Electronic Supporting Information Hyperbranched Conjugated Poly ( tetraphenylethene ) : Synthesis , Aggregation-Induced Emission , Fluorescent Photopatterning , Optical Limiting and Explosive Detection

Tetraphenylethene-containing diyne (1), named 1,2-bis(4-ethynylphenyl)-1,2-diphenylethene, was synthesized and polymerized by TaBr5 catalyst, affording the hyperbranched polymer hb-P1 with a high molecular weight (Mw up to 157 800) in a nearly quantitative yield. The cyclotrimerization of 1-(4-ethynylphenyl)-1,2,2-triphenylethene was also carried out to give 1,3,5- and 1,2,4-tris[4-(1,2,2-triphenylvinyl)phenyl]benzene (1,3,5-2 and 1,2,4-2) that served as model compounds for structural characterization and properties investigation. The structures of hb-P1 and 2 are characterized by MS, IR, and NMR spectroscopies with satisfactory results. All the molecules and polymer are completely soluble in common organic solvents such as chloroform, toluene and THF. They show high thermal stability with degradation temperatures up to 443 and 446 °C, respectively, in nitrogen and air. Whereas their solutions are almost non-emissive or weakly fluorescent, their aggregates in poor solvents and solid powders emit intensely with fluorescence quantum yields up to 81%, demonstrating a novel phenomenon of aggregation-induced or enhanced emission. The unreacted triple bonds on the periphery of hb-P1 allow its thin film to cross-link under UV irradiation, generating well-resolved photopatterns. The hyperbranched polymer can limit harsh laser pulses. Its emission can be quenched efficiently by picric acid in solution and aggregated states with large quenching constants, suggesting that it is a promising fluorescent chemosensor for explosives detection.


Experimental Section
Synthesis.The synthetic routes for compound 1 and 3 are shown in Scheme 3 and 4.
Detailed experimental procedures are given below.

1,2-Bis(4-ethynylphenyl)-1,2-diphenylethene (1).
Into a 100 mL round bottom flask were placed 40 mL of THF solution of 10 (1.57g, 3 mmol) and 12 mL of 1 M THF solution of tetrabutylammonium fluoride.The mixture was stirred for 3 h and the reaction was terminated by adding 40 mL of water.The mixture was extracted with 200 mL dichloromethane three times.The organic layers were combined and washed with brine twice.The mixture was dried over 5 g of anhydrous sodium sulfate for 2 h.
50.HRMS (MALDI-TOF): m/z 1068.5785(M + , calcd 1068.4695).Polymerization.The polymerization reaction and manipulation were carried out under nitrogen using Schlenk techniques in a vacuum-line system except for the purification of the resultant polymer, which was done in an open atmosphere.Typical Electronic Supplementary Material (ESI) for Polymer Chemistry This journal is © The Royal Society of Chemistry 2012 Fig. S1.GPC chromatogram of hb-P1.
Fig. S8.(A) Photographs of 1,2,42 in THF/water mixtures with different water fractions (f w ) taken under 365 nm UV illumination from a hand-held UV lamp.(B) Emission spectra of 1,2,42 in THF/water mixtures.(C) Plot of (I/I o ) values versus the compositions of the aqueous mixtures.Solution concentration: 10 M; excitation wavelength: 327 nm.

Table of Contents Synthesis and CharacterizationsTable S1 .
Crystal Data and Structure Refinement for Compound Z1.

Table S2 .
Crystal Data and Structure Refinement for Compound E1.

Table S2 . Crystal Data and Structure Refinement for Compound E1 (CCDC 834092)
Electronic Supplementary Material (ESI) for Polymer Chemistry This journal is © The Royal Society of Chemistry 2012 Electronic Supplementary Material (ESI) for Polymer Chemistry This journal is © The Royal Society of Chemistry 2012