjacent layers are further connected by C—H…O hydrogen bonds, C—H…π interactions, C—O…π interactions and N—O…π interactions to form a three‐dimensional structure in the solid state. In addition, the compound exhibits strong fluorescence emissions in the solid state at room temperature.     

A new one‐dimensional coordination polymer of 5‐(1,3‐dioxo‐4,5,6,7‐tetraphenylisoindolin‐2‐yl)isophthalic acid with manganese

The coordination polymer catena‐poly[[(dimethylformamide‐κO)[μ₃‐5‐(1,3‐dioxo‐4,5,6,7‐tetraphenylisoindolin‐2‐yl)isophthalato‐κ⁴O¹,O^1′:O³:O^3′](methanol‐κO)manganese(III)] dimethylformamide monosolvate], {[Mn(C₄₀H₂₃NO₆)(CH₃OH)(C₃H₇NO)]·C₃H₇NO}_n, has been synthesized from the reaction of 5‐(1,3‐dioxo‐4,5,6,7‐tetraphenylisoindolin‐2‐yl)isophthalic acid and manganese(II) acetate tetrahydrate in a glass tube at room temperature by solvent diffusion. The Mn^II centre is hexacoordinated by two O atoms from one chelating carboxylate group, by two O atoms from two monodentate carboxylate groups and by one O atom each from a methanol and a dimethylformamide (DMF) ligand. The single‐crystal structure crystallizes in the triclinic space group P. Moreover, the coordination polymer shows one‐dimensional 2‐connected {0} uninodal chain networks, and free DMF molecules are connected to the chains by O—H...O hydrogen bonds. The thermogravimetric and photoluminescent properties of the compound have also been investigated.     

Synthesis of chromophores and polyimides with a green chemistry approach for second‐order nonlinear optical applications

This article presents the synthesis of nonlinear optical responsive chromophores by adopting a green chemistry approach by coupling N‐methyl‐N‐(2‐hydroxyethyl)‐4‐amino benzaldehyde with barbituric acid, 1,3‐indanedione, and 1,3‐diethyl‐2‐thiobarbituric acid as the acceptors through stilbene linkage. We performed the synthesis in less than 10 minutes at room temperature with water as a solvent without catalyst. Two different side‐chain polyimides were synthesized from poly(hydroxy‐imide)s with chromophores by Mitsunobu reaction. The chromophores were characterized by Fourier transform infrared, ¹H NMR, ¹³C NMR, and elemental analysis. However, the polyimides were characterized by Fourier transform infrared and ¹H NMR. The inherent viscosities (η_inh) of polyimides were determined by Ubbelohde viscometer, which ranged between 0.1793 and 0.1890 dL/g. The molecular weights of the polyimides were determined using gel permeation chromatography and were in range of 23 000 to 26 000. Polyimides demonstrated an excellent solubility in polar aprotic solvents, indicating good processability. Thermal behavior of these polyimides was studied by differential scanning calorimetry and thermogravimetric analysis. The T_g's were in the range of 185°C to 255°C. The change in the molecular orientation in the polymer films after electrical poling was ascertained using ultraviolet‐visible spectrophotometer and atomic force microscopy. The thicknesses and refractive indices of the thin films were determined by an ellipsometer. The second harmonic generation coefficients of the corona‐poled polymer films at T_opt's, determined by the Maker fringe technique, ranged between 59.33 and 77.82 pm/V. High thermal endurance observed for the polyimides is attributed to the extensive hydrogen bonds in the matrix. The developed polyimides showed no decay in second harmonic generation signals below 110°C, indicating the acceptance for nonlinear optical devices.     

Novel triarylamine‐based alternating conjugated polymer with high hole mobility: Synthesis,electro‐optical,and electronic properties

Novel bi‐triphenylamine‐containing aromatic dibromide M3 , N,N‐bis(4‐bromophenyl)‐N′,N′‐dipheny‐l,4‐phenylenediamine, was successfully synthesized. The novel conjugated polymer P1 having number‐average molecular weight of 1.31 × 10⁴ was prepared via Suzuki coupling from the dibromide M3 and 9,9‐dioctylfluorene‐2,7‐diboronic acid bis(1,3‐propanediol) ester. Polymer P1 had excellent thermal stability associated with a high glass‐transition temperature (T_g = 141 °C). The hole‐transporting and UV‐vis‐near‐infrared electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the conjugated polymer films cast onto indium‐tin oxide‐coated glass substrates exhibited two reversible oxidation redox couples at E_1/2 values of 0.73 and 1.13 V versus Ag/Ag⁺ in acetonitrile solution. The hole mobility of the conjugated polymer P1 revealed ～10^?3 cm² V^?1 s^?1, which is much higher than that of other conjugated polymer systems. The observed UV‐vis‐near‐infrared absorption change in the conjugated polymer film P1 at applied potentials ranging from 0.00 to 1.23 V are fully reversible and associated with strong color changes from pale yellowish in its neutral form to green and blue in its oxidized form. Using a combination of experimental study and theoretical investigation, we proposed an oxidation mechanism based on molecular orbital theory, which explains the cyclic voltammetry experimental results well. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Regioselective Synthesis of Trichloromethyl‐Substituted Salicylates and Cyclohexenones by One‐Pot Cyclizations of 1,3‐Bis(trimethylsilyloxy)buta‐1,3‐dienes

A variety of 6‐(trichloromethyl)salicylates (=2‐hydroxy‐6‐(trichloromethyl)benzoates) were prepared by TiCl₄‐mediated cyclization of 1,3‐bis(trimethylsilyloxy)buta‐1,3‐dienes with 1,1,1‐trichloro‐4,4‐dimethoxybut‐3‐en‐2‐one. The employment of trimethylsilyl trifluoromethanesulfonate (Me₃SiOTf) as Lewis acid resulted in the formation of trichloromethyl‐substituted cyclohexenones. The cyclizations proceeded with good‐to‐very‐good regioselectivities.     

A novel cobalt(II) coordination polymer with an unusual four‐connected 42.63.8 topology

In the cobalt(II) coordination polymer poly[[(μ₂‐benzene‐1,3‐dicarboxylato){μ₂‐1,1′‐[2,2′‐oxybis(ethane‐2,1‐diyl)]di‐1H‐imidazole}cobalt(II)] monohydrate], {[Co(C₁₀H₁₄N₄O)(C₈H₄O₄)]·H₂O}_n, two crystallographically distinct Co^II cations are four‐coordinated by N₂O₂ donor sets in distorted tetrahedral geometries. The Co^II centers are connected by benzene‐1,3‐dicarboxylate (m‐BDC) anions, giving two types of linear chains, which are further joined via meso‐helical 1,1′‐[2,2′‐oxybis(ethane‐2,1‐diyl)]di‐1H‐imidazole ligands to yield a thick two‐dimensional slab. The compound displays a two‐dimensional four‐connected 4².6³.8 topology, which is unprecedented in coordination polymers.     

Preparation,Structure, and Optical Properties of the 1D Chain Red Luminescent Europium Coordination Polymer: {[Eu2L6(DMF)­(H2O)]·2DMF·H2O}n (L = C9H6ClO2–)

The 1D chain red luminescent europium coordination polymer: {[Eu₂L₆(DMF)(H₂O)] · 2DMF · H₂O}_n ( I ) (L = 4‐chloro‐cinnamic acid anion, C₉H₆ClO₂^–, DMF = N, N‐dimethylformamide) was synthesized by the reaction of Eu(OH)₃ and 4‐chloro‐cinnamic acid ligand. The structure of the coordination polymer was determined by single‐crystal X‐ray diffraction analysis. It reveals that there exists two crystallographically nonequivalent europium atoms in each unit of this coordination polymer and Eu³⁺ ions are connected by two alternating bridging modes to form an endless polymer structure. The luminescent properties and energy transfer process in the complex are investigated at room temperature.     

Poly­[[μ2‐aqua‐bis­[(1,10‐phenanthro­line)nickel(II)]]‐di‐μ2,μ4‐5‐nitro‐1,3‐benzene­di­carboxyl­ato]

The reaction of Ni(CH₃COO)₂·4H₂O, 5‐nitro‐1,3‐benzene­di­carboxylic acid (H₂nmbdc), 1,10‐phenanthroline and water under hydro­thermal conditions yields the first reported two‐dimensional nickel coordination polymer with water‐ and carboxyl­ate‐bridged dimeric units, viz. [Ni₂(C₈H₃NO₆)₂(C₁₂H₈N₂)₂(H₂O)]_n. The coordination polyhedron of the Ni^II ion in the title structure is an octahedron defined by an N₂O₄ donor set. The water mol­ecule is positioned on a mirror plane and the 5‐nitro‐1,3‐benzene­di­carboxylate group is located on a twofold axis. Two types of nmbdc²⁻ coordination mode are observed: one is a bis‐monodentate mode, μ₂‐nmbdc²⁻, and the other is a bis‐bridging mode, μ₄‐nmbdc²⁻. The dimeric unit in the title compound is similar to the structural moiety in urease. In the two‐dimensional framework in the title compound, strong stacking interactions between benzene rings (μ₂‐nmbdc²⁻ and μ₄‐nmbdc²⁻) and 1,10‐phenanthroline ligands are observed.     

A two‐dimensional silver–iodide organic network constructed from a unique [Ag6I6] hexagonal prism‐based one‐dimensional column motif

A novel two‐dimensional coordination polymer, poly[[μ₂‐1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)propane]di‐μ₄‐iodido‐di‐μ₃‐iodido‐silver(I)], [Ag₄I₄(C₁₁H₁₆N₄)]_n, (I), has been synthesized by solvothermal reaction of AgNO₃, KI and 1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)propane (bmimp). In (I), the two unique Ag^I cations have AgNI₃ and AgI₄ four‐coordinated tetrahedral geometries. The bmimp ligand has imposed twofold symmetry. The Ag^I cations and iodide anions form a unique one‐dimensional polymeric column motif incorporating [Ag₆I₆] hexagonal prisms, which are then connected by bmimp ligands to form two‐dimensional organic–inorganic layers. The layers are arranged in parallel in an ABAB fashion and are packed into the resultant three‐dimensional supramolecular framework by van der Waals interactions.     

Z and E isomers of butenedioic acid with 2‐amino‐1,3‐thiazole: 2‐amino‐1,3‐thiazolium hydrogen maleate and 2‐amino‐1,3‐thiazolium hydrogen fumarate

Maleic acid and fumaric acid, the Z and E isomers of butenedioic acid, form 1:1 adducts with 2‐amino‐1,3‐thiazole, namely 2‐amino‐1,3‐thiazolium hydrogen maleate (2ATHM), C₃H₅N₂S⁺·C₄H₃O₄⁻, and 2‐amino‐1,3‐thiazolium hydrogen fumarate (2ATHF), C₃H₅N₂S⁺·C₄H₃O₄⁻, respectively. In both compounds, protonation of the ring N atom of the 2‐amino‐1,3‐thiazole and deprotonation of one of the carboxyl groups are observed. The asymmetric unit of 2ATHF contains three independent ion pairs. The hydrogen maleate ion of 2ATHM shows a short intramolecular O—H...O hydrogen bond with an O...O distance of 2.4663 (19) Å. An extensive hydrogen‐bonded network is observed in both compounds, involving N—H...O and O—H...O hydrogen bonds. 2ATHM forms two‐dimensional sheets parallel to the ab plane, extending as independent parallel sheets along the c axis, whereas 2ATHF forms two‐dimensional zigzag layers parallel to the bc plane, extending as independent parallel layers along the a axis.     

catena‐Poly[[nickel(II)‐μ2‐[1,3‐bis(imidazol‐1‐ylmethyl)benzene‐κ2N3:N3′]‐μ2‐(5‐carboxybenzene‐1,3‐dicarboxylato‐κ4O1,O1′:O3,O3′)] 0.41‐hydrate]

The title compound, {[Ni(C₉H₄O₆)(C₁₄H₁₄N₄)]·0.41H₂O}_n, exhibits a three‐dimensional hydrogen‐bonded supramolecular framework. The Ni^II cation is six‐coordinated in a distorted triangular prism defined by two N atoms from two 1,3‐bis(imidazol‐l‐ylmethyl)benzene (bix) ligands and four O atoms from two 5‐carboxybenzene‐1,3‐dicarboxylate (HBTC) dianions. The bix molecules and HBTC dianions both act as bidentate ligands, linking the Ni^II cations to form a one‐dimensional coordination polymer. A two‐dimensional wave‐like net is constructed by O—H...O hydrogen bonds linking adjacent chains. Partially occupied solvent water molecules fill the cavities and link these layers to form a three‐dimensional supramolecular structure via O—H...O hydrogen bonds. The title compound was also characterized by powder X‐ray diffraction and thermogravimetric analysis.     

Design and Synthesis of Photoaffinity Probe Candidates for the GABA-gated Chloride Channel

In order to characterize binding sites of insecticidal compounds on GABA gated chloride channel,new photoaf-finity probe candidates based on 5e-t-butyl-2e-[4-(substituted-propynyl)phenyl]-1,3-dithiane for the noncompetitiveblocker(NCB)site of the γ-aminobutyric acid(GABA)-gated chloride channel were designed and synthesized,andtheir potency as an inhibitor on NCB was measured by 4'-ethynyl-4-n-[2,3-~3H_2]-propylbicycloorthobenzoate(~3HEBOB)assay.The synthesized compounds showed high inhibition activities with half maximum inhibition concen-trations(IC_(50))of lower than 35 nmol/L and were very stable in binding conditions as well photoreacted quickly at300 nm light.These new compounds are expected to be good photoaffinity labeling probes if radioisotope iodine isincorporated.