Rigid Linear and Star-Shaped π-Conjugated 2,2‘:6‘,2‘ ‘-Terpyridine Ligands with Blue Emission

Abstract

A series of rigid linear and star-shaped pi-conjugated 2,2':6',2"-terpyridine derivatives with the C-C single-, double-, and triple-bond linkages have been developed through the Suzuki, the Sonogashira, and the Wittig reactions. Such large rigid ligands exhibit strong blue emission in dilute solutions. [structure: see text]

Shape‐Persistent, Truxene‐Based, Nano‐Sized Bisterpyridine Ruthenium(II) Complexes: Synthesis and Photophysical Properties

“…394 nm belonging to the absorption band of the thienylterpyridinefunctionalized truxene groups. In comparison with the absorption spectra of other phenylterpyridine-functionalized truxenes (l max % 342 nm), [19] the low energy bands of the star-shaped 7 were red-shifted by 52 nm, indicative of enhanced conjugation through the thienyl spacer. Both ligands are fluorescent with the emission spectrum of 1 characterized by an intense emission band at 359 nm, a less intense band at higher energy (343 nm), and a lower energy shoulder shifted to the red at 376 nm.…”

One‐Pot Multicomponent Synthesis of Azaindoles and Pyrroles from One Molecule of a Silicon‐Tethered Diyne and Three or Two Molecules of Organonitriles Mediated by Zirconocene

“…Thus, subjecting the bromine-bearing azaindoles 1 n and 1 o to Suzuki coupling conditions with benzeneboronic acid gave the corresponding arylated azaindoles 1 p and 1 q in yields of 53 and 82 %, respectively (see Scheme 3). [14,15] Formation of pyrroles from one molecule of a silicon-tethered diyne and two molecules of the same organonitrile: It was previously found that iPrCN, a relatively bulky organonitrile, could stop the above reaction involving two molecules of organonitriles midway to give multisubstituted pyrroles upon hydrolysis of the reaction mixtures. [9] Inspired by this finding, we searched for a variety of organonitriles with appropriate steric hindrance to stop the reaction midway and efficiently prepare substituted pyrroles 3.…”

π‐Conjugated 2,2′:6′,2″‐Bis(terpyridines): Systematical Tuning of the Optical Properties by Variation of the Linkage between the Terpyridines and the π‐Conjugated System

“…Compounds 2, 7, 14-18, T14 and T15 were prepared following previously published protocols. [17,27,43] All the terpyridine derivatives were purified by flash column chromatography (neutral alumina, CH 2 Cl 2 /MeOH as eluent) or preparative size-exclusion chromatography (BioBeads ® S-X5, toluene as eluent). The commercially available boronic acids 5 and 6 were converted into the corresponding ethylene glycol boronate by heating with ethylene glycol at reflux in toluene.…”

“…The general reaction scheme for the synthesis of the bis(terpyridines) T8-T16 by linking functionalized 4Ј-phenyl-2,2Ј:6Ј,2ЈЈ-terpyridines 17 and 18 to the spacer units 8-16 is shown in Figure 1. By using halogen end-groups, the systems were coupled to a terpyridine derivative bearing an ethynyl functionality (17) by Sonogashira reaction to yield the conjugated bis(terpyridines) T10, T11 and T15. The Huisgen 1,3-dipolar cycloaddition reaction [33] under Cu I catalysis, one of the socalled "click" reactions, [34][35][36][37][38] was used to connect the terpyridine and the spacer in the cases of compounds T12, T13 and T16.…”

“…[6,15,17,26,27] To enable the preparation of metallo-polymers exhibiting absorption over a wide range of the visible spectrum, we aimed to tune the band gap of our systems in an easy and systematic manner. The exchange of a phenyl moiety of the conjugated substituent by, for example, an anthracene or fluorene, enables the variation of the absorption of the derived terpyridyl system over a range of more than 100 nm.…”