共查询到20条相似文献,搜索用时 31 毫秒
1.
Isao Yamaguchi Yukako Tsuse 《Journal of polymer science. Part A, Polymer chemistry》2014,52(4):481-492
Polythiophenes with reactive Zincke salt structure, P4ThPy+DNP(Cl?)‐a and P5ThPy+DNP(Cl?)‐a , were synthesized by the oxidation polymerization of oligothiophenes, such as 3'‐(4‐N‐(2,4‐dinitrophenyl)pyridinium chloride)?2,2':5',2'';5'',2'''‐quarterthiophene ( 4ThPy+DNP(Cl?) ) and 4''‐(4‐N‐(2,4‐dinitrophenyl)pyridinium chloride)?2,2';5',2'';5'',2''';5''',2''''‐quinquethiophene ( 5ThPy+DNP(Cl?) ), with iron(III) chloride. The reaction of P5ThPy+DNP(Cl?)‐a with R‐NH2 [R = n‐hexyl (Hex) and phenyl (Ph)] substituted the 2,4‐dinitrophenyl group into the R group with the elimination of 2,4‐dinitroaniline to yield P5ThPy+R(Cl?) . Similarly, model compounds, 4ThPy+R(Cl?) and 5ThPy+R(Cl?) (R = Hex and Ph), were also synthesized. In contrast to the photoluminescent 4ThPy and 5ThPy , the compounds P4ThPy+DNP(Cl?)‐a , P5ThPy+DNP(Cl?)‐a , and P5ThPy+R(Cl?) showed no photoluminescence because their internal pyridinium rings acted as quenchers. Cyclic voltammetry measurements suggested that P4ThPy+DNP(Cl?)‐a , P5ThPy+DNP(Cl?)‐a , and P5ThPy+R(Cl?) received an electrochemical reduction of the pyridinium and 2,4‐dinitrophenyl groups and oxidation of the polymer backbone. P4ThPy+DNP(Cl?)‐a and P5ThPy+DNP(Cl?)‐a were electrically conductive (ρ = 3.0 × 10 ? 6 S cm ? 1 and 2.1 × 10 ? 6 S cm ? 1, respectively) in the nondoped state. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 481–492 相似文献
2.
Isao Yamaguchi Hideo Higashi Shunsuke Kimura Moriyuki Sato 《Helvetica chimica acta》2010,93(5):819-828
Diacetylenes (DAs) having a dipolar D‐π‐A structure (D=donor: amino group; π=π‐conjugation core; A=acceptor: pyridinium (Py) and bipyridinium (BPy) groups), i.e., 4 (APBPyDA) and 5 (APPyPyDA), or an A‐π‐A structure, i.e., 7 (DBPyDA) and 8 (PyDA(Cl)), were obtained by 1 : 1 and 1 : 2 reactions of 4,4′‐(buta‐1,3‐diyne‐1,4‐diyl)bis[benzenamine] (APDA; 3 ) with 1‐(2,4‐dinitrophenyl)‐1′‐hexyl‐4,4′‐bipyridinium bromide chloride (1 : 1 : 1) ( 1 ), 1‐(2,4‐dinitrophenyl)‐4‐(pyridin‐4‐yl)pyridinium chloride ( 2 ), or 1‐(2,4‐dinitrophenyl)pyridinium chloride ( 6 ) (Schemes 1 and 2). The anion‐exchange reactions of 8 with NaI and Li(TCNQ) (TCNQ?=2,2′‐(cyclohexa‐2,5‐diene‐1,4‐diylidene)bis[propanedinitrile] radical ion (1?)) yielded the corresponding I? and TCNQ? salts 9 (PyDA(I)) and 10 (PyDA(TCNQ)). Compounds 10 and 4 exhibited a UV/VIS absorption due to a charge transfer between the TCNQ? and the pyridinium groups and a strong solute–solvent interaction of a dipolar solute molecule in the polar environment, respectively. Compounds 8 – 10 exhibited photoluminescence in solution, whereas 4 and 7 did not because of the presence of the 4,4′‐bipyridinium quenching groups. Differential‐scanning‐calorimetry (DSC) measurements suggested that the DAs obtained in this study can be converted into poly(diacetylenes) by thermal polymerization. 相似文献
3.
Dr. Dan Lis Dr. Julien Guthmuller Prof. Dr. Benoît Champagne Dr. Christophe Humbert Dr. Bertrand Busson Dr. André Peremans Dr. Francesca Cecchet 《Chemphyschem》2013,14(6):1227-1236
The vibrational nonlinear activity of films of 2,4‐dinitrophenyl phospholipid (DNP) at the solid interface is measured by sum‐frequency generation spectroscopy (SFG). Hybrid bilayers are formed by a Langmuir–Schaefer approach in which the lipid layer is physisorbed on top of a self‐assembled monolayer of dodecanethiol on Pt with the polar heads pointing out from the surface. The SFG response is investigated in two vibrational frequency domains, namely, 3050–2750 and 1375–1240 cm?1. The first region probes the CH stretching modes of DNP films, and the latter explores the vibrational nonlinear activity of the 2,4‐dinitroaniline moiety of the polar head of the lipid. Analysis of the CH stretching vibrations suggests substantial conformational order of the aliphatic chains with only a few gauche defects. To reliably assign the detected SFG signals to specific molecular vibrations, DFT calculations of the IR and Raman activities of molecular models are performed and compared to experimental solid‐state spectra. This allows unambiguous assignment of the observed SFG vibrations to molecular modes localized on the 2,4‐dinitroaniline moiety of the polar head of DNP. Then, SFG spectra of DNP in the 1375–1240 cm?1 frequency range are simulated and compared with experimental ones, and thus the 1,4‐axis of the 2,4‐dinitrophenyl head is estimated to have tilt and rotation angles of 45±5° and 0±30°, respectively. 相似文献
4.
Takakazu Yamamoto Keisuke Honda 《Journal of polymer science. Part A, Polymer chemistry》1998,36(13):2201-2207
Palladium–catalyzed polycondensation between 2,5–diiodo–3–hexylthiophene I–Th(Hex)–I with mixtures of p–diethynylbenzene HCC—Ph—CCH and α,ω–diethynylalkane HCC(CH2)lCCH (l = 3 or 8) gives poly(aryleneethynylene) PAE–type copolymers [CC(CH2)lCC—Th(Hex)]m[CC—Ph—CC—Th(Hex)]n containing the methylene unit. The copolymers have a molecular weight (Mn) of about 1.2 × 104 as determined by GPC (polystyrene standard) and are considered to possess essentially a random sequences in view of the —CC(CH2)lCC— and —CC—Ph—CC— units as judged from their UV–visible spectra. By the incorporation of the (CH2)l unit, the λmax position of the corresponding PAE homopolymer [CC—Ph—CC—Th(Hex)]n is shifted to a shorter wavelength. However, the copolymers give rise to a photoluminescence PL peak essentially agreeing with a PL peak of the homopolymer, suggesting occurrence of energy transfer in the copolymer. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2201–2207, 1998 相似文献
5.
Peter G. Jones Fabiola Vancea Regine Herbst‐Irmer 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(11):o665-o668
In the isomeric title compounds, viz. 2‐, 3‐ and 4‐(chloromethyl)pyridinium chloride, C6H7ClN+·Cl?, the secondary interactions have been established as follows. Classical N—H?Cl? hydrogen bonds are observed in the 2‐ and 3‐isomers, whereas the 4‐isomer forms inversion‐symmetric N—H(?Cl??)2H—N dimers involving three‐centre hydrogen bonds. Short Cl?Cl contacts are formed in both the 2‐isomer (C—Cl?Cl?, approximately linear at the central Cl) and the 4‐isomer (C—Cl?Cl—C, angles at Cl of ca 75°). Additionally, each compound displays contacts of the form C—H?Cl, mainly to the Cl? anion. The net effect is to create either a layer structure (3‐isomer) or a three‐dimensional packing with easily identifiable layer substructures (2‐ and 4‐isomers). 相似文献
6.
Wilfredo Hernndez Evgenia Spodine Rainer Richter Karl‐Heinz Hallmeier Uwe Schrder Lothar Beyer 《无机化学与普通化学杂志》2003,629(14):2559-2565
The platinum(II) mixed ligand complexes [PtCl(L1‐6)(dmso)] with six differently substituted thiourea derivatives HL, R2NC(S)NHC(O)R′ (R = Et, R′ = p‐O2N‐Ph: HL1; R = Ph, R′ = p‐O2N‐Ph: HL2; R = R′ = Ph: HL3; R = Et, R′ = o‐Cl‐Ph: HL4; R2N = EtOC(O)N(CH2CH2)2N, R′ = Ph: HL5) and Et2NC(S)N=CNH‐1‐Naph (HL6), as well as the bis(benzoylthioureato‐κO, κS)‐platinum(II) complexes [Pt(L1, 2)2] have been synthesized and characterized by elemental analysis, IR, FAB(+)‐MS, 1H‐NMR, 13C‐NMR, as well as X‐ray structure analysis ([PtCl(L1)(dmso)] and [PtCl(L3, 4)(dmso)]) and ESCA ([PtCl(L1, 2)(dmso)] and [Pt(L1, 2)2]). The mixed ligand complexes [PtCl(L)(dmso)] have a nearly square‐planar coordination at the platinum atoms. After deprotonation, the thiourea derivatives coordinate bidentately via O and S, DMSO bonds monodentately to the PtII atom via S atom in a cis arrangement with respect to the thiocarbonyl sulphur atom. The Pt—S‐bonds to the DMSO are significant shorter than those to the thiocarbonyl‐S atom. In comparison with the unsubstituted case, electron withdrawing substituents at the phenyl group of the benzoyl moiety of the thioureate (p‐NO2, o‐Cl) cause a significant elongation of the Pt—S(dmso)‐bond trans arranged to the benzoyl‐O—Pt‐bond. The ESCA data confirm the found coordination and bonding conditions. The Pt 4f7/2 electron binding energies of the complexes [PtCl(L1, 2)(dmso)] are higher than those of the bis(benzoylthioureato)‐complexes [Pt(L1, 2)2]. This may indicate a withdrawal of electron density from platinum(II) caused by the DMSO ligands. 相似文献
7.
Glenna So Ming Tong Dr. Yuen‐Chi Law Dr. Steven C. F. Kui Dr. Nianyong Zhu Dr. King Hong Leung Dr. David Lee Phillips Prof. Chi‐Ming Che Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(22):6540-6554
The complexes [Pt(tBu3tpy){C?C(C6H4C?C)n?1R}]+ (n=1: R=alkyl and aryl (Ar); n=1–3: R=phenyl (Ph) or Ph‐N(CH3)2‐4; n=1 and 2, R=Ph‐NH2‐4; tBu3tpy=4,4’,4’’‐tri‐tert‐butyl‐2,2’:6’,2’’‐terpyridine) and [Pt(Cl3tpy)(C?CR)]+ (R=tert‐butyl (tBu), Ph, 9,9’‐dibutylfluorene, 9,9’‐dibutyl‐7‐dimethyl‐amine‐fluorene; Cl3tpy=4,4’,4’’‐trichloro‐2,2’:6’,2’’‐terpyridine) were prepared. The effects of substituent(s) on the terpyridine (tpy) and acetylide ligands and chain length of arylacetylide ligands on the absorption and emission spectra were examined. Resonance Raman (RR) spectra of [Pt(tBu3tpy)(C?CR)]+ (R=n‐butyl, Ph, and C6H4‐OCH3‐4) obtained in acetonitrile at 298 K reveal that the structural distortion of the C?C bond in the electronic excited state obtained by 502.9 nm excitation is substantially larger than that obtained by 416 nm excitation. Density functional theory (DFT) and time‐dependent DFT (TDDFT) calculations on [Pt(H3tpy)(C?CR)]+ (R= n‐propyl (nPr), 2‐pyridyl (Py)), [Pt(H3tpy){C?C(C6H4C?C)n?1Ph}]+ (n=1–3), and [Pt(H3tpy){C?C(C6H4C?C)n?1C6H4‐N(CH3)2‐4}]+/+H+ (n=1–3; H3tpy=nonsubstituted terpyridine) at two different conformations were performed, namely, with the phenyl rings of the arylacetylide ligands coplanar (“cop”) with and perpendicular (“per”) to the H3tpy ligand. Combining the experimental data and calculated results, the two lowest energy absorption peak maxima, λ1 and λ2, of [Pt(Y3tpy)(C?CR)]+ (Y=tBu or Cl, R=aryl) are attributed to 1[π(C?CR)→π*(Y3tpy)] in the “cop” conformation and mixed 1[dπ(Pt)→π*(Y3tpy)]/1[π(C?CR)→π*(Y3tpy)] transitions in the “per” conformation. The lowest energy absorption peak λ1 for [Pt(tBu3tpy){C?C(C6H4C?C)n?1C6H4‐H‐4}]+ (n=1–3) shows a redshift with increasing chain length. However, for [Pt(tBu3tpy){C?C(C6H4C?C)n?1C6H4‐N(CH3)2‐4}]+ (n=1–3), λ1 shows a blueshift with increasing chain length n, but shows a redshift after the addition of acid. The emissions of [Pt(Y3tpy)(C?CR)]+ (Y=tBu or Cl) at 524–642 nm measured in dichloromethane at 298 K are assigned to the 3[π(C?CAr)→π*(Y3tpy)] excited states and mixed 3[dπ(Pt)→π*(Y3tpy)]/3[π(C?C)→π*(Y3tpy)] excited states for R=aryl and alkyl groups, respectively. [Pt(tBu3tpy){C?C(C6H4C?C)n?1C6H4‐N(CH3)2‐4}]+ (n=1 and 2) are nonemissive, and this is attributed to the small energy gap between the singlet ground state (S0) and the lowest triplet excited state (T1). 相似文献
8.
Tae‐Jin Kim Sung‐Kwan Kim Beom‐Jun Kim Ho‐Jin Son Jong Sok Hahn Minserk Cheong Prof. Mariusz Mitoraj Dr. Monika Srebro Łukasz Piękoś Artur Michalak Prof. Sang Ook Kang Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(19):5630-5644
A series of mono‐, bis‐, and tris(phenoxy)–titanium(IV) chlorides of the type [Cp*Ti(2‐R? PhO)nCl3?n] (n=1–3; Cp*=pentamethylcyclopentadienyl) was prepared, in which R=Me, iPr, tBu, and Ph. The formation of each mono‐, bis‐, and tris(2‐alkyl‐/arylphenoxy) series was authenticated by structural studies on representative examples of the phenyl series including [Cp*Ti(2‐Ph? PhO)Cl2] ( 1 PhCl2 ), [Cp*Ti(2‐Ph? PhO)2Cl] ( 2 PhCl ), and [Cp*Ti(2‐Ph? PhO)3] ( 3 Ph ). The metal‐coordination geometry of each compound is best described as pseudotetrahedral with the Cp* ring and the 2‐Ph? PhO and chloride ligands occupying three leg positions in a piano‐stool geometry. The mean Ti? O distances, observed with an increasing number of 2‐Ph? PhO groups, are 1.784(3), 1.802(4), and 1.799(3) Å for 1 PhCl2 , 2 PhCl , and 3 Ph , respectively. All four alkyl/aryl series with Me, iPr, tBu, and Ph substituents were tested for ethylene homopolymerization after activation with Ph3C+[B(C6F5)4]? and modified methyaluminoxane (7% aluminum in isopar E; mMAO‐7) at 140 °C. The phenyl series showed much higher catalytic activity, which ranged from 43.2 and 65.4 kg (mmol of Ti?h)?1, than the Me, iPr, and tBu series (19.2 and 36.6 kg (mmol of Ti?h)?1). Among the phenyl series, the bis(phenoxide) complex of 2 PhCl showed the highest activity of 65.4 kg (mmol of Ti?h)?1. Therefore, the catalyst precursors of the phenyl series were examined by treating them with a variety of alkylating reagents, such as trimethylaluminum (TMA), triisobutylaluminum (TIBA), and methylaluminoxane (MAO). In all cases, 2 PhCl produced the most catalytically active alkylated species, [Cp*Ti(2‐Ph? PhO)MeCl]. This enhancement was further supported by DFT calculations based on the simplified model with TMA. 相似文献
9.
Isao Yamaguchi Yoshiaki Gobara Moriyuki Sato 《Journal of polymer science. Part A, Polymer chemistry》2007,45(8):1507-1514
Reactions of N‐(2,4‐dinitrophenyl)pyridinium chloride with 2,5‐dimethyl‐1,4‐phenylenediamine in 1:2, 1:1.5, 1:1, and 2:1 molar ratios caused the ring opening of the pyridinium ring and thereby yielded polymers ( P1 – P4 ) consisting of 5‐(2,5‐dimethyl‐1,4‐phenylene)penta‐2,4‐dienylideneammonium chloride (unit A) and N‐2,5‐dimethyl‐1,4‐phenylene diaza[12]annulenium dichloride (unit B). The 1H NMR spectra suggested that the composition ratios of unit A to unit B in P1 – P4 were 0.98:0.02, 0.94:0.06, 0.81:0.19, and 0.79:0.21, respectively. P1 – P4 showed an absorption maximum (λmax) at a longer wavelength than the monomers because of the expansion of the π‐conjugation system. Films of P3 and P4 showed λmax at a considerably longer wavelength than those in solution, and this was attributable to the ordered structures of the polymers in the solid state. Powder X‐ray diffraction analysis supported the ordered structures of P3 and P4 . Pellets molded from P3 and P4 exhibited a metallic luster, whereas those from P1 and P2 did not show such a luster. Cyclic voltammetry measurements indicated that P1 – P4 were electrochemically active in films. The thermal stability of the polymers depended on the composition ratios of unit A to unit B. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1507–1514, 2007 相似文献
10.
Homolytic,Heterolytic, Mesolytic ‐ As You Like It: Steering the Cleavage of a HC(sp3)−C(sp3)H Bond in Bis(1H‐2,1‐benzazaborole) Derivatives
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Martin Hejda Prof. Antonín Lyčka Dr. Tomáš Mikysek Dr. Roman Jambor Prof. Aleš Růžička Dr. Jaromír Vinklárek Dr. Claudia Wilfer Dr. Alexander Hoffmann Prof. Sonja Herres‐Pawlis Dr. Libor Dostál 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15340-15349
A set of (3,3′)‐bis(1‐Ph‐2‐R‐1H‐2,1‐benzazaborole) compounds, in which R=tBu (Bab‐tBu)2 , R=Dipp (Bab‐Dipp)2 or R=tBu and Dipp (Bab‐Dipp)(Bab‐tBu) , was synthesized and fully characterized using 1H, 11B, 13C, and 15N NMR spectroscopy as well as single‐crystal X‐ray diffraction analysis. The central HC(sp3)?C(sp3)H bond with restricted rotation at the junction of both 1H‐2,1‐benzazaborole rings displayed an intriguing reactivity. It was demonstrated that this bond is easily mesolytically cleaved using alkali metals to form the respective aromatic 1Ph‐2R‐1H‐2,1‐benzazaborolyl anions M+(THF) n (Bab‐tBu)? (M=Li, Na, K) and K+(THF) n (Bab‐Dipp)? . Furthermore, the central HC(sp3)?C(sp3)H bond of bis(1H‐2,1‐benzazaborole)s is also homolytically cleaved either by heating or photochemical means, giving corresponding 1Ph‐2R‐1H‐2,1‐benzazaborolyl radicals (Bab‐tBu). and (Bab‐Dipp)., which rapidly self‐terminate. Nevertheless, their formation was unambiguously established by NMR analysis of the reaction mixtures containing products of the self‐termination of the radicals after heating or irradiation. (Bab‐Dipp). radical was also characterized using EPR spectroscopy. Importantly, it turned out that the essentially non‐polarized HC(sp3)?C(sp3)H bond in (Bab‐tBu)2 is also cleaved heterolytically with 2 equiv of MeLi, giving the mixture of Li+(SOL) n (Bab‐tBu)? (SOL=THF or Et2O) and lithium methyl‐substituted borate complex Li+(SOL) n (Bab‐tBu‐Me)? in a diastereoselective fashion. 相似文献
11.
Ju‐Yeon Lee Eun‐Ju Park 《Journal of polymer science. Part A, Polymer chemistry》2002,40(11):1742-1748
Methyl 3,4‐di‐(2′‐hydroxyethoxy)benzylidenecyanoacetate ( 3 ) was prepared by hydrolysis of methyl 3,4‐di‐(2′‐vinyloxyethoxy)benzylidenecyanoacetate ( 2 ). Diol 3 was condensed with 2,4‐toluenediisocyanate, 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate, and 1,6‐hexamethylenediisocyanate to yield polyurethanes 4 – 6 containing the nonlinear optical chromophore 3,4‐dioxybenzylidenecyanoacetate. The resulting polyurethanes 4 – 6 were soluble in common organic solvents such as acetone and dimethylformamide. Polymers 4 – 6 indicated thermal stability up to 300 °C in thermogravimetric thermograms with glass‐transition temperature values obtained from differential scanning calorimetric thermograms in the range of 78–102 °C. The second‐harmonic generation coefficients (d33) of the poled polymer films were around 6.9 × 10?9 esu. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1742–1748, 2002 相似文献
12.
Reactions of Aryl Benzoates with Potassium Aryloxides: Solvent Effects on Reaction Pathway and Kinetics
下载免费PDF全文
![点击此处可从《国际化学动力学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Irina A. Khalfina 《国际化学动力学杂志》2015,47(5):302-314
Temperature dependences of the relative reactivity of potassium aryloxides XC6H4O?K+ toward 2,4‐dinitrophenyl benzoate in 50 mol% dimethylformamide (DMF)–50 mol% H2O mixture have been studied using the competitive reactions technique. Correlation analyses of the relative rate constants kX/kH and differences in the activation parameters (ΔΔН≠ and ΔΔS≠) of the competitive reactions have revealed the existence of two isokinetic series of the reactions of 2,4‐dinitrophenyl benzoate with potassium aryloxides with electron‐donating substituent (EDS) and electron‐withdrawing substituent (EWS), respectively. We have investigated the effect of the substituent X on the activation parameters for each isokinetic series and concluded that the mechanism of the reactions of 2,4‐dinitrophenyl benzoate with potassium aryloxides XC6H4O?K+ in 50 mol% DMF–50 mol% H2O mixture is the same as in DMF. Analysis of the obtained data with using the method of two‐dimensional reaction coordinate diagram leads to the conclusion that the variation of the solvent from DMF to 50 mol% DMF–50 mol% H2O mixture affects the reaction pathway. The rate constant kX for the reaction of 3‐nitrophenyl benzoate with potassium 4‐methoxyphenoxide and the relative rate constants kX/kH for the reaction of 3‐nitrophenyl benzoate with potassium aryloxides XC6H4O?K+ with EDS were measured in 50 mol% DMF–50 mol% H2O mixtures at 25°C, and it has been shown that the addition of water to DMF does not change the mechanism but slows down these reactions. 相似文献
13.
Marzena Białek Monika Pochwała Grzegorz Spaleniak 《Journal of polymer science. Part A, Polymer chemistry》2014,52(15):2111-2123
A series of novel titanium(IV) complexes bearing tetradentate [ONNO] salan type ligands: [Ti{2,2′‐(OC6H3‐5‐t‐Bu)2‐NHRNH}Cl2] (Lig1TiCl2: R = C2H4; Lig2TiCl2: R = C4H8; Lig3TiCl2: R = C6H12) and [Ti{2,2′‐(OC6H2‐3,5‐di‐t‐Bu)2‐NHC6H12NH}Cl2] (Lig4TiCl2) were synthesized and used in the (co)polymerization of olefins. Vanadium and zirconium complexes: [ M{2,2′‐(OC6H3‐3,5‐di‐t‐Bu)2‐NHC6H12NH}Cl2] (Lig4VCl2: M = V; Lig4ZrCl2: M = Zr) were also synthesized for comparative investigations. All the complexes turned out active in 1‐octene polymerization after activation by MAO and/or Al(i‐Bu)3/[Ph3C][B(C6F5)4]. The catalytic performance of titanium complexes was strictly dependent on their structures and it improves for the increasing length of the aliphatic linkage between nitrogen atoms (Lig1TiCl2 << Lig2TiCl2 < Lig3TiCl2) and declines after adding additional tert‐Bu group on the aromatic rings (Lig3TiCl2 < Lig4TiCl2). The activity of all titanium complexes in ethylene polymerization was moderate and the properties of polyethylene was dependent on the ligand structure, cocatalyst type, and reaction conditions. The Et2AlCl‐activated complexes gave polymers with lover molecular weights and bimodal distribution, whereas ultra‐high molecular weight PE (up to 3588 kg mol?1) and narrow MWD was formed for MAO as a cocatalyst. Vanadium complex yielded PE with the highest productivity (1925.3 kg molv?1), with high molecular weight (1986 kg mol?1) and with very narrow molecular weight distribution (1.5). Copolymerization tests showed that titanium complexes yielded ethylene/1‐octene copolymers, whereas vanadium catalysts produced product mixtures. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2111–2123 相似文献
14.
Mohammad Mazloum‐Ardakani Mohammad Ali Sheikh‐Mohseni Bibi‐Fatemeh Mirjalili 《Electroanalysis》2013,25(8):2021-2029
In this paper, the use of a carbon paste electrode (CPE) modified by (E)‐3‐((2‐(2,4‐dinitrophenyl)hydrazono)methyl)benzene‐1,2‐diol (DHB) and carbon nanotubes (CNTs) for the determination of glutathione (GSH), uric acid (UA) and penicillamine (PA) is described. Initially, cyclic voltammetry was used to investigate the redox properties of the modified electrode in phosphate buffer. Next, the electrocatalytic oxidation of GSH via EC′ mechanism at the modified electrode was described. At the optimum pH of 7.0, the oxidation of GSH occurs at a potential that is 530 mV less positive than that of an unmodified carbon paste electrode. The values of the diffusion coefficient (D=2.5×10?6 cm2 s?1) and the catalytic rate constant (k=1.7×103 M?1 s?1) were calculated for GSH, using chronoamperometry. Based on differential pulse voltammetry, the oxidation of GSH exhibited a dynamic range between 0.4 and 700.0 µM and a detection limit (3σ) of 70.0 nM. Also, simultaneous determination of GSH, UA and PA was described at the modified electrode. Finally, this method was used for the determination of these substances in synthetic solutions and blood serum samples. 相似文献
15.
Syntheses and Crystal Structures of [Cu4(As4Ph4)2(PRR′2)4], [Cu14(AsPh)6(SCN)2(PEt2Ph)8], [Cu14(AsPh)6Cl2(PRR′2)8], [Cu12(AsPh)6(PPh3)6], [Cu10(AsPh)4Cl2(PMe3)8], [Cu12(AsSiMe3)6(PRR′2)6], and [Cu8(AsSiMe3)4(PtBu3)4] (R, R′ = Organic Groups) Through the reaction of CuSCN with AsPh(SiMe3)2 in the presence of tertiary phosphines the compounds [Cu4(As4Ph4)2(PRR′2)4] ( 1 – 3 ) ( 1 : R = R′ = nPr, 2 : R = R′ = Et; 3 : R = Me, R′ = nPr) and [Cu14(AsPh)6(SCN)2(PEt2Ph)8] ( 4 ) can be synthesised. Using CuCl instead of CuSCN results to the cluster complexes [Cu14(AsPh)6Cl2(PRR′2)8] ( 5–6 ) ( 5 : R = R′ = Et; 6 : R = Me, R′ = nPr), [Cu12(AsPh)6(PPh3)6] ( 7 ) and [Cu10(AsPh)4Cl2(PMe3)8] ( 8 ). Through reactions of CuOAc with As(SiMe3)3 in the presence of tertiary phosphines the compounds [Cu12(AsSiMe3)6(PRR′2)6] ( 9 – 11 ) ( 9 : R = R′ = Et; 10 : R = Ph, R′ = Et; 11 : R = Et, R′ = Ph) and [Cu8(AsSiMe3)4(PtBu3)4] ( 12 ) can be obtained. In each case the products were characterised by single‐crystal‐X‐ray‐structure‐analyses. As the main structure element 1 – 3 each have two As4Ph42–‐chains as ligands. In contrast 4 – 12 contain discrete AsR2–ligands. 相似文献
16.
Bernd Wrackmeyer Christian Khler Wolfgang Milius Jean Michel Grevy Zureima García‐Hernndez Rosalinda Contreras 《Heteroatom Chemistry》2002,13(7):667-676
The preferred conformation of aminophosphanes with bulky amino groups ( 1–20 ) was determined by NMR spectroscopy in solution, in two cases in the solid state ( 11,17 ) and in one case ( 11 ) by X‐ray crystallography. Trimethylsilylaminodiphenylphosphanes Ph2PN(R)SiMe3 (R = Bu ( 1 ), Ph ( 2 ), 2‐pyridyl ( 3 ), 2‐pyrimidyl ( 4 ), Me3Si ( 5 )), amino(chloro)phenylphosphanes Ph(Cl)PNRR′ (R = Bz, R′ = Me ( 6 ), R = Bz, R′ = tBu ( 7 ), R = Et, R′ = Ph ( 8 )), amino(chloro)tert‐butylphosphanes tBu(Cl)PNRR′ (R = R′ = iPr ( 9 ), R = Me, R′ = tBu ( 10 ), R = Bz, R′ = tBu ( 11 ), R = H, R′ = tBu ( 12 ), R = Et, R′ = Ph ( 13 ), R = iPr, R′ = Ph ( 14 ), R = Bu, R′ = Ph ( 15 ), R = Bz, R′ = Ph ( 16 ), R = R′ = Ph ( 17 ), R = R′ = Me3Si ( 18 )), 3‐tert‐butyl‐2‐chloro‐1,3,2‐oxazaphospholane ( 19 ), and benzyl(tert‐butyl)aminodichlorophosphane ( 20 ) were studied by 1H, 13C, 15N, 29Si, and 31P NMR spectroscopy. In all cases, the more bulky substituent at the nitrogen atom prefers the syn‐position with respect to the assumed orientation of the phosphorus lone pair of electrons. Many of the derivatives studied adopt this preferred conformation even at room temperature. Numerous signs of coupling constants 1J(31P, 15N), 2J(31P, 13C), and 2J(31P, 29Si) were determined. Low temperature NMR spectra were measured for derivatives for which rotation about the P N bond at room temperature is fast, showing the presence of two rotamers at low temperature. The respective conformation of these rotamers could be assigned by 13C, 15N, and 31P NMR spectroscopy. Isotope‐induced chemical shifts 1Δ15/14N(31P) were determined for all compounds at natural abundance of 15N by using Hahn‐echo extended polarization transfer experiments. The molecular structure of 11 in the solid state reveals pyramidal surroundings of the nitrogen atom and mutual trans‐positions of the tert‐butyl groups at phosphorus and nitrogen. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:667–676, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10084 相似文献
17.
The reaction of [Pt(CH2COMe)(Ph)(cod)] (cod=1,5‐cyclooctadiene) with (ArCH2NH2CH2‐C6H4COOH)+(PF6)? (Ar=4‐tBuC6H4 or 9‐anthryl) in the presence of cyclic oligoethers such as dibenzo[24]crown‐8 (DB24C8) and dicyclohexano[24]crown‐8 (DC24C8) produces {(ce)[ArCH2NH2CH2C6H4COOPt(Ph)(cod)]}+(PF6)? (ce=DB24C8 or DC24C8, Ar=4‐tBuC6H4 or 9‐anthryl) with interlocked structures. FABMS and NMR spectra of a solution of these compounds indicate that the Pt complexes with a secondary ammonium group and DB24C8 (or DC24C8) make up the axis and cyclic components, respectively. Temperature‐dependent 1H NMR spectra of a solution of {(DB24C8)[4‐tBuC6H4CH2NH2CH2‐C6H4COOPt(Ph)(cod)]}+(PF6)? ({(DB24C8)[ 4 ‐H]}+(PF6)?) show equilibration with free DB24C8 and the axis component. The addition of DB24C8 to a solution of {(DC24C8)[ 4 ‐H]}+(PF6)? causes partial exchange of the macrocyclic component of the interlocked molecules, giving a mixture of {(DC24C8)[ 4 ‐H]}+(PF6)?, {(DB24C8)[ 4 ‐H]}+(PF6)?, and free macrocyclic compounds. The reaction of 3,5‐Me2C6H3COCl with {(DB24C8)[ 4 ‐H]}+(PF6)? affords the organic rotaxane {(DB24C8)(4‐tBuC6H4CH2NH2CH2‐C6H4COOCOC6H3Me2‐3,5)}+(PF6)? through C? O bond formation between the aroyl group and the carboxylate ligand of the axis component. The addition of 2,2′‐bipyridine (bpy) to a solution of {(DB24C8)[ 4 ‐H]}+(PF6)? induces the degradation of the interlocked structure to form a complex with trigonal bipyramidal coordination, [Pt(Ph)(bpy)(cod)]+(PF6)?, whereas the reaction of bpy with [Pt(OCOC6H4Me‐4)(Ph)(cod)] produces the square‐planar complex [Pt(OCOC6H4Me‐4)(Ph)(bpy)]. 相似文献
18.
Xiaoyu Chen Binbin Ma Dr. Xingyong Wang Shengxin Yao Lichen Ni Zhaoyi Zhou Prof. Yizhi Li Prof. Wei Huang Prof. Jing Ma Prof. Jinglin Zuo Prof. Xinping Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(37):11828-11836
Salts that contain radical cations of benzidine (BZ), 3,3′,5,5′‐tetramethylbenzidine (TMB), 2,2′,6,6′‐tetraisopropylbenzidine (TPB), and 4,4′‐terphenyldiamine (DATP) have been isolated with weakly coordinating anions [Al(ORF)4]? (ORF=OC(CF3)3) or SbF6?. They were prepared by reaction of the respective silver(I) salts with stoichiometric amounts of benzidine or its alkyl‐substituted derivatives in CH2Cl2. The salts were characterized by UV absorption and EPR spectroscopy as well as by their single‐crystal X‐ray structures. Variable‐temperature UV/Vis absorption spectra of BZ . +[Al(ORF)4]? and TMB . +[Al(ORF)4]? in acetonitrile indicate an equilibrium between monomeric free radical cations and a radical‐cation dimer. In contrast, the absorption spectrum of TPB . +SbF6? in acetonitrile indicates that the oxidation of TPB only resulted in a monomeric radical cation. Single‐crystal X‐ray diffraction studies show that in the solid state BZ and its methylation derivative (TMB) form radical‐cation π dimers upon oxidation, whereas that modified with isopropyl groups (TPB) becomes a monomeric free radical cation. By increasing the chain length, π stacks of π dimers are obtained for the radical cation of DATP. The single‐crystal conductivity measurements show that monomerized or π‐dimerized radicals (BZ . +, TMB . +, and TPB . +) are nonconductive, whereas the π‐stacked radical (DATP . +) is conductive. A conduction mechanism between chains through π stacks is proposed. 相似文献
19.
Wirnhier E Döblinger M Gunzelmann D Senker J Lotsch BV Schnick W 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(11):3213-3221
Poly(triazine imide) with intercalation of lithium and chloride ions (PTI/Li+Cl?) was synthesized by temperature‐induced condensation of dicyandiamide in a eutectic mixture of lithium chloride and potassium chloride as solvent. By using this ionothermal approach the well‐known problem of insufficient crystallinity of carbon nitride (CN) condensation products could be overcome. The structural characterization of PTI/Li+Cl? resulted from a complementary approach using spectroscopic methods as well as different diffraction techniques. Due to the high crystallinity of PTI/Li+Cl? a structure solution from both powder X‐ray and electron diffraction patterns using direct methods was possible; this yielded a triazine‐based structure model, in contrast to the proposed fully condensed heptazine‐based structure that has been reported recently. Further information from solid‐state NMR and FTIR spectroscopy as well as high‐resolution TEM investigations was used for Rietveld refinement with a goodness‐of‐fit (χ2) of 5.035 and wRp=0.05937. PTI/Li+Cl? (P63cm (no. 185); a=846.82(10), c=675.02(9) pm) is a 2D network composed of essentially planar layers made up from imide‐bridged triazine units. Voids in these layers are stacked upon each other forming channels running parallel to [001], filled with Li+ and Cl? ions. The presence of salt ions in the nanocrystallites as well as the existence of sp2‐hybridized carbon and nitrogen atoms typical of graphitic structures was confirmed by electron energy‐loss spectroscopy (EELS) measurements. Solid‐state NMR spectroscopy investigations using 15N‐labeled PTI/Li+Cl? proved the absence of heptazine building blocks and NH2 groups and corroborated the highly condensed, triazine‐based structure model. 相似文献
20.
John Giantsidis Mark M. Turnbull 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):334-335
The title compound, 2‐amino‐5‐carboxypyridinium chloride, C6H7N2O2+·Cl?, was isolated from a 1 M HCl aqueous solution containing 2‐amino‐5‐cyanopyridine. The structure is held together by extensive hydrogen bonding between the chloride ions and the carboxylic acid, amino and pyridinium H atoms. The molecules pack as sheets, with the sheets at a distance of 3.21 (3) Å from one another. 相似文献