Aminomethyl-pyrene

Then, we synthesized AB6 dendron 31 with six molecules of aminomethyl-pyrene as reporter units and the f-butyloxycarbonyl (Boc) protecting group as a trigger (Fig. 5.23). The dendron was designed to release its six tail units upon removal of the protecting group. 

Molecular structure of a self-immolative AB6 dendron with aminomethyl-pyrene reporter units and a Boc protecting group as a trigger. 

FIGURE 5.24 Release of aminomethyl-pyrene from dendron 31 upon removal of the Boc protecting group trigger (1 1 MeOH/DMSO mixture with 2% aqueous solution of Bu4NOH) ( ) Control reaction under similar conditions with dendron 31 with the Boc trigger intact (A)-... 

Next, we synthesized a second generation of self-immolative dendron with a similar tail-unit and photo-labUe trigger (Uke compound 25). We repeated the previous experiment and monitored the release of the tail-molecules. It was clearly observed (data not shown) that upon cleavage of the trigger, the self-immolative release of aminomethyl-pyrene is initiated and completed after 21 h. 

Fig. 3 HPLC chromatograms of first generation self-immolative dendron activation to release aminomethyl-pyrene (compound 27 [50 p,M] in methanol with 10% triethylamine). a Before radiation, b After radiation, f = 0. ct = 4h. dt=llh...

Styrene and NHS active ester repeat units is reacted with the fluorescent dye 1-aminomethyl pyrene. The reaction is schematically depicted in Fig. 21. The monolayer thickness is approximately 42 nm. The active ester content of the copolymer is 30 mol%. A quartz slide is used as substrate. Figure 22 shows theUV/ vis spectrum of the polymer monolayer after extraction. The absorption spectrum of the 1-aminomethyl pyrene is clearly visible. The absorption maximum is located at 340 nm, the maximum of the emission at 376 nm in good agreement with literature data for comparable compounds not attached to a solid surface [60,61]. The substrates show, after deposition of the monolayer, a blue fluorescence if the sample is irradiated with light having a wavelength of 360 nm. 

Other related complexes involved poly(ethylene-co-methacrylic acid) with poly(ethyloxazoline) [91] block-copolymers of styrene-methacrylic acid-styrene with pyrene and other aromatic species [92] and complexes of poly(ethylene-co-methacrylic acid) (a commercially available ionomer ) with zinc(ll) salts and l,3-6/5(aminomethyl)cyclohexane [92]. One commercial ionomer (ACR-1560 of Dupont-Mitsui Polychemicals Co., Ltd.) is a copolymer of 94.6mol 7o of ethylene and 5.6mol< o of methacrylic acid. Complexes were prepared with 0.6mol% of a zinc(ll) salt, 0.4mol% l,3-Z)/5(aminomethyl)cyclohexane (BAC), and with 0.6mol o of the zinc salt and 0.4mol% BAC by a melt reaction [94]. 

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