Poly[(2,2′,5′,2″-tetramethoxy-p-terphenyl-5,5″-ylene)propylene]: Synthesis and physical properties of a novel amorphous regularly segmented conjugated polymer

Distyrylbenzene-based segmented conjugated polymers: Synthesis, thin film morphology and chemosensing of hydrophobic and hydrophilic nitroaromatics in aqueous media

“…Both polymers easily gave smooth thin films casted on quartz plates. These findings are consistent with our current thinking that the forced angular disposition of the gem-chromophores linked by a single sp3-carbon atom brings about highly distorted main chains that hamper ordering processes [21]. The twisted nature of Pa is highlighted by the HF-3c molecular model of the tetramer shown in Fig.…”

“…4b. The maxima, vibronic structure with a prominent A 1 absorption transition peak and two distinct emission bands, E 1 and E 2 , full width at half-maximum (FWHM) of the absorption and fluorescence bands and stokes shifts of Ma and Pa on one side and Mb and Pb on the other are quite similar in solution (see also Table 1), thereby arguing for the effective electronic isolation of gem-chromophores by isopropyl groups in the polymer main chain [21,25]. Spectra in the solid state were recorded periodically from the pristine films, then after mild annealing at 50 °C for 3 h under vacuum, and finally after annealing for 2 h under nitrogen at 100 °C in the case of the model compounds and at 180 °C for the polymers.…”

“…Therefore, in our studies we focused on the small isopropylidene spacer as the key element in designing regularly SCPs with amorphous morphologies which would ideally present optical properties insensible to the aggregation state. Thus, we were successful in obtaining polymeric amorphous assemblies of biphenylene [20], terphenylene [21], quaterphenylene [24] and diphenylfluorenylene [25] groups with good film-forming properties that are solution processable and each show similar optical responses either in solution or in solid state. Besides, despite the absence of side chains in the polymer architecture which is usually a condition to obtain soluble aromatic polymeric materials, we found that polymer solubilities are notably enhanced when the aromatic segments are tethered by the meta rather than para positions [25,26]; the same finding has been reported for quaterphenylenes linked with oligo(ethylene glycol) spacers [12].…”

“…1,4-Bis(chloromethyl)-2,5-diethoxybenzene (1b) was prepared from diethoxybenzene by chloromethylation according to the procedure of Wood and Gibson [43]. 2,2-bis(4-methoxyphenyl)propane (4) was prepared according to the literature [21].…”

“…In this context, an efficacious concept of macromolecular design aiming to customize the physical and electronic properties of conjugated polymers consists in the regular insertion in the polymer backbone of atomic or molecular motifs which tailor the π-conjugation length. Thus, a variety of regularly segmented conjugated polymers (SCPs) have been synthesized by linking aromatic segments of discrete size with spacers such as biphenylene [8], binaphthylene [9], paracyclophane [10], linear alkylene [11,12] and oxyethylene chains [13], oxygen atoms [14], silicon atoms [15,16] and sp 3 -carbon atoms of the norbornylene [17], fluorenylidene [18] and isopropylidene groups [19][20][21] all of which break conjugation in a controlled manner.…”