Acceptor-donor-acceptor conjugated oligomers based on diketopyrrolopyrrole and thienoacenes with four,five and six rings for organic thin-film transistors

Three acceptor-donor-acceptor(A-D-A) conjugated oligomers, i.e., O1, O2 and O3, have been synthesized using diketopyrrolopyrrole(DPP) as an electron-acceptor unit, and naphtho[1,2-b:5,6-b']dithiophene(NDT), anthra[1,2-b:5,6-b']dithiophene(ADT) or dithieno[3,2-b:3',2'-b']naphtho[1,2-b:5,6-b']dithiophene(DTNDT) as electron-donor unit. These oligomers exhibit identical highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) energy levels, which were ca.-5.1 and-3.3 eV, respectively. Upon thermal annealing, all three oligomers formed thin films with ordered microstructures, and their organic thin film transistors(OTFTs) exhibited p-type transport behavior. The mobility was increased with an extension of the size of D-units. O3 showed the best OTFT performance with the mobility of up to 0.20 cm~2·V~(-1)·s~(-1). The film quality of O3 was improved by adding 1 wt% poly(methylmethacrylate)(PMMA). In consequence, the mobility of the O3-based devices was further enhanced to 0.30 cm~2·V~(-1)·s~(-1).     

Thermodynamic characteristics of the dissolution of glycine,glycylglycine, and glycylglycylglycine in aqueous solutions of sodium dodecyl sulfate at <Emphasis Type="Italic">Т</Emphasis> = 298.15 K

the enthalpies of dissolution of glycine (Gly), glycylglycine (GlyGly), and glycylglycylglycine (GlyGlyGly) are measured in aqueous solutions of sodium dodecyl sulfate (SDS) at SDS concentrations m = 0–0.7 mol kg^?1 and Т = 298.15 K by means of calorimetry. The obtained data are used to calculate the standard values of enthalpies of dissolution (Δ_sol H ^m ) and enthalpies of transfer (Δ_tr H ^m ) of glycine and its oligomers from water to SDS aqueous solutions. The dependences of Δ_sol H ^m and Δ_tr H ^m on SDS concentration in an aqueous solution at a constant concentration of glycine and its oligomers are determined. A comparative analysis of the thermodynamic characteristics of Gly, GlyGly, and GlyGlyGly transfer within the studied range of SDS concentrations is performed. The results are interpreted in terms of ion–ion, ion–polar, and hydrophobic interactions between SDS and molecules of glycine and its oligomers.     

Differential thermogravimetric curves for a mixture of evaporable and degradable chain oligomers

Since the boiling point of oligomers increases with increasing chain length, differential thermogravimetric (DTG) curves of polymerization products are uniquely related to the molecular mass distribution of the oligomers in the chain length region in which the degradation rate is less than the rate of evaporation. Degradation is manifested by narrow, chain length-invariant peaks of the DTG curves so that they are distinguishable from broad DTG bands due to the evaporation of the mixture of oligomers. The detachment of the terminal groups at a temperature T₁ and main chain scission at T_d > T₁ are accompanied by dimerization of macroradicals, evaporation of the dimers in the T₁ < T < T_d interval, and appearance of the full degradation peak at T ≈ T_d. The pattern of DTG curves based on these concepts has been calculated on the assumption of free convection in the boundary layer and a spatially uniform degradation in the melt. As an example, DTG curves for the products of tetrafluoroethylene polymerization in liquid solutions have been considered.     

Synthesis of Block Copolymers of Styrene with <Emphasis Type="Italic">D</Emphasis>,<Emphasis Type="Italic">L</Emphasis>-Lactide by the Sequential Controlled Cationic Polymerization and Ring-Opening Anionic Polymerization

The cationic polymerization of styrene initiated by the system 2-chloro-2-phenylpropane–TiCl₄–pyridine is studied in a mixture CH₂Cl₂–n-hexane at a temperature of –80°С. It is shown that under these conditions polymerization occurs via the living mechanism at [monomer]: [initiator] ≤ 100. The method of preparing polystyrenes with terminal primary hydroxyl groups (M_n = 4000–10000 g/mol) by the sequential controlled cationic polymerization of styrene and the in situ alkylation of 4-phenoxy-1-butanol by polystyrene macrocations is proposed. The resulting functionalized polystyrenes are used as macroinitiators of anionic-coordination ring-opening polymerization of D,L-lactide in the presence of tin bis(2-ethyl hexanoate) [Sn(Oct)₂] in toluene at 80°С. Copolymers polystyrene-block-poly(D,L-lactide) with the controlled length of the poly(D,L-lactide) block (M_n = 10000–17000 g/mol) and a relatively low molecular-weight distribution (M_w/M_n = 1.6–1.8) are synthesized. Formation of the block copolymers is confirmed by ¹Н NMR spectroscopy, gel-permeation chromatography, and atomic force microscopy.     

Synthesis of ultra high molecular weight poly(dimethyldiallyl ammonium chloride)

In the study we reported the synthesis of poly-(dimethyldiallyl ammonium chloride) (PDMDAAC) with ultra high molecular weight. The polymerization method consists in the following: the ultra-high purity monomer synthesized in lab was used as the raw material, and APS as the initiator. APS was added in a lump and the polymerization temperature was increased stepwise to complete the polymerization gradually in 9 h reaction time. The maximum intrinsic viscosity ([η]) of PDMDAAC reached 3.66 dL g^–1 at a monomer conversion rate (Conv) of 96.71%. The structure and properties of PDMDAAC were characterized using FTIR, NMR, GPC-MALLS, and DTA-TG. The effects of polymerization conditions, such as the polymerization temperature, m(DMDAAC), m(APS): m(DMDAAC), and m(Na₄EDTA): m(DMDAAC), on the [η] and Conv of products were investigated. Meanwhile, the effects of the monomer purity on the [η] of products were compared. The results showed that the types and amount of impurities in monomer solution are two key factors, which affect the polymerization and, thus, the molecular weight of products.     

Atom transfer radical polymerization of methyl methacrylate using copper-based homogeneous and heterogeneous catalysts

This study aimed at polymerization of methyl methacrylate with novel catalysts in the atom transfer radical polymerization (ATRP) condition at 90 °C. This was accomplished using CuBr/N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (CuBr–AEAPTMS) as a homogeneous catalyst and one time with CuBr@AEAPTMS/SBA-15 as a heterogeneous catalyst. Catalysts were characterized using TGA, FT-IR, and UV–Vis spectroscopy. The structural analysis of the polymer was carried out by ¹³C NMR spectroscopy and GPC. Three characteristic parts of polymer produced by ATRP method including the initiator, monomer units, and end group was shown in ¹³C NMR spectra. In addition, the presence of C–Br unit showed that the polymerization process is alive. The ¹H NMR analysis was used for kinetic investigation of methyl methacrylate polymerization with homogeneous and heterogeneous catalysts that showed high monomer conversion (98 and 90% after 35 min, respectively) and good control of molecular weight with a dispersity (Р= 1.5–1.7). In addition, the plot of ln ([monomer]₀/[monomer] _t ) versus time gave linear relationships indicating a constant concentration of the propagating species throughout the polymerization. Finally, the results of the polymerization using heterogeneous catalyst compared with homogeneous catalyst revealed that it was according to ATRP method.     

Synthesis of urethane—acrylic multi-block copolymers via electrochemically mediated ATRP

The electrochemically mediated atom transfer radical polymerisation (eATRP) of n-butyl acrylate was investigated under a variety of catalyst concentrations. Poly(n-butyl acrylate)-block-polyurethane-block-poly(n-butyl acrylate) copolymers were prepared via electrochemically mediated atom transfer radical polymerisation (eATRP) using only 7 × 10^?6 mole % of Cu^II complex. The successful chain extension and formation of penta-block copolymers confirmed the living nature of the poly(alkyl acrylates) prepared by eATRP. In this work, the tri-block and penta-block urethane-acrylate copolymers were synthesised for the first time by using tertiary bromine-terminated polyurethane macro-initiators as transitional products reacting with n-butyl acrylate, and subsequently with tert-butyl acrylate in the presence of the Cu^IIBr₂/TPMA catalyst complex. The results of ¹H NMR spectral studies support the formation of tri-block poly(n-butyl acrylate)-block-polyurethane-block-poly(n-butyl acrylate) copolymers, and penta-block poly(tert-butyl acrylate)-block-poly(n-butyl acrylate)-block-polyurethane-block-poly(n-butyl acrylate)-block-poly(tert-butyl acrylate) copolymers.     

Alternative preparation and characterization of platinum(II) organometallic dinuclear complexes and oligomers with 3,8-diethynylphenanthroline derivatives

Novel platinum(II) organometallic dinuclear complexes and oligomers with two types of phenanthroline ligands, namely 3,8-diethynylphenanthroline (L1) and 3,8-bis-(4-ethynyl-phenylethynyl)-1,10-phenanthroline (L2), were synthesized from trans-Pt(PBu₃)₂(1-ethynyl-4-methyl-benzene)Cl and trans-Pt(PBu₃)₂Cl₂ by transmetalation of copper ion. The alternative procedure targeted platinum oligomer termination selection of either chloride or respective phenanthrolines and was successfully performed with different purifications by extraction and column chromatography. The structural formulae of these platinum complexes and oligomers were revealed with by analysis of both ³¹P{¹H}-NMR and ¹H-NMR spectral data. Alternative preparations of platinum oligomers with two types between chloride and respective phenanthroline termination are very useful for the selective synthesis for hybrid polymers with the coupling reaction with two different platinum oligomers with different diethynylaryl ligands. The platinum organometallic compounds showed similar absorption bands in the UV–Vis region. Those prepared with L1 had a strong absorption band at around 400 nm, assignable to the lowest energy metal-perturbed ¹[π–π*] transitions, while in compounds prepared with L2, the strong band appeared around 410 nm, because L2 has an extended π conjugation relative to L1. No distinct differences were observed in the absorption spectra of these platinum oligomers between the different terminal structures, chloride or various phenanthrolines. The luminescence spectra of the platinum compounds prepared with either L1 or L2, however, showed a distinct difference. Those with L1 showed only a phosphorescence assignable to a typical metal-perturbed ³[π–π*] transition with vibronic progressions centered at around 530 nm in deoxygenated CH₂Cl₂ at room temperature, while those with L2 showed weak dual emissions assignable to a mixture of typical metal-perturbed ¹[π–π*] and ³[π–π*] transitions in the visible region.     

Synthesis of bifunctional thieno[3,2-c]pyrazole,pyrazolothieno[2,3-d]pyrimidin derivatives and their antimicrobial activities

A simple and convenient route was performed for the synthesis of some new heterocyclic compounds based on thieno[3,2-c]pyrazole derivative for antimicrobial evaluation. The key intermediate, 5-amino-3-methyl-1-phenyl-1H-thieno[3,2-c]pyrazole-6-carbohydrazide 3, was prepared by Gewald’s synthesis of Ethyl 5-amino-3-methyl-1-phenyl-1H-thieno[3,2-c]pyrazole-6-carboxylate 2. This intermediate reacted with various reagents to afford different fused and polyfunctional substituted. The structures of these compounds were confirmed by elemental analysis, IR, ¹H NMR, ¹³C NMR and mass spectral data. All the new synthesized compounds were screened for various microorganisms such as Aspergillus fumigatus; Geotrichum candidum; Syncephalastrum racemosum (Fungus); Candida albicans (Yeast fungus); Staphylococcus aureus; Bacillus subtilis (as Gram-positive bacteria); Pseudomonas aeruginosa and Escherichia coli (as Gram-negative bacteria) by the disc diffusion method. In general, the novel synthesized compounds possessed moderate to high antimicrobial activity against the previously mentioned microorganisms.     

Synthesis,characterization, and antibacterial activity of some thiazoles derived from allyl thioureas

Synthesis of thiazoles was carried out from allyl thioureas using different cyclizing agents such as hydrogen chloride gas and bromine. Synthesized compounds were characterized by IR, ¹H and ¹³C NMR, mass spectrometry, and elemental analysis. The synthesized thiazoles were evaluated for their antibacterial activity against Gram postitive (Lactobacillus bulgaris and Streptococcus mitis) and Gram negative (Yersinia) as well as antifungal activity against Aspergillus niger fungi.     

Study of fluoroalkylsilanes,a new class of amphiphilic oligomers: Determination of end groups and chain length

Radiation-initiated polymerization of tetrafluoroethylene (TFE) in the liquid alkylsilanes Si(CH₃)₄ (I), C₂H₅Si(CH₃)₃ (II), and ClSi(CH₃)₃ (III) produces fluoroalkylsilane oligomers with the general formula R(C₂F₄) _n X, where X = H or Cl in I, II, and III and R is one of the radicals generated by the abstraction of H from the methyl and ethyl groups in I and II or Cl detachment from III. The nature of R has been determined using an NMR technique, and the molecular mass distribution (MMD) has been found from abundances in anion progressions in mass spectra and from DTG and GPC data. At initial TFE concentrations (C ₀) changed from 0.4, 1, and 0.13 to 1, 2.7, and 0.7 mol/L in I, II and III, respectively, the average chain length 〈n〉 increases from 4–5 to 10–12 and the MMD changes from the unimodal to the bimodal pattern in which the proportion of oligomers with n < 6 decreases with increasing C ₀. As 〈n〉 increases and the MMD changes, the homogeneous solution becomes colloidal and then turns into a gel. The colloidal particles are largely composed of long oligomers, and the number of solvent molecules per C₂F₄ unit decreases with an increase in C ₀ and is 4–7 in the gel.     

Spectroscopic characterization,X-ray structure and DFT studies on 4-[3-(2,5-dimethylphenyl)-3-methylcyclobutyl]-N-methylthiazol-2-amine

The titled molecule 4-[3-(2,5-dimethylphenyl)-3-methylcyclobutyl]-N-methylthiazol-2-amine (C₁₇H₂₂N₂S) is synthesized and characterized by ¹H NMR, ¹³C NMR, IR, and X-ray single crystal determination. The compound crystallizes in the monoclinic space group P2_1/c with a = 6.3972(4) Å, b = 9.4988(6) Å, c = 26.016(2) Å and β = 93.496(7)°. In addition to the molecular geometry from the X-ray determination, vibrational frequencies and gauge, including the atomic orbital (GIAO), ¹H and ¹³C NMR chemical shift values of the titled compound in the ground state are calculated using the density functional (B3LYP) method with 6-31G(d), 6-31++G(d,p) and 6-311+G(2d,p) basis sets. The calculated results show that the optimized geometries can well reproduce the crystal structure. Moreover, the theoretical vibrational frequencies and chemical shift values show good agreement with the experimental values. The predicted nonlinear optical properties of the titled compound are greater than those of urea. DFT calculations of the molecular electrostatic potentials and frontier molecular orbitals of the titled compound are carried out at the B3LYP/6-31G(d) level of theory.     

Efficient synthesis of bis-isoxazole ethers via 1,3-dipolar cycloaddition catalysed by Zn/Zn<Superscript>2+</Superscript> and their antifungal activities

An efficient method was developed for synthesising isoxazoles. A series of novel bis-isoxazole ether compounds VI, VII and VIII were synthesised starting from different substituted aldehydes (I) via a 1,3-dispolar cycloaddition using Zn/Zn²⁺ as a catalyst; these were characterised by FT-IR, HRMS, ¹H NMR and ¹³C NMR spectroscopy. In addition, the antimicrobial properties of the synthesised products were investigated. The synthesised compounds exhibited significant antifungal activities in comparison with the standard drugs, fluconazole and itraconazole. It was found that Candida albicans was sensitive to 2-substituted phenyl bis-isoxazole ethers bearing pyridyl.     

Synthesis and biological activities of novel quinazolinone derivatives containing a 1,2,4-triazolylthioether moiety

A series of novel quinazolinone derivatives containing a 1,2,4-triazolylthioether moiety were synthesised and their antimicrobial activities were evaluated. All the target compounds were characterised by ¹H NMR, ¹³C NMR, ESI-MS, IR and elemental analyses. The single crystal structure of 3-((5-((2-fluorobenzyl)thio)-4-phenyl-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIi) was also determined. The preliminary bioassays indicated that some of the target compounds possessed good antimicrobial activities. For example, 3-((4-phenyl-5-((4-(trifluoromethyl)benzyl)thio)-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIs) exhibited the best inhibitory effect against Xanthomonas oryzae pv. oryzae and Xanthomonas axonopodis pv. citri with the half-effective concentration (EC₅₀) values of 47.6 μg mL^?1 and 22.1 μg mL^?1, respectively, which were superior to the commercial bactericide, bismerthiazol. Meanwhile, 3-((5-((4-chlorobenzyl)thio)-4-phenyl-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIh) exhibited better fungicidal activities against Pellicularia sasakii and Colletotrichum capsici at the concentration of 50 μg mL^?1, in comparison with the commercial fungicide, hymexazol.     

One-step preparation of sulfonated carbon and subsequent preparation of hybrid material with polyaniline salt: a promising supercapacitor electrode material

The present trend to increase the energy density of electrochemical supercapacitor is to hybrid the electrochemical double layer capacitance electrode materials of carbon with loading or encapsulation of transition metal oxide or conductive polymeric pseudocapacitor materials as the binary or ternary hybrid electrochemical active materials. In this work, we selected polyaniline salt-sulfonated carbon hybrid (PANI-SA?C _SA ) as a cheaper electrode material for supercapacitor electrode. Sulfonated carbon (C _SA ) was prepared from hydrothermal carbonization of furaldehyde and p-toluenesulfonic acid. Polyaniline-sulfate salt containing sulfonated carbon was prepared by chemical oxidative polymerization of aniline using ammonium persulfate in presence of sulfuric acid and sulfonated carbon via aqueous, emulsion and interfacial polymerization pathways. Formation of hybrid material was confirmed from scanning electron microscopy. Among the hybrid prepared with three different polymerization pathways, hybrid prepared by aqueous polymerization pathway showed better electrochemical performance. The specific capacitance of the hybrid prepared via aqueous polymerization was 600 F g^?1, which is higher than that of the pristine PANI-SA (350 F g^?1) and C _SA (30 F g^?1). Hybrid material was subjected for 8000 charge-discharge cycles and at 8000 cycles; it showed 88% retention of its original specific capacitance value of 485 F g^?1 with coulombic efficiency (97–100%). These results showed that C _SA micro spheres prevent the degradation of PANI-SA chains during charge/discharge cycles. Specific capacitance, cycle life, low solution resistance, low charge transfer resistance and high phase angle value of PANI-SA?C _SA supercapacitor cell indicates a higher performance supercapacitor system.

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Graphical abstract Synthesis of hybrid of sulfonated carbon with polyaniline sulfate salt and its supercapacitor performance Ravi Bolagam, Palaniappan Srinivasan,^* Rajender Boddula

     

Effect of alkali metal salts on decomposition of ionic liquid like organic salt

N ¹,N ¹,N ²,N ²-tetramethylethane-1,2-diamine-based ionic salts (TMEDA), N ¹,N ¹,N ¹,N ²,N ²,N ²-hexamethylethane-1,2-diaminium dicyanamide (HMEDA-(DCA)₂) were prepared following the quaternization and subsequent ion exchange. The chemical structure of the HMEDA-(DCA)₂ was confirmed using ¹³C NMR spectrum and elemental analysis. The corresponding viscosity of its 60 wt% solution was found to be lower than 5 cP at room temperature, which was critical for propellant application. The ignition delay of 40 wt% HMEDA-(DCA)₂ solution was decreased to 20–30 ms dramatically using alkali metal salts, Li(CH₃COO), Mg(CH₃COO)₂, and Ca(CH₃COO)₂ as a co-catalyst when white fume nitric acid was utilized as an oxidizer.     

Crystalline inclusion complexes of diterpenoid isosteviol with aromatic compounds

Crystalline inclusion complexes of diterpenoid isosteviol (ent-16-ketobeyeran-19-oic acid) with individual benzene, o-, m-, p-xylenes, ethylbenzene, isopropylbenzene, o-and m-nitoranilins, benzaldehyde, styrene and naphthalene are obtained and characterized by single crystal X-ray diffraction. As determined by GC and ¹H NMR spectroscopy, isosteviol selectively includes toluene from the equimolar benzene-toluene mixture, o-xylene from a commercial mixture of xylenes, o-and m-nitroanilins from their mixture with p-nitroanilin, and also styrene from styrene-ethylbenzene and styrene-isopropylbenzene mixtures thus yielding crystalline inclusion complexes.     

Precise molecular weight determination and structure characterization of end-functionalized polymers: An NMR approach <Emphasis Type="Italic">via</Emphasis> combination of one-dimensional and two-dimensional techniques

We present here the application of one-dimensional and two-dimensional NMR techniques to characterize the structure of methoxyl end-functionalized polystyrenes (PS). The peaks in ¹H-NMR spectra corresponding to main-chain, side-chain and chain-end groups are assigned by ¹H-¹H gCOSY, ¹H-¹³C gHSQC and gHMBC spectra. For the first time, the spin-lattice relaxation time (T ₁) of protons of the chain-ends is revealed to be affected more by polymer molecular weight (MW) than by the protons of the main-chains and the side-chains (almost independent from MW). As a result, a much higher delay time (d1) for chain-ends (d1 > 20T ₁) is needed for quantitative NMR measurement when using end-group estimation method to obtain the MW of PS, which is in accordance with the value estimated by GPC. An improved method for the polymer MW determination is established, by combination of different NMR techniques to distinguish the peaks, and a large d1 setting to achieve quantitative NMR analysis.     

Biodegradable poly(butylene succinate-<Emphasis Type="Italic">co</Emphasis>-butylene dimerized fatty acid)s: Synthesis,crystallization, mechanical properties,and rheology

Poly(butylene succinate-co-butylene dimerized fatty acid) (P(BS-co-BDFA)) copolyesters were synthesized from succinic acid (SA) and dimerized fatty acid (DFA) with 1,4-butanediol (BDO) through a two-step process of esterification and polycondensation. The polyester compositions and physical properties of copolyesters were investigated by GPC, ¹H NMR and ¹³C NMR, DSC, WAXD, DMA, TGA, tensile and rheology test. The melting temperature (T_m), and crystallization temperature (T_c) decreased gradually as the content of DFA monomer increased. P(BS-co-BDFA) copolyesters showed the same crystal structure as the PBS homopolyester. Besides, TGA results indicated that P(BS-co-BDFA)s were of higher thermal stabilities. Moreover, it was found that the synthesized P(BS-co-BDFA)s showed the maximum elongation at break (591%) as the DFA contents were 10 mol%. Rheology analysis indicated that the viscoelastic behavior of the polyesters greatly depended on the molecular weight of polyesters.     

The doubly thermo-responsive triblock copolymer nanoparticles prepared through seeded RAFT polymerization

The doubly thermo-responsive triblock copolymer nanoparticles of polystyrene-block-poly(N-isopropylacrylamide)-block-poly[N,N-(dimethylamino) ethyl methacrylate] (PS-b-PNIPAM-b-PDMAEMA) are successfully prepared through the seeded RAFT polymerization in situ by using the PS-b-PNIPAM-TTC diblock copolymer nanoparticles as the seed. The seeded RAFT polymerization undergoes a pseudo-first-order kinetics procedure, and the molecular weight increases with the monomer conversion linearly. The hydrodynamic diameter (D _h) of the triblock copolymer nanoparticles increases with the extension of the PDMAEMA block. In addition, the double thermo-response behavior of the PS-b-PNIPAM-b-PDMAEMA nanoparticles is detected by turbidity analysis, temperature-dependent 1H-NMR analysis, and DLS analysis. The seeded RAFT polymerization is believed as a valid method to prepare triblock copolymer nanoparticles containing two thermo-responsive blocks.