Metal complexes of 2,3-quinoxalinedithiol

The Electronic Structure and Spectroscopy of Metallo‐Dithiolene Complexes

“…Interestingly, variable-temperature absorption data for the oxo-molybdenum(dithiolene) complex [MoO-(quinoxaline-2,3-dithiolate) 2 ] À reveals the highly thermochromic nature of this compound. Although the observed thermochromism may be explained within the context of valence tautomerism, a more general description has recently been put forth, namely, thermally driven intramolecular CT, as this more accurately reflects the highly covalent nature of the MoÀ ÀS bonds and extreme noninnocence of the quinoxaline-2,3-dithiolate ligand (110,250,(329)(330)(331)405 À is highly thermochromic, and turns dark orange almost instantaneously upon lowering the temperature. The observed thermochromism is readily evident in the variable temperature electronic absorption spectra presented in Fig.…”

A convenient synthesis of new pyrazolylquinoxalines from 1,5-benzodiazepine-2-thione

“…IR (KBr, cm -1 ) 1620 (C=O), 1675 (C=O). 1 Thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)methylene-2-oxo-1-(3(5)-phenylpyrazol-5(3)-yl)-1,2,3,4-tetrahydroquinoxaline (10). To a solution of 6 (2x10 -3 mole) and 1.5 equiv.…”

“…227-229°C. IR (KBr, cm -1 ): 3300 (NH), 1670 cm -1 (C=O), 1221cm -1 (C=S), 1 Methyl-3,4-dihydro-3-thioxo-2H-1,2,4-triazol-5-yl)methylene-2-oxo-1-(3(5)-phenylpyrazol-5(3)-yl)-1,2,3,4-tetrahydroquinoxaline (12). A suspension of the thiosemicarbazide 11 (0.5x10 -3 mol) and 1.5 equiv.…”

“…It is well known that the quinoxaline derivatives are used as dyes to detect metals and anions. 1,2 They are also used as agrochemicals, 3 anti-virals, 4 antimicrobials, 5 and for the treatment of tuberculosis, 6 and human cancer cell lines, 7 and herbicides. 8 We have continued our investigations and prepared new quinoxaline derivatives in the hope that they may possess various pharmacological activities.…”

Recent trends in isomeric thienoquinoxalines [1980‐2000]

“…Quinoxaline derivatives have a variety of uses, such as colorimetric reagents for the detection and quantitative estimation of metals [48,49], dyes [50], and even as heatstable oil additives [51]. Some derivatives of thieno- [3,4-b]quinoxaline 1b were reported to possess analgesic and anti-inflammatory activities [42,52].…”