9,10‐Diaminoanthracenes Revisited: The Influence of N‐Substituents on Their Electronic States

The electronic and molecular structures of 9,10‐diamino‐substituted anthracenes with different N‐substituents have been re‐examined. In particular, different N‐substituents influence both the electronic and molecular structures of the oxidized species of 9,10‐diaminoanthracenes. The anthrylene moiety of 9,10‐bis(N,N‐di(p‐anisyl)amino)anthracene retains its planarity during the course of two successive one‐electron oxidations, whereas 9,10‐bis(N,N‐dimethylamino)anthracene and 9,10‐bis(N‐p‐anisyl‐N‐methylamino)anthracene undergo a substantial structural change to a butterfly‐like structure through a two‐electron oxidation process. The structural changes observed for the oxidized states are ascribed to significant differences in the frontier molecular orbitals of the above‐mentioned three kinds of 9,10‐diaminoanthracenes due to different extents of mixing between the amine‐localized and anthrylene‐localized orbitals.     

Synthesis of a Pentacene‐Type Silaborin via Double Dehydrogenative Cyclization of 1,4‐Diboryl‐2,5‐disilylbenzene

A new pentacene‐type silaborin, in which three benzene rings are bridged by silicon and boron atoms, has been synthesized and characterized by using NMR spectroscopy and X‐ray crystallographic analysis. The precursor, 1,4‐bis(dimesitylboryl)‐2,5‐bis(phenylsilyl)benzene ( 4 ), was prepared by stepwise introduction of a silyl group and a boryl group to a benzene ring starting from 1,4‐dibromobenzene. Double cyclization of 4 proceeds by a H‐Mes exchange and a B‐H/C‐H dehydrogenative condensation to afford pentacene‐type silaborin 5 . X‐ray crystal structure analysis reveals that 5 adopts a bent structure rather than a planar one. UV/Vis spectra and DFT calculations for 5 reveal a lowering of the LUMO energy level compared with corresponding anthracene‐type 3 .     

Polyaromatic Profluorescent Nitroxide Probes with Enhanced Photostability

Novel profluorescent mono‐ and bis‐isoindoline nitroxides linked to napthalimide and perylene diimide structural cores are described. These nitroxide‐fluorophore probes display strongly suppressed fluorescence in comparison to their corresponding non‐radical diamagnetic methoxyamine derivatives. The perylene‐based probe possessing two isoindoline systems tethered through ethynyl linkages was shown to be the most photostable in solution, demonstrating significantly enhanced longevity over the 9,10‐bis(phenylethynyl)anthracene fluorophore used in previous profluorescent nitroxide probes.     

Reactions of polystyryllithiums and model lithium carbanions with 9,10‐bis(halomethyl)anthracenes

The direct and nearly quantitative incorporation of 9,10‐anthracenylidene (AN) chromophores into polystyrene occurred via the reaction of polystyryllithium (PSLi) with 9,10‐bis(chloromethyl)anthracene (BCMA) at ?78 °C in tetrahydrofuran (THF)/ hexane containing between 30 and 40 vol % hexane. Although the reaction of PSLi and BCMA or 9,10‐bis(bromomethyl)anthracene (BBMA) in THF at ?78 °C gave nearly quantitative coupling, typically only 30–50% AN incorporation was observed, as determined by ultraviolet–visible spectrometry. Model coupling reactions of 3,3‐dimethyl‐1,1‐diphenyl‐1‐lithiobutane, (1,1,2,2‐tetramethyl)propylcyclopentadienyllithium, 9‐methylfluorenyllithium, and triphenylmethyllithium with BCMA or BBMA at ?78 °C in THF in nearly all cases gave several AN‐containing coupling products. This was consistent with lithium–halogen exchange leading to the linking of multiple AN groups. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3121–3129, 2001     

Novel conjugated polymer containing anthracene backbone: Addition polymer of 9, 10-diethynylanthracene with 9, 10-anthracenedithiol and its properties

9,10-Diethynylanthracene was prepared by the alkaline hydrolysis of 9,10-bis (trimethylsilylethynyl) anthracene. Another new monomer of 9, 10-anthracenedithiol was prepared by the reduction of anthracene polydisulfide. A crystalline conjugated polymer of 9,10-diethynylanthracene with 9,10-anthracenedithiol was synthesized in a THF solution at 50°C by UV irradiation or by using radical initiators. The molecular weight (M?_n) of the insoluble polymer in THF is about 20000–30000 and the soluble is about 4000. From the sulfur content and IR spectrum of the insoluble polymer, it is realized that the obtained polymer has the alternating structure consisting of 9,10-diethynylanthracene and 9,10-anthracenedithiol units. X-ray pattern indicated that the polymer has a layer structure. The conductivity of the undoped polymer was about 10^?11S/cm, but enhanced up to 10^?6 S/cm by doping with iodine. The enhancement of the conductivity seems to be the existence of the CT complex among the polymer backbone and iodine or iodine anion.     

新型有机硒化合物的合成及其离子识别研究

设计合成了四个含有氢蒽基团的新型有机硒化合物1,8-二-(2-苄硒基)丙氧基-9,10-二氢蒽(L_1)、1,8-氧双(亚乙硒基丙氧基)-9,10-二氢蒽(L_2)、1,8-二-(2-苄硒基)乙氧基-9,10-二氢蒽(L_3)、1,8-氧双(亚乙硒基亚乙氧基)-9,10-二氢蒽(L_4),利用~1H NMR、~(13)C NMR对化合物进行了结构表征,采用荧光光谱法测定了主体对客体阳离子的识别性能。研究结果发现只有化合物L_1对Ag~+具有选择识别能力,且对Ag~+表现出"off-on"开关性能。化合物L_2与Ag~+和K~+络合后荧光略有增强。     

Solvent Influence on the Diels‐Alder Reaction Rates of 9‐(Hydroxymethyl)anthracene and 9,10‐Bis(hydroxymethyl)anthracene with Two Maleimides

The rates of the Diels–Alder reaction of 9‐(hydroxymethyl)anthracene and 9,10‐bis(hydroxymethyl)anthracene with maleic anhydride and two maleimides, N‐ethyl‐ and N‐phenylmaleimide, have been studied at various temperatures and pressures in different solvent media. A rate acceleration in water in comparison with organic solvents is observed. Thermodynamic functions of activation for the reaction of 9,10‐bis(hydroxymethyl)anthracene with N‐ethylmaleimide in binary 1,4‐dioxane–water mixtures are determined. From the observed tendencies, it can be concluded that acceleration of the Diels–Alder reactions in water is linked with an energetically favorable dehydration of the reaction centers of the reactants on the way to the activated complex. Addition of an organic cosolvent makes the desolvation of these centers less favorable.     

The Radical Anion and Dianion of Tetraazapentacene

The mono‐ and bis‐reduction of 6,13‐bis((triisopropylsilyl)ethynyl)quinoxalino[2,3‐b]phenazine ( 1 ) with potassium anthracenide in THF is reported. Both the radical anion 1 ^.? and the dianion 1 ^2? were isolated and characterized by optical and structural (single‐crystal X‐ray diffraction) methods. Solutions of the radical anion 1 ^{. ?} were stable in air for several hours and characterized by EPR spectroscopy. Dianion 1 ^2? is highly fluorescent and photostable.     

High Tg,ambipolar, and near‐infrared electrochromic anthraquinone‐based aramids with intervalence charge‐transfer behavior

Two novel series of ambipolar and near‐infrared electrochromic aromatic polyamides with electroactive anthraquinone group were synthesized from new aromatic diamines, 2‐(bis(4‐aminophenyl)amino)anthracene‐9,10‐dione and 2‐(4‐(bis(4‐aminophenyl)amino)phenoxy)anthracene‐9,10‐dione, respectively, via low‐temperature solution polycondensation reaction. These polymers were readily soluble in many polar solvents and showed useful levels of thermal stability associated with high glass‐transition temperatures (T_g) (285–360 °C). Electrochemical studies of these electrochromic polyamides revealed ambipolar behavior with reversible redox couples and high contrast ratio both in the visible range and near‐infrared region. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Homoleptic 2,2′‐bipyridine metalates(–I) of iron and cobalt,one cocrystallized with an anthracene radical anion and the other with neutral anthracene

Homoleptic 2,2′‐bipyridine (bipy) metalates of iron and cobalt have been synthesized directly from the corresponding homoleptic anthracene metalates. In the iron structure, bis[([2.2.2]cryptand)potassium(I)] tris(2,2′‐bipyridine)ferrate(–I) anthracene(–I), [K(C₁₈H₃₆N₂O₆)]₂[Fe(C₁₀H₈N₂)₃](C₁₄H₁₀), the asymmetric unit contains one potassium complex cation in a general position, the Fe center and one and a half bipy ligands of the ferrate complex on a crystallographic twofold axis that includes the Fe atom, and one half of an anthracene radical anion whose other half is generated by a crystallographic inversion center. The cations and anions are well separated and the geometry about the Fe center is essentially octahedral. In the cobalt structure, ([2.2.2]cryptand)potassium(I) bis(2,2′‐bipyridine)cobaltate(–I) anthracene hemisolvate tetrahydrofuran (THF) disolvate, [K(C₁₈H₃₆N₂O₆)][Co(C₁₀H₈N₂)₂]·0.5C₁₄H₁₀·2C₄H₈O, the asymmetric unit contains the cation, anion, and both cocrystallized THF solvent molecules in general positions, and one half of a cocrystallized anthracene molecule whose other half is generated by a crystallographic inversion center. The cation and anion are well separated and the ligand planes in the cobaltate anion are periplanar. Each anthracene molecule is midway between and is oriented perpendicular to a pair of symmetry‐related bipy ligands such that aromatic donor–acceptor interactions may play a role in the packing arrangement. The lengths of the bonds that connect the bipy rings support the assertion that the ligands are bipy radical anions in the iron structure. However, in the case of cobalt, these lengths are between the known ranges for a bipy radical anion and a bipy dianion, and therefore no conclusion can be made from the crystallography alone. One cocrystallized THF solvent molecule in the cobalt structure was modeled as disordered over three positions with appropriate geometric and thermal restraints, which resulted in a refined component mass ratio of 0.412 (4):0.387 (3):0.201 (3).     

Synthesis and Crystal Structure of a Dinuclear Silver(I) Metallocyclophane with N‐Heterocyclic Carbene Linkage

Reaction of the carbene precursor 9,10‐bis(N‐ethylimidazoliummethyl)anthracene hexafluorophosphate ( 1 ) and Ag₂O yielded the dinuclear metallocyclophane ( 2 ) in high yield. The structures of 1 and 2 were determined by X‐ray crystallography.     

Synthesis,Spectroscopic Properties and Crystal Structure of 3,3＇-（Anthracene-9,10-diyl）bis（1-phenylpropan-1-one）

The compound 3,3'-(anthracene-9,10-diyl)bis(1-phenylpropan-1-one)(C32H26O2,Mr=442.55) has been synthesized by the reaction of 2,2'-(anthracene-9,10-diylbis(methy-lene))bis(1,3-diphenylpropane-1,3-dione) with CsCO3,and its structure was characterized by 1H NMR and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic,space group P21/c with a=9.154(3),b=5.2777(16),c=24.897(7) nm,β=107.337(10)°,Z=2 and V=1.1482 nm3.X-ray analysis indicates that an intermolecular hydrogen bond C(8)-H(8A)…O(1),weak C-H···π between H(9A) and the centre of anthracene rings and weak π-π interactions between two anthracene ring planes are observed.     

Steric effects in the electroreduction of 9-anthryl styryl ketone and 9,10-anthryl bis(styryl ketone)

The electrochemical behavior of 9-anthryl styryl ketone (ASK) and 9,10-anthryl bis(styryl ketone) (ABSK) in acetonitrile and N,N-dimethylformamide at a Pt electrode was investigated by cyclic and rotating ring disk electrode (RRDE) voltammetry and controlled potential coulometry. ASK is reduced in a reversible one-electron step to form the radical anion which rapidly couples (k₂=10⁵M^?1 s^?1) to form the dimeric dianion. The dimer can be reoxidized to form ASK. ABSK is reversibly reduced to the stable dianion which shows no tendency to couple. The cyclic voltammogram wave shape suggests that the styryl-keto groups in the 9-and 10-positions are non-interacting so that the reduction occurs in two steps whose standard potentials differ by the statistically predicted 36 mV.     

Synthesis and thermal and spectroscopic properties of macrocyclic vinyl aromatic polymers

Well‐defined and narrow molecular weight distribution macrocyclic poly(2‐vinylnaphthalene) (P2VN) and poly(2‐vinyl‐9,9‐dimethylfluorene) (PDMVF) containing a single 1,4‐benzylidene or 9,10‐anthracenylidene unit have been synthesized via the potassium naphthalide initiated polymerization of the monomers followed by the end‐to‐end coupling of the resulting P2VN dianions under high‐dilution conditions with 1,4‐bis(bromomethyl)benzene or 9,10‐bis(chloromethyl)anthracene. Molecular characterization has been carried out by size exclusion chromatography, nuclear magnetic resonance, differential scanning calorimetry, ultraviolet–visible spectroscopy, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. The thermal properties show distinct differences between the cyclic and matching linear polymers, with the macrocycles showing much higher glass‐transition and decomposition temperatures. The absorption bands are both hyperchromic and hypochromic with respect to the model aromatic compounds, and this is consistent with intensity borrowing. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5488–5503, 2004     

付氏反应中自由基的鉴定及其生成机理

本文通过一系列卤代烃与苯的付氏反应的ESR谱,研究了自由基物种的生成机理:它们起因于Lewis酸对由Scholl反应所生成的9,10-二取代蒽进行单电子氧化,并建立了一种生成9,10-二取代蒽自由基正离子的简单方法。首次报道了一个新自由基正离子1,2,3,4,5,6,7,8-八氘蒽的ESR谱。     

STUDIES ON SOME INTERMEDIATES AND PRODUCTS OF THE PHOTOREDUCTION OF 9,10-ANTHRAQUINONE *,†

Abstract— The mechanism of the photoreduction of 9,10-anthraquinone (AQ) in alcohol and hexane has been studied by flash photolysis. The fluorescence spectrum of the photoproduct, 9,10-dihydroxy anthracene shows a large shift between hexane and ethanol. The quantum yields of photoreduction for AQ are solvent-dependent, the reaction between the solvent radical and AQ determining the quantum yield.
The absorption spectrum of the 9,10-anthrasemiquinone (AQH.) has a long-wavelength absorption band with peaks at 631 and 678 nm. The second-order decay constants for AQH. were estimated to be 1.3 × 10⁹, 6.7 × 10⁸ and 2.0 × 10⁸ M ^-1 sec^-1 in ethanol, 2-propanol and ethylene glycol, respectively.
A long-wavelength absorption band was observed for 9,10-anthrasemiquinone radical anion, having peaks at 776 and 860 nm; epsi;_max= 1900 at 776 nm. This spectrum is compared with the spectra of 9,10-dihydroxy anthracene mono- and di-anions. The 9,10-anthrasemiquinone radical anion was found to photoreduce quantitatively to 9,10-dihydroxy anthracene mono-anion with a quantum yield of 0.1.     

Supramolecular template‐directed synthesis of stable and high‐efficiency photoluminescence 9,10‐diphenylanthryl‐bridged ladder polysiloxane

A soluble well‐defined 9,10‐diphenylanthryl‐bridged ladder polysiloxane ( DPAnLP ) was prepared via supramolecular assembly‐directed condensation polymerization of silanols. The ladder superstructure ( LS ) was obtained via a synergistic interaction of H‐bonding and π–π stacking between polymerizable precursor 2‐tert‐butyl‐9,10‐bis(methyldihydroxylsilyl)anthracene in organic solvent. The resultant LS was then used as template to direct the condensation of silanol groups to obtain DPAnLP with high regularity. It was found that DPAnLP can emit blue light (430 nm) with great stability and high efficiency in both solution and solid film, which indicated a well organizing of fluorophore within confined environment (ladder structure). TGA and DSC measurements showed that DPAnLP had good thermal stability, and cyclic voltammetry detection gave a low‐lying highest occupied molecular orbital level. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2491–2497, 2010     

Catalytic activities of NHC‐PdCl2 species based on functionalized tetradentate imidazolium salt in three types of C‐C coupling reactions

A functionalized tetradentate imidazolium salt 9,10‐bis{di[2′‐(N‐ethylimidazolium‐1‐yl)ethyl]aminomethyl}anthracene tetrakis(hexafluorophosphate) ( 1 ) has been synthesized and characterized. The catalytic activity of the NHC‐PdCl₂ species formed by compound 1 and PdCl₂ was tested in Suzuki‐Miyaura, Heck‐Mizoroki and Sonogashira reactions. The results showed that this catalytic system was effective for above three types of C‐C coupling reactions.     

Highly Conducting and Flexible Radical Crystals

Together with high conductivity, high flexibility is an important property required for next generation organic electronic components. Both properties are difficult to achieve together especially when the components are crystalline because of the intrinsic high brittleness of organic molecular crystals. We report an organic radical crystal system that has both high flexibility and high conductivity. The crystal consists of 9,10‐bis(phenylethynyl)anthracene radical cation ( BPEA^.+ ) units, and shows flexibility under pressure with high conductivity in ambient condition exhibiting average conductivity of 2.68 S cm^?1 when normal linear shape, as well as 2.43 S cm^?1 when bent. The structural analysis reveals that both a short π–π distance (3.290 Å) between BPEA^.+ units that are aligned along the crystal length direction, and the presence of PF₆^? counter ions induce flexibility and high electrical conductivity.     

Solvatochromism,Reversible Chromism and Self‐Assembly Effects of Heteroatom‐Assisted Aggregation‐Induced Enhanced Emission (AIEE) Compounds

Two compounds, 9,10‐bis[2‐(quinolyl)vinyl]anthracene (BQVA) and 9,10‐bis[2‐(naphthalen‐2‐yl)vinyl]anthracene (BNVA), have been synthesised and investigated. Both of them have aggregation‐induced enhanced emission (AIEE) properties. Heteroatom‐assisted BQVA shows solvatochromism, reversible chromism properties and self‐assembly effects. When increasing the solvent polarities, the green solution of BQVA turns to orange with a redshift of the fluorescence emission wavelengths from λ=527 to 565 nm. Notably, BQVA exhibits reversible chromism properties, including mechano‐ and thermochromism. The as‐prepared BQVA powders show green fluorescence (λ_em=525 nm) and the colour can turn into orange (λ_em=573 nm) after grinding. Interestingly, the orange colour can return at high temperature. Based on these reversible chromism properties, a simple and convenient erasable board has been designed. Different from BQVA, non‐heteroatom‐assisted BNVA has no clear chromic processes. The results obtained from XRD, differential scanning calorimetry, single‐crystal analysis and theoretical calculations indicate that the chromic processes depend on the heteroatoms in BQVA. Additionally, BQVA also exhibits excellent self‐assembly effects in different solvents. Homogeneous nanospheres are formed in mixtures of tetrahydrofuran and water, which are then doped into silica nanoparticles and treated with 3‐aminopropyltriethoxysilane to give amino‐functionalised nanoparticles (BQVA?AFNPs). The BQVA?AFNPs could be used to stain protein markers in polyacrylamide gel electrophoresis.