Optical spectra of the CoCl2/PEG systems

Experimental (FTIR, Raman, UV–visible and PL) and theoretical (DFT and TDDFT) studies on bis(8–hydroxyquinolinium) tetrachlorocobaltate(II) compound

“…Moreover, the absorption spectrum shows a characteristic multicomponent band of typical tetrahedral-like Co-complex in the visible region. They are located at 636, 665 and 689 nm and it should be attributed to the three spin-allowed d-d electronic transitions ( 4 ‫ܣ‬ ଶ (F) → 4 ܶ ଵ (p)) as expected by crystal field theory and as mentioned in some bibliographic data [54][55][56]. In addition, broad absorption band in the UV region is observed and correspond to two absorption maximum at 328 and 375 nm.…”

Synthesis, structure and antimicrobial activity of manganese(II) and cobalt(II) complexes of the polyether ionophore antibiotic Sodium Monensin A

“…The electronic spectrum obtained from MeCN solutions consists of intense bands at 595 nm (e = 222 M À1 cm À1 ) and 687 nm (e = 346 M À1 cm À1 ). The visible electronic spectrum of 3 is typical for non-simple d-d transitions in tetrahedral Co(II) complexes [58,59]. The blue colour of precipitate and its MeCN solutions suggests retention of Co(II) tetrahedral stereochemistry both in the solid state and in non-polar solvents.…”

Ligational behavior of a bidentate coumarin derivative towards CoII, NiII, and CuII: synthesis, characterization, electrochemistry, and antimicrobial studies

“…The electronic spectrum of cobalt complex consists of 3 and 2 bands assignable to tetrahedral geometry [21]. The intense band at 15,060 cm À1 is assigned as 3 arising from 4 T 1 (P) 4 A 2 (F) and the band at 7663 cm À1 is attributed to 2 …”