Direct nucleophilic aromatic substitution reactions in the syntheses of anthraquinone derivatives: Chemistry and binding of podands, crown ethers, and a cryptand

Y-Shaped Acceptor-π-Donor-π-Acceptor Configured Anthraquinone-Tethered Phenothiazine Molecular Scaffold for High-Performance Organic Pseudocapacitors

For the first time acceptor-π-donor-π-acceptor (A-π-D-π-A) based Y-type organic electrode material have been designed and successfully utilized in supercapacitor (SC) application. This Y-type molecular architecture coined as AQ-Im-PTZ-Im-AQ based on anthraquinone (AQ) (A)-imidazole (Im) (π)-phenothiazine (PTZ) (D)-imidazole (Im) (π)-anthraquinone (AQ) (A) in combination with graphite foil (GF). As-fabricated PTZ-Im-AQ/GF and AQ-Im-PTZ-Im-AQ/GF electrode have shown the good energy storage properties in three-electrode supercapacitor system. Moreover, two-electrode symmetric supercapacitor (SSC) device based on AQ-Im-PTZ-Im-AQ/GF electrode exhibited specific capacitance (Csp) of 68.97 F g-1 at 1 A g-1 current density. The specific electron density (ED) of SSC was observed to be 12.06 Wh kg-1 at a specific power density (PD) of 1798.50 W kg-1. The SSC device exhibited 81.62 % of Csp retention after 5000 galvanostatic charge-discharge (GCD) cycles. For real world applications, AQ-Im-PTZ-Im-AQ/GF electrode was tested in symmetric Csp coin cell with applied potential voltage window of -0.4 to 1.0 V was found to be 112.32 F g-1 at 0.5 A g-1. Moreover, it realized high specific capacitance and high energy density of 19.66 Wh kg-1 at 891.94 W kg-1 power density. As a results, AQ-Im-PTZ-Im-AQ/GF make as an attractive electrode material for application in next-generation SCs.

Synthesis and antiproliferative activity of thiazole-fused anthraquinones

Heterocyclic derivatives of anthraquinone demonstrated a high potential for the development of new antitumor compounds. In this study, we report a scheme for the synthesis of thiazole-fused anthraquinones and the results of their antiproliferative activity. A convenient metal-free method for the thiolation of anthraquinone derivatives has been proposed for the preparation of the key intermediates. C-S bond formation upon nucleophilic substitution of the bromine atom in anthraquinone with 4-methoxybenzyl mercaptan readily occurs under mild conditions using t-BuOK as a base. This process was used for the preparation of anthra[2,3-d]thiazoles with various substituents at position 2, in particular the alkoxycarbonyl group. Study of the chemical properties resulted in the transformation of anthra[2,3-d]thiazole-2-carboxylic acid into a series of carboxamides. Screening the antiproliferative effect revealed moderate activity of compounds 12b and 12d against human cancer cells, showing weaker activity than anthra[2,3-d]thiophene analogs and indicating a crucial role of the heterocyclic nucleus in the antitumor potency of heteroareneanthraquinones.

Luminescence Detection of Transition and Heavy Metals by Inversion of Excited States: Synthesis, Spectroscopy, and X-ray Crystallography of Ca, Mn, Pb, and Zn Complexes of 1,8-Anthraquinone-18-Crown-5

A lumophore composed of anthraquinone attached to a macrocyclic polyether ring containing an intraannular carbonyl is capable of selectively detecting Pb(2+)() ion in solution using an alternative photophysical detection mechanism. Of the various methods available for detection of ions in solution, a mechanism involving inversion of excited states has not been previously employed for the detection of transition and heavy metals. In this mechanism, nonradiative n-pi transitions are replaced by radiative pi-pi transitions upon complexation by a suitable guest cation. Optimum fluorescence enhancement is achieved using cations of high charge, large cations that form long bonds within the host, and cations which do not coordinate solvent or the counteranion, all of which are necessary for inversion of excited states to occur. Photophysical properties and binding constants of this new class of luminescence sensors are provided, as well as the X-ray crystallographic results for Pb(2+), Mn(2+), and Zn(2+) complexes of 1,8-oxybis(ethylene-oxyethyleneoxy)anthracene-9,10-dione (1), referred to as 1,8-anthraquinone-18-crown-5. ([1.Pb](ClO(4))(2) (2) (monoclinic, P21/n, a = 8.0303(6) A, b = 25.976(2) A, c = 12.1616(9) A, beta = 94.956(1) degrees , Z = 4, 4980 reflections [I > or = 2sigma(I)], R1 = 0.0266, wR2, 0.0500, 173(2) K). [1.Mn(H(2)O)(NCCH(3))](ClO(4))(2) (5) (monoclinic, P21/c, a = 10.132(2) A, b = 11.8030(4) A, c = 23.999(7) A, beta = 95.75(2) degrees , Z = 4, 3000 reflections [I > or = 2sigma(I)], R1 = 0.0488, wR2, 0.0938, 203(2) K). [1.Zn(H(2)O)(NCCH(3))](ClO(4))(2) (6) (monoclinic, P21/c, a = 10.177(10) A, b = 11.977(6) A, c = 24.166(4) A, beta = 95.83(4) degrees , Z = 4, 3061 reflections [I > or = 2sigma(I)], R1 = 0.0673, wR2, 0.1729, 295(2) K).).

Luminescence and structural comparisons of strong-acid sensor molecules. 2

Anthraquinone-containing cyclic polyether hosts form 1:1 complexes with hydronium ion, producing large enhancements in luminescence via inversion of npi* and pipi* exited states. We have characterized the binding of hydronium ion within these host molecules and have synthesized a large variety of analogous hosts that contain different structural and electronic features that allow better understanding of what controls binding and luminescence capacity in this class of fluorescent sensor molecules. X-ray crystallography of an anthraquinone host that contains terminal amine functional groups rather than terminal ether groups is investigated, and complete proton transfer to carbonyl groups is observed in concentrated sulfuric acid media that also produces a previously unobserved luminescence.