Non-K Region Disubstituted Pyrenes (1,3-, 1,6- and 1,8-) by (Hetero)Aryl Groups - Review

Disubstituted pyrenes at the non-K region by the same or di erent (hetero)aryl groups have proven to be an increasingly interesting area of research for scientists over the last decade due to their optical and photophysical properties. However, in this area, there is no systematization of the structures and synthesis methods nor their limitations. In this review, all approaches to the synthesis of these compounds, starting from the commercially available pyrene are described. Herein, the ways of obtaining of disubstituted intermediates based on bromination and acylation reaction are presented. This is crucial in the determination of the possibility of further functionalization by using coupling, cycloaddition, condensation, etc. reactions. Moreover, the application of disubstituted pyrenes in the synthesis of 1,3,6,8-tetrasubstituted was also reviewed. This review describes the directions of research on chemistry of disubstituted pyrenes

Pyrene derivatives with two types of substituents at positions 1, 3, 6, and 8-fad or necessity?

1,3,6,8-Tetrasubstituted pyrene derivatives with two types of substituents in an asymmetry or axial symmetry pattern have been prepared and characterized. To the best of our knowledge, these compounds are compared for the first time to their analogs containing the same substituent at all four positions, which explains the need for their synthesis. We present information on the chemistry of pyrenes, which are substituted in the non-K region, to help obtain the most efficient materials. Moreover, theoretical studies were extended to analogs which contain the first type of substituent at positions 1 and 3, whereas the second type of substituent is located at positions 6 and 8, for which the synthesis is nontrivial. The obtained data show which trend these kinds of molecules will follow

Jedno- i dwurdzeniowe związki koordynacyjne rutenu, osmu i irydu z cyklometalującymi ligandami pirenowymi i terpirydynowymi

The presented doctoral dissertation is devoted to fundamental research in the field of synthesis and comprehensive characterization of new, double NCN-cyclometalating ligands based on pyrene structure and tridentate ligands which are derivatives of 2,2':6',2''- terpyridine and its analogs. These ligands in the next stages of the research were used in obtaining of new designed mono- and binuclear complexes of ruthenium, osmium and iridium with the general chemical formula [(NNN)M(NCN-pyrene-NCN)M(NNN)]ⁿ and [(NNN)M(NCN-pyrene-NCN)]m. The current state of knowledge in the field of that kind of compounds is just five scientific papers published by the team from the Chinese Academy of Sciences under the leadership of Professor Yu-Wu Zhong, where the ruthenium was the only one used. Furthermore, NCN-cyclometalating pyrene ligands have been described in the literature insignificantly. That makes the field of science definitely requires the development and undertaking of in-depth research that will allow a better understanding of the relation between structure and properties. As in the case of ligands, the purpose of the work is also the characterization of the target complexes, including the examination of thermal stability and optical properties. In addition, at the stage of planning the structures of synthesized ligands and complexes, as well as the analysis of their properties, they were supported by computational methods based on the DFT (density functional theory) and TD-DFT (time-dependent density functional theory) methods. In the area of the NCN-cyclometalating pyrene ligands, pyrene derivatives containing at positions 1,3,6 and 8 pyridyl, pyrazolyl, triazolyl and tetrazolyl substituents were obtained. The results of the research have shown that structural changes within pyrene systems do not affect their optical properties, which has also been proved by quantum chemical calculations; frontier orbitals are mainly located on the pyrene, the contribution of substituent orbitals increases in the following order: pyridyl, triazolyl, tetrazolyl, pyrazolyl. This is due to the geometry of the molecule, as indicated by the change in the angle between the pyrene and the substituent, which decreases exactly in the same series. In the field of research dedicated to derivatives of 4'-phenyl-2,2':6',2''-terpyridine, compounds containing fluoroene, anthracene, carbazole, triazole and tetrazole motifs were obtained based on coupling and cycloaddition reactions. Based on the physicochemical and theoretical studies, the nature of the terpyridine ligand was recognized which was crucial in the next stage of research devoted to complexes. Complexes of ruthenium, osmium and iridium were obtained and thoroughly examined. Differences and similarities of the properties between mononuclear and binuclear compounds of ruthenium and osmium were presented. Furthermore, the effect of the absence of symmetry on the properties of the ruthenium complexes was also checked. The next part was the investigation of the influence of coordinated metal, i.e. ruthenium, osmium and iridium on the properties of complexes built of the same ligands. Studies have also been conducted in the field of mononuclear osmium complexes in order to determine the effect of heteroaryl groups in the bridging ligand on the properties of the target compounds

Investigations of new phenothiazine-based compounds for dye-sensitized solar cells with theoretical insight

New D- -D- -A low-molecular-weight compounds, based on a phenothiazine sca old linked via an acetylene unit with various donor moiety and cyanoacrylic acid anchoring groups, respectively, were successfully synthesized. The prepared phenothiazine dyes were entirely characterized using nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. The compounds were designed to study the relationship between end-capping donor groups’ structure on their optoelectronic and thermal properties as well as the dye-sensitized solar cells’ performance. The e ect of -conjugation enlargement by incorporation of di erent heterocyclic substituents possessing various electron–donor a nities was systematically experimentally and theoretically examined. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were implemented to determine the electronic properties of the novel molecules

Influence of the substituent D/A at the 1,2,3-triazole ring on novel terpyridine derivatives:synthesis and properties

In this study, we newly designed and developed a synthesis route based on the 1,3-dipolar cycloaddition of the derivatives of 40-(1,2,3-triazol-4-yl)phenyl-2,20:60,200-terpyridine with various (hetero)aryl substituents, differing in electronic character, on a triazol ring. The obtained compounds were comprehensively characterized by UV-Vis spectroscopy and electrochemical and thermal studies. Moreover, preliminary biological tests were conducted. The investigation allowed the selection of materials with the most promising properties with particular emphasis on the nature of the substituents. In addition, theoretical studies (DFT and TD-DFT) were performed to verify the comprehensive understanding of experimental results

Evaluation of pulsed laser deposited thin films properties on the basis of the nanoindentation test

The overall goal of the research, is development of the numerical model capable of replicating local heterogenous material behavior of thin film materials under loading conditions. This particular work is focused on determination of flow stress characteristics of investigated TiN thin film based on the nanoindentation test. To properly recalculate measured load-displacement values into the required stress-strain curve an inverse analysis techniques are used. Subsequent stages including deposition process of TiN layer, room temperature nanoindentation tests and development of direct problem numerical model for the inverse analysis are described. Capabilities of the approach are also discussed within the work

DFT/TD-DFT Framework of Mixed-Metal Complexes with Symmetrical and Unsymmetrical Bridging Ligands—Step-By-Step Investigations: Mononuclear, Dinuclear Homometallic, and Heterometallic for Optoelectronic Applications

Recently, mono- and dinuclear complexes have been in the interest of scientists due to their potential application in optoelectronics. Herein, progressive theoretical investigations starting from mononuclear followed by homo- and heterometallic dinuclear osmium and/or ruthenium complexes with NCN-cyclometalating bridging ligands substituted by one or two kinds of heteroaryl groups (pyrazol-1-yl and 4-(2,2-dimethylpropyloxy)pyrid-2-yl) providing the short/long axial symmetry or asymmetry are presented. Step-by-step information about the particular part that built the mixed-metal complexes is crucial to understanding their behavior and checking the necessity of their eventual studies. Evaluation by using density functional theory (DFT) calculations allowed gaining information about the frontier orbitals, energy gaps, and physical parameters of complexes and their oxidized forms. Through time-dependent density functional theory (TD-DFT), calculations showed the optical properties, with a particular emphasis on the nature of low-energy bands. The presented results are a clear indication for other scientists in the field of chemistry and materials science

1,3-Di(hetero)aryl-7-substituted Pyrenes—An Undiscovered Area of Important Pyrene Derivatives

In this work, the necessity of synthesis of 1,3-di(hetero)aryl-7-substituted pyrenes is presented based on the results of theoretical calculations by using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) by using Gaussian 09 program with B3LYP exchange-correlation functional and 6-31G** basis set. What is more, the synthetic routes with feasible reagents and conditions are presented. The subject of theoretical considerations are two pyrene derivatives which contain at position 1 and 3 pyrazolyl substituents and at position 7 amine (1) or boron (2) derivative. The theoretical calculations were also performed for the osmium complexes with mentioned ligands (3 and 4). The influence of electron-donating/accepting character of the substituent at position 7 of pyrene on the properties of molecules has been established

Bromopyrene Symphony: Synthesis and Characterisation of Isomeric Derivatives at Non-K Region and Nodal Positions for Diverse Functionalisation Strategies

Pyrene, a renowned aromatic hydrocarbon, continues to captivate researchers due to its versatile properties and potential applications across various scientific domains. Among its derivatives, bromopyrenes stand out for their significance in synthetic chemistry, materials science, and environmental studies. The strategic functionalisation of pyrene at non-K region and nodal positions is crucial for expanding its utility, allowing for diverse functionalisation strategies. Bromo-substituted precursors serve as vital intermediates in synthetic routes; however, the substitution pattern of bromoderivatives significantly impacts their subsequent functionalisation and properties, posing challenges in synthesis and purification. Understanding the distinct electronic structure of pyrene is pivotal, dictating the preferential electrophilic aromatic substitution reactions at specific positions. Despite the wealth of literature, contradictions and complexities persist in synthesising suitably substituted bromopyrenes due to the unpredictable nature of substitution reactions. Building upon historical precedents, this study provides a comprehensive overview of bromine introduction in pyrene derivatives, offering optimised synthesis conditions based on laboratory research. Specifically, the synthesis of mono-, di-, tri-, and tetrabromopyrene isomers at non-K positions (1-, 3-, 6-, 8-) and nodal positions (2-, 7-) is systematically explored. By elucidating efficient synthetic methodologies and reaction conditions, this research contributes to advancing the synthesis and functionalisation strategies of pyrene derivatives, unlocking new possibilities for their utilisation in various fields

The Impact of a 1,2,3-Triazole Motif on the Photophysical Behavior of Non-K Tetrasubstituted Pyrene with a Substitution Pattern Providing the Long Axial Symmetry

1,3,6,8-Tetrasubstituted pyrene derivatives with two types of substituents (4-(2,2-dimethyl propyloxy)pyridine, 1-decyl-1,2,3-triazole, 1-benzyl-1,2,3-triazole, and pyrazole), substituted in such a way that provides the long axial symmetry, are prepared and characterized in the present study. To the best of our knowledge, the pyrene derivative containing the same heteroaryl motif (triazole) but substituted by two various alkyls, straight decyl and benzyl-based side chains (C), is reported for the first time. For comparison, compounds with one kind of triazole motif and substituted pyridine or pyrazole groups were prepared (A and B). The photophysical properties of all molecules were evaluated by thermogravimetric analysis (TGA) and UV-Vis spectroscopy (absorption and emission spectra, quantum yields, and fluorescence lifetimes). The obtained results were compared to analogues substituted at the 1,3,6,8 positions by one kind of substituent and also with all the 1,3,6,8-tetrasubstituted pyrenes reported in the literature substituted by two kinds of substituents with a substitution pattern that provides long axial symmetry. In addition, theoretical studies based on DFT and TD-DFT were performed that supported the interpretation of the experimental results. The photophysical properties of tetrasubstituted pyrene derivatives having triazole units at the 1,8-positions, respectively, and other identical substituents at the 3,6 positions show the dominance of triazole units in the pyrene framework; the dominance is even higher in the case of the substitution of 1,3,6,8 positions by triazoles, but containing two various alkyls