Synthesis and Characterization of Novel para- and meta-Phenylenevinylene Derivatives:  Fine Tuning of the Electronic and Optical Properties of Conjugated Materials

Abstract

We report the synthesis of novel phenylenevinylene derivatives that allow for the introduction of meta versus para connections on the phenylene rings, as well as the incorporation of nitrogen atoms within the conjugated backbone and the attachment of electroactive substituents. We assess the impact of the various derivatization schemes on the electronic and optical properties by means of gas-phase ultraviolet photoelectron spectroscopy (UPS) and optical absorption and emission measurements; the evolution of the experimental data is further supported by the results of quantum-chemical calculations. We demonstrate that the electronic and optical properties of phenylenevinylene chains, and by extension those of many conjugated materials, can be tuned over a large energy range by a tailored design of the molecular structures.

Synthesis and Spectroscopy of Poly(9,9-dihexylfluorene-2,7-diyl-co-9,9-dihexylfluorene-3,6-diyl)s and Their Model Oligomers

“…The above observations are consistent with previously observed interruption in the degree of delocalization by the meta-linkages in phenylenevinylene oligomers. 22,23 The excited-state energies and absorption maxima of the oligomers were calculated using the ZINDO 24 method. This method has been successfully used to account for the optical properties of conjugated polyphenylenevinylene-type systems.…”

Revealing Topological Influence of Phenylenediamine Unit on Physicochemical Properties of Donor‐Acceptor‐Donor‐Acceptor Thermally Activated Delayed Fluorescent Macrocycles

“…To date, topological influence of phenylene unit ( meta versus para ) on the properties of phenylene‐linked linear π‐electron conjugated systems, such as oligo(phenylenevinylene)s, [14] oligo(phenylene ethynylene)s, [15] oligo(aniline)s, [16] phenylene‐bridged bis(triarylamine)s [17] and bis(ethynyltriarylamine)s, [18] phenylene‐linked N‐annulated perylene diimide dimers, [19] aminostilbenes, [20] and bis(ethynylene)phenylene‐linked donor (carbazole) and acceptor (naphthalimides) compound, [21] has been moderately explored. The topology in phenylene unit in these previously investigated π‐conjugated systems gives an impact on properties such as HOMO−LUMO optical gap, [14] photoluminescence quantum yield (PLQY), [15] spin localization of radical cation, [16,17] the rate of charge separation, [19] for instance. Nevertheless, such topological studies of π‐conjugated macrocyclic compounds are quite limited to cyclic oligo(phenylenediamine)s [22] and B‐π‐N ambipolar macrocycles [23] .…”

Spectroscopic insights on the interaction between 4-(3,4 dimethoxyphenyl)-6-hydroxy-2- methylpyrimidine-5-carbonitrile and tryptophan.

“…Pyrimidine also plays a role of analgesic, antihypertensive, antipyretic, anti-inflammatory, antineoplastic, antibacterial, antiprotozoal, antifungal, antiviral and antifolate drugs and as pestisides, herbicides and plant growth regulators [9][10][11]. Pyrimidine analogous compounds were extensively investigated as electroluminescent materials in the past and as a two-photon absorption organic chromophores [12,13]. There is investigation on effect of pyrimidine additives on the dye sensitized solar cell performance [14].…”