Conjugated polymers with anionic dyes: Synthesis,properties, and sensing ability for nucleosides,DNA, and BSA

The reaction of N-(2,4-dinitrophenyl)pyridinium chloride (salt[Cl⁻]) with sodium salts of anionic dyes, such as acid red 52 (AR52), acid violet 49 (AV49), and coomassie brilliant blue G-250 (CBBG250) involves an anion exchange between the chloride anion of salt(Cl⁻) and sulfonium anion of the dyes, resulting in the generation of novel Zincke salts, namely, salt(AR52), salt(AV49), and salt(CBBG250), respectively. Reactions of salt(AR52), salt(AV49), and salt(CBBG250) with piperazine in the absence of catalysts resulted in the opening of the pyridinium ring to yield ionic polymers comprising units of 5-piperazinium-2,4-dienylideneammonium and the corresponding dye anion, namely polymer(AR52), polymer(AV49), and polymer(SBBG250), respectively. The corresponding model compounds for the polymers were also synthesized by reacting salt(AR52), salt(AV49), and salt(CBBG250) with piperidine. Polymer(AV49) and polymer(SBBG250) were found to be suitable for the detection of nucleosides, DNA, and proteins, realized by monitoring the changes in their UV–vis absorption spectra, arising from the anionic dyes within the polymers. The polymers and the model compounds were electrochemically oxidized in solution.     

Ionic polymers with expanded π‐conjugation systems derived from through‐space interaction in piperazinium and homopiperazinium rings

Reactions of N‐(2,4‐dinitrophenyl)‐4‐arylpyridinium chlorides (aryl (Ar) = phenyl and 4‐biphenyl) with piperazine or homopiperazine caused opening of the pyridinium ring and yielded polymers that consisted of 5‐piperazinium‐3‐arylpenta‐2,4‐dienylideneammonium chloride (? N(CH₂CH₂)₂N⁺ (Cl^?)?CH? CH?C(Ar)? CH?CH? ) or 5‐homopiperazinium‐3‐arylpenta‐2,4‐dienylideneammonium chloride (? N(CH₂CH₂CH₂)(CH₂CH₂)N⁺ (Cl^?)?CH? CH?C(Ar)? CH?CH? ) units. ¹H NMR spectral analysis suggested that the π‐electrons of the penta‐2,4‐dienylideneammonium group of the polymers were delocalized. UV‐visible spectral measurements revealed that the π‐conjugation system expanded along the polymer chains because of the orbital interaction between electrons of the two nitrogen atoms of the piperazinium and homopiperazinium rings. However, the π‐conjugation length depended on the distance between the two nitrogen atoms; that is, the polymers containing the piperazinium ring had a longer π‐conjugation length than those containing the homopiperazinium ring. Conversion of the piperazinium and homopiperazinium rings from the boat to the chair form led to a decrease in the π‐conjugation length. The surface of pellets that were molded from the polymers exhibited metallic luster, and these polymers underwent electrochemical oxidation in solution. Copyright © 2010 Society of Chemical Industry     

Synthese von Hetaryl‐pyridiniumsalzen und kondensierten 3‐Amino‐pyrid‐2‐onen

1‐(3‐Coumaryl)‐pyridinium salts 3 and 1‐(3‐coumaryl)‐tetrahydrothiophenium salts 5 were synthesized from 2‐acylphenyl chloro‐ or bromoacetates 2 . 2‐Chloro‐N¹‐(3,4‐dimethoxyphenyl)‐acetamide and substituted 2‐chloro‐N¹‐(2‐thienyl)‐acetamides 8 react with acetyl chloride and pyridine to yield the quinolinyl‐ and (thieno[2,3‐b]pyridin‐5‐yl)‐pyridinium salts 10 . Fused thieno[2,3‐b]pyridin‐ones 19 were formed from N‐chloroacetyl‐2‐aminothiophen‐3‐carbonitriles 16 with pyridine via Thorpe‐Ziegler cyclization and followed by cyclodehydrogenation. In presence of pyridine alkyl 2‐chloro‐acetylaminobenzoates 21 yield 3‐(1‐pyridinio)‐quinoline‐4‐olates 23 . Zincke‐cleavage of 10 and 23 with hydrazinium hydroxide leads to fused 3‐amino‐pyridine‐2‐ones 11 and 3‐amino‐4‐hydroxy‐quinoline‐2‐ones 24 , respectively. Oxazoloquinolines 25 were synthesized from 24 with acetic anhydride.     

Turn‐on chemosensors for silver ions based on oligomers with diaza‐16‐crown 6‐ether receptors and aromatic fluorophore end groups

The reaction of N‐(2,4‐dinitrophenyl)pyridinium chloride ( 1 ), diaza‐18‐crown 6‐ether (DA18C6) and 2,5‐bis(aminophenyl)‐1,3,4‐oxadiazole ( 2 ) caused the opening of the pyridinium ring and yielded an ionic oligomer (oligomer‐1) comprising a 5‐DA18C6‐penta‐2,4‐dienylideneammonium chloride main chain and 2‐(4‐aminophenyl)‐5‐phenyl‐1,3,4‐oxadiazole or 2‐(4‐N‐phenylpyridinium)‐5‐phenyl‐1,3,4‐oxadiazole end groups. Accordingly, the reaction of 1 , DA18C6 and 2,7‐diaminofluorene ( 3 ) yielded oligomer‐2. The structures of oligomer‐1 and oligomer‐2 were determined by comparing their ¹H NMR spectra with those of model compounds, which were synthesized by the 1:1 reaction of 1 with 2 or 3 . Oligomer‐1 and oligomer‐2 exhibited weak bluish‐green photoluminescence (PL) before the inclusion of Ag⁺ in the DA18C6 receptor, after which they exhibited strong bluish‐green PL. These observations can be explained by the occurrence of photoinduced electron transfer in the oligomers. Copyright © 2011 Society of Chemical Industry     

Synthesis and chemical properties of electrochromic π‐conjugated polyphenylenes with pendant viologen‐TCNQ salts

Polyphenylene (PP) with NH₂ side groups, namely, PFluNH ₂ , was synthesized by the Pd‐catalyzed reaction of 2,5‐dibromoaniline with 9,9‐dihexylfluorene‐2,7‐diboronic acid bis(1,3‐propanediol) ester. The reaction of PFluNH ₂ with 1‐hexyl‐1′‐(2,4‐dinitrophenyl)‐4,4′‐bipyridinium diiodide ( SaltBPy(I^?) ) eliminated 2,4‐dinitroaniline to yield PPs with viologen (1,1′‐disubstituted 4,4′‐bipyridinium dications), PFluBPy(I^?) . The reaction of PFluBPy(I^?) with Li⁺TCNQ ^? resulted in anion exchange between Cl ^? and TCNQ ^? , and yielded PFluBPy(TCNQ^?) . The reaction of PFluBPy(TCNQ^?) with the neutral TCNQ⁰ resulted in an interaction between TCNQ ^? and TCNQ⁰, and yielded PFluBPy(TCNQ^?‐TCNQ⁰) . Cyclic voltammetry measurements suggested that an electrochemical reduction of the viologen moiety and oxidation of the polymer backbone within PFluBPy(TCNQ^?) and PFluBPy(TCNQ^?‐TCNQ⁰) . Furthermore, this reaction was accompanied by electrochromism. The electric conductivities (σ) of the pellets molded from PFluBPy(TCNQ^?) to PFluBPy(TCNQ^?‐TCNQ⁰) were 2.7 × 10 ^{? 4} and 4.2 × 10 ^{? 4} Scm ^{? 1}, respectively; these σ values were higher than that observed for PFluNH ₂ (σ < 10 ^{? 8} Scm ^{? 1}) due to the self‐doping in the polymers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of homo‐ and copolymers of 3‐(2‐cyano ethoxy)methyl‐ and 3‐[methoxy(triethylenoxy)]methyl‐3′‐methyl‐oxetane

Two oxetane‐derived monomers 3‐(2‐cyanoethoxy)methyl‐ and 3‐(methoxy(triethylenoxy)) methyl‐3′‐methyloxetane were prepared from the reaction of 3‐methyl‐3′‐hydroxymethyloxetane with acrylonitrile and triethylene glycol monomethyl ether, respectively. Their homo‐ and copolyethers were synthesized with BF₃· Et₂O/1,4‐butanediol and trifluoromethane sulfonic acid as initiator through cationic ring‐opening polymerization. The structure of the polymers was characterized by FTIR and¹H NMR. The ratio of two repeating units incorporated into the copolymers is well consistent with the feed ratio. Regarding glass transition temperature (T_g), the DSC data imply that the resulting copolymers have a lower T_g than pure poly(ethylene oxide). Moreover, the TGA measurements reveal that they possess in general a high heat decomposition temperature. The ion conductivity of a sample (P‐AN 20) is 1.07 × 10^?5 S cm^?1 at room temperature and 2.79 × 10^?4 S cm^?1 at 80 °C, thus presenting the potential to meet the practical requirement of lithium ion batteries for polymer electrolytes. Copyright © 2005 Society of Chemical Industry     

Synthesis and characterization of poly(ester‐ether‐imide)s derived from 5‐(4‐trimellitimidophenoxy)‐1‐trimellitimido naphthalene

A series of novel aromatic poly(ester‐ether‐imide)s with inherent viscosity values of 0.44–0.74 dL g^?1 were prepared by the diphenylchlorophosphate‐activated direct polycondensation of an imide ring‐containing diacid namely 5‐(4‐trimellitimidophenoxy)‐1‐trimellitimido naphthalene ( 1 ) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. Owing to comparison of the characterization data, an ester‐containing model compound ( 2 ) was also synthesized by the reaction of 1 with phenol. The model compound 2 and the resulted polymers were fully characterized by FT‐IR and NMR spectroscopy. The ultraviolet λ_max values of the poly(ester‐ether‐imide)s were also determined. The resulting polymers exhibited an excellent organosolubility in a variety of high polar solvents such as N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethyl sulfoxide, and N‐methyl‐2‐pyrrolidone. They were soluble even in common less polar organic solvents such as pyridine, m‐cresol, and tetrahydrofuran on heating. Crystallinity of the polymers was estimated by means of wide‐angle X‐ray diffraction. The resulted polymers exhibited nearly an amorphous nature. From differential scanning calorimetry thermograms, the polymers showed glass‐transition temperatures between 221 and 245°C. Thermal behaviors of the obtained polymers were characterized by thermogravimetric analysis, and the 10% weight loss temperatures of the poly(ester‐ether‐imide)s were found to be over 410°C in nitrogen. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Carbazole‐bound ferrocenium salt as an efficient cationic photoinitiator for epoxy polymerization

The low absorption of cyclopentadienyl‐Fe‐cumene hexafluorophosphate (I‐261) above 300 nm limits its utilization of longer wavelength emission from light sources. We report here the synthesis and photoactivity of a carbazole‐bound ferrocenium salt, cyclopentadienyl‐Fe‐carbazole hexafluorophosphate ([Cp‐Fe‐carbazole]⁺PF₆^?), which efficiently absorbs radiation between 300 and 400 nm. Its photoactivity is higher than that of I‐261 as a cationic photoinitiator. When the photosensitizer benzoyl peroxide (BPO) is employed, [Cp‐Fe‐carbazole]⁺PF₆^? can obviously be sensitized. Two other ferrocenium salts with amine groups, cyclopentadienyl‐Fe‐aniline hexafluorophosphate ([Cp‐Fe‐aniline]⁺PF₆^?) and cyclopentadienyl‐Fe‐p‐methylaniline hexafluorophosphate ([Cp‐Fe‐p‐methylaniline]⁺PF₆^?) were also studied. As photoinitiators, they perform poorly and can not be sensitized by BPO. Copyright © 2005 Society of Chemical Industry     

Melt polycondensation of L‐lactic acid catalyzed by 1,3‐dialkylimidazolium ionic liquids

BACKGROUND: In syntheses of biodegradable and bioresorbable polymers, efficient metal‐free catalysts are very desirable as the resulting products may be more biocompatible. As an attempt to find new metal‐free catalysts, 1,3‐dialkylimidazolium salts, the most commonly used ionic liquids or organic melt salts, were used as single‐component catalysts in the melt polycondensation of L ‐lactic acid for the first time. The resulting poly(L ‐lactic acid) (PLLA) was characterized using gel permeation chromatography, ¹³C NMR, DSC and polarimetry. RESULTS: It has been found that less bulky substituents on the imidazolium ring are conducive to catalytic activity. PLLA with molar mass of about 20 000 g mol^?1 was synthesized at high yield (over 70%) in the presence of various 1,3‐dialkylimidazolium salts. The product exhibits satisfactory color (white to slightly yellow), optical purity (89–95%) and crystallinity (40–55%). A possible catalytic mechanism is proposed. CONCLUSION: As compared with the well‐known binary catalyst system SnCl₂ · 2H₂O/toluene sulfonic acid, the catalysts used in this investigation are better in terms of increasing PLLA yield and preventing discoloration and comparable in terms of racemization. Copyright © 2008 Society of Chemical Industry     

Studies on Energetic Compounds Part 23: Preparation,Thermal and Explosive Characteristics of Transition Metal Salts of 5‐Nitro‐2,4‐Dihydro‐3H‐1,2,4‐Triazole‐3‐One (NTO)

Five transition metal salts of 5‐nitro‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐one, [namely M(NTO)_n⋅mH₂O where M is Ag, Hg, Cd, Cr, Fe where n=1,2,2,3,3 and m=1,2,2,8,2 respectively] were prepared and characterized (hereafter these compounds will be named as AgNTO, HgNTO, CdNTO, CrNTO and FeNTO, respectively). Their thermal decomposition was investigated by TG, DTA whereas explosive behaviour has been studied in terms of explosion delay, impact and friction sensitivities. Further, kinetic parameters have been derived using non‐isothermal TG data and mechanism of thermolysis has also been proposed. It seems that dehydration takes place prior to the evolution of NO₂ and the subsequent ring rupture yielding metal oxide. AgNTO on the other hand yields metallic silver. Dehydration in the case of HgNTO occurs in two steps: at each step one molecule is lost. All the salts are insensitive to impact and at the same time insensitive to friction up to 360 N.     

Synthesis and electro‐optical properties of novel Y‐type polyurethanes containing dioxynitrostilbene

3,4‐Di‐(2′‐hydroxyethoxy)‐4′‐nitrostilbene (2) was prepared by the reaction of 2‐iodoethanol with 3,4‐dihydroxy‐4′‐nitrostilbene. Diol 2 was condensed with 2,4‐toluenediisocyanate, 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate and 1,6‐hexamethylenediisocyanate to yield novel Y‐type polyurethanes 3–5 containing dioxynitrostilbene as a non‐linear optical (NLO)‐chromophore. Polymers 3–5 were soluble in common organic solvents, such as acetone and DMF. These polymers showed thermal stability up to 280 °C in TGA thermograms with T_g values in the range of 100–143 °C in DSC thermograms. The approximate lengths of aligned NLO‐chromophores of the polymers estimated from AFM images were around 2 nm. The SHG coefficients (d₃₃) of poled polymer films were around 4.5 × 10^?8 esu. Poled polymer films had improved temporal and long‐term thermal stability owing to the hydrogen bonding of urethane linkage and the main‐chain character of the polymer structure, which are acceptable for NLO device applications. Copyright © 2004 Society of Chemical Industry     

Organometallic synthesis of n‐type π‐conjugated polymers with dopant cation trapping sites and stability of n‐doping state against air

n‐Type π‐conjugated polymers comprising a 1,2,4‐triazole ring substituted by a benzo‐15‐crown 5‐ether (benzo15C5) subunit at the 4‐position of the 1,2,4‐triazole ring and n‐type aromatic rings such as pyridine‐2,5‐diyl and 2,1,3‐benzothiadiazole‐4,7‐diyl rings were synthesized by organometallic polycondensation. The UV‐visible spectra of the polymers exhibited absorption maxima (λ_max values) at a longer wavelength than that exhibited by 3,5‐bis(2‐bromopyridyl)‐4‐benzo15C5‐1,2,4‐triazole, revealing that their π‐conjugation system was expanded along the polymer chain. The polymers with the benzo15C5 subunit underwent an electrochemical reduction (n‐doping), and the corresponding oxidation (n‐dedoping) occurred at an unusually high potential in an acetonitrile solution of NaClO₄; the factor responsible for the unusually high oxidation potential was the stabilized n‐doping state that was attributed to the inclusion of Na⁺ in the 15C5 ring. The polymers with the benzo15C5 subunit exhibited a considerably higher stability of the n‐doping state in air than did those without this subunit. Copyright © 2012 Society of Chemical Industry     

Synthesis and chemical properties of polyethyleneimines crosslinked by penta-2,4-dienylideneammonium unit

The reaction of N-(2,4-dinitrophenyl)pyridinium anion ( salt(A) ; A = Cl⁻, FeCl₄⁻, and (CN)₂N⁻) with linear polyethyleneimine (LPEI; M_n = 20 380) and branched polyethyleneimines (BPEI1; M_n = 600, BPEI2; M_n = 10 000) at various molar feed ratios without using a catalyst resulted in pyridinium ring opening to yield ionic LPEI and BPEIs that were crosslinked by conjugated penta-2,4-dienylideneammonium (PDA) units, LPEI-PDA , BPEI1-PDA , and BPEI2-PDA , respectively. A model compound was synthesized by the reaction of salt(Cl) with diethylamine. The solubilities of BPEI1-PDA and BPEI2-PDA depended on the feed ratios between salt(Cl) and BPEI1 or BPEI2. Dipping LPEI-PDA into water and methanol yielded hydro- and organogels, respectively. UV–vis and reflection measurements revealed an expanded π-conjugation length between the polymer chains due to the through-space orbital interaction of the electrons on the two nitrogen atoms at the crosslinked positions in LPEI-PDA , BPEI1-PDA , and BPEI2-PDA . Cyclic voltammetry analysis suggested that the polymers underwent electrochemical oxidation. Measurement using a superconducting quantum interference device (SQUID) indicated that LPEI-PDA having FeCl₄⁻ anions was paramagnetic. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48712.     

New low bandgap conjugated polymer derived from 2, 7‐carbazole and 5, 6‐bis(octyloxy)‐4, 7‐di(thiophen‐2‐yl) benzothiadiazole: Synthesis and photovoltaic properties

To develop conjugated polymers with low bandgap, deep HOMO level, and good solubility, a new conjugated alternating copolymer PC‐DODTBT based on N‐9′‐heptadecanyl‐2,7‐carbazole and 5, 6‐bis(octyloxy)‐4,7‐di(thiophen‐2‐yl)benzothiadiazole was synthesized by Suzuki cross‐coupling polymerization reaction. The polymer reveals excellent solubility and thermal stability with the decomposition temperature (5% weight loss) of 327°C. The HOMO level of PC‐DODTBT is ‐5.11 eV, indicating that the polymer has relatively deep HOMO level. The hole mobility of PC‐DODTBT as deduced from SCLC method was found to be 2.03 × 10^?4 cm²/Versus Polymer solar cells (PSCs) based on the blends of PC‐DODTBT and [6,6]‐phenyl‐C₇₁‐butyric acid methyl ester (PC₇₁BM) with a weight ratio of 1:2.5 were fabricated. Under AM 1.5 (AM, air mass), 100 mW/cm^?2 illumination, the devices were found to exhibit an open‐circuit voltage (V_oc) of 0.73 V, short‐circuit current density (J_sc) of 5.63 mA/cm^?2, and a power conversion efficiency (PCE) of 1.44%. This photovoltaic performance indicates that the copolymer is promising for polymer solar cells applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Investigations on pyridinium salts as a solid‐state ionics

The object of this work is to prepare polymer poly(2vinylpyridine), P‐2VP, and its salts like P‐2VP‐HI, P‐2VP‐HIO₃, and P‐2VP‐HIO₄. The formation of P‐2VP salts was confirmed by IR and ¹H NMR techniques. Conductivities of these were determined in solid state at various temperatures from 30 to 90°C. Observations indicated that the addition of I^? or IO₃^? or IO₄^? ions affect the ionic conductivity of P‐2VP. Molecular mass determination and analytical results indicated that 94, 92.5, and 95% of the pyridine molecules in the P‐2VP chain were hydroiodated, iodated, and periodated, respectively, with the corresponding acids of iodine. The total ionic transport number and activation energy of the polymers were also determined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Polymerization of 4‐(4′‐N‐1,8‐naphthalimidophenyl)‐1,2,4‐triazolidine‐3,5‐dione with diisocyanates

4‐(4′‐Aminophenyl)‐1,2,4‐triazolidine‐3,5‐dione ( 1 ) was reacted with 1,8‐naphthalic anhydride ( 2 ) in a mixture of acetic acid and pyridine (3 : 2) under refluxing temperature and gave 4‐(4′‐N‐1,8‐naphthalimidophenyl)‐1,2,4‐triazolidine‐3,5‐dione ( NIPTD ) ( 3 ) in high yield and purity. The compound NIPTD was reacted with excess n‐propylisocyanate in N,N‐dimethylacetamide solution and gave 1‐(n‐propylamidocarbonyl)‐4‐[4′‐(1,8‐naphthalimidophenyl)]‐1,2,4‐triazolidine‐3,5‐dione ( 4 ) and 1,2‐bis(n‐propylamidocarbonyl)‐4‐[4′‐(1,8‐naphthalimidophenyl)]‐1,2,4‐ triazolidine‐3,5‐dione ( 5 ) as model compounds. Solution polycondensation reactions of monomer 3 with hexamethylene diisocyanate ( HMDI ), isophorone diisocyanate ( IPDI ), and tolylene‐2,4‐diisocyanate ( TDI ) were performed under microwave irradiation and conventional solution polymerization techniques in different solvents and in the presence of different catalysts, which led to the formation of novel aliphatic‐aromatic polyureas. The polycondensation proceeded rapidly, compared with conventional solution polycondensation, and was almost completed within 8 min. These novel polyureas have inherent viscosities in a range of 0.06–0.20 dL g^?1 in conc. H₂SO₄ or DMF at 25°C. Some structural characterization and physical properties of these novel polymers are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2861–2869, 2003     

Polymerization of 1,3‐dienes containing functional groups: 8. Free‐radical polymerization of 2‐triethoxysilyl‐ 1,3‐butadiene

The presence of a bulky substituent at the 2‐position of 1,3‐butadiene derivatives is known to affect the polymerization behavior and microstructure of the resulting polymers. Free‐radical polymerization of 2‐triethoxysilyl‐1,3‐butadiene ( 1 ) was carried out under various conditions, and its polymerization behavior was compared with that of 2‐triethoxymethyl‐ and other silyl‐substituted butadienes. A sticky polymer of high 1,4‐structure ( ) was obtained in moderate yield by 2,2′‐azobisisobutyronitrile (AIBN)‐initiated polymerization. A smaller amount of Diels–Alder dimer was formed compared with the case of other silyl‐substituted butadienes. The rate of polymerization (R_p) was found to be R_p = k[AIBN]^0.5[ 1 ]^1.2, and the overall activation energy for polymerization was determined to be 117 kJ mol^?1. The monomer reactivity ratios in copolymerization with styrene were r ₁ = 2.65 and r_st = 0.26. The glass transition temperature of the polymer of 1 was found to be ?78 °C. Free‐radical polymerization of 1 proceeded smoothly to give the corresponding 1,4‐polydiene. The 1,4‐E content of the polymer was less compared with that of poly(2‐triethoxymethyl‐1,3‐butadiene) and poly(2‐triisopropoxysilyl‐1,3‐butadiene) prepared under similar conditions. Copyright © 2010 Society of Chemical Industry     

Novel poly(3,4‐dialkoxythiophene)s carrying 1,3,4‐oxadiazolyl‐biphenyl moieties: synthesis and nonlinear optical studies

Two new donor–acceptor types of polymer, poly{2‐(biphenyl‐4‐yl)‐5‐[3,4‐dialkoxy‐5‐(1,3,4‐oxadiazol‐2‐yl)thiophen‐2‐yl]‐1,3,4‐oxadiazole}s, were synthesized starting from 2,2′‐sulfanediyldiacetic acid and diethyl ethanedioate through multi‐step reactions. The polymerization was carried out via the polyhydrazide precursor route. The optical and charge‐transporting properties of the polymers were investigated using UV‐visible and fluorescence emission spectroscopic and cyclic voltammetric studies. The polymers showed bluish‐green fluorescence in solutions. The electrochemical band gaps of the polymers were determined to be 2.16 and 2.22 eV. The nonlinear optical properties of the polymers were investigated at 532 nm using the single‐beam Z‐scan technique with nanosecond laser pulses. The polymers showed strong optical limiting behaviour due to effective three‐photon absorption. The values of the three‐photon absorption coefficients for the polymers were found to be 9 × 10^?24 and 17 × 10^?24 m³ W^?2, which are comparable to those of good optical limiting materials. Copyright © 2010 Society of Chemical Industry     

Synthesis and biological activity of medium range molecular weight polymers containing exo‐3,6‐epoxy‐1,2,3,6‐tetrahydrophthalimidocaproic acid

A new monomer, exo‐3,6‐epoxy‐1,2,3,6‐tetrahydrophthalimidocaproic acid (ETCA), was prepared by reaction of maleimidocaproic acid and furan. The homopolymer of ETCA and its copolymers with acrylic acid (AA) or with vinyl acetate (VAc) were obtained by photopolymerizations using 2,2‐dimethoxy‐2‐phenylacetophenone as an initiator at 25 °C. The synthesized ETCA and its polymers were identified by FTIR, ¹H NMR and ¹³C NMR spectroscopies. The apparent average molecular weights and polydispersity indices determined by gel permeation chromatography (GPC) were as follows: M_n = 9600 g mol^?1, M_w = 9800 g mol^?1, M_w/M_n = 1.1 for poly(ETCA); M_n = 14 300 g mol^?1, M_w = 16 200 g mol^?1, M_w/M_n = 1.2 for poly(ETCA‐co‐AA); M_n = 17 900 g mol^?1, M_w = 18 300 g mol^?1, M_w/M_n = 1.1 for poly(ETCA‐co‐VAc). The in vitro cytotoxicity of the synthesized compounds against mouse mammary carcinoma and human histiocytic lymphoma cancer cell lines decreased in the following order: 5‐fluorouracil (5‐FU) ≥ ETCA > polymers. The in vivo antitumour activity of the polymers against Balb/C mice bearing sarcoma 180 tumour cells was greater than that of 5‐FU at all doses tested. © 2001 Society of Chemical Industry     

Synthesis and biological activity of phthalimide‐based polymers containing 5‐fluorouracil

The attachment of anticancer agents to polymers is a promising approach towards reducing the toxic side‐effects and retaining the potent antitumour activity of these agents. A new tetrahydrophthalimido monomer containing 5‐fluorouracil (ETPFU) and its homopolymer and copolymers with acrylic acid (AA) and with vinyl acetate (VAc) have been synthesized and spectroscopically characterized. The ETPFU contents in poly(ETPFU‐co‐AA) and poly(ETPFU‐co‐VAc) obtained by elemental analysis were 21 mol% and 20 mol%, respectively. The average molecular weights of the polymers determined by gel permeation chromatography were as follows: M_n = 8900 g mol^?1, M_w = 13 300 g mol^?1, M_w/M_n = 1.5 for poly(ETPFU); M_n = 13 500 g mol^?1, M_w = 16 600 g mol^?1, M_w/M_n = 1.2 for poly(ETPFU‐co‐AA); M_n = 8300 g mol^?1, M_w = 11 600 g mol^?1, M_w/M_n = 1.4 poly(ETPFU‐co‐VAc). The in vitro cytotoxicity of the compounds against FM3A and U937 cancer cell lines increased in the following order: ETPFU > 5‐FU > poly(ETPFU) > poly(ETPFU‐co‐AA) > poly(ETPFU‐co‐VAc). The in vivo antitumour activities of all the polymers in Balb/C mice bearing the sarcoma 180 tumour cell line were greater than those of 5‐FU and monomer at the highest dose (800 mg kg^?1). © 2002 Society of Chemical Industry