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Functional Corannulene: Diverse Structures,Enhanced Charge Transport,and Tunable Optoelectronic Properties 下载免费PDF全文
Chemical functionalization of various hydrocarbons, such as coronene, corannulene, and so forth, shows good promise in electronics applications because of their tunable optoelectronic properties. By using quantum chemical calculations, we have investigated the changes in the corannulene buckybowl structure, which greatly affect its electronic and optical properties when functionalized with different electron‐withdrawing imide groups. We find that the chemical nature and position of functional groups strongly regulate the stacking geometry, π‐stacking interactions, and electronic structure. Herein, a range of optoelectronic properties and structure–property relationships of various imide‐functionalized corannulenes are explored and rationalized in detail. In terms of carrier mobility, we find that the functionalization strongly affects the reorganization energy of corannulene, while the enhanced stacking improves hopping integrals, favoring the carrier mobility of crystals of pentafluorophenylcorannulene‐5‐monoimide. The study shows a host of emerging optoelectronic properties and enhancements in the charge‐transport characteristics of functionalized corannulene, which may find possible semiconductor and electronics applications. 相似文献
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A complex [Cu2Br2(L)2]n(1) (L=bis(2-pyrimidinylthio)methane) has been synthesized and structurally characterized. Complex 1 contains dinuclear Cu2Br2 units, which are linked by ditopic L to form a 2D layer structure with a 36-membered macrometallocycle. The adjacent layers are further connected through interpyrimidyl rings C-H…N and π-π interactions to give rise to a three-dimensional supramolecular structure. Complex 1 also displays strong green solid-state photoluminescence, due to metal-to-ligand charge-transfer (MLCT) at room temperature. CCDC: 711434. 相似文献
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Jakub Ostapko Dr. Krzysztof Nawara Michał Kijak Dr. Joanna Buczyńska Dr. Barbara Leśniewska Dr. Mariusz Pietrzak Grażyna Orzanowska Prof. Jacek Waluk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(48):17311-17320
Among seven possible nitrogen‐in constitutional isomers of porphyrin only one, porphycene, has been obtained so far in the free, unsubstituted form. Herein, the synthesis of another isomer, parent hemiporphycene ( HPc ), and its thorough structural, spectral, photophysical, electrochemical, and theoretical characterization are reported. Most of the properties of HPc are intermediate between those of porphyrin and porphycene, as evidenced by the values of inner‐cavity dimensions, orbital‐energy splittings, absorption coefficients, magnetic circular dichroism parameters, NH‐stretching frequencies, fluorescence quantum yields, tautomerization rates, and redox potentials. The largest differences arise with respect to tautomerism, due to the low symmetry of HPc and inequivalence of the four nitrogen atoms that define the inner cavity. Two trans tautomers are observed, separated in energy by about 1 kcal mol?1. Tautomerization from the higher‐ to the lower‐energy form is detected in the lowest‐excited singlet state and occurs at a rate that is about four orders of magnitude lower than that observed for porphycene. Hemiporphycene is a very good model for the investigation of inequivalent intramolecular H‐bonds present in one molecule; two such bonds in HPc reveal unusual characteristics, and the bond strength results from the interplay between the N ??? N distance and the N?H?N angle. 相似文献
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Dipl.‐Chem. Tobias F. Schneider Dipl.‐Chem. Johannes Kaschel Shahid I. Awan Dr. Birger Dittrich Dr. Daniel B. Werz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(37):11276-11288
The synthesis of oligocyclic oligoacetals using five‐membered rings as repetitive unit is described. Furan was used as the starting material, which is converted by a three‐step procedure consisting of twofold cyclopropanation, reduction, and oxidative ring enlargement into a tricyclic bis(enol ether). A repetition of this synthetic procedure leads to the formation of extended oligoacetal systems. Insights into the structures were gained by X‐ray crystallographic investigations and revealed helical arrangements of the subunits in the solid‐state. DFT (B3LYP) calculations have been carried out to elucidate the transition state of the ring enlargement and the flexibility of the annelated oligocyclic systems. Strain energies and topologies of potential cyclically condensed oligoacetals are predicted. 相似文献
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Shuhei Akahori Prof. Dr. Takahiro Sasamori Prof. Dr. Hiroshi Shinokubo Prof. Dr. Yoshihiro Miyake 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(31):8178-8184
Quadruply BN-fused tetrathia[8]circulenes were synthesized through four-fold electrophilic borylation. The single-crystal X-ray diffraction analysis revealed that the BN-fused tetrathia[8]circulene with peripheral phenyl groups exhibits crystal polymorphism, in which the circulene core adopts both planar and saddle conformations in the solid state. The experimental and theoretical studies revealed that the weaker aromaticity of azaborine compared with benzene renders the flexibility of the BN-fused tetrathia[8]circulenes. 相似文献
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Two europium trifluoroacetate complexes, Eu(CF3COO)3·phen ( 1 ) and Eu(CF3COO)3·bpy ( 2 ) (where phen=1,10‐phenanthroline, bpy=2,2′‐bipyridine), were synthesized and characterized by elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), photoluminescence (PL) spectroscopy and thermogravimetric analysis (TA). Single‐crystal X‐ray structure has been determined for the complex [Eu2(CF3COO)6·(phen)3·(H2O)2]·EtOH. The crystal structure of [Eu2(CF3COO)6·(phen)3·(H2O)2]·EtOH shows that two different coordination styles with europium ions coexist in the same crystal and have entirely different coordination geometries and numbers. This crystal can be considered as an 1:1 adduct of [Eu(CF3COO)3·(Phen)2·H2O]·EtOH (9‐coordination part) and Eu(CF3COO)3·phen·H2O (8‐coordination part). The excitation spectra of the two complexes demonstrate that the energy collected by "antenna ligands" is transferred to Eu3+ ions efficiently. The room‐temperature PL spectra of the complexes are composed of the typical Eu3+ ions red emission, due to transitions between 5D0→7FJ(J=0→4). The lifetimes of 5D0 of Eu3+ in the complexes were examined using time‐resolved spectroscopic analysis, and the lifetime values of Eu(CF3COO)3·phen and Eu(CF3COO)3·bpy were fitting with bi‐exponential (2987 and 353 µs) and monoexponential (3191 µs) curves, respectively. In order to elucidate the energy transfer process of the europium complexes, the energy levels of the relevant electronic states had been estimated. The thermal analyses indicate that they are all quite stable to heat. 相似文献
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Anupam Bhim Prof. Jean-Pascal Sutter Prof. Jagannatha Gopalakrishnan Prof. Srinivasan Natarajan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(6):1995-2008
The stuffed tridymite structure Ba(Zn/Co)1−xSi1−xM2xO4 (M=Al3+ and Fe3+) is explored for the possible multiferroic behavior and to develop new inorganic colored materials. The compounds were synthesized by employing conventional solid-state chemistry methods in the temperature range 1100–1175 °C for 24 h. The powder X-ray diffraction (PXRD) and Rietveld refinement studies indicate that the compounds stabilize in the P63 space group (no. 173). The refinement results were also rationalized by employing Raman spectroscopic studies. The compounds were found to be second harmonic generation (SHG) active and show weak ferroelectric behavior. The co-substitution of Co2+ and Fe3+ in the structure gives rise to a weak ferromagnetic behavior to the compound, BaCo0.75Si0.75Fe0.5O4, making it a multiferroic material. The optical studies on the prepared compounds exhibited blue color (Co2+ in Td geometry), purple color (Ni2+ in Td geometry), and simultaneous substitution of Co2+ and Fe3+ gives rise to blue-green color owing to metal-to-metal charge transfer (MMCT) effect. 相似文献
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Dr. Jinchong Xiao Shuwei Liu Yi Liu Li Ji Prof. Xuewei Liu Prof. Hua Zhang Prof. Xiaowei Sun Prof. Qichun Zhang 《化学:亚洲杂志》2012,7(3):561-564
A novel compound, 5,7,14,16‐tetraphenyl‐8:9,12:13‐bisbenzo‐hexatwistacene ( TBH ), has been successfully synthesized through a retro‐Diels–Alder reaction. Single‐crystal structure analysis indicated that TBH has a twisted configuration with a torsion angle of 27.34°. The HOMO–LUMO gap of TBH calculated from the difference between the half‐wave redox potentials (E1/2ox=+0.40 eV and E1/2red=?1.78 eV) is 2.18 eV, which is in good agreement with the band gap (2.19 eV) derived from the UV/Vis absorption data. In addition, organic light‐emitting devices using TBH as emitter have been fabricated. The results revealed that TBH is a promising red light‐emitting candidate for applications in organic light‐emitting diodes. 相似文献
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Harald Brand Peter Mayer Dr. Axel Schulz Prof. Dr. Thomas Soller Alexander Villinger 《化学:亚洲杂志》2008,3(6):1050-1058
In a new synthetic approach phenylcyanamide (Hpca) was synthesized by methylation of phenylthiourea followed by a basic work‐up. All products along the synthetic route have been fully characterized by means of NMR, IR, and X‐ray studies. The first structural report of neutral mixed crystals of phenylcyanamide containing monomeric and trimeric Hpca is presented. Examination of these intriguing mixed crystals revealed the formation of distinct layers of monomeric and trimeric Hpca. These layers are interconnected by weak hydrogen bonds. The trimer represents triphenylisomelamine, which readily isomerizes to the triphenylmelamine in the melt, in accord with computations at the B3LYP level, indicating an exothermic process (ΔH=?49.4 kcal mol?1). Pure trimeric Hpca (triphenylisomelamine) was obtained either by recrystallization of the mixed crystals from boiling water or by trimerization of monomeric Hpca in isopropanol for 12 h under reflux conditions. For comparison tritylcyanamide (Htca) and potassium phenylcyanamide as an [18]crown‐6 complex [K([18]crown‐6)pca] have been synthesized, and the solid‐state structures were determined using X‐ray diffraction techniques. The thermal behavior was studied by thermo‐analytical experiments. In agreement with the experimental results, computations predict an exothermic cyclotrimerization process for Hpca (ΔH=?41.3 kcal mol?1). 相似文献
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Dr. Ulrich Mayerhöffer Marcel Gsänger Dr. Matthias Stolte Benjamin Fimmel Prof. Dr. Frank Würthner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(1):218-232
A broad series of more than 20 acceptor‐substituted squaraines was synthesized that feature different acceptor functionalities at the central squaraine four‐membered ring. The influence of these acceptor units on the reactivity of semisquaraine precursors and stability of the respective squaraines were explored. Thereby the dicyanovinyl group was found to be the most versatile acceptor group that enabled various modifications at the donor moiety of the squaraine scaffold, leading to an extended series of dicyanovinyl‐functionalized squaraines. The variation of donor units afforded a set of NIR fluorophores that cover a wavelength region from the visible at about 650 nm far into the NIR up to 920 nm with fluorescence quantum yields between 0.93 and 0.11 and outstanding optical brightness. This excellent optical property is related to a rigid molecular scaffold that is fixed in an all‐cis configuration by the additional dicyanovinyl acceptor unit. The change of the molecular symmetry from C2h to C2v upon functionalization of the squaraine core with dicyanovinyl acceptor group has been confirmed in solution by electro‐optical absorption (EOA) spectroscopy, revealing permanent ground‐state dipole moments μg in the range between 4.3 and 6.4 D. These dipole moments direct an antiparallel packing of the molecules in the solid state according to single‐crystal X‐ray analyses achieved for four dicyanovinyl‐functionalized squaraines. The structural properties, the EOA results, as well as the band shapes of the optical spectra indicate that these polymethine dyes are cyanine‐type chromophores. It is worth noting that the orientation of the dipole moment vectors is orthogonal to the orientation of the transition dipole moment vectors, which is an uncommon but characteristic feature of this rather novel class of polymethine dyes. With regard to applications of these dyes in organic solar cells, their redox properties were also studied by cyclic voltammetry. 相似文献
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共轭CN与非共轭CF3吸电子取代基对PPV类衍生物分子结构及光电性质的影响 总被引:1,自引:0,他引:1
运用密度泛函DFT B3LYP/6-31G(d)方法对CN和CF3吸电子基团取代的PPV类衍生物的三聚体进行了几何构型优化,并采用含时密度泛函TD-DFT、B3LYP/6-31G(d)方法计算了其相应化合物的紫外吸收光谱.通过对CN和CF3取代的PPV类衍生物的分子几何结构、前线分子轨道能级、电子云分布规律的分析,从理论上解释了共轭CN与非共轭CF3吸电子取代基对其光谱性质影响的差异:前者使相应PPV类衍生物的吸收光谱发生红移,后者则发生蓝移.计算结果还表明用TD-DFT方法计算该体系的紫外吸收光谱值与实验数据吻合得很好;另外引入CN和CF3基团之后,使其相应的PPV衍生物的LUMO能级降低,电子亲合势增加,都是很好的电子传输材料. 相似文献
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Tuning the Electronic Nature of Mono‐Bay Alkynyl–Phenyl‐Substituted Perylene Bisimides: Synthesis,Structure, and Photophysical Properties 下载免费PDF全文
Ruchika Mishra Dr. Jong Min Lim Minjung Son Piyush Panini Prof. Dr. Dongho Kim Prof. Dr. Jeyaraman Sankar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(19):5776-5786
Perylene bisimide (PBI) derivatives with various alkynyl–phenyl substituents at a single bay position have been synthesised by Sonogashira coupling. NMR spectroscopic studies reveal the unsymmetric nature of the dyads. All of the dyads undergo two reversible reductions, which demonstrates their structural and electrochemical rigidity. The synthesised dyads show a remarkable redshift in their absorption maxima and sharp vibronic progression. Electron‐rich substituents facilitate efficient charge transfer from the substituent HOMO to the electron‐deficient PBI core. The most interesting spectral signatures were exhibited by a PBI with a strongly electron‐donating ethynyl(dimethylaminophenyl) substituent. The steady‐state features of this PBI showed a broad absorption that covered almost the whole visible region with no emission. A twisted intramolecular charge‐transfer (TICT) process, related to the rotational motion of ethynyl(dimethylaminophenyl) PBI, was also demonstrated. Computational investigations shed light on the coplanarity of the various substituents with respect to the PBI core; the PBI core itself remains flat without any noticeable deformation even after mono‐functionalisation. This illustrates that mono‐functionalisation exerts meagre steric hindrance on the bay positions relative to disubstituted analogues. Despite several previous reports on the structural characterisation of 1,7‐disubstituted PBI derivatives, we present the first structural characterisation of a mono‐bay ethynyl‐phenyl substituted PBI. The solid‐state structure of the phenyl derivative has a flat PBI core without any noticeable steric constraints from the substituents, as predicted. In contrast, single‐crystal X‐ray analysis for the mono‐bromo bay‐substituted PBI shows that the bromine substituent is not in the plane of the PBI core. 相似文献
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Dr. Joydeb Goura Dr. Bassem S. Bassil Xiang Ma Ananthu Rajan Dr. Eufemio Moreno-Pineda Prof. Jürgen Schnack Dr. Masooma Ibrahim Prof. Annie K. Powell Prof. Mario Ruben Jingjing Wang Prof. Laurent Ruhlmann Prof. Ulrich Kortz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(61):15081-15085
The 36-NiII-containing 54-tungsto-6-silicate, [Ni36(OH)18(H2O)36(SiW9O34)6]6− ( Ni36 ) was synthesized by a simple one-pot reaction of the Ni2-pivalate complex [Ni2(μ-OH2)(O2CCMe3)4(HO2CCMe3)4] with the trilacunary [SiW9O34]10− polyanion precursor in water and structurally characterized by a multitude of physicochemical techniques including single-crystal XRD, FTIR, TGA, elemental analysis, magnetic and electrochemical studies. Polyanion Ni36 comprises six equivalent {NiII6SiW9} units which are linked by Ni−O−W bridges forming a macrocyclic assembly. Magnetic studies demonstrate that the {Ni6} building blocks in Ni36 remain magnetically intact while forming a hexagonal ring with antiferromagnetic exchange interactions between adjacent {Ni6} units. Electrochemical studies indicate that the first reduction is reversible and associated with the WVI/V couple, whereas the second reduction is irreversible attributed to the NiII/0 couple. 相似文献
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Christopher Schwarz Dr. Thorsten Scherpf Ilja Rodstein Dr. Julia Weismann Dr. Kai-Stephan Feichtner Prof. Dr. Viktoria H. Gessner 《ChemistryOpen》2019,8(5):621-626
The α-metallated ylides [Ph3P−C−Z]−M+ (with Z=SO2Tol or CN and M=Na or K) were used as versatile nucleophiles for the facile access to ylide-substituted compounds. Halogenations, alkylations, carbonylations and functionalization reactions with main group element halides were easily accomplished by simple trapping reactions with the appropriate electrophiles. X-ray crystallographic studies of all compounds – including the first structures of α-fluorinated P-ylides – showed remarkable differences in the ylide backbone depending on the substituents. In the fluorinated compounds, a change from a fully planar to a pyramidalized ylidic carbon centre was observed despite the strongly anion-stabilizing ability of the yldiide substituent. π-Donation from the ylide substituent also resulted in geometric restrictions depending on the steric and electronic properties of the introduced substituents. 相似文献
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G. M. Kuzmicheva V. N. Kokunova A. V. Mitin I. E. Kostyleva E. P. Khlybov A. S. Andreenko 《Journal of Structural Chemistry》2004,45(2):231-252
This paper reports on synthesis and X-ray diffraction study of two groups of phases obtained from batch mixtures: (La,Sr
k+1(Ru,Cu)
k
O3k+1 and (La,Sr)3(Ru,Cu)3O6+ (group I); RuSr2LnCu2O8– (Ln = Nd for the first time, Sm, Eu, Gd, (Gd,Y) for the first time), RuSr2(Ln,Ce4+)2Cu2O10– (Ln = Pr and Nd for the first time, Sm, Eu, Gd, (Gd,Y) for the first time), and (Ru,Cu)Sr2(Ln,Ce4+)2Cu2O10– (Ln = Tb and Y for the first time) (group II). In group I, phases with K2NiF4, Sr3Ti2O7, and cubic perovskite type structures are typically formed; in group II, these are respectively (Ru,Cu)(Sr,Ln)2(Ln,Sr)Cu2O8– (1212 type), (Ru,Cu)(Sr,Ln)2(Ln,Ce4+)2Cu2O10– (1222 type), and cubic perovskite type structures (the content of the latter depends on the type of Ln). Variation of the formal charge (f.c.) of Ru (group I) and Cu (group II) was evaluated in relation to the cation composition of the phases (groups I and II) and the content of superstoichiometric oxygen (group II). Phases of 1222 type with Ln = Nd, Sm, Eu, Gd, and (Gd,Y) and phases of 1212 type with Ln = Gd exhibited superconducting properties with T
c max 40 K. 相似文献
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Arvind Chaudhary Dr. Sankar Prasad Rath 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(24):7404-7417
The encapsulation of tetracyanoquinodimethane (TCNQ) and fluorescent probe acridinium ions (AcH+) by diethylpyrrole‐bridged bisporphyrin (H4DEP) was used to investigate the structural and spectroscopic changes within the bisporphyrin cavity upon substrate binding. X‐ray diffraction studies of the bisporphyrin host (H4DEP) and the encapsulated host–guest complexes (H4DEP ? TCNQ and [H4DEP ? AcH]ClO4) are reported. Negative and positive shifts of the reduction and oxidation potentials, respectively, indicated that it was difficult to reduce/oxidize the encapsulated complexes. The emission intensities of bisporphyrin, upon excitation at 560 nm, were quenched by about 65 % and 95 % in H4DEP ? TCNQ and [H4DEP ? AcH]ClO4, respectively, owing to photoinduced electron transfer from the excited state of the bisporphyrin to TCNQ/AcH+; this result was also supported by DFT calculations. Moreover, the fluorescence intensity of encapsulated AcH+ (excited at 340 nm) was also remarkably quenched compared to the free ions, owing to photoinduced singlet‐to‐singlet energy transfer from AcH+ to bisporphyrin. Thus, AcH+ acted as both an acceptor and a donor, depending on which part of the chromophore was excited in the host–guest complex. The electrochemically evaluated HOMO–LUMO gap was 0.71 and 1.42 eV in H4DEP ? TCNQ and [H4DEP ? AcH]ClO4, respectively, whilst the gap was 2.12 eV in H4DEP. The extremely low HOMO–LUMO gap in H4DEP ? TCNQ led to facile electron transfer from the host to the guest, which was manifested in the lowering of the CN stretching frequency (in the solid state) in the IR spectra, a strong radical signal in the EPR spectra at 77 K, and also the presence of low‐energy bands in the UV/Vis spectra (in the solution phase). Such an efficient transfer was only possible when the donor and acceptor moieties were in close proximity to one another. 相似文献