One‐dimensional CuII coordination polymers containing C2h‐symmetric 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate linkers

Two new one‐dimensional Cu^II coordination polymers (CPs) containing the C_2h‐symmetric terphenyl‐based dicarboxylate linker 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate (3,3′‐TPDC), namely catena‐poly[[bis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ⁴O,O′:O′′:O′′′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂]·H₂O}_n, (I), and catena‐poly[[aquabis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ²O³:O^3′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂(H₂O)]·H₂O}_n, (II), were both obtained from two different methods of preparation: one reaction was performed in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar. Both reactions afforded crystals of different colours, i.e. violet plates for (I) and blue needles for (II), both of which were analysed by X‐ray crystallography. The 3,3′‐TPDC bridging ligands coordinate the Cu^II ions in asymmetric chelating modes in (I) and in monodenate binding modes in (II), forming one‐dimensional chains in each case. Both coordination polymers contain two coordinated dimethylamine ligands in mutually trans positions, and there is an additional aqua ligand in (II). The solvent water molecules are involved in hydrogen bonds between the one‐dimensional coordination polymer chains, forming a two‐dimensional network in (I) and a three‐dimensional network in (II).     

Thermal Behavior of N,N＇Bis[N-（2,2,2-trinitroethyl）-N-nitro]ethylenediamine

The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N‐N‐bis[N‐(2,2,2‐tri‐nitroethyl)‐N‐nitro]ethylenediamine in a temperature‐programmed mode have been investigated by means of differential scanning calorimetry (DSC). The results show that kinetic model function in differential form, apparent activation energy E_a and pre‐exponential factor A of this reaction are 3(1 ‐α)^2/3, 203.67 kJ·mol^?1 and 10^20.61s^?1, respectively. The critical temperature of thermal explosion of the compound is 182.2 °C. The values of ΔS^≠ ΔH^≠ and ΔG^≠ of this reaction are 143.3 J·mol^?1·K^?1, 199.5 kJ·mol^?1 and 135.5 kJ·mol^?1, respectively.     

A Novel,One‐Pot Four‐Component Route to 2′‐Thioxo‐2′,3′‐dihydrospiro[indole‐3,6′‐[1,3]thiazin]‐2‐one Derivatives

An efficient route to 2′,3′‐dihydro‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives is described. It involves the reaction of isatine, 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ⁵‐phosphanylidene)ethan‐1‐one, and different amines in the presence of CS₂ in dry MeOH at reflux (Scheme 1). The alkyl carbamodithioate, which results from the addition of the amine to CS₂, is added to the α,β‐unsaturated ketone, resulting from the reaction between 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ⁵‐phosphanylidene)ethan‐1‐one and isatine, to produce the 3′‐alkyl‐2′,3′‐dihydro‐4′‐phenyl‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives in excellent yields (Scheme 2). Their structures were corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and by elemental analyses.     

Thermal Behavior of 2‐(Dinitromethylene)‐1,3‐diazacyclopentane

A new compound, 2‐(dinitromethylene)‐1,3‐diazacyclopentane (DNDZ), was prepared by the reaction of 1,1‐diamino‐2,2‐dinitroethylene (FOX‐7) with 1,2‐diaminoethane in N‐methylpyrrolidone (NMP). Thermal decomposition of DNDZ was studied under non‐isothermal conditions by DSC, TG/DTG methods, and the enthalpy, apparent activation energy and pre‐exponential factor of the exothermic decomposition reaction were obtained as 317.13 kJ·mol^?1, 269.7 kJ·mol^?1 and 10^24.51 s^?1, respectively. The critical temperature of thermal explosion was 261.04°C. Specific heat capacity of DNDZ was determined with a micro‐DSC method and a theoretical calculation method, and the molar heat capacity was 205.41 J·mol^?1·K^?1 at 298.15 K. Adiabatic time‐to‐explosion was calculated to be a certain value between 263–289 s. DNDZ has higher thermal stability than FOX‐7.     

5,5′‐Hydrazinebistetrazole: An Oxidation‐stable Nitrogen‐rich Compound and Starting Material for the Synthesis of 5,5′‐Azobistetrazolates

All 5,5′‐hydrazinebistetrazoles reported in the literature are sensitive to oxidation and react with atmospheric oxygen to yield the corresponding 5,5′‐azobistetrazolates on time. Herewith, we report on the synthesis of the free acid 5,5′‐hydrazinebistetrazole (HBT) which showed to be stable on air for extended periods of time. The compound was fully characterized by analytical and spectroscopic methods and its X‐ray structure was determined by diffraction techniques. Besides, we determined its explosive properties by BAM methods and calculated its heat of formation (+414 kJ mol^?1), detonation velocity (8523 m s^?1) and detonation pressure (27.7 GPa). HBT proved to be very safe to handle (impact sensitivity: >30 J, friction sensitivity: ～108 N) and was used as a starting material for the synthesis of some already reported 5,5′‐azobistetrazolates: NH₄⁺, NH₂NH₃⁺, Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, Mg²⁺, Ca²⁺, Sr²⁺ and Ba²⁺.     

Masking of Lewis acidity trends in the solid‐state structures of trichlorido‐ and tribromido(2,2′:6′,2′′‐terpyridine‐κ3N,N′,N′′)gallium(III)

The molecular structures of trichlorido(2,2′:6′,2′′‐terpyridine‐κ³N,N′,N′′)gallium(III), [GaCl₃(C₁₅H₁₁N₃)], and tribromido(2,2′:6′,2′′‐terpyridine‐κ³N,N′,N′′)gallium(III), [GaBr₃(C₁₅H₁₁N₃)], are isostructural, with the Ga^III atom displaying an octahedral geometry. It is shown that the Ga—N distances in the two complexes are the same within experimental error, in contrast to expected bond lengthening in the bromide complex due to the lower Lewis acidity of GaBr₃. Thus, masking of the Lewis acidity trends in the solid state is observed not only for complexes of group 13 metal halides with monodentate ligands but for complexes with the polydentate 2,2′:6′,2′′‐terpyridine donor as well.     

Two Bulky Conjugated 4′‐(4‐Hydroxyphenyl)‐4,2′:6′,4′′‐terpyridine‐based Layered Complexes: Synthesis,Structure, and Photocatalytic Hydrogen Evolution Activity

Two new layered complexes with the formulas of {[Cu(H₂O)(HL)₂Cl](NO₃)}_n ( 1 ) and {[Cu(H₂O)₂(HL)₂](NO₃)₂}_n ( 2 ) were solvothermally synthesized by the reactions of the bulky conjugated 4′‐(4‐hydroxyphenyl)‐4,2′:6′,4′′‐terpyridine ligand (HL) with different Cu^II salts, which were further used as photocatalysts to achieve hydrogen production from water splitting. Single‐crystal structural analyses reveal that both complexes feature coplanar (4 4) layers with different connection manners between the HL extended Z‐shaped chains. More interestingly, 1 possessing more negative conduction band potential and higher structural stability exhibits a large hydrogen production rate of 2.43 mmol · g^–1 · h^–1, which is four times higher than that of 2 . Thus, the Cu^II‐based coordination polymers modified by the bulky conjugated organic ligand can become potentially promising non‐Pt photocatalysts for hydrogen production from water splitting.     

Synthesis and photovoltaic investigation of dithieno[2,3‐d:2′,3′‐d′]‐benzo[1,2‐b:3,4‐b′:5,6‐d″]trithiophene‐based conjugated polymer with an enlarged π‐conjugated system

Compared with benzo[1,2‐b:3,4‐b′:5,6‐d″]trithiophene (BTT), an extended π‐conjugation fused ring derivative, dithieno[2,3‐d:2′,3′‐d′]benzo[1,2‐b:3,4‐b′:5,6‐d″]trithiophene (DTBTT) has been designed and synthesized successfully. For investigating the effect of extending conjugation, two wide‐bandgap (WBG) benzo[1,2‐b:4,5‐b′]dithiophene (BDT)‐based conjugated polymers (CPs), PBDT‐DTBTT, and PBDT‐BTT, which were coupled between alkylthienyl‐substituted benzo[1,2‐b:4,5‐b′]dithiophene bistin (BDT‐TSn) and the weaker electron‐deficient dibromides DTBTTBr₂ and BTTBr₂ bearing alkylacyl group, were prepared. The comparison result revealed that the extending of conjugated length and enlarging of conjugated planarity in DTBTT unit endowed the polymer with a wider and stronger absorption, more ordered molecular structure, more planar and larger molecular configuration, and thus higher hole mobility in spite of raised highest occupied molecular orbital (HOMO) energy level. The best photovoltaic devices exhibited that PBDT‐DTBTT/PC₇₁BM showed the power conversion efficiency (PCE) of 2.73% with an open‐circuit voltage (V_OC) of 0.82 V, short‐circuit current density (J_SC) of 6.29 mA cm^?2, and fill factor (FF) of 52.45%, whereas control PBDT‐BTT/PC₇₁BM exhibited a PCE of 1.98% under the same experimental conditions. The 38% enhanced PCE was mainly benefited from improved absorption, and enhanced hole mobility after the conjugated system was extended from BTT to DTBTT. Therefore, our results demonstrated that extending the π‐conjugated system of donor polymer backbone was an effective strategy of tuning optical electronic property and promoting the photovoltaic property in design of WBG donor materials.     

Two Energetic Salts based on 5,5′‐Bitetrazole‐1,1′‐diolate: Syntheses,Characterization, and Properties

Two salts based on 1H,1′H‐5,5′‐bitetrazole‐1,1′‐diolate (BTO) anion with pyrazole ( 1 ) and imidazole ( 2 ) cations were synthesized with metathesis reactions. Structural characterization was accomplished for them by using the element analysis, Fourier transform infrared spectroscopy (FT‐IR), NMR and mass spectrum, and X‐ray single crystal diffraction. Thermal analysis for the title salts were determined by means of differential scanning calorimetry (DSC) and thermogravimetry‐derivative thermogravimetry (TG‐DTG) as well as the calculation of non‐isothermal kinetic parameters. Consequently, both salts shown acceptable thermal stabilities as the decomposition temperatures were over 200 °C. The enthalpies of formation were calculated for these salts using the measured combustion energies with a result of 70.6 kJ · mol^–1 for 1 and –47.8 kJ · mol^–1 for 2 , respectively. Impact and friction sensitivities were also tested and the results indicated that these salts both have low sensitivities (>40 J, 120 N). The title energetic salts possess acceptable performance, they can therefore be applied in the field of energetic materials.     

Design,Synthesis and Biological Evaluation of Novel N‐(4‐([2,2′:5′,2′′‐Terthiophen]‐5‐yl)‐2‐methylbut‐3‐yn‐2‐yl) Benzamide Derivatives

On the basis of the principle of combination of active groups, a series of novel N‐(4‐([2,2′:5′,2′′‐terthiophen]‐5‐yl)‐2‐methylbut‐3‐yn‐2‐yl) benzamide derivatives were designed, synthesized and systematically evaluated for their antiviral activity against tobacco mosaic virus (TMV). The bioassay results showed that most of these compounds displayed good anti‐TMV activity, and some of them exhibited higher antiviral activity than commercial Ningnanmycin. Especially, compound 8e with excellent anti‐TMV activity (inactivation activity, 92.3%/500 µg·mL^?1; curative activity, 85.7%/500 µg·mL^?1 and protection activity, 64.7%/500 µg·mL^?1) emerged as a potential inhibitor of plant virus TMV. Quantitative structure‐activity relationship studies proved that the van der Waals volume (V) and electronic parameter (∑(∑σ_o+σ_p) and ∑σ_m) for the substituent R¹ were very important for antiviral activities in this class of compounds.     

Synthesis and Crystal Structures of O‐2′,3′‐Cyclic Cyclopentanone and Cyclohexanone Ketals of the Cytostatic 5‐Fluorouridine

The synthesis of two O‐2′,3′‐cyclic ketals, i.e., 5 and 6 , of the cytostatic 5‐fluorouridine ( 2 ), carrying a cyclopentane and/or a cyclohexane ring, respectively, is described. The novel compounds were characterized by ¹H‐, ¹⁹F‐, and ¹³C‐NMR, and UV spectroscopy, as well as by elemental analyses. Their crystal structures were determined by X‐ray analysis. Both compounds 5 and 6 show an anti‐conformation at the N‐glycosidic bond which is biased from +ac to +ap compared to the parent nucleoside 2 . The sugar puckering is changed from ^2′E to _3′E going along with a reduction of the puckering amplitude τ_m by ca. 10–13° due to the ketalization. The conformation about the sugar exocyclic bond C(4′)? C(5′) of 5 and 6 remains unchanged, i.e., g⁺, compared with compound 2 .     

A three‐dimensional CdII coordination polymer constructed from 1,1′‐biphenyl‐2,2′,5,5′‐tetracarboxylate and 1,4‐bis(1H‐imidazol‐1‐yl)benzene ligands

The title coordination polymer, poly[[aqua(μ₅‐1,1′‐biphenyl‐2,2′,5,5′‐tetracarboxylato)bis[μ₂‐1,4‐bis(1H‐imidazol‐1‐yl)benzene]dicadmium(II)] dihydrate], {[Cd₂(C₁₆H₆O₈)(C₁₂H₁₀N₄)₂(H₂O)]·2H₂O}_n, was crystallized from a mixture of 1,1′‐biphenyl‐2,2′,5,5′‐tetracarboxylic acid (H₄bpta), 1,4‐bis(1H‐imidazol‐1‐yl)benzene (1,4‐bib) and cadmium nitrate in water–dimethylformamide. The crystal structure consists of two crystallographically independent Cd^II cations, with one of the Cd^II cations possessing a slightly distorted pentagonal bipyramidal geometry. The second Cd^II centre is coordinated by carboxylate O atoms and imidazole N atoms from two separate 1,4‐bib ligands, displaying a distorted octahedral CdN₂O₄ geometry. The completely deprotonated bpta⁴⁻ ligand, exhibiting a new coordination mode, bridges five Cd^II cations to form one‐dimensional chains viaμ₃‐η¹:η²:η¹:η² and μ₂‐η¹:η¹:η⁰:η⁰ modes, and these are further linked by 1,4‐bib ligands to form a three‐dimensional framework with a (4².6⁴)(4.6²)(4³.6⁵.7²) topology. The structure of the coordination polymer is reinforced by intermolecular hydrogen bonding between carboxylate O atoms, aqua ligands and crystallization water molecules. The solid‐state photoluminescence properties were investigated and the complex might be a candidate for a thermally stable and solvent‐resistant blue fluorescent material.     

Two ZnII‐based MOFs constructed with biphenyl‐2,2′,5,5′‐tetracarboxylic acid and flexible N‐donor ligands: syntheses,structures and properties

Two new Zn²⁺‐based metal–organic frameworks (MOFs) based on biphenyl‐2,2′,5,5′‐tetracarboxylic acid, i.e. H₄(o,m‐bpta), and N‐donor ligands, namely, poly[[(μ₄‐biphenyl‐2,2′,5,5′‐tetracarboxylato)bis{[1,3‐phenylenebis(methylene)]bis(1H‐imidazole)}dizinc(II)] dimethylformamide monosolvate dihydrate], {[Zn₂(C₁₆H₆O₈)(C₁₄H₁₄N₄)₂]·C₃H₇NO·2H₂O}_n or {[Zn₂(o,m‐bpta)(1,3‐bimb)₂]·C₃H₇NO·2H₂O}_n ( 1 ) {1,3‐bimb = [1,3‐phenylenebis(methylene)]bis(1H‐imidazole)}, and poly[[(μ₄‐biphenyl‐2,2′,5,5′‐tetracarboxylato)bis{[1,4‐phenylenebis(methylene)]bis(1H‐imidazole)}dizinc(II)] monohydrate], {[Zn₂(C₁₆H₆O₈)(C₁₄H₁₄N₄)₂]·H₂O}_n or {[Zn₂(o,m‐bpta)(1,4‐bimb)₂]·H₂O}_n ( 2 ) {1,4‐bimb = [1,4‐phenylenebis(methylene)]bis(1H‐imidazole)}, have been synthesized under solvothermal conditions. The complexes were characterized by IR spectroscopy, elemental analysis, single‐crystal X‐ray diffraction and powder X‐ray diffraction analysis. Structurally, the (o,m‐bpta)^4? ligands are fully deprotonated and combine with Zn²⁺ ions in μ₄‐coordination modes. Complex 1 is a (3,4)‐connected porous network with honeycomb‐like [Zn₂(o,m‐bpta)]_n sheets formed by 4‐connected (o,m‐bpta)^4? ligands. Complex 2 exhibits a (2,4)‐connected network formed by 4‐connected (o,m‐bpta)^4? ligands linking Zn²⁺ ions in left‐handed helical chains. The cis‐configured 1,3‐bimb and 1,4‐bimb ligands bridge Zn²⁺ ions to form multi‐membered [Zn₂(bimb)₂] loops. Optically, the complexes show strong fluorescence and display larger red shifts compared to free H₄(o,m‐bpta). Complex 2 shows ferroelectric properties due to crystallizing in the C_2v polar point group.     

1,1′‐Diethyl‐4,4′‐bipyridine‐1,1′‐diium bis(1,1,3,3‐tetracyano‐2‐ethoxypropenide): multiple C—H...N hydrogen bonds form a complex sheet structure

In the title salt, C₁₄H₁₈N₂²⁺·2C₉H₅N₄O⁻, the 1,1′‐diethyl‐4,4′‐bipyridine‐1,1′‐diium dication lies across a centre of inversion in the space group P2₁/c. In the 1,1,3,3‐tetracyano‐2‐ethoxypropenide anion, the two independent –C(CN)₂ units are rotated, in conrotatory fashion, out of the plane of the central propenide unit, making dihedral angles with the central unit of 16.0 (2) and 23.0 (2)°. The ionic components are linked by C—H...N hydrogen bonds to form a complex sheet structure, within which each cation acts as a sixfold donor of hydrogen bonds and each anion acts as a threefold acceptor of hydrogen bonds.     

Conformational polymorphs of 22‐cyano‐N‐methyl‐5‐phenylpent‐2‐en‐4‐ynamide

Although the two polymorphic modifications, (I) and (II), of the title compound, C₁₃H₁₀N₂O, crystallize in the same space group (P2₁/c), their asymmetric units have Z′ values of 1 and 2, respectively. These are conformational polymorphs, since the mol­ecules in phases (I) and (II) adopt different rotations of the phenyl ring with respect the central 2‐cyano­carboxy­amino­prop‐2‐enyl fragment. Calculations of crystal packing using Cerius² [Molecular Simulations (1999). 9685 Scranton Road, San Diego, CA 92121, USA] have shown that (I) is more stable than (II), by 1.3 kcal mol^?1 for the crystallographically determined structures and by 1.56 kcal mol^?1 for the optimized structures (1 kcal mol^?1 = 4.184 kJ mol^?1). This difference is mainly attributed to the different strengths of the hydrogen bonding in the two forms.     

Spectroscopic Studies on the Binding of Kaempferol‐3,7‐α‐L‐rhamnopyranoside to Bovine Serum Albumin

The binding of kaempferol‐3,7‐α‐L‐rhamnopyranoside (KRR) with bovine serum albumin (BSA) was investigated by different spectroscopic methods under simulative physiological conditions. Analysis of ?uorescence quenching data of BSA by KRR at different temperatures using Stern‐Volmer methods revealed the formation of a ground state KRR‐BSA complex with moderate binding constant of the order 10⁴ L·mol^?1. The existence of some metal ions could weaken the binding of KRR on BSA. The changes in the van't Hoff enthalpy (ΔH⁰) and entropy (ΔS⁰) of the interaction were estimated to be ?26.53 kJ·mol^?1 and 3.33 J·mol^?1·K^?1 and both hydrophobic and electrostatic forces contributed to stabilizing the BSA‐KRR complex. According to the F?ster theory of non‐radiation energy transfer, the distance r between the donor (BSA) and the acceptor (KRR) was obtained (r=2.83 nm). Site marker competitive experiments showed that KRR could bind to Site I of BSA. In addition, synchronous fluorescence, UV‐Vis absorption and circular dichroism (CD) results indicated that the KRR binding could cause conformational changes of BSA.     

A three‐dimensional ZnII coordination polymer constructed from 1,1′‐biphenyl‐2,2′,4,4′‐tetracarboxylate and 1,4‐bis(1H‐imidazol‐1‐yl)benzene ligands exhibiting photoluminescence

Ligands based on polycarboxylic acids are excellent building blocks for the construction of coordination polymers; they may bind to a variety of metal ions and form clusters, as well as extended chain or network structures. Among these building blocks, biphenyltetracarboxylic acids (H₄bpta) with C ₂ symmetry have recently attracted attention because of their variable bridging and multidentate chelating modes. The new luminescent three‐dimensional coordination polymer poly[(μ₅‐1,1′‐biphenyl‐2,2′,4,4′‐tetracarboxylato)bis[μ₂‐1,4‐bis(1H‐imidazol‐1‐yl)benzene]dizinc(II)], [Zn₂(C₁₆H₆O₈)(C₁₂H₁₀N₄)]_n , was synthesized solvothermally and characterized by single‐crystal X‐ray diffraction, elemental analysis and IR spectroscopy. The crystal structure contains two crystallographically independent Zn^II cations. Both metal cations are located on twofold axes and display distorted tetrahedral coordination geometries. Neighbouring Zn^II centres are bridged by carboxylate groups in the syn –anti mode to form one‐dimensional chains. Adjacent chains are linked through 1,1′‐biphenyl‐2,2′,4,4′‐tetracarboxylate and 1,4‐bis(1H‐imidazol‐1‐yl)benzene ligands to form a three‐dimensional network. In the solid state, the compound exhibits blue photoluminescence and represents a promising candidate for a thermally stable and solvent‐resistant blue fluorescent material.     

Poly(ethylene terephthalate) reinforced by N,N′‐diphenyl biphenyl‐3,3′,4,4′‐tetracarboxydiimide moieties

Starting with 3,3′,4,4′‐biphenyltetracarboxylic dianhydride and methyl aminobenzoate, we synthesized a novel rodlike imide‐containing monomer, N,N′‐bis[p‐(methoxy carbonyl) phenyl]‐biphenyl‐3,3′,4,4′‐tetracarboxydiimide (BMBI). The polycondensation of BMBI with dimethyl terephthalate and ethylene glycol yielded a series of copoly(ester imide)s based on the BMBI‐modified poly(ethylene terephthalate) (PET) backbone. Compared with PET, these BMBI‐modified polyesters had higher glass‐transition temperatures and higher stiffness and strength. In particular, the poly(ethylene terephthalate imide) PETI‐5, which contained 5 mol % of the imide moieties, had a glass‐transition temperature of 89.9 °C (11 °C higher than the glass‐transition temperature of PET), a tensile modulus of 869.4 MPa (20.2 % higher than that of PET), and a tensile strength of 80.8 MPa (38.8 % higher than that of PET). Therefore, a significant reinforcing effect was observed in these imide‐modified polyesters, and a new approach to higher property polyesters was suggested. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 852–863, 2002; DOI 10.1002/pola.10169     

Enhanced third‐order nonlinear optical properties determined in thin films using the Z‐scan technique: bis(μ‐4,4′‐oxydibenzoato)bis[(4′‐phenyl‐2,2′:6′,2′′‐terpyridine)cobalt(II)]

π‐Conjugated organic materials exhibit high and tunable nonlinear optical (NLO) properties, and fast response times. 4′‐Phenyl‐2,2′:6′,2′′‐terpyridine (PTP) is an important N‐heterocyclic ligand involving π‐conjugated systems, however, studies concerning the third‐order NLO properties of terpyridine transition metal complexes are limited. The title binuclear terpyridine Co^II complex, bis(μ‐4,4′‐oxydibenzoato)‐κ³O,O′:O′′;κ³O′′:O,O′‐bis[(4′‐phenyl‐2,2′:6′,2′′‐terpyridine‐κ³N,N′,N′′)cobalt(II)], [Co₂(C₁₄H₈O₅)₂(C₂₁H₁₅N₃)₂], (1), has been synthesized under hydrothermal conditions. In the crystal structure, each Co^II cation is surrounded by three N atoms of a PTP ligand and three O atoms, two from a bidentate and one from a symmetry‐related monodentate 4,4′‐oxydibenzoate (ODA²⁻) ligand, completing a distorted octahedral coordination geometry. Neighbouring [Co(PTP)]²⁺ units are bridged by ODA²⁻ ligands to form a ring‐like structure. The third‐order nonlinear optical (NLO) properties of (1) and PTP were determined in thin films using the Z‐scan technique. The title compound shows a strong third‐order NLO saturable absorption (SA), while PTP exhibits a third‐order NLO reverse saturable absorption (RSA). The absorptive coefficient β of (1) is −37.3 × 10⁻⁷ m W⁻¹, which is larger than that (8.96 × 10⁻⁷ m W⁻¹) of PTP. The third‐order NLO susceptibility χ⁽³⁾ values are calculated as 6.01 × 10⁻⁸ e.s.u. for (1) and 1.44 × 10⁻⁸ e.s.u. for PTP.     

Synthesis and properties of new soluble aromatic polyamides and polyimides on the basis of N,N′‐bis(3‐aminobenzoyl)‐N,N′‐diphenyl‐1,4‐phenylenediamine

A new N‐phenylated amide (N‐phenylamide) unit containing aromatic diamine, N,N′‐bis(3‐aminobenzoyl)‐N,N′‐diphenyl‐1,4‐phenylenediamine, was prepared by the condensation of N,N′‐diphenyl‐1,4‐phenylenediamine with 3‐nitrobenzoyl chloride, followed by catalytic reduction. Two series of organosoluble aromatic poly(N‐phenylamide‐imide)s and poly(N‐phenylamide‐amide)s with inherent viscosities of 0.58–0.82 and 0.56–1.21 dL/g were prepared by a conventional two‐stage method and the direct phosphorylation polycondensation, respectively, from the diamine with various aromatic dianhydrides and aromatic dicarboxylic acids. All polyimides and polyamides are amorphous and readily soluble in many organic solvents such as N,N‐dimethylacetamide and N‐methyl‐2‐pyrrolidone. These polymers could be solution cast into transparent, tough, and flexible films with high tensile strengths. These polyimides and polyamides had glass‐transition temperatures in the ranges of 230–258 and 196–229 °C, respectively. Decomposition temperatures of the polyimides for 10% weight loss all occurred above 500 °C in both nitrogen and air atmospheres. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2564–2574, 2002