Synthesis of novel multifunctional carbazole-based molecules and their thermal, electrochemical and optical properties

Abstract

Two novel carbazole-based compounds 7a and 7b were synthesised as potential candidates for application in organic electronics. The materials were fully characterised by NMR spectroscopy, mass spectrometry, FTIR, thermogravimetric analysis, differential scanning calorimetry, cyclic voltammetry, and absorption and emission spectroscopy. Compounds 7a and 7b, both of which were amorphous solids, were stable up to 291 °C and 307 °C, respectively. Compounds 7a and 7b show three distinctive absorption bands: high and mid energy bands due to locally excited (LE) transitions and low energy bands due to intramolecular charge transfer (ICT) transitions. In dichloromethane solutions compounds 7a and 7b gave emission maxima at 561 nm and 482 nm with quantum efficiencies of 5.4% and 97.4% ± 10%, respectively. At positive potential, compounds 7a and 7b gave two different oxidation peaks, respectively: quasi-reversible at 0.55 V and 0.71 V, and reversible at 0.84 V and 0.99 V. At negative potentials, compounds 7a and 7b only exhibited an irreversible reduction peak at −1.86 V and −1.93 V, respectively.

The Investigation of Fluorescence Biothiol Sensor Properties of 2-(N-hexyl-carbazole-3'-yl)-4- formylpyridine

“…First of all, absorption and emission properties of probe 1 in DMSO:HEPES buffer solution (1:9 v/v, pH=7.4) were investigated by UV-Vis and fluorescence spectroscopy, respectively (Figure 1). Probe 1 displayed similar absorption and emission profiles as reported previously (Altinolcek et al, 2020) in DCM and different solvents. In UV-vis, high-energy bands and mid-energy bands were assigned to -* and n-* transitions, whereas low-energy bands were assigned to intramolecular charge transfer (ICT) transition.…”

“…Probe 1 was synthesised in four steps from carbazole as described previously (Altinolcek et al, 2020). Biothiols of Cys (L-Cysteine), Hcy (DL-Homocysteine) and GSH (L-Glutathione reduced) was ordered from Sigma Aldrich and were stored at the recommended temperature (Hcy: -20°C, Cys and GSH: +2-8°C).…”

“…These changes occur via a different emission mechanism. In this paper, we choose carbazole as a fluorophore and aldehyde group as a recognition site and from this we previously synthesised a probe: 2-(N-hexyl-carbazole-3'-yl)-4formylpyridine 1 and reported literature by us (Altinolcek et al, 2020). We examined the adduct formation between probe 1 and biothiols by 1 H NMR, MS, UV-vis and PL spectrometers.…”

Analysis of a Product Cleaner for Car Windows and Identification of its Surfactants by Infrared Absorption Spectra and Calculation of Band Gap Energy by its Reflectance Graph

“…The band gap is generally obtained from optical absorption edge energy, which is defined as the minimum photon energy required to excite an electron from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) [1,2]. The detergent product analyzed here was a mixture of anionic surfactant and non-ionic surfactant, as well as soap and chelating agent and colourants.…”

2-(carbazole-3'-yl)-5-formylpyridine: Investigation of the Fluorescence Biothiol Sensor Property

“…Literatürde bu konuda birçok çalışma da mevcuttur [12][13][14][15][16][17][18]. Biz ise bu çalışmada tiyollerin aldehitlerle verdiği halkalaşma reaksiyonunu kullanarak daha önce sentezini rapor ettiğimiz [19] 2-(N-hekzil-karbazol-3'-il)-5-formilpiridin molekülü Prob 1'in floresans sensör özelliğini inceleyeceğiz. Ayrıca bu halkalaşma reaksiyonun oluşumunu NMR ve MS gibi spektroskopik yöntemlerle de takip ederek teyit edeceğiz.…”