Large π-Extension of Carbon Nanorings by Incorporating Hexa-peri-hexabenzocoronenes

Synlett ◽  
2017 ◽  
Vol 28 (14) ◽  
pp. 1671-1677 ◽  
Author(s):  
Dapeng Lu ◽  
Shengsheng Cui ◽  
Pingwu Du
Keyword(s):  
Photophysical Properties ◽  
Synthetic Methods ◽  
Conjugated Systems ◽  
Aromatization Reaction ◽  
Longitudinal Extension ◽  
Carbon Nanorings

Recently, we reported the synthesis of two novel large π-extended carbon nanorings by incorporating hexa-peri-hexabenzocoronenes: cyclo[12]-paraphenylene[2]-2,11-hexa-peri-hexabenzocoronene ([12,2]CPHBC) and the [4]cyclo-2,11-para-hexa-peri-hexabenzocoronene ([4]CHBC). The successful synthesis was achieved by the rationally designed pathways via palladium-, nickel-, or platinum-mediated reactions and the final aromatization reaction. This Synpacts article highlights the synthetic methods to achieve these carbon nanorings with large conjugated systems. We also summarize the representative characterization evidences and interesting photophysical properties of these carbon nanoring structures. Furthermore, the selective supramolecular host–guest interaction between [4]CHBC and C70 is briefly discussed. The new π-extended carbon nanorings can be considered as examples of longitudinal extension of the cycloparaphenylene scaffold, forming large conjugated CNT segments.1 Introduction2 Large π-Extended Carbon Nanorings by Incorporating Hexa-peri-hexabenzocoronenes3 Conclusions

scholarly journals Synthesis and Characterization of Acridinium Dyes for Photoredox Catalysis

Synlett ◽  
2019 ◽  
Vol 30 (07) ◽  
pp. 827-832 ◽  
Author(s):  
Alexander White ◽  
Leifeng Wang ◽  
David Nicewicz
Keyword(s):  
Photophysical Properties ◽  
Direct Conversion ◽  
Systematic Investigation ◽  
Synthetic Methods ◽  
Synthesis And Characterization ◽  
Substitution Effects ◽  
Photoredox Catalysis ◽  
Methods Development

Photoredox catalysis is a rapidly evolving platform for synthetic methods development. The prominent use of acridinium salts as a sustainable option for photoredox catalysts has driven the development of more robust and synthetically useful versions based on this scaffold. However, more complicated syntheses, increased cost, and limited commercial availability have hindered the adoption of these catalysts by the greater synthetic community. By utilizing the direct conversion of a xanthylium salt into the corresponding acridinium as the key transformation, we present an efficient and scalable preparation of the most synthetically useful acridinium reported to date. This divergent strategy also enabled the preparation of a suite of novel acridinium dyes, allowing for a systematic investigation of substitution effects on their photophysical properties.

Complexation of carbon nanorings with fullerenes

2006 ◽  
Vol 78 (4) ◽  
pp. 831-839 ◽  
Author(s):  
Takeshi Kawase ◽  
Masaji Oda
Keyword(s):  
Inclusion Complexes ◽  
Dipolar Interaction ◽  
The Novel ◽  
Conjugated Systems ◽  
Hollow Space ◽  
Wide Contact ◽  
The Stability ◽  
Deep Cavities ◽  
Related Compounds ◽  
Carbon Nanorings

To explore the supramolecular properties of the hollow space of carbon nanotubes, the belt-shaped conjugated systems with sizable and deep cavities are intriguing molecules. Recently, we found that the "carbon nanorings", cyclic [6]paraphenyleneacetylene ([6]CPPA), and the related compounds involving two naphthylene rings, form stable inclusion complexes with fullerenes in solution as well as in the solid state. The stability of these complexes correlates well with the van der Waals (VDW) contact between the host and guest. Thus, carbon nanorings having a deep cavity should form considerably stable complexes with fullerenes. In this context, we have designed a new carbon nanoring, cyclic [6](1,4)naphthyleneacetylene. The host forms considerably stable inclusion complexes with fullerenes and can act as the best fluorescence sensor for fullerenes among all the known hosts. The NMR spectra reveal the formation of two major conformational isomers, in which five or six naphthylene rings surround a guest molecule to gain wide contact area. The high affinity between C60 and naphthylene rings similar to an ion-dipolar interaction plays an important role in the novel guest-induced conformation fixation.

The impact of heteroatom substitution on cross-conjugation and its effect on the photovoltaic performance of DSSCs – a computational investigation of linear vs. cross-conjugated anchoring units

2018 ◽  
Vol 20 (35) ◽  
pp. 22660-22673 ◽  
Author(s):  
Mahalingavelar Paramasivam ◽  
Ramesh Kumar Chitumalla ◽  
Joonkyung Jang ◽  
Ji Ho Youk
Keyword(s):  
Photophysical Properties ◽  
Energy Levels ◽  
Photovoltaic Performance ◽  
Computational Investigation ◽  
Conjugated Systems ◽  
Reverse Trend ◽  
Heteroatom Substitution ◽  
The Impact

The heteroatom substitution on cross conjugation takes a reverse trend to the linear π-conjugated systems by means of energy levels and photophysical properties. The resultant changes directly affecting the photovoltaic performance of DSSCs.

Metal-to-Ligand Charge Transfer Excited States in π-Conjugated Systems

2001 ◽  
Vol 665 ◽  
Author(s):  
Yiting Li ◽  
C. Ed Whittle ◽  
Keith A. Walters ◽  
Kevin D. Ley ◽  
Kirk S. Schanze
Keyword(s):  
Optical Properties ◽  
Charge Transfer ◽  
Excited States ◽  
Transition Metal Complexes ◽  
Transient Absorption ◽  
Photophysical Properties ◽  
Transient Absorption Spectroscopy ◽  
Conjugated Oligomers ◽  
Conjugated Systems ◽  
Ligand Charge Transfer

ABSTRACTThis paper overviews recent work that examined the optical properties of mono-disperse, PPE-based π-conjugated oligomers that contain a 2,2-bipyridine-5,5'-diyl metal coordinating unit. The photophysical properties of the free oligomers and metallated oligomers that contain the -Ru(bpy)22+ and -Re(CO)3Cl transition metal complexes coordinated to the bpy-diyl unit have been characterized by absorption, photoluminescence and transient absorption spectroscopy. In addition, we report the photophysics of a novel organometallic “square” that features “sides” consisting of a PPE-type π-conjugated oligomer and “corners” that consist of (dbubpy)PtII(acetylide)2 units (where dbubpy = 4,4'-di-tert-butyl-2,2'-bipyridine).

scholarly journals Porphyrinoids as a platform of stable radicals

2018 ◽  
Vol 9 (6) ◽  
pp. 1408-1423 ◽  
Author(s):  
Daiki Shimizu ◽  
Atsuhiro Osuka
Keyword(s):  
Synthetic Methods ◽  
Conjugated Systems ◽  
Stable Radicals

This review surveys four types of stable porphyrinoid radical and covers their synthetic methods and properties. The remarkable radical-stabilizing abilities of porphyrinoid stem from their unique macrocyclic conjugated systems with high electronic and structural flexibilities.

Design of novel conjugated systems bearing donor-acceptor groups (pyrene-bodipy): Optical, photophysical properties and energy transfer

2021 ◽  
Vol 185 ◽  
pp. 108925
Author(s):  
Andrea García-Rodríguez ◽  
Pasquale Porcu ◽  
Aldo S. Estrada-Montaño ◽  
Mireille Vonlanthen ◽  
Ricardo D. Martínez-Serrano ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Photophysical Properties ◽  
Conjugated Systems ◽  
Donor Acceptor

scholarly journals Photophysical Properties and Electronic Structure of Symmetrical Curcumin Analogues and Their BF2 Complexes, Including a Phenothiazine Substituted Derivative

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2299
Author(s):  
Emese Gál ◽  
Levente Csaba Nagy
Keyword(s):  
Theoretical Study ◽  
Photophysical Properties ◽  
Emission Spectra ◽  
Molecular Structures ◽  
Excitation Energies ◽  
Dft Methods ◽  
Conjugated Systems ◽  
Vertical Excitation ◽  
Td Dft ◽  
The One

Symmetrically substituted curcumin analogue compounds possess electron donor moieties at both ends of the conjugated systems; their difluoroboron complexes were synthesized, and their structures were fully characterized. A novel compound with enhanced photophysical properties bearing phenothiazine moieties is reported. The introduction of BF2 into the molecular structures resulted in bathochromic shifts both in the absorption and emission spectra, indicating that the π-conjugation was more extended than the one in the initial compounds. The solvatochromic effects were studied, which in case of the phenothiazinyl-curcumin BF2 complex was the most notable. Theoretical study of the investigated compounds was carried out using DFT and TD-DFT methods to evaluate the ground state geometries and vertical excitation energies.

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