Ru catalyzed cyclodimerization of bis(2‐thienyl)acetylene and bis(3‐thienyl)acetylene. Synthesis properties of 4,5,6‐tris(2‐thienyl)benzo(b)thiophene and 5,6,7‐tris(3‐thienyl)benzo[b]thiophene

Activated dihydridocarbonyltris(triphenylphosphine)ruthenium catalyzes the cyclodimerization of both bis(2‐thienyl)acetylene and bis(3‐thienyl)acetylene to yield, respectively, 4,5,6‐tris(2′‐thienyl)‐benzo[b]thiophene and 5,6,7‐tris(3′‐thienyl)benzo[b]thiophene. These fluoresce in the blue. Both undergo irreversible one electron oxidation at & sim1.1 mV versus Ag/Ag⁺ electrode, consistent with oxidation of the benzo[b]thiophene nuclei rather than the substituent thiophene rings.     

Synthesis and characterization of poly(1,4‐bis((E)‐2‐(3‐dodecylthiophen‐2‐yl)vinyl)benzene) derivatives

New amorphous semiconducting copolymers, poly(9,9‐dialkylfluorene)‐alt‐(3‐dodecylthienyl‐divinylbenzene‐3‐dodecylthienyl) derivatives (PEFTVB and POFTVB), were designed, synthesized, and characterized. The structure of copolymers was confirmed by H NMR, IR, and elemental analysis. The copolymers showed very good solubility in organic solvents and high thermal stability with high T_g of 178–185 °C. The weight average molecular weight was found to be 107,900 with polydispersity of 3.14 for PEFTVB and 76,700 with that of 3.31 for POFTVB. UV–vis absorption studies showed the maximum absorption at 428 nm (in solution) and 435 nm (in film) for PEFTVB and at 430 nm (in solution) and 436 nm (in film) for POFTVB. Photoluminescence studies showed the emission at 498 nm (in solution) and 557 nm (in film) for PEFTVB and at 498 nm (in solution) and 536 nm (in film) for POFTVB. The solution‐processed thin‐film transistors showed the carrier mobility of 2 × 10^?4 cm² V^?1 s^?1 for PEFTVB‐based devices and 2 × 10^?5 cm² V^?1 s^?1 for POFTVB‐based devices. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3942–3949, 2010     

(2‐Amino­ethoxy)­bis(2‐thienyl)­boron

In the five‐membered ring in the title compound, (2‐amino­ethoxy)­bis(2‐thienyl)­boron, C₁₀H₁₂BNOS_2, the B atom is four‐coordinate with dimensions N—B 1.654 (3), O—B 1.479 (3), and C—B 1.606 (3) and 1.609 (3) Å. An intermolecular hydrogen bond between an amino H atom and the ethoxy O atom links the mol­ecules into infinite chains along the a axis. Only one of the two amino H atoms is involved in hydrogen bonding because there is only the one acceptor atom, the ethoxy O atom, and the molecular geometry precludes formation of a second hydrogen bond by the second amino H atom.     

N‐Benzyl‐2,5‐bis(2‐thienyl)­pyrrole

The solid‐state structure of the title compound, C₁₉H₁₅NS₂, is unusual among substituted thiophene/pyrrole derivatives in that the molecular packing is dominated by π–π interactions between the benzyl substituents. This may be due to the large torsion angles observed between adjacent heterocycles. Torsion angles between adjacent rings in poly­pyrrole and poly­thio­phene conducting polymers are related to conjugation length and the conductivity properties of the polymer materials. The title compound crystallizes in space group P2₁/c with two mol­ecules in the asymmetric unit, both of which exhibit disorder in one of their thio­phene rings.     

1,4‐Bis(2‐benzimidazolyl)­benzene

The title compound, C₂₀H₁₄N₄, lies about an inversion centre and the benz­imidazole moiety and the phenyl ring are twisted by 30.9 (1)°. The benz­imidazole moiety is completely planar, with a maximum deviation of 0.009 (2) Å. Intermolecular N—­H?N hydrogen bonds give rise to a layered structure, with the layers stacked by van der Waals interactions.     

Oxidation polymerization of a charge‐transfer complex of 2,6‐bis(2‐thienyl)‐1,4‐dithiafulvene with 7,7,8,8‐tetracyanoquinodimethane

A π‐conjugated poly(α‐dithienylen‐dithiafulvene) ( 2 ) was obtained by the oxidation polymerization of 2,6‐bis(2‐thienyl)‐1,4‐dithiafulvene ( 1 ) as a dithiafulvene monomer derived from 4‐(2‐thienyl)‐1,2,3‐thiadiazole. When a solution of 1 in CHCl₃ was added to a stirred solution of FeCl₃ in CHCl₃, only the low‐molecular‐weight product 2 was obtained. The mixture was stirred for 15 h with an N₂ flow. The polymerization at higher temperatures resulted in polymers with large insoluble fractions. A higher molecular weight polymer was obtained by the oxidation polymerization of a charge‐transfer complex of 1 with 7,7,8,8‐tetracyanoquinodimethane (compound 3 ). In contrast to 2 , polymer 4 was readily soluble in dimethyl sulfoxide, dimethylformamide, and acetone and partially soluble in tetrahydrofuran and methanol and had a larger molecular weight (peak top molecular weight = 37,000). The conductivity of polymer 4 was 3 orders of magnitude larger than that of polymer 2 . © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6592–6598, 2005     

A novel parallel interpenetrating two‐dimensional (4,4) network: poly[[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene](μ2‐naphthalene‐1,4‐dicarboxylato)zinc(II)]

In the title coordination compound, [Zn(C₁₂H₆O₄)(C₁₄H₁₄N₄)]_n, the two Zn^II centers exhibit different coordination environments. One Zn^II center is four‐coordinated in a distorted tetrahedral environment surrounded by two carboxylate O atoms from two different naphthalene‐1,4‐dicarboxylate (1,4‐ndc) anions and two N atoms from two distinct 1,4‐bis(imidazol‐1‐ylmethyl)benzene (1,4‐bix) ligands. The coordination of the second Zn^II center comprises two N atoms from two different 1,4‐bix ligands and three carboxylate O atoms from two different 1,4‐ndc ligands in a highly distorted square‐pyramidal environment. The 1,4‐bix ligand and the 1,4‐ndc anion link adjacent Zn^II centers into a two‐dimensional four‐connected (4,4) network. The two (4,4) networks are interpenetrated in a parallel mode.     

Synthesis and photovoltaic properties of 2,6‐bis(2‐thienyl) benzobisazole and 4,8‐bis(thienyl)‐benzo[1,2‐B:4,5‐B′]dithiophene copolymers

In an effort to design efficient low‐cost polymers for use in organic photovoltaic cells the easily prepared donor–acceptor–donor triad of a either cis‐benzobisoxazole, trans‐benzobisoxazole or trans‐benzobisthiazole flanked by two thiophene rings was combined with the electron‐rich 4,8‐bis(5‐(2‐ethylhexyl)‐thien‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithiophene. The electrochemical, optical, morphological, charge transport, and photovoltaic properties of the resulting terpolymers were investigated. Although the polymers differed in the arrangement and/or nature of the chalcogens, they all had similar highest occupied molecular orbital energy levels (?5.2 to ?5.3 eV) and optical band gaps (2.1–2.2 eV). However, the lowest unoccupied molecular orbital energy levels ranged from ?3.1 to ?3.5 eV. When the polymers were used as electron donors in bulk heterojunction photovoltaic devices with PC₇₁BM ([6,6]‐phenyl C₇₁‐butyric acid methyl ester) as the acceptor, the trans‐benzobisoxazole polymer had the best performance with a power conversion efficiency of 2.8%. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 316–324     

Poly[(μ4‐biphenyl‐3,3′,4,4′‐tetracarboxylato)bis[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene]dicobalt(II)]

The asymmetric unit of the title two‐dimensional coordination polymer, [Co₂(C₁₆H₆O₈)(C₁₄H₁₄N₄)₂]_n, contains one Co²⁺ ion, half of a biphenyl‐3,3′,4,4′‐tetracarboxylate (bptc) anion lying about an inversion centre and one 1,4‐bis(imidazol‐1‐ylmethyl)benzene (bix) ligand. The Co^II atom is coordinated by three carboxylate O atoms from two different bptc ligands and two N atoms from two bix ligands constructing a distorted square pyramid. Each Co²⁺ ion is interlinked by two bptc anions, while each bptc anion coordinates to four Co atoms as a hexadentate ligand so that four Co^II atoms and four bptc anions afford a larger 38‐membered ring. These inorganic rings are further extended into a two‐dimensional undulated network in the (10) plane. Two Co^II atoms in adjacent 38‐membered rings are joined together by pairs of bix ligands forming a 26‐membered [Co₂(bix)₂] ring that is penetrated by a bptc anion; these components share a common inversion centre.     

Concomitant but disappearing: two polymorphs of 1,4‐bis(tribromomethyl)benzene

The title compound, C₈H₄Br₆, (I), initially crystallized from deuterochloroform as the comcomitant polymorphs (Ia) (prisms, space group P2₁/n, Z = 2) and (Ib) (hexagonal plates, space group C2/c, Z = 4). The molecules in both forms display crystallographic inversion symmetry. All further attempts to crystallize the compound led exclusively to (Ib), so that (Ia) may be regarded as a `disappearing polymorph'. Surprisingly, however, the density of (Ia) is greater than that of (Ib). The only significant difference between the molecular structures is the orientation of the CBr<sub>3</sub> groups. The molecular packing of both structures is largely determined by Br...Br interactions, although (Ia) also displays a C—H...Br hydrogen bond and both polymorphs display one Br...π contact. For (Ia), six of the eight contacts combine to form a tube‐like substructure parallel to the a axis. For (Ib), the two shortest Br...Br contacts link `half' molecules consisting of C—CBr₃ groups to form double layers parallel to (001) in the regions z≃, .     

Synthesis of new 3,3′‐(1,4‐phenylene)bis(1,5‐diones) derivatives

Several 3,3′‐(1,4‐phenylene)bis(1,5‐diones) and their chalcone precursors have been prepared in good to excellent yield via aldol addition and Michael addition starting from 3‐acetyl‐2,5‐dimethylfuran or 3‐acetyl‐2,5‐dimethyl‐thiophene with terephthalaldehyde in the presence of appropriate base NaOH or lithium diisopropylamide. The kind and amount of alkali played a critical role in improving the reaction rates and yields of the products. J. Heterocyclic Chem., (2011).     

A three‐dimensional coordination polymer based on the Zn4(μ3‐OH)2 unit: poly[[(μ4‐benzene‐1,4‐dicarboxylato)bis(μ3‐benzene‐1,4‐dicarboxylato)bis(μ3‐hydroxido)bis(1,10‐phenanthroline‐5,6‐dione)tetrazinc] dihydrate]

The title compound, {[Zn₄(C₈H₄O₄)₃(OH)₂(C₁₂H₆N₂O₂)₂]·2H₂O}_n, has been prepared hydrothermally by the reaction of Zn(NO₃)₂·6H₂O with benzene‐1,4‐dicarboxylic acid (H₂bdc) and 1,10‐phenanthroline‐5,6‐dione (pdon) in H₂O. In the crystal structure, a tetranuclear Zn₄(OH)₂ fragment is located on a crystallographic inversion centre which relates two subunits, each containing a [ZnN₂O₄] octahedron and a [ZnO₄] tetrahedron bridged by a μ₃‐OH group. The pdon ligand chelates to zinc through its two N atoms to form part of the [ZnN₂O₄] octahedron. The two crystallographically independent bdc²⁻ ligands are fully deprotonated and adopt μ₃‐κO:κO′:κO′′ and μ₄‐κO:κO′:κO′′:κO′′′ coordination modes, bridging three or four Zn^II cations, respectively, from two Zn₄(OH)₂ units. The Zn₄(OH)₂ fragment connects six neighbouring tetranuclear units through four μ₃‐bdc²⁻ and two μ₄‐bdc²⁻ ligands, forming a three‐dimensional framework with uninodal 6‐connected α‐Po topology, in which the tetranuclear Zn₄(OH)₂ units are considered as 6‐connected nodes and the bdc²⁻ ligands act as linkers. The uncoordinated water molecules are located on opposite sides of the Zn₄(OH)₂ unit and are connected to it through hydrogen‐bonding interactions involving hydroxide and carboxylate groups. The structure is further stabilized by extensive π–π interactions between the pdon and μ₄‐bdc²⁻ ligands.     

Poly[[sesqui[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene‐κ2N:N′](carbonato‐κ2O,O′)copper(II)] 1,4‐bis(imidazol‐1‐ylmethyl)benzene hemisolvate pentahydrate]

The asymmetric unit of the title compound, {[Cu(CO₃)(C₁₄H₁₄N₄)_1.5]·0.5C₁₄H₁₄N₄·5H₂O}_n, contains one Cu^II cation in a slightly distorted square‐pyramidal coordination environment, one CO₃²⁻ anion, one full and two half 1,4‐bis(imidazol‐1‐ylmethyl)benzene (bix) ligands, one half‐molecule of which is uncoordinated, and five uncoordinated water molecules. One of the coordinated bix ligands and the uncoordinated bix molecule are situated about centers of symmetry, located at the centers of the benzene rings. The coordinated bix ligands link the copper(II) ions into a [Cu(bix)_1.5]_n molecular ladder. These molecular ladders do not form interpenetrated ladders but are arranged in an ABAB parallel terrace, i.e. with the ladders arranged one above another, with sequence A translated with respect to B by 8 Å. To best of our knowledge, this arrangement has not been observed in any of the molecular ladder frameworks synthesized to date. The coordination environment of the Cu^II atom is completed by two O atoms of the CO₃²⁻ anion. The framework is further strengthened by extensive O—H...O and O—H...N hydrogen bonds involving the water molecules, the O atoms of the CO₃²⁻ anion and the N atoms of the bix ligands. This study describes the first example of a molecular ladder coordination polymer based on bix and therefore demonstrates further the usefulness of bix as a versatile multidentate ligand for constructing coordination polymers with interesting architectures.     

Poly[tetrasodium(I)‐tetra‐μ2‐bis(butane‐1,4‐diyldioxy)borato‐μ2‐1,4‐butane­diol]

In the title compound, [Na₄(C₈H₁₆BO₄)₄(C₄H₁₀O₂)]_n, there are two coordination types for the four independent Na⁺ cations: two Na⁺ cations bond to six diolate O atoms [Na—O = 2.305 (2)–2.609 (2) Å], while the other two are five‐coordinate via one 1,4‐butane­diol [2.289 (2) and 2.349 (3) Å] and four diolate O atoms [2.295 (2)–2.408 (2) Å]. Corresponding to this, there are three‐ and four‐coordinate diolate O atoms, the latter bridging Na atoms. The 1,4‐butane­diol mol­ecules lie on inversion centres. The boron stereochemistry shows minor local perturbations from its usual tetrahedral state [B—O = 1.457 (4)–1.503 (4) Å]. The resulting polymer packs as sheets parallel to the (10) plane crosslinked by the butane­diol mol­ecules. The structure was solved using data from a multiple crystal.     

Synthesis and characterization of soluble fluorine‐containing polyimides based on 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene

The synthesis and properties of a class of soluble fluorine‐containing aromatic polyimides are described. Substituents of trifluoromethyl groups on the aromatic rings of paralinked aromatic ether diamine conferred the polymer prepared thereof with enhanced solubility, low‐moisture absorption, and low dielectric constants. The polyimides also exhibited exceptional thermal stability, good mechanical properties, and excellent hygrothermal resistance. These outstanding combined features ensure the polymers are desirable candidate materials for advanced microelectronics applications. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2581–2590, 2001     

Poly[[(μ2‐biphenyl‐2,4′‐dicarboxylato)[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene]cadmium(II)] 0.15‐hydrate]

The asymmetric unit of the title two‐dimensional coordination polymer, {[Cd(C₁₄H₈O₄)(C₁₄H₁₄N₄)]·0.15H₂O}_n, is composed of one Cd^II cation, one biphenyl‐2,4′‐dicarboxylate (bpdc) anion, one 1,4‐bis(imidazol‐1‐ylmethyl)benzene (bix) ligand and 0.15 solvent water molecules. The coordination environment of the Cd^II cation is defined by four carboxylate O atoms from two different bpdc anions in a chelating mode and two N atoms from two distinct bix ligands, constructing a distorted trigonal prism polyhedron. Two inversion‐related Cd^II cations are bridged together by two positionally disordered bpdc anions, forming a 22‐membered ring with a Cd...Cd distance of 9.1966 (9) Å. These rings are then further linked by two bix ligands, extending into a two‐dimensional layer along (102) with 6³ topology.     

(1,3‐Dimethylimidazolidine‐2‐selone‐κSe)bis(1,10‐phenanthroline‐κ2N,N′)copper(II) bis(perchlorate) and bis(2,2′‐bipyridyl‐κ2N,N′)(imidazolidine‐2‐thione‐κS)copper(II) bis(perchlorate)

In the first title salt, [Cu(C₁₂H₈N₂)₂(C₅H₁₀N₂Se)](ClO₄)₂, the Cu^II centre occupies a distorted trigonal–bipyramidal environment defined by four N donors from two 1,10‐phenanthroline (phen) ligands and by the Se donor of a 1,3‐dimethylimidazolidine‐2‐selone ligand, with the equatorial plane defined by the Se and by two N donors from different phen ligands and the axial sites occupied by the two remaining N donors, one from each phen ligand. The Cu—N distances span the range 1.980 (10)–2.114 (11) Å and the Cu—Se distance is 2.491 (3) Å. Intermolecular π–π contacts between imidazolidine rings and the central rings of phen ligands generate chains of cations. In the second salt, [Cu(C₁₀H₈N₂)₂(C₃H₆N₂S)](ClO₄)₂, the Cu^II centre occupies a similar distorted trigonal–bipyramidal environment comprising four N donors from two 2,2′‐bipyridyl (bipy) ligands and an S donor from an imidazolidine‐2‐thione ligand. The equatorial plane is defined by the S donor and two N donors from different bipy ligands. The Cu—N distances span the range 1.984 (6)–2.069 (7) Å and the Cu—S distance is 2.366 (3) Å. Intermolecular π–π contacts between imidazolidine and pyridyl rings form chains of cations. A major difference between the two structures is due to the presence in the second complex of two N—H...O hydrogen bonds linking the imidazolidine N—H hydrogen‐bond donors to perchlorate O‐atom acceptors.     

1,4‐Bis(p‐tolyl­ethynyl)benzene

The rod‐like molecule of the title hydro­carbon, C₂₄H₁₈, is centrosymmetric, with the centroid of the central benzene ring residing on an inversion center. The molecules display a planar conformation of the benzene rings and aggregate into stacks along the [010] direction via Csp³—H⋯π(arene) interactions, thus forming a stair‐like pseudo‐two‐dimensional network. Each molecule acts as both a C—H hydrogen donor and a π‐arene acceptor, forming four hydrogen bonds per molecule.     

Synthesis,crystal structure and photophysical properties of 1,4‐bis(1,3‐diazaazulen‐2‐yl)benzene: a new π building block

A dimerized 1,3‐diazaazulene derivative, namely 1,4‐bis(1,3‐diazaazulen‐2‐yl)benzene [or 2,2′‐(1,4‐phenylene)bis(1,3‐diazaazulene)], C₂₂H₁₄N₄, (I), has been synthesized successfully through the condensation reaction between 2‐methoxytropone and benzene‐1,4‐dicarboximidamide hydrochloride, and was characterized by ¹H NMR and ¹³C NMR spectroscopies, and ESI–MS. X‐ray diffraction analysis reveals that (I) has a nearly planar structure with good π‐electron delocalization, indicating that it might serve as a π building block. The crystal belongs to the monoclinic system. One‐dimensional chains were formed along the a axis through π–π interactions and adjacent chains are stabilized by C—H…N interactions, forming a three‐dimensional architecture. The solid emission of (I) in the crystalline form exhibited a 170 nm red shift compared with that in the solution state. The observed optical bandgap for (I) is 3.22 eV and a cyclic voltammetry experiment confirmed the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). The calculated bandgap for (I) is 3.37 eV, which is very close to the experimental result. In addition, the polarizability and hyperpolarizability of (I) were appraised for its further application in second‐order nonlinear optical materials.     

Poly[[μ2‐1,3‐bis(pyridin‐4‐yl)propane](μ3‐1,4‐phenylenediacetato)cadmium]

Solvothermal reaction between Cd(NO₃)₂, 1,4‐phenylenediacetate (1,4‐PDA) and 1,3‐bis(pyridin‐4‐yl)propane (bpp) afforded the title complex, [Cd(C₁₀H₈O₄)(C₁₃H₁₄N₂)]_n. Adjacent carboxylate‐bridged Cd^II ions are related by an inversion centre. The 1,4‐PDA ligands adopt a cis conformation and connect the Cd^II ions to form a one‐dimensional chain extending along the c axis. These chains are in turn linked into a two‐dimensional network through bpp bridges. The bpp ligands adopt an anti–gauche conformation. From a topological point of view, each bpp ligand and each pair of 1,4‐PDA ligands can be considered as linkers, while the dinuclear Cd^II unit can be regarded as a 6‐connecting node. Thus, the structure can be simplified to a two‐dimensional 6‐connected network.