Optical characterization of amorphous oligo(4,4′-biphenylene-1,1-substituted methylene)s

Chemosensing of nitroaromatics with a new segmented conjugated quaterphenylene polymer

“…Thus, we found that oligo(biphenylmethylene)s, where the spacer is a single saturated carbon atom, form amorphous glasses. 16 We have further extended our studies to a poly(terphenylenepropylene) segmented CP whose highly rigid and contorted structure also forms very stable disordered morphology with decreased segmental interactions. 17 The amorphous nature and high solubility of these materials suggested to us that efficient packing in the solid state is frustrated thus originating void space which could eventually foster analyte exchange with the media.…”

Triptycene: No Homoconjugation Effect for Extending Optical Properties of π-Conjugated Oligomers

“…Recent advances in the studies of π-conjugated oligomers have continued to establish that they are well-suited photoluminescent materials for applications in organic optoelectronic/semiconductor devices and chemical sensors. Studies of a series of π-conjugated oligomers 1 alternated by sp 3 centers suggested effective homoconjugation via the linker, and strong evidence of such extended homoconjugation was clearly illustrated in examples such as 2 and 3 . A similar observation was also made in their corresponding polymers. ,, Iptycenes (triptycene is the smallest member) have also been targets for constructing new molecules and materials .…”

“…Studies of a series of π-conjugated oligomers 1 alternated by sp 3 centers suggested effective homoconjugation via the linker, and strong evidence of such extended homoconjugation was clearly illustrated in examples such as 2 and 3 . A similar observation was also made in their corresponding polymers. ,, Iptycenes (triptycene is the smallest member) have also been targets for constructing new molecules and materials . The electronic spectrum of tripytcene 4 or its derivatives showed inconclusive homoconjugation among the benzene rings.…”

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

“…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.…”

“…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].…”