Dataset Information

Switchable ?-electronic network of bis(?-oligothienyl)-substituted hexaphyrins between helical versus rectangular circuit.

ABSTRACT: The switching phenomena of conformation with ?-electronic network through deprotonation-protonation processes were investigated by employing a series of 5,20-bis(?-oligothienyl) substituted hexaphyrins(1.1.1.1.1.1). They showed significant changes in the absorption and emission spectra with deprotonation, and returned to the initial state with protonation. Through NMR measurements and single crystal X-ray diffraction analysis, we found that the 5,20-bis(?-oligothienyl) substituted hexaphyrins, which possess acyclic, helical electronic networks involving oligothienyl chains in dumbbell conformations (type-I) in a neutral form, underwent effective deprotonation upon treatment with tetrabutylammonium fluoride (TBAF) to generate the corresponding dianions, which display cyclic electronic networks with enhanced aromaticity in rectangular conformations (type-II). Our quantum calculation results provide an unambiguous description for the switchable conformation and ?-conjugation, which revealed that a deprotonation-induced enhanced aromatic conjugation pathway is involved in the switchable ?-electronic network.

SUBMITTER: Oh J

PROVIDER: S-EPMC5977443 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Switchable π-electronic network of bis(α-oligothienyl)-substituted hexaphyrins between helical <i>versus</i> rectangular circuit.

Oh Juwon J Mori Hirotaka H Sung Young Mo YM Kim Woojae W Osuka Atsuhiro A Kim Dongho D

Chemical science 20151208 3

The switching phenomena of conformation with π-electronic network through deprotonation-protonation processes were investigated by employing a series of 5,20-bis(α-oligothienyl) substituted hexaphyrins(1.1.1.1.1.1). They showed significant changes in the absorption and emission spectra with deprotonation, and returned to the initial state with protonation. Through NMR measurements and single crystal X-ray diffraction analysis, we found that the 5,20-bis(α-oligothienyl) substituted hexaphyrins, w ...[more]

PMID: 29910912

Similar Datasets

Project description:Advanced analytical applications require smart materials and sensor systems that are able to adapt or be configured to specific tasks. Based on reversible photochemistry in nanoporous materials, we present a sensor array with a selectivity that is reversibly controlled by light irradiation. The active material of the sensor array, or electronic nose (e-nose), is based on metal-organic frameworks (MOFs) with photoresponsive fluorinated azobenzene groups that can be optically switched between their trans and cis state. By irradiation with light of different wavelengths, the trans-cis ratio can be modulated. Here we use four trans-cis values as defined states and employ a four-channel quartz-crystal microbalance for gravimetrically monitoring the molecular uptake by the MOF films. We apply the photoprogrammable e-nose to the sensing of different volatile organic compounds (VOCs) and analyze the sensor array data with simple machine-learning algorithms. When the sensor array is in a state with all sensors either in the same trans- or cis-rich state, cross-sensitivity between the analytes occurs and the classification accuracy is not ideal. Remarkably, the VOC molecules between which the sensor array shows cross-sensitivity vary by switching the entire sensor array from trans to cis. By selectively programming the e-nose with light of different colors, each sensor exhibits a different isomer ratio and thus a different VOC affinity, based on the polarity difference between the trans- and cis-azobenzenes. In such photoprogrammed state, the cross-sensitivity is reduced and the selectivity is enhanced, so that the e-nose can perfectly identify the tested VOCs. This work demonstrates for the first time the potential of photoswitchable and thus optically configurable materials as active sensing material in an e-nose for intelligent molecular sensing. The concept is not limited to QCM-based azobenzene-MOF sensors and can also be applied to diverse sensing materials and photoswitches.

Dataset Information

Switchable ?-electronic network of bis(?-oligothienyl)-substituted hexaphyrins between helical versus rectangular circuit.

Publications

Switchable π-electronic network of bis(α-oligothienyl)-substituted hexaphyrins between helical <i>versus</i> rectangular circuit.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets