Mendeleev Commun., 2017, 27, 363–365 – 363 – Mendeleev Communications © 2017 Mendeleev Communications. Published by ELSEVIER B.V. on behalf of the N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences. Fluorescent compounds have been long used in various fields of science, from materials chemistry to biosensor development or live systems investigations. 1–3 The last decade has witnessed a significant advance in the synthesis and applications of the boron dipyrromethene (BODIPY) derivatives. 4–6 To date, BODIPY- based fluorescent dyes with the emission from blue to red and further to the infrared spectral range have been synthesized. 7,8 However, green fluorescent BODIPY variants are the most popular ones owing to their high brightness and facile synthesis. 9–11 At present, 1,3,5,7-tetramethyl-BODIPY (TMB) derivatives are in high demand, since their fluorophore core is protected by four methyl groups minimizing fluorescence quenching induced by interfluorophore interactions. 12 There is a great need for fluorophore–polymer conjugates due to the development of solid-state dye-lasers, 7 mechanochromic materials, 13 light emitting diodes, 14 and nanoscale luminescent materials with well-controlled sizes, shapes and emission colors. 15 Siloxane polymers are of a particular interest owing to their high stability and outstanding thermal and optical characteristics. 16–18 Here, we report the coupling of a TMB derivative to a siloxane polymer. The resulting polymer acquired fluorescence properties, which dramatically changed in different solvents. The obtained compound showed a marked susceptibility to structuration, unusual for other siloxane polymers. To conjugate to a siloxane polymer, we synthesized a meso- decene-TMB derivative equipped with a terminal vinyl group attached to the long aliphatic spacer (Scheme 1), which allowed us to perform subsequent conjugation to target objects by the hydrosilylation reaction using the Karstedt’s catalyst. Recently, compound 3 was synthesized in 14% yield and used for labeling of sphingosines 19 and estradiol. 20 In the present work, we improved the earlier reported procedure and raised the yield up to 63%. In our study, undec-10-enoic acid 1 was converted into its chloride 2 by the treatment with thionyl chloride. 21 Next several steps were performed without isolation of semiproducts. Reac- tion between undec-10-enoyl chloride 2 and 2,4-dimethylpyrrole followed by the treatment with DIPEA and boron trifluoride diethyl etherate brought about BODIPY derivative 3 in 63% isolated † yield. Compound 3 dissolved in different organic solvents showed characteristic sharp absorbance and emission peaks at Synthesis and crystal structure of a meso-decene-BODIPY dye as a functional bright fluorophore for silicone matrices Alexey A. Pakhomov,* a Veronika B. Mironiuk, a,b Yuriy N. Kononevich, b Alexander A. Korlyukov, b Alexander D. Volodin, b Tatyana A. Pryakhina, b Vladimir I. Martynov a and Aziz M. Muzafarov b,c a M. M. Shemyakin–Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russian Federation. Fax: +7 495 336 6166; e-mail: alpah@mail.ru b A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 119991 Moscow, Russian Federation c N. S. Enikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Sciences, 117393 Moscow, Russian Federation DOI: 10.1016/j.mencom.2017.07.013 25 mm N B N Me Me Me Me F F Karstedt’s cat. Si O Si O Me Me Me H Toluene + 8 CH2 30 n Si O Si O Me Me Me 30 n 9 N B N Me Me Me Me F F A meso-decene-BODIPY dye was synthesized and conjugated to a polydimethylsiloxane. Fluorescence properties of the obtained polymer drastically changed in different solvents. The polymer showed an unusual for other siloxane polymers trend to structuration. † All solvents were purified before use. Undec-10-enoic acid, thionyl chloride, 2,4-dimethylpyrrole, DIPEA and BF 3 ·Et 2 O were purchased from Acros Organics and used without purification. Platinum(0) 1,3-divinyl- 1,1,3,3-tetramethyldisiloxane complex solution (in xylene, 2% Pt) was purchased from Sigma-Aldrich. The reactions were monitored by TLC using Fluka silica gel (60 F 254) plates (0.25 mm). Column chromato- graphy was carried out using Merck 60 (230–400 mesh) silica gel. Visualization was accomplished with UV light. Melting points were determined in capillary tubes. IR spectra were recorded with a Bruker Equinox 55/S spectrometer. 1 H, 13 C, and 19 F NMR spectra were recorded with a Bruker Avance II spectrometer (300 MHz) and a Bruker Avance 600 spectrometer (600 MHz). HRMS spectra (ESI) were measured using a Bruker micrOTOF II instrument (ESI). UV-VIS absorption spectra were recorded with a Cary 50 Bio (Varian) spectrophotometer. Fluorescence spectroscopic measurements were carried out using a Cary Eclipse (Varian) spectrofluorometer. Fluorescence spectra were measured at optical density of ~0.05. The quantum yield of luminescence was determined using fluorescence in 0.1 M NaOH water solution (F F = 0.92) as a standard. 4 5 SOCl 2 N H Me Me 1 Karstedt’s catalyst Toluene BF 3 ·Et 2 O, DIPEA CH 2 Cl 2 8 O OH 2 8 O Cl , Si O Si O Me Me Me 30 n 9 N B N Me Me Me Me F F Si O Si O Me Me Me H 30 n 3 8 N B N Me Me Me Me F F Scheme 1