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1.
Dr. Gang Li Yuechao Wu Dr. Junkuo Gao Junbo Li Prof. Dr. Yang Zhao Prof. Dr. Qichun Zhang 《化学:亚洲杂志》2013,8(7):1574-1578
Two novel larger azaacenes with six or ten N atoms in their backbones, benzannelated 9,11,13,22,24,26‐hexazatetrabenzo[a,c,l,n]heptacene ( HATBH , 1 ) and benzannelated 9,26‐dihydro‐9,11,13,22,24,26‐hexaza‐tetrapyrido[3,2‐a: 2′,3′‐c: 3′′,2′′‐l: 2′′′,3′′′‐n]heptacene ( DHATPH, 2 ), have been successfully synthesized in two steps. The theoretical band gaps estimated through DFT calculations for HATBH ( 1 ) and DHATPH ( 2 ) are 1.949 eV and 2.278 eV, which are close to the experimentally obtained optical band gaps (2.14 eV and 2.39 eV). Interestingly, HATBH ( 1 ) can act as efficient anion sensor for F? and H2PO4?, while DHATPH ( 2 ) selectively responds to F? among the ten different anions used (F?, Cl?, Br?, I?, PF6?, HSO4?, NO3?, BF4?, AcO?, and H2PO4?). Our synthetic strategy could offer a promising and easy way to obtain even larger azaacenes. 相似文献
2.
Chao Chen Huapeng Ruan Zhongtao Feng Yong Fang Shuxuan Tang Yue Zhao Gengwen Tan Yuanting Su Xinping Wang 《Angewandte Chemie (International ed. in English)》2020,59(29):11794-11799
Although diradicals and azaacenes have been greatly attractive in fundamental chemistry and functional materials, the isolable diradical dianions of azaacenes are still unknown. Herein, we describe the first isolation of pyrene‐fused azaacene diradical dianion salts [(18‐c‐6)K(THF)2]+[(18‐c‐6)K]+? 1 2?.. and [(18‐c‐6)K(THF)]2+? 2 2?.. by reduction of the neutral pyrene‐fused azaacene derivatives 1 and 2 with excess potassium graphite in THF in the presence of 18‐crown‐6. Their electronic structures were investigated by various experiments, in conjunction with theoretical calculations. It was found that both dianions are open‐shell singlets in the ground state and their triplet states are thermally readily accessible owing to the small singlet–triplet energy gap. This work provides the first examples of crystalline diradical dianions of azaacenes with considerable diradical character. 相似文献
3.
Yang Lu Zi‐Di Yu Run‐Zhi Zhang Ze‐Fan Yao Hao‐Yang You Li Jiang Hio‐Ieng Un Bo‐Wei Dong Miao Xiong Jie‐Yu Wang Jian Pei 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(33):11512-11516
Low n‐doping efficiency and inferior stability restrict the thermoelectric performance of n‐type conjugated polymers, making their performance lag far behind of their p‐type counterparts. Reported here are two rigid coplanar poly(p‐phenylene vinylene) (PPV) derivatives, LPPV‐1 and LPPV‐2 , which show nearly torsion‐free backbones. The fused electron‐deficient rigid structures endow the derivatives with less conformational disorder and low‐lying lowest unoccupied molecular orbital (LUMO) levels, down to ?4.49 eV. After doping, two polymers exhibited high n‐doping efficiency and significantly improved air stability. LPPV‐1 exhibited a high conductivity of up to 1.1 S cm?1 and a power factor as high as 1.96 μW m?1 K?2. Importantly, the power factor of the doped LPPV‐1 thick film degraded only 2 % after 7 day exposure to air. This work demonstrates a new strategy for designing conjugated polymers, with planar backbones and low LUMO levels, towards high‐performance and potentially air‐stable n‐type polymer thermoelectrics. 相似文献
4.
Rational Design of Ni Nanoparticles on N‐Rich Ultrathin Carbon Nanosheets for High‐Performance Supercapacitor Materials: Embedded‐ Versus Anchored‐Type Dispersion
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Mei Yang Yiren Zhong Dr. Liwei Su Prof. Jinping Wei Prof. Zhen Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(17):5046-5053
Highly dispersed Ni nanoparticles (NPs) and abundant functional N‐species were integrated into ultrathin carbon nanosheets by using a facile and economical sol–gel route. Embedded‐ and anchored‐type configurations were achieved for the dispersion of Ni NPs in/on N‐rich carbon nanosheets. The anchored‐type composite exhibited outstanding pseudocapacitance of 2200 F g?1 at 5 A g?1 with unusual rate capability and extraordinary cyclic stability over 20 000 cycles with little capacitance decay. Aqueous asymmetric supercapacitors fabricated with this composite cathode demonstrated a high energy density of 51.3 Wh kg?1 at a relatively large power density of 421.6 W kg?1, along with outstanding cyclic stability. This approach opens an attractive direction for enhancing the electrochemical performances of metal‐based supercapacitors and can be generalized to design high‐performance energy‐storage devices. 相似文献
5.
Dr. Shuaijun Yang Bowen Shan Dr. Xiaomin Xu Prof. Dr. Qian Miao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19):6637-6642
The synthesis of novel π‐extended N‐heteroacenes, which have a large tetraazaacene subunit and a quinoxaline subunit connected through a four‐membered ring, is reported. They were studied with experimental and computational methods in comparison to the corresponding tetraazaacenes. As found from the DFT calculation, the four‐membered ring is a better linker than a five‐membered ring or a C?C single bond to extend N‐heteroacenes for a new design of n‐type semiconductors in terms of the spatial delocalization and energy level of LUMO as well as the reorganization energy. In solution‐processed thin film transistors, the π‐extended N‐heteroacenes are found to function as n‐type semiconductors with field effect mobility of up to 0.02 cm2 V?1 s?1 under ambient conditions. 相似文献
6.
Design,Synthesis, and Structural Analysis of Divalent NI Compounds and Identification of a New Electron‐Donating Ligand
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Prof. Dr. Prasad V. Bharatam Minhajul Arfeen Neha Patel Priyanka Jain Sonam Bhatia Prof. Dr. Asit K. Chakraborti Dr. Sadhika Khullar Vijay Gupta Prof. Dr. Sanjay K. Mandal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(3):1088-1096
The dative‐bond representation (L→E) in compounds with main group elements (E) has triggered extensive debate in the recent past. The scope and limits of this nonclassical coordination bond warrant comprehensive exploration. Particularly compounds with (L→N←L′)+ arrangement are of special interest because of their therapeutic importance. This work reports the design and synthesis of novel chemical species with the general structural formula (L→N←L′)+ carrying the unusual ligand cyclohexa‐2,5‐diene‐4‐(diaminomethynyl)‐1‐ylidene. Four species belonging to the (L→N←L′)+ class carrying this unconventional ligand were synthesized. Quantum chemical and X‐ray diffraction analyses showed that the electronic and geometric parameters are consistent with those of already reported divalent NI compounds. The molecular orbital analysis, geometric parameters, and spectral data clearly support the L→N and N←L′ interactions in these species. The newly identified ligand has the properties of a reactive carbene and high nucleophilicity. 相似文献
7.
Ning‐Hai Hu Katsuyuki Aoki Adegboye O. Adeyemo George N. Williams 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1064-1066
In the title compound, 3‐[(4‐amino‐2‐methyl‐5‐pyrimidin‐1‐io)methyl]‐5‐(2‐hydroxyethyl)‐4‐methylthiazolium(2+) bis(tetrafluoroborate), C12H18N4OS2+·2BF4?, the divalent thiamine cation (in the F conformation) is associated with BF4? anions via two characteristic bridging interactions between the thiazolium and pyrimidinium rings, i.e. C—H?BF4??pyrimidinium and N—H?BF4??thiazolium interactions. Thiamine molecules are linked by N—H?O hydrogen bonds to form a helical chain structure. 相似文献
8.
Self‐Directed Orientation of Molecular Columns Based on n‐Type Hexaazatrinaphthylenes (HATNAs) for Electron Transport
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Xu‐Ying Liu Dr. Takayuki Usui Prof. Dr. Junichi Hanna 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(44):14207-14212
Self‐organizing n‐type hexaazatrinaphthylenes (HATNAs) with various bay‐located side chains have been synthesized. The HATNA derivatives are able to form long‐range molecular columns with self‐directed growth directions. In particular, alkyl‐substituted HATNAs showed in‐plane molecular columns with axes parallel to substrates, whereas the columnar orientation of the HATNAs with alkylethynyl or alkylthio groups strongly depended on the length of the introduced side chains. Interestingly, the derivative with octylthio chains exhibited out‐of‐plane molecular columns, in which electron mobility of up to 10?3 cm2 V?1 s?1 was determined through the time‐of‐flight technique, highlighting the fact that such molecular columns based on bay‐substituted HATNAs are promising n‐type semiconductors for device applications. 相似文献
9.
Mark Niemeyer 《无机化学与普通化学杂志》2003,629(9):1535-1540
Reaction of Copper Aryls with Imidazol‐2‐ylidenes or Triphenylphosphane — Formation of 1:1‐Adducts with Two‐coordinate Copper Atoms The reaction of the copper aryls CuDmp (Dmp = 2, 6‐Mes2C6H3; Mes = 2, 4, 6‐Me3C6H2) and CuMes with the σ‐donors triphenylphosphane and 1, 3‐Di‐iso‐propyl‐4, 5‐dimethylimidazol2‐ylidene affords the adducts DmpCu←PPh3 ( 1 ), DmpCu←C{N(iPr)CMe}2 ( 2 ) and MesCu←C{N(iPr)CMe}2 ( 3 ) in yields between 65 and 84 %. The colorless compounds were characterized by 1H and 13C‐NMR‐spectroscopy, single crystal structure analysis as well as by 31P NMR‐spectroscopy ( 1 ), elemental analysis ( 2 ), mass spectrometry ( 2 , 3 ), IR‐spectroscopy ( 2 ) and melting point ( 2 , 3 ). In the solid state structures the two‐coordinate copper atoms possess relatively short Cu—P and Cu—C(carbene) distances of 218, 91(11) ( 1 ), 190, 2(3) ( 2 ) and 191, 1(4) pm ( 3 ). 相似文献
10.
Jie Zhou Xinxing Yin Zihao Dong Amjad Ali Zhaoning Song Niraj Shrestha Sandip Singh Bista Qinye Bao Randy J. Ellingson Yanfa Yan Weihua Tang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(39):13855-13859
Organic p‐type semiconductors with tunable structures offer great opportunities for hybrid perovskite solar cells (PVSCs). We report herein two dithieno[3,2‐b:2′,3′‐d]pyrrole (DTP) cored molecular semiconductors prepared through π‐conjugation extension and an N‐alkylation strategy. The as‐prepared conjugated molecules exhibit a highest occupied molecular orbital (HOMO) level of ?4.82 eV and a hole mobility up to 2.16×10?4 cm2 V?1 s?1. Together with excellent film‐forming and over 99 % photoluminescence quenching efficiency on perovskite, the DTP based semiconductors work efficiently as hole‐transporting materials (HTMs) for n‐i‐p structured PVSCs. Their dopant‐free MA0.7FA0.3PbI2.85Br0.15 devices exhibit a power conversion efficiency over 20 %, representing one of the highest values for un‐doped molecular HTMs based PVSCs. This work demonstrates the great potential of using a DTP core in designing efficient semiconductors for dopant‐free PVSCs. 相似文献
11.
Full Characterization and Photoelectrochemical Behavior of Pyrene‐fused Octaazadecacene and Tetraazaoctacene
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Zilong Wang Jianwei Miao Dr. Guankui Long Dr. Peiyang Gu Dr. Junbo Li Prof. Dr. Naoki Aratani Prof. Dr. Hiroko Yamada Prof. Dr. Bin Liu Prof. Dr. Qichun Zhang 《化学:亚洲杂志》2016,11(4):482-485
The preparation of large azaacenes is very important because of their great potential in organic electronics. In this report, we successfully synthesized and fully characterized two stable pyrene‐fused large azaacenes: octaazadecacene and tetraazaoctacene through employing a relatively moderate aromatic unit pyrene as imbedded species in the backbone of azaacenes to ensure large conjugation and stability. The photoelectrochemical (PEC) studies indicate that both azaacenes display n‐type semiconductor behavior. 相似文献
12.
Andrew Hempel Norman Camerman Zbigniew Dauter Donald Mastropaolo Arthur Camerman 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):455-456
The crystal structure of the title compound, C19H26NO+·Cl? (common name: N,N‐diethyl‐2‐[(4‐phenylmethyl)phenoxy]‐ethanamine hydrochloride), contains one molecule in the asymmetric unit. The planes through the two phenyl rings are roughly perpendicular. Protonation occurs at the N atom, to which the Cl? ion is linked via an N—H?Cl hydrogen bond. The molecule adopts an eclipsed rather than extended conformation. 相似文献
13.
Gaobo Lin Lingna Wang Yizhou Yang Zitong Liu Guanxin Zhang Deqing Zhang 《化学:亚洲杂志》2019,14(10):1712-1716
Conjugated molecules with low lying LUMO levels are demanding for the development of air stable n‐type organic semiconductors. In this paper, we report a new A‐D‐A′‐D‐A conjugated molecule ( DAPDCV ) entailing diazapentalene (DAP) and dicyanovinylene groups as electron accepting units. Both theoretical and electrochemical studies manifest that the incorporation of DAP unit in the conjugated molecule can effectively lower the LUMO energy level. Accordingly, thin film of DAPDCV shows n‐type semiconducting behavior with electron mobility up to 0.16 cm2?V?1?s?1 after thermal annealing under N2 atmosphere. Moreover, thin film of DAPDCV also shows stable n‐type transporting property in air with mobility reaching 0.078 cm2?V?1?s?1. 相似文献
14.
Yu‐Liang Shan Dr. Wai‐Leung Yim Dr. Cheuk‐Wai So 《Angewandte Chemie (International ed. in English)》2014,53(48):13155-13158
The synthesis of an N‐heterocyclic silylene‐stabilized digermanium(0) complex is described. The reaction of the amidinate‐stabilized silicon(II) amide [LSiN(SiMe3)2] ( 1 ; L=PhC(NtBu)2) with GeCl2?dioxane in toluene afforded the SiII–GeII adduct [L{(Me3Si)2N}Si→GeCl2] ( 2 ). Reaction of the adduct with two equivalents of KC8 in toluene at room temperature afforded the N‐heterocyclic carbene silylene‐stabilized digermanium(0) complex [L{(Me3Si)2N}Si→ Ge?Ge←Si{N(SiMe3)2}L] ( 3 ). X‐ray crystallography and theoretical studies show conclusively that the N‐heterocyclic silylenes stabilize the singlet digermanium(0) moiety by a weak synergic donor–acceptor interaction. 相似文献
15.
14/15N N.M.R. and 11B N.M.R. Data of Trifluoromethylthioamino-boranes with Natural Isotope Abundance (Part 2) 14/15N as well as 11B-NMR data for trifluoromethylthioabminoboranes of the types XnB[N(SCF3)2], with X = F, Cl, Br, N3, or NHSCF3, n = 0, 1 or 2, and Cl3?nB(NHSCF3)n with n = 1, 2 or 3, as well as for the amine-borne Me3NBCl2N(SCF3)2 and the cyclic borazene (CF3SNHBNH)3 are reported. These data are used, together with a qualitative analysis of the bonding situation based on observed rotational barriers and known structures, to analyse for B ← N back donation in these compounds. Relatively small variations in δ14/15N compared to those observed for alkylaminoboranes as well as large variations in δ11B are suggestive of small contributions only from back bonding. In addition the ?halogene like”? nature of the (CF3S)2N group is confirmed. For the series X2BN(SCF3)2 (X = F, Cl, Br on N3), XB[N(SCF3)2]2 (X = Cl, Br, N3 or N(SCF3)2) and Cln?3B(NHSCF3)n (n = 1, 2 or 3) a linear relationship for δ11B and δ14/15N is observed. It is furtheron demonstrated that hitherto known δ14/15N/11B correlations are valid only in case of strong B ← N back donation. 相似文献
16.
Romesh J. Patel Timothy B. Tighe Ilia N. Ivanov Michael A. Hickner 《Journal of Polymer Science.Polymer Physics》2011,49(17):1269-1275
3‐hexylthiophene was electropolymerized on a carbon nanotube (CNT)‐laden fluorine‐doped tin oxide substrate. Scanning electron microscopy and Raman spectroscopy revealed that the polymer was infused throughout the thickness of the 150‐nm thick CNT mat, resulting in a conducting composite film with a dense CNT network. The electropolymerized poly(3‐hexylthiophene) (e‐P3HT)/CNT composites exhibited photoluminescence intensity quenching by as much as 92% compared to the neat e‐P3HT, which provided evidence of charge transfer from the polymer phase to the CNT phase. Through‐film impedance and J‐V measurements of the composites gave a conductivity (σ) of 1.2 × 10?10 S cm?1 and zero‐field mobility (μ0) of 8.5 × 10?4 cm2 V?1 s?1, both of which were higher than those of neat e‐P3HT films (σ = 9.9 × 10?12 S cm?1, μ0 = 3 × 10?5 cm2 V?1 s?1). In electropolymerized samples, the thiophene rings were oriented in the (010) direction (thiophene rings parallel to substrate), which resulted in a broader optical absorbance than for spin coated samples, however, the lack of long‐range conjugation caused a blueshift in the absorbance maximum from 523 nm for unannealed regioregular P3HT (rr‐P3HT) to 470 nm for e‐P3HT. Raman spectroscopy revealed that π‐π stacking in e‐P3HT was comparable to that in rr‐P3HT and significantly higher than in regiorandom P3HT (ran‐P3HT) as shown by the principal Raman peak shift from 1444 to 1446 cm?1 for e‐P3HT and rr‐P3HT to 1473 cm?1 for ran‐P3HT. This work demonstrates that these polymer/CNT composites may have interesting properties for electro‐optical applications. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1269–1275, 2011 相似文献
17.
Bernd Wrackmeyer Christine Schödel Rhett Kempe Germund Glatz Awal Noor 《无机化学与普通化学杂志》2016,642(17):922-924
Complete hydroboration of cyclododecatrienes was reported to give two isomers, depending on conditions. The assignment of their structure had been attempted without unequivocal proofs. We have now used NMR spectroscopy (11B, 13C, 15N and 23Na NMR) to study the sodium amides of these two polycyclic boranes. In addition, one of the isomeric borates could be crystallized, and the X‐ray analysis revealed a cis‐,cis‐,trans configuration of the six‐membered rings reversing the original structural assignment. 相似文献
18.
Fei He Qiu‐Hong Pan Ying Shi Xue‐Ting Zhang Chang‐Qing Duan 《Journal of mass spectrometry : JMS》2009,44(5):633-640
Autoxidation of flavan‐3‐ols was carried out in aqueous/methanol model solutions under mildly acidic conditions (pH 6.0), and these autoxidation products were analyzed by using high performance liquid chromatography (HPLC) coupled with tandem mass spectrometry (MS/MS). The results showed that (+)‐catechins and (?)‐epicatechins generated autoxidation reaction with each other to form a series of oligomers that had the same [M ? H]? molecular ions (MS1) as those of natural procyanidins, but had completely different fragment ions (MS2). According to MS/MS analysis, the major fragments of these oligomers were derived not only from the retro‐Diels–Alder (RDA) dissociations on the C‐rings of the flavan‐3‐ol units, but also from the quinone‐methide (QM) cleavage of the interflavan linkages (IFL), and thus they were identified as B‐type dehydrodicatechins, B‐type dehydrotricatechins and A‐type dehydrotricatechins, respectively. The potential structures of their [M ? H]? molecular ions and partial fragment ions were deduced on the basis of the MS/MS characterization and the oxidation of flavan‐3‐ols in previous reports. Some specific fragment ions were found to be very useful for identifying the autoxidation oligomers (the B‐type dehydrodicatechins at m/z 393, the B‐type dehydrotricatechins at m/z 681 and the A‐type dehydrotricatechins at m/z 725). Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
19.
Sebastian N. Intorp Manuel Hodecker Matthias Müller Olena Tverskoy Marco Rosenkranz Evgenia Dmitrieva Alexey A. Popov Frank Rominger Jan Freudenberg Andreas Dreuw Uwe H. F. Bunz 《Angewandte Chemie (International ed. in English)》2020,59(30):12396-12401
Quinoidal azaacenes with almost pure diradical character (y=0.95 to y=0.99) were synthesized. All compounds exhibit paramagnetic behavior investigated by EPR and NMR spectroscopy, and SQUID measurements, revealing thermally populated triplet states with an extremely low‐energy gap ΔEST′ of 0.58 to 1.0 kcal mol?1. The species are persistent in solution (half‐life≈14–21 h) and in the solid state they are stable for weeks. 相似文献
20.
Adolfo Ensuncho M. Jennifer Lafont Alexandra Rotinov Rosa M. Domínguez Armando Herize Gabriel Chuchani Jairo Quijano 《国际化学动力学杂志》2001,33(8):465-471
The gas‐phase elimination kinetics of the ethyl ester of two α‐amino acid type of molecules have been determined over the temperature range of 360–430°C and pressure range of 26–86 Torr. The reactions, in a static reaction system, are homogeneous and unimolecular and obey a first‐order rate law. The rate coefficients are given by the following equations. For N,N‐dimethylglycine ethyl ester: log k1(s?1) = (13.01 ± 3.70) ? (202.3 ± 0.3)kJ mol?1 (2.303 RT)?1 For ethyl 1‐piperidineacetate: log k1(s?1) = (12.91 ± 0.31) ? (204.4 ± 0.1)kJ mol?1 (2.303 RT)?1 The decompositon of these esters leads to the formation of the corresponding α‐amino acid type of compound and ethylene. However, the amino acid intermediate, under the condition of the experiments, undergoes an extremely rapid decarboxylation process. Attempts to pyrolyze pure N,N‐dimethylglycine, which is the intermediate of dimethylglycine ethyl ester pyrolysis, was possible at only two temperatures, 300 and 310°C. The products are trimethylamine and CO2. Assuming log A = 13.0 for a five‐centered cyclic transition‐state type of mechanism in gas‐phase reactions, it gives the following expression: log k1(s?1) = (13.0) ? (176.6)kJ mol?1 (2.303 RT)?1. The mechanism of these α‐amino acids differs from the decarbonylation elimination of 2‐substituted halo, hydroxy, alkoxy, phenoxy, and acetoxy carboxylic acids in the gas phase. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33:465–471, 2001 相似文献