Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (3)

Search Parameters:
Keywords = pentagonal conjugate

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
17 pages, 3000 KB  
Article
Tetraanion of Tetracyclopentatetraphenylene Derivative: Global Versus Local Conjugation Modes
by Hirokazu Miyoshi, Ryosuke Sugiura, Ryohei Kishi, Atsuya Muranaka, Masanobu Uchiyama, Nagao Kobayashi, Yutaka Ie, Masayoshi Nakano and Yoshito Tobe
Chemistry 2025, 7(2), 51; https://doi.org/10.3390/chemistry7020051 - 31 Mar 2025
Cited by 1 | Viewed by 1888
Abstract
Multiple reduced π-conjugated hydrocarbons exhibit π-electron conjugation modes different from neutral species due to the distinct number of electrons. Herein, we report the generation of a 32 π-electron tetraanion of a derivative of a doubly cyclic π-conjugated system with 28 π-electrons, tetracyclopentatetraphenylene (TCPTP), [...] Read more.
Multiple reduced π-conjugated hydrocarbons exhibit π-electron conjugation modes different from neutral species due to the distinct number of electrons. Herein, we report the generation of a 32 π-electron tetraanion of a derivative of a doubly cyclic π-conjugated system with 28 π-electrons, tetracyclopentatetraphenylene (TCPTP), through an exhaustive reduction with potassium. Although aggregation causes some complications, based on spectroscopic and theoretical investigations, it is revealed that negative charges are located at the outer and inner peripheries, suggesting that the tetraanion adopts a globally delocalized double annulenoid (annulene-within-an-annulene, AWA) mode, with 22 π-electron outer and 10 π-electron inner aromatic perimeters. On the other hand, excess charges of the outer perimeter are mainly located at the apical position of the pentagonal rings, indicating a significant contribution of the cyclopentadienide form. The theoretical analysis of magnetically induced ring current tropicities reveals counter-rotating ring currents at the outer and inner rings, supporting the predominant contribution of the cyclopentadienide form. Full article
Show Figures

Figure 1

14 pages, 2899 KB  
Article
Pentacyanoammineferrate-Based Non-Enzymatic Electrochemical Biosensing Platform for Selective Uric Acid Measurement
by Won-Yong Jeon, Chang-Jun Lee, Tun Naw Sut, Hyug-Han Kim and Young-Bong Choi
Sensors 2021, 21(5), 1574; https://doi.org/10.3390/s21051574 - 24 Feb 2021
Cited by 6 | Viewed by 3251
Abstract
The electrochemical-based detection of uric acid (UA) is widely used for diagnostic purposes. However, various interfering species such as ascorbic acid, dopamine, and glucose can affect electrochemical signals, and hence there is an outstanding need to develop improved sensing platforms to detect UA [...] Read more.
The electrochemical-based detection of uric acid (UA) is widely used for diagnostic purposes. However, various interfering species such as ascorbic acid, dopamine, and glucose can affect electrochemical signals, and hence there is an outstanding need to develop improved sensing platforms to detect UA with high selectivity. Herein, we report a pentagonal mediator-based non-enzymatic electrochemical biosensing platform to selectively measure UA in the presence of interfering species. The working electrode was fabricated by electrodepositing polymerized 1-vinylimidazole (PVI), which has an imidazole ligand, onto indium tin oxide (ITO), and then conjugating nickel ions to the PVI-coated ITO electrode. Electrode performance was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements and integrated together with pentacyanoammineferrate, which can bind to the amine groups of UA and function as an electron transferring mediator. The experimental results showed a wide linear range of UA concentration-dependent responses and the multi-potential step (MPS) technique facilitated selective detection of UA in the presence of physiologically relevant interfering species. Altogether, these findings support that pentacyanoammineferrate-based non-enzymatic electrodes are suitable biosensing platforms for the selective measurement of UA, and such approaches could potentially be extended to other bioanalytes as well. Full article
(This article belongs to the Special Issue Label-Free Biosensors for Medicine and Biotechnology)
Show Figures

Figure 1

13 pages, 1429 KB  
Article
Syntheses and Self-assembling Behaviors of Pentagonal Conjugates of Tryptophane Zipper-Forming Peptide
by Kazunori Matsuura, Kazuya Murasato and Nobuo Kimizuka
Int. J. Mol. Sci. 2011, 12(8), 5187-5199; https://doi.org/10.3390/ijms12085187 - 15 Aug 2011
Cited by 11 | Viewed by 9904
Abstract
Pentagonal conjugates of tryptophane zipper-forming peptide (CKTWTWTE) with a pentaazacyclopentadecane core (Pentagonal-Gly-Trpzip and Pentagonal-Ala-Trpzip) were synthesized and their self-assembling behaviors were investigated in water. Pentagonal-Gly-Trpzip self-assembled into nanofibers with the width of about 5 nm in neutral water (pH 7) via formation of [...] Read more.
Pentagonal conjugates of tryptophane zipper-forming peptide (CKTWTWTE) with a pentaazacyclopentadecane core (Pentagonal-Gly-Trpzip and Pentagonal-Ala-Trpzip) were synthesized and their self-assembling behaviors were investigated in water. Pentagonal-Gly-Trpzip self-assembled into nanofibers with the width of about 5 nm in neutral water (pH 7) via formation of tryptophane zipper, which irreversibly converted to nanoribbons by heating. In contrast, Pentagonal-Ala-Trpzip formed irregular aggregates in water. Full article
(This article belongs to the Special Issue Molecular Self-Assembly 2011)
Show Figures

Graphical abstract

Back to TopTop