Spectroscopic and electrochemical properties of 2-aminophenothiazine

Abstract

Phenothiazines derivatives are versatile compounds that are used in many fields, depending on the type and position of the substitution on the parent molecule. The photochemical, photophysical and electrochemical properties of several phenothiazine derivatives have been previously reported in detail. However, no reports have been presented for 2-aminophenothiazine (APH), a candidate that provides for the further chemical modification and the introduction of specific substituents. In this work, the photophysical and electrochemical properties of APH were measured in acetonitrile. The APH ground state absorption and fluorescence spectrum (φf < 0.01) are similar to the corresponding that of PH parent molecule. A mono exponential decay fluorescence lifetime of 0.65 ns was determined for APH in acetonitrile. Characterization of the 355 nm nanosecond laser flash photolysis transient species reveals the presence of the triplet-triplet transient intermediate with a high intersystem crossing quantum yield (φT = 0.72 ± 0.07), indicating that the APH main excited state deactivation channel is intersystem crossing. The oxidation potential of APH is lower than phenothiazine parent molecule ((0.38 V vs 0.69 V vs Ag/AgCl(sat)). Altogether, these results show that APH has photochemical and photophysical properties similar to the phenothiazine parent molecule, but with the possibility of providing an amino functionality at 2-position for further chemical modification.

Photooxidation Mechanism of Levomepromazine in Different Solvents

“…The emission spectrum of LPZ consists of a single broad band with a maximum centered at 450 nm in all solvents (predicted at 446 nm in MeCN by TD‐DFT, Fig. and Table ), similar to those reported for phenothiazine , promazine (PZ) and some perphenazine derivatives . All these compounds normally show relatively large bathochromic shifts.…”

Microwave‐Assisted Catalytic Amination of Phenothiazine; Reliable Access to Phenothiazine Analogues of Tröger's Base

“…The core structures of PTB 5a-d were identical, as established by 1 H, 13 the aromatic (δ = 6.6-7.2 ppm) and aliphatic (δ = 1.5 ppm, 3 H, t, and 4 ppm, 2 H, q) region, respectively. The recorded NOEDIFF spectra of 5b show spatial interactions between aromatic protons in the 4-position of the phenothiazine (δ = 6.64 ppm, s) and the endo CH 2 protons of the diazocine unit, thus providing evidence for the regioselectivity of the cyclization.…”

“…Nitro-phenothiazine derivatives have most often been used as starting materials, based on strategies using reducing agents such as Zn/ZnCl 2 , [11] Sn, [12] or SnCl 2 , [13] and HCl, Ni and acetic acid or hydrazine hydrate, [14] as well as catalytic hydrogenations with catalysts such as Raney nickel, [15] or palladium on carbon. Nitro-phenothiazine derivatives have most often been used as starting materials, based on strategies using reducing agents such as Zn/ZnCl 2 , [11] Sn, [12] or SnCl 2 , [13] and HCl, Ni and acetic acid or hydrazine hydrate, [14] as well as catalytic hydrogenations with catalysts such as Raney nickel, [15] or palladium on carbon.…”

Solvent mediated morphological control of aniline stabilized cobalt oxide nanoparticles

“…Transient spectra of aminyl and amine radical cation have also been reported in the region ∼415-430 nm [35]. Thus, these absorptions may have an origin in the formation of similar species in the solution and the adsorption of these along with aniline molecules on the surface of cobalt nanoclusters, thereby stabilizing them.…”