Structure Determination of Photoproducts of Anthracenes with (Arylmethoxymethyl) Sidechains

Dobis, Silvia; Schollmeyer, Dieter; Gao, Chunmei; Cao, Derong; Meier, Herbert

doi:10.1002/ejoc.200700140

Cited by 8 publications

(13 citation statements)

References 21 publications

(26 reference statements)

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“…Irradiation ( λ ≥300 nm) of 6 G 0 leads to the well‐known [4π+4π] cyclodimerization 15. In this case we found a highly regioselective head‐to‐tail process 16. 17 A monomolecular photoreaction could not be found, even at high dilution.…”

Section: Resultsmentioning

confidence: 70%

“…[15] In this case we found a highly regioselective head-to-tail process. [16,17] A monomolecular photoreaction could not be found, even at high dilution. The dendrimers 6 G i (i = 1-3) behave completely differently.…”

Section: Introductionmentioning

confidence: 87%

“…Bis(benzyloxy)-3-oxahexacyclo-A C H T U N G T R E N N U N G [7.6.6.25,8 .01,5 .010,15 .016,21 ]tricosa-6,10,12,14,16,18,20,22-octaene (7 G 0 ): Yield: quantitative, m.p. 70 8C (decomp); 1 H NMR (CDCl 3 ): d = 3.24 (m, 1 H; 8-H), 3.59/4.25 (AB, 2 J = À10.8 Hz, 4 H; g-CH 2 ), 3.90 (s, 2 H; b-CH 2 ), 4.28 (d, 3 J = 11.4 Hz, 1 H; 9-H), 4.48 (d, 4 J = 2.0 Hz, 2 H; 6-H, 23-H), 4.75 (s, 2 H; a-CH 2 ), 7.07-7.36 ppm (m, 18 H; aromat.…”

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Optical Switching and Antenna Effect of Dendrimers with an Anthracene Core

et al. 2007

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Dendrimers 6G(i) (i=1-4) consisting of an anthracene core and Fréchet dendrons which are attached via a CH(2)OCH(2) chain in the 9-position undergo quantitative and completely reversible intramolecular [4pi+4pi] cycloaddition. The process can be monitored by absorption and fluorescence measurements. The Fréchet dendrons act as an energy funnel that collects and focuses the photon energy but does not change the photostationary states, which for both directions are completely on the product side when the separate chromophores are selectively irradiated. The quantum yields of anthracene fluorescence and of singlet energy transfer from the dendrons to the core were studied as a function of dendrimer generation.

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confidence: 70%

Section: Introductionmentioning

confidence: 87%

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Optical Switching and Antenna Effect of Dendrimers with an Anthracene Core

et al. 2007

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“…The possible photoproducts of 3a-n are shown in Scheme 1. [4][5][6][7][8] Apart from the cyclomers 4, head-to-tail dimers 5 and head-to-head dimers 5¢ can be expected. 9,10 Compared to 5, the dimers 5¢ are highly thermolabile.…”

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“…3.0 mM only small amounts of 4b are formed and 5b is obtained in 82% isolated yield. 5 The preferred reaction route can even be altered in the case of 3e. The ratio 91:9 of 4/5 shown in Table 2 can be changed to 22:78 when the concentration of 3e is raised from 1.8 mM to 113.0 mM.…”

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Competition between Inter- and Intramolecular Photocycloaddition Reactions of 9-Substituted Anthracenes

Cao¹,

Gao²,

Dobis³

et al. 2007

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I n t r a -a n d I n t e r m o l e c u l a r P h o t o c y c l o a d d i t i o n o f 9 -S u b s t i t u t e d A n t h r a c e n e sAbstract: A number of 9-[(arylmethoxy)methyl]anthracenes were prepared and their photoreactivity was studied. The intramolecular [4p+4p]cycloaddition competes with the intermolecular head-totail [4p+4p] cyclodimerization. The aryl substituents control the selectivity; concentration only plays a role in selectivity in certain cases. The complete reversibility of the cycloaddition makes this process suitable as a molecular switch, provided that traces of acids are avoided; when acid is present the cyclomers pursue an irreversible enol ether cleavage route.Reversible photochemical reactions between compounds that have different absorption (and/or emission) are of great interest for optical switching and optical data storage processes. 1 Recently, we developed such a system, which is based on the intramolecular [4p+4p] cycloaddition of benzene and anthracene moieties. 2 A prerequisite condition for this reaction is that the two chromophores are linked by a three-atom chain, like CH 2 -O-CH 2 . Useful switching systems should have clean, uniform reactions in both directions. The [4p+4p] cyclodimerization is an alternative photoreaction of anthracenes and is an old and well-known process. 1e,3 Therefore, we have now studied the competition between the desired intramolecular [4p+4p] cycloaddition and possible intermolecular [4p+4p] cyclodimerizations. For this purpose, 9-[(arylmethoxy)methyl]anthracenes 3 were generated. Their preparation was based on the nucleophilic substitution of 1 and 2 (Williamson synthesis), whereby the role of nucleophile and electrophile can be exchanged (Table 1, Methods A and B). The best results were obtained by using phase-transfer conditions (KOH, TBAB).The possible photoproducts of 3a-n are shown in Scheme 1. 4-8 Apart from the cyclomers 4, head-to-tail dimers 5 and head-to-head dimers 5¢ can be expected. 9,10 Compared to 5, the dimers 5¢ are highly thermolabile. In the past such compounds were usually detected in solution by NMR measurements of the crude product mixture. Nevertheless, many head-to-head dimers 5¢ have been reported. 4,11,12 In the first approximation, the compounds 3a-n contain two separate chromophores. Therefore, selective irradiation (l ≥300 nm) into the anthracene chromophore is possible. This precondition is necessary in order to prevent the light-induced reverse reactions 4,5,5¢ → 3. Table 2 shows the product ratios 4/5 that were obtained in the irradiation experiments of 3a-h. The halogen-containing compounds 3i-k are highly light sensitive. However, their irradiation yields product mixtures in which dimers, but no cyclomers, can be detected by 1 H NMR and FD-MS measurements; 3k reacts even in daylight. Compound 3l was studied in another context. 7 For the compounds 3a and 3m, no cyclomers 4a and 4m were reported, but mixtures of dimers 5a/5¢a and 5m/5¢m, respectively, were found; 4 on irradiation compound 3n shows a quantitative intram...

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Fabrication of PEG‐anthracene/alginate double‐network hydrogels and their application in photolithography

Ma,

Song,

Yang

et al. 2023

J of Applied Polymer Sci

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The development of double‐network hydrogels provides a feasible strategy to improve the mechanical properties of pure organic hydrogels. We report a new type of dynamic double‐network hydrogels based on alginate and four‐armed PEG bearing anthracene at the terminal group. The ductile network is constructed through the photopolymerization of four‐armed PEG‐anthracene using the dimerization of terminal anthracene as the cross‐linking point, and alginate as the brittle network. The doping of alginate improves the precursor viscosity of solution and slows its fluidity. In particular, the inclusive metal cations endow the hydrogels with good conductivity. As the demonstration toward photolithography, the letter patterns and a parallel circuit are fabricated through the mask exposure method. By employing selective photo‐crosslinking, their shapes and patterns can be precisely controlled. Owing to the photo‐responsive features of the PEG‐anthracene network, the hydrogels also behave dynamically mechanical and shape‐memory properties via switching the irradiation wavelength. In addition, the water retention capacity can be improved by adding glycerol. This work demonstrates that anthracene is an effective photopolymerization unit in constructing dynamic double‐network hydrogels that show potential applications in smart soft materials.

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Structure Determination of Photoproducts of Anthracenes with (Arylmethoxymethyl) Sidechains

Cited by 8 publications

References 21 publications

Optical Switching and Antenna Effect of Dendrimers with an Anthracene Core

Optical Switching and Antenna Effect of Dendrimers with an Anthracene Core

Competition between Inter- and Intramolecular Photocycloaddition Reactions of 9-Substituted Anthracenes

Fabrication of PEG‐anthracene/alginate double‐network hydrogels and their application in photolithography

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