Synthesis and electroluminescent properties of a novel 1,3,4‐oxadiazole‐containing polymer

The new blue light polymer, poly(1′,4′‐phenylene‐1″,4″‐[2″‐(2″″‐ethylhexyloxy)]phenylene‐1‴,4‴‐phenylene‐2,5‐oxadiazolyl) (PPEPPO) was synthesized through the Suzuki reaction of diboronic acid, 2‐methoxy‐[5‐(2′‐ethylhexyl)oxy]‐1,4‐benzene diboronic acid (MEHBBA) and dibromide, 2,5‐bis(4′‐bromophenyl)‐1,3,4‐oxadiazole. This polymer was characterized with various spectroscopic methods. The solid PL spectrum of PPEPPO has a maximum peak at 444 nm corresponding to blue light. Blue LED has been fabricated using this polymer as the electroluminescent layer, ITO as the anode, and aluminum as cathode. This device emitted a blue light, with 40 V of turn‐on voltage. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3086–3091, 2000     

A new terpyridine tethered polythiophene: Electrosynthesis and characterization

A novel polythiophene bearing a pendant terpyridine moiety has been synthesized by electrochemical polymerization of a new thiophene monomer, namely 4′‐(2,2′:5′,2″‐terthien‐3′‐ethynyl)‐2,2′:6′,2″‐terpyridine (TAT). The insertion of a conjugated ethynyl spacer between the terthiophene and the terpyridine fragments provides for an effective extension of the delocalization of electrons within the structural unit and the polymer as a whole. The synthesis and characterization of the relevant monomer, the electrosynthesis of the corresponding polymer and its electrochemical, UV–visible spectroelectrochemical and IR characterization are described. Finally, a comparison between the electrochemical, spectroscopic, and spectroelectrochemical properties of PTAT and the analogue, saturated‐spacer PTTT (TTT = 4′‐[(2,2′:5′,2″‐terthien‐3′‐yl)methoxy]‐2,2′:6′,2″‐terpyridine) polymer is discussed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis,Characterization and Reactions of 4‐Hydrazino‐2‐methylpyrimidino[4′5′:4,5]thiazolo[3,2‐a]benzimidazole

4‐Hydrazino‐2‐methylpyrimidino[4′,5′:4,5]thiazolo[3,2‐a]benzimidazole ( 4 ) was obtained from hydrazinolysis of the 4‐chloro derivative 3 with hydrazine hydrate. The hydrazino derivative 4 was further cyclized to the corresponding pyrazole 5 , pyrazolone 6 and 5‐methyl‐1,2,4‐triazolo[1″,5″:3′,4′]pyrimidino[5′,6′:5,4]‐thiazolo[3,2‐a]benzimidazole ( 9 ) and 5‐methy‐1,2,4‐triazolo[4″,3″:3′,4′]pyrimidino[5′,6′:5,4]thiazolo‐[3,2‐a]benzimidazole ( 10 ), respectively. The triazolo derivative 10 was isomerized to the triazolo derivative 9 under a variety of reaction conditions.     

4,4′′′′‐Azobis[2,2′: 6′,2″‐terpyridine] and its Metal Complexes

By two different routes, 4,4′′′′‐azobis[2,2′: 6′,2″‐terpyridine] was synthesized. Its ruthenium complexes show interesting metal‐to‐ligand charge transfer (MLCT) absorption maxima in the electronic spectra. They represent the first ruthenium complexes of terpyridine units to give blue solutions.     

Synthesis,characterization, and evaluation of biological activities of new 4′‐substituted ruthenium (II) terpyridine complexes: Prospective anti‐inflammatory properties

The synthesis and characterization of Ru (II) terpyridine complexes derived from 4′ functionalized 2,2′:6′,2″‐terpyridine (tpy) ligands are reported. The heteroleptic complexes comprise the synthesized ligands 4′‐(2‐thienyl)‐ 2,2′:6′,2″‐terpyridine) or (4′‐(3,4‐dimethoxyphenyl)‐2,2′:6′,2″‐terpyridine and (dimethyl 5‐(pyrimidin‐5‐yl)isophthalate). The new complexes [Ru(4′‐(2‐thienyl)‐2,2′:6′,2″‐terpyridine)(5‐(pyrimidin‐5‐yl)‐isophthalic acid)Cl₂] ( 9 ), [Ru(4′‐(3,4‐dimethoxyphenyl)‐2,2′:6′,2″‐terpyridine)(5‐(pyrimidin‐5‐yl)‐isophthalic acid)Cl₂] ( 10 ), and [Ru(4′‐(2‐thienyl)‐2,2′:6′,2″‐terpyridine)(5‐(pyrimidin‐5‐yl)‐isophthalic acid)(NCS)₂] ( 11 ) were characterized by ¹H‐ and ¹³C‐NMR spectroscopy, C, H, N, and S elemental analysis, UPLC‐ESI‐MS, TGA, FT‐IR, and UV‐Vis spectroscopy. The biological activities of the synthesized ligands and their Ru (II) complexes as anti‐inflammatory, antimicrobial, and anticancer agents were evaluated. Furthermore, the toxicity of the synthesized compounds was studied and compared with the standard drugs, namely, diclofenac potassium and ibuprofen, using hemolysis assay. The results indicated that the ligands and the complex 9 possess superior anti‐inflammatory activities inhibiting albumin denaturation (89.88–100%) compared with the standard drugs (51.5–88.37%) at a concentration of 500 μg g^?1. These activities were related to the presence of the chelating N‐atoms in the ligands and the exchangeable chloro‐ groups in the complex. Moreover, the chloro‐ and thiophene groups in complex 9 produce a higher anticancer activity compared with its isothiocyanate derivative in the complex 11 and the 3,4‐dimethoxyphenyl moiety in complex 10 . Considering the toxicity results, the synthesized ligands are nontoxic or far less toxic compared with the standard drugs and the metal complexes. Therefore, these newly synthesized compounds are promising anti‐inflammatory agents in addition to their moderate unique broad antimicrobial activity.     

Star‐shaped polystyrenes with glycoconjugated periphery and interior: Synthesis and entrapment of hydrophilic molecule

Star‐shaped polystyrenes with acetyl glucose in the periphery and interior were synthesized via two‐steps, 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO)‐mediated living radical polymerizations. In the first step, styrene (St) was polymerized with 4‐[1′‐(2″,2″,6″,6″‐tetramethyl‐1″‐piperidinyloxy)ethyl]phenyl 2,3,4,6‐tetra‐O‐acetyl‐β‐D ‐glucopyranoside, 1 , at 120 °C to afford a TEMPO‐terminated polystyrene with acetyl glucose in the chain‐end, arm‐polymer 2 . Similarly, St was polymerized with 1‐phenyl‐1‐(2′,2′,6′,6′‐tetramethyl‐1′‐piperidinyloxy)ethane, 3 , to obtain a TEMPO‐terminated polystyrene, arm‐polymer 4 . In the second step, the coupling reaction of arm‐polymer 2 was performed using divinylbenzene (DVB) as a linking agent in m‐xylene at 138 °C, giving a star‐shaped polystyrene with acetyl glucose in the periphery, 5 . The coupling reaction of arm‐polymer 4 with DVB was carried out in the presence of 1 , which produced a star‐shaped polystyrene with acetyl glucose in the interior, 6 . Dynamic laser light scattering (DLS) measurements indicated that 5 and 6 existed as the particles in toluene with the average diameters ranging from 12–40 nm. The numbers of the arm (N_arm) were 12–23 and 6–64 for 5 and 6 , respectively, which were determined by their isolated yields and static laser light scattering (SLS) measurements. The numbers of the acetyl glucose units (N₁) were 12–23 and 9–104 for 5 and 6 , respectively, which were determined from specific rotation ([α]₃₆₅). Finally, 5 and 6 were modified by deacetylation using sodium methoxide, producing star‐shaped polystyrenes with glucose in the periphery and interior, 7 and 8 , respectively. The final architectures were found to entrap a hydrophilic molecule at their glycoconjugated periphery or interior in good solvents for polystyrene such as chloroform. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4373–4381, 2005     

New Monoterpene-Substituted Dihydrochalcones from Piper aduncum

Five New unusual monoterpene-substituted dihydrochalcones, the adunctins A–E (1″S)-1-{2′-hydroxy-4′-methoxy-6′-[4″-methyl-1″-(1?-methylethyl)cyclohex-3″ -en-1″ -yloxy]phenyl}-3-phenylpropan-1-one ( 1 ), (5aR*,8R*,9aR*)-3-phenyl-1-[5′,8′,9′,9′a-tetrahydro-3′-hydroxy-1′-methoxy-8′-(1″-methylethyl)-5′-a-methyldibenzo-[b,d]furan-4′-yl]propan-1-one ( 2 ), (2′R*,4″S*)-1-{6′-hydroxy-4′-methoxy-4″-(1?-methylethyl)spiro[benzo[b]-furan-2′(3′H),1″ -cyclohex-2″ -en]-7′-yl}-3-phenylpropan-1-one ( 3 ), (2′R*,4″R*)-1-{6′-hydroxy-4′-methylethyl-4″-(1?-methylethyl)spiro[benzo[b]furan-2′(3′H),1″-cyclohex-2″-en]-7′-yl}-3-phenypropan-1-one ( 4 ), and (5′aR*,6′S*, 9′R*,9′aS*)-1-[5′a,6′,7′,8′,9′a-hexahydro-3′,6′-methoxy-6′-methyl-9′-(1″-methylethyl)dibenzo[b,d]-furan-4′-yl]-3-phenylpropan-1-one ( 5 ) were isolated from the leaves of Piper aduncum (Piperaceae) by preparative liquid chromatography. In addition, (?)-methyllindaretin ( 6 ), trans-phytol, and α-tocopherol ( = vitamin E) were also isolated and identified. The structures were elucidated by spectroscopic methods, including 1D- and 2D-NMR spectroscopy as well as single-crystal X-ray diffraction analysis. The antibacterial and cytotoxic potentials of the isolates were also investigated.     

Photochemische reaktionen von übergansmetall-olefinkomplexen: III. [4 + 6]-cycloaddition konjugierter diene an hexacarbonyl-μ-η6:6(-1,1′-bi(2,4,6-cycloheptatrien-1-yl)dichrom(O)

UV irradiation of hexacarbonyl-μ-η^6:6-1,1′-bi(2,4,6-cycloheptatrien-1-yl)dichromium(O) (I) in THF in the presence of 1,3-butadiene (A), E-1,3-pentadiene (B) and EE-2,4-hexadiene (C) causes preferentially a twofold [4 + 6]-cycloaddition and formation of the hexacarbonyl-μ-2–5 : 8.9-η-2′–5′ : 8′,9′-η-11,11′-bi(bicyclo-[4.4.1]undeca-2,4,8-trien-11-yl)dichromium(O) complexes (IVA–IVC). Partial decomplexation after the first [4 + 6]-cycloaddition yields isomeric tricarbonyl-2–5:8,9-η- (IIA–IIC) and tricarbonyl-2′–7′-η-{11-(2′,4′,6′-cycloheptatrien-1′-yl)bicyclo[4.4.1]undeca-2,4,8-triene}chromium(O) complexes (IIIA–IIIC). With 2,3-dimethyl-1,3-butadiene (D) mainly dicarbonyl-2–6 : 2′–4′-η-{1-(2′,3′-dimethyl-3′-buten-1′,2′-diyl)-7-(8″,9″-dimethylbicyclo[4.4.1]undeca-2″, 4″,8″-trien-11″-yl)cyclohepta-3,5-dien-2-yl}chromium(O) (VD) besides small amounts of pentacarbonyl-μ-2–6 : 2′–4′-η-2″–7″-η-{1-(2′,3′-dimethyl-3′-buten-1′,2′-diyl)-7-(2″, 4″,6″-cycloheptatrien-1″-yl)cyclohepta-3,5-dien-2-yl}dichromium(O) (VID) and tricarbonyl-2′-7′-η-{11-(2′,4′,6′-cycloheptatrien-1′-yl)-8,9-dimethyl-bicyclo[4.4.1]undeca-2,4,8-triene}-chromium(O) (IIID) is obtained. VD adds readily CO to yield tricarbonyl-2–5 : 8,9-η-11,11′-bi(8,9-dimethyl-bicyclo[4.4.1]undeca-2,4,8-trien-11-yl)chromium(O) (VIID). Finally D adds to VID under formation of pentacarbonyl-μ-2–6 : 2′–4′-η-2″–5″ : 8″,9″-η-{1-(2′,3′-dimethyl-3′-buten-1′,2′-diyl)-7-(8″,9″-dimethyl-bicyclo[4.4.1]- undeca-2″,4″,8″-trien-11″-yl)cyclohepta-3,5-dien-2-yl}dichromium(O) (VIIID). From IVA–IVC the hydrocarbon ligands (IXA–IXC) can be liberated by P(OCH₃)₃ in good yields. The structures of the compounds IIA–IXC were determined by IR     

Synthesis of poly(p‐phenylene vinylene)‐ and poly(phenylene ethynylene)‐based polymers containing p‐terphenyl in the main chain with alkoxyphenyl side groups

Starting from the pyrylium salt and following a facile synthetic route, we synthesized and polymerized 4,4″‐diiodo‐2′,6′‐di[4‐(2′‐ethylhexyl)oxy]phenyl‐p‐terphenyl with p‐divinylbenzene or p‐diethynylbenzene. The resulting polymers had moderate molecular weights, were amorphous, and dissolved in tetrahydrofuran and chloroform, with glass‐transition temperatures of 120–131 °C. The polymers behaved as violet‐blue‐emitting materials with photoluminescence maxima around 420 and 450 nm in solution and in thin films, respectively. They possessed well‐defined chromophores resulting from steric interactions in the polymer chain. The photoluminescence quantum yields were up to 0.29. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2591–2600, 2002     

Magnetic properties of a polyfluorene derivative containing complexed neodymium ions

Poly[9,9′‐dihexylfluorene‐2,7‐diyl)‐6,6″‐(2,2′:6′,2″‐terpyridine)] (LaPPS75) and its complexes with neodymium were synthesized and characterized. Magnetic measurements showed that the noncomplexed polymer presented a ferromagnetic contribution due to the formation of π stacking, and that in absence of those, the ferromagnetic behavior is suppressed. The pristine polymer, the complexed one and a low‐molecular‐weight model compound with the same structure of the complexed site in the parent polymer were studied. The observed behavior found is presented and discussed, the most important finding was that when a conjugated chain is used as a host for the metallic ion, an amplification of four times for the magnetization is achieved, using the same metallic content for complexed polymer and model compound for comparison. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 304–311     

Synthesis,structure, and conformation of terphenylene-derived azacalix[4]aromatics

Several novel azacalix[4]aromatics constituting terphenylene units have been synthesized via sequential nucleophilic aromatic substitution reactions of 5′-t-butyl-(1,1′:3′,1″-terphenyl)-3,3″-diamine 9 and 5′-t-butyl-(1,1′:3′,1″-terphenyl)– 4,4″-diamine 11 with 1,5-difluoro-2,4-dinitrobenzene and cyanuric chloride, respectively. The bridging –NH– functions of the tetra-nitro substituted azacalix[2]arene[2]terphenylenes 1 and 2 have been transformed to the corresponding –N(CH₃)– bridged azacalix[2]arene[2]terphenylenes 3 and 4 via N-alkylation. Single crystal X-ray analysis revealed that the terphenyl-3,3″-diamine derived azacalix[2]terphenylene[2]triazine 5 adopts a distorted chair conformation in the solid state, and the terphenyl-4,4″-diamine derived azacalix[2]terphenylene[2]triazine 6 was found to adopt a 1,3-alternate conformation.     

Intricacies of ligand coordination in tricarbonylchromium(0) complexes with ortho‐ and para‐fluorobiphenyls

The steric and electronic factors that influence which of the two rings of a substituted biphenyl ligand coordinates to chromium are of interest and it has been suggested that haptotropic rearrangements within these molecules may be limited if the arene–arene dihedral angle is too large. Two tricarbonylchromium(0) complexes and their respective free ligands have been characterized by single‐crystal X‐ray diffraction. In the solid state, tricarbonyl[(1′,2′,3′,4′,5′,6′‐η)‐2‐fluoro‐1,1′‐biphenyl]chromium(0), [Cr(C₁₂H₉F)(CO)₃], (I), exists as the more stable isomer with the nonhalogenated arene ring ligated to the metal center. Similarly, tricarbonyl[(1′,2′,3′,4′,5′,6′‐η)‐4‐fluoro‐1,1′‐biphenyl]chromium(0) crystallizes as the more stable isomer with the phenyl ring bonded to the Cr⁰ center. The arene–arene dihedral angles in these complexes are 55.77 (4) and 52.4 (5)°, respectively. Structural features of these complexes are compared to those of the DFT‐optimized geometries of ten tricarbonyl[(η⁶‐C₆H₅)(4‐F‐C₆H₄)]chromium model complexes. The solid‐state structures of the free ligands 2‐fluoro‐1,1′‐biphenyl and 4‐fluoro‐1,1′‐biphenyl, both C₁₂H₉F, exhibit arene–arene dihedral angles of 54.83 (7) and 0.71 (8)°, respectively. The molecules of the free ligands occupy crystallographic twofold axes and exhibit positional disorder. Weak intermolecular C—H…F interactions are observed in all four structures.     

4′-(二茂铁基)-2,2′∶6′,2″-三联吡啶钴(Ⅱ)配合物混合价态的电荷转移

设计合成了4′-(二茂铁基)-2,2′∶6′,2″-三联吡啶钴(Ⅱ)配合物1以及参比配合物4′-(4-甲苯基)-2,2′∶6′,2″-三联吡啶钴(Ⅱ)配合物2和2,2′∶6′,2″-三联吡啶钴(Ⅱ)配合物3,配合物1中二茂铁基给电子基团的引入使其在可见光区的吸收明显增强,并在部分氧化时呈现混合价态的电荷转移(MVCT)吸收.     

Synthesis,Characterization and Fluorescent Properties of Three One‐Dimensional Coordination Polymers Derived from Polypyridyl Ligands

Three one‐dimensional coordination polymers, [MnCl₂(4‐pyterpy)]∙2CHCl₃ ( 1 ), [Mn(NO₃)₂(4‐pyterpy)]∙CHCl₃ ( 2 ) and [Ag(NO₃)(3‐pyterpy)]∙H₂O ( 3 ) (4‐pyterpy = 4′‐(4‐pyridyl)‐2,2′:6′,2″‐terpyridine and 3‐pyterpy = 4′‐(3‐pyridyl)‐2,2′:6′,2″‐terpyridine) were synthesized and characterized by X‐ray diffraction. All three compounds exhibit a rare “head‐to‐tail” coordination of the multidentate ligand, but differ significantly in their polymer chain conformations. Additionally, the fluorescent properties of all three compounds were investigated and show a weak, ligand‐centered fluorescence at 416–418 nm.     

Synthesis and Reactions of Pyrido[2,1‐a]isoquinolin‐4‐yl Formimidate Derivatives and Antimicrobial Activities of Isolated Products

Treatment of arylidene malononitriles 2A – C with 1‐cyanomethylisoquinoline 1 afforded 4‐amino‐2‐arylpyrido[2,1‐a ]isoquinoline‐1,3‐dicarbonitrile derivatives 5A – C , which converted to formimidates 6A – C via reaction with triethylorthoformate. Treatment of the latter compounds with hydrazine hydrate gave the corresponding amino–imino compounds 7A – C , which underwent Dimroth rearrangement to afford 13‐aryl‐1‐hydrazinylpyrimido[5′,4′:5,6]pyrido[2,1‐a ]isoquinoline‐12‐carbonitrile 8A – C . The latter reacted with aldehyde to give 9a – i . Oxidative cyclization of the latter compounds 9a – i gave [1,2,4]triazolo[4″,3″:1′,6′]‐pyrimido[5′,4′:5,6]pyrido[2,1‐a ]isoquinolines 10a , d , g . Such compounds isomerized to the thermodynamically more stable isomers [1,2,4]triazolo[1″,5″:1′,6′]pyrimido[5′,4′:5,6]‐pyrido[2,1‐a ]isoquinolines 11a , d , g . Antimicrobial activities for some compounds were studied.     

Back‐bonding in Organonickel Complexes with Terpyridine Ligands – A Structural Approach

A series of organonickel complexes [(R′terpy)Ni(aryl)]X (R′terpy = derivatives of 2,2′;6′,6″‐terpyridine; R′ = 4‐H, 4‐Cl, 4‐Tol and 4,4′,4″‐^tBu₃; aryl = 2,6‐dimethylphenyl = Xyl or 2,4,6‐trimethylphenyl = Mes; X = Br or PF₆) have been prepared and characterized. The crystal structures exhibit a number of intermolecular H bond type interactions, but the structure determining force seems to be the packing of the aryl co‐ligands. The molecules reveal rather undistorted square planar coordination with a N₃C ligand set, the central Ni–N bond being remarkably short, despite the expected strong trans influence of the aryl co‐ligands. The long‐wavelength absorptions were assigned to charge transfer transitions. No emission is observed at ambient temperature in the solid and in solution and at low temperature in glasses.     

Highly efficient polymer‐stabilized palladium heterogeneous catalyst: Synthesis,characterization and application for Suzuki–Miyaura and Mizoroki–Heck coupling reactions

A suitable approach to stabilize palladium nanoparticles (Pd NPs), with an average diameter of 3–4 nm, on magnetic polymer is described. A new magnetic polymer containing 4′‐(4‐hydroxyphenyl)‐2,2′:6′,2″‐terpyridine (HPTPy) ligand was prepared by the polymerization of itaconic acid (ITC) as a monomer and trimethylolpropane triacrylate (TMPTA) as a cross‐linker and fully characterized. Pd NPs embedded on the magnetic polymer were successfully applied in Suzuki–Miyaura and Mizoroki–Heck coupling reactions under low palladium loading conditions, and provided the corresponding products with excellent yields (up to 98%) and high catalytic activities (TOF up to 257 hr^?1). Also, the catalyst can be easily separated and reused for at least consecutive five times with a small drop in catalytic activity.     

Synthesis of electroactive polystyrene derivatives para‐substituted with π‐conjugated oligothiophene via postgrafting functionalization

Two electroactive polystyrene derivatives para‐ substituted with π‐conjugated oligothiophene, poly(5‐hexyl‐5″‐(4‐vinylphenyl)‐2,2′:5′,2″‐terthiophene) ( PH3TS ), and poly(5‐hexyl‐5″″‐(4‐vinylphenyl)‐2,2′:5′,2″:5″,2″′:5″′,2″″‐quinquethiophene) ( PH5TS ) have been successfully synthesized via the Stille coupling reaction between tributyltin postfunctionalized poly(4‐(2‐thiophenyl)styrene) ( PTS ) and bromo‐oligothiophene. The effect of the chain length of the pendant oligothiophenes on properties of the resulting polymers including solubility, thermal stability, optical absorption, and electroactivation energy levels has been studied by using a variety of techniques such as thermogravimetric analyzer, differential scanning calorimetry, UV–Vis, Fluorescence, and cyclic voltammetry. With shielding of the hexyl terminal groups attached to the pendant oligothiophene units, no obvious chain aggregation was observed for both PH3TS and PH5TS even in a poor solvent environment. When compared with conventional linear conjugated polymer systems, the concept of grafting electroactive units as pendant side chains via postfunctionalizing aliphatic polymers might offer a strategy to precisely synthesize new electroactive polymer materials for a number of organic electronic applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Design and property of thermoresponsive core–shell fluorescent nanoparticles via RAFT polymerization and suzuki coupling reaction

The polymerization of a 2,7‐dibromocarbazole‐containing functional monomer, 6‐(2,7‐dibromo‐9H‐carbazol‐9‐yl)hexyl methacrylate (DBCzMA), was successfully carried out via the reversible addition‐fragmentation chain transfer (RAFT) technology. The polymerization behavior possessed the feature of “living”/controlled radical polymerization, for example, the first‐order kinetics, the linear increase of the molecular weight of the polymer with the monomer conversion and relatively narrow molecular weight distribution (M_w/M_n ≤ 1.27). The amphiphilic copolymers, poly(DBCzMA_m‐b‐NIPAM_n), with different chain length of poly(DBCzMA) and poly(N‐isopropylacrylamide) (PNIPAM), were successfully prepared via RAFT chain‐extension reaction, using poly(DBCzMA) as the macromolecular chain transfer agent (macro‐CTA) and NIPAM as the second monomer. Modification of 2,7‐dibromide groups in amphiphilic copolymer poly(DBCzMA‐b‐NIPAM) via Suzuki coupling reaction employed 2,7‐bis(4′,4′,5′,5′‐tetramethyl‐1′,3′,2′‐dioxaborolan‐2′‐yl)‐N?9″‐heptadecanylcarbazole as the other reaction material to afford a poly(2,7‐carbazole)‐containing crosslinked materials. The stable and uniform core–shell fluorescent nanoparticles were successfully prepared in water. The formed fluorescent nanoparticles showed good thermoresponsive properties, which is confirmed by dynamic light scattering observation. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4021–4030     

Synthesis and photophysical properties of polyfluorenes bearing silicon‐based functional groups

Five polyfluorenes bearing bulky trimethylsilyl (PTMS1 and PTMS2), tris(trimethylsilyl)silyl (PTTMS1), and silsesquioxane groups (PPOSS1 and PPOSS2) were synthesized through palladium‐catalyzed Suzuki coupling reactions. In the solution state, every polymer showed comparable ultraviolet–visible spectra, and they emitted blue light with high quantum efficiency. In the solid state, however, three trimethylsilyl‐functionalized polyfluorenes indicated redshifts of the fluorescence peak. In particular, PTMS1 and PTTMS1, having a hydrogen at the C‐9 position of fluorene, also showed green‐light emissions. After the annealing of the spin‐coated films, the blue‐emissive peak decreased and the green‐emissive peak became stronger in the photoluminescence spectra of three trimethylsilyl‐functionalized polyfluorenes. In contrast, PPOSS2 showed a pure blue‐light emission in the film state and even after the thermal treatment, which could be accomplished by the encapsulation of the polymer chains by the large polyhedral oligomeric silsesquioxane molecule. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2119–2127, 2005