Coordination complexes of iron(III) with 3-hydroxy-2(1H)-pyridinone, 2,3-dihydroxybenzoic acid and 3,4-dihydroxybenzoic acid: preparation and characterization in the solid state

The Role of the −OH Groups within Mn12Clusters in Electrocatalytic Water Oxidation

“…This observation suggests that 2,3-DHBA might bind to the Mn-oxo core in ad ifferent binding mode than the typical carboxylate binding mode known for Mn 12 clusters. The ligand 2,3-DHBA has several possible binding modes resulting from the structural proximity of the ÀOH substituent to the carboxylic acid; these include the typical bridging binding mode present in Mn 12 clusters, whichi nvolves the carboxylic edge only, [27] and the salicylate binding mode that involves bindingt hrough the acid and the adjacent ÀOH substituent, as studied for various metals complexese mploying such ligand [33][34][35][36][37][38][39] (Scheme 2). The bindingm ode of 2,3-DHBAtom etal centers should be pH controlled because it depends on the abstraction of the proton from the ortho ÀOH group.…”

“…These include the appearanceo fanew bend at 788 cm À1 corresponding to 1,2,3 tri-substituted benzene for 2,3DHMn 12 (based on comparison between the spectra of 2,3DHMn 12 and its free ligand, 2,3DHBA, Figure S8 B) and as hift in n(CÀOH) band relatively to Mn 12 DH,w hichc an be explained by the existence of strong hydrogen bonds between adjacent phenolic OHs and the carbonyl [40] in 2,3DHMn 12 .I mportantly,anew peak at 1490 cm À1 , assigned to CÀCr ing stretching mode was observed, and this is ac haracteristic spectralf eature of metal complexes employing the catechol-type ligands indicating the formation of a salicylate complex. [38,41] S6 and S7). Even thought he full mass could not be detected, the obtained masses were assigned to the clusterb ased on the high 4-fold symmetryo ft hese clusters is presenting.…”

Liquid-Liquid Extraction-Chromogenic Systems Containing Iron(III), 4-Nitrocatechol and Tetrazolium Salts

“…Iron is an important environmental and bioelement, which forms complexes with various catecholicligands [1][2][3][4][5][6][7] . The complexation behaviour of Fe(III) towards the well-known analytical reagent 4-nitrobenzene-1,2-diol (4-nitrocatechol, 4NC) (8,9) has been studied in connection with designing new chelators for treating iron overload 10,11 , nonheme iron-containing enzymes [12][13][14] , surface chemistry 15 , chemistry of the marine environment 16 , stability assessment and comparative studies 17 .…”

Electrospray mass spectral studies on molybdenum complexes with 2,3‐ and 2,5‐dihydroxybenzoic acid and their degradation products

“…Metal complexes of these ligands have been studied by our group in the past, focusing on the type of coordination and their degradation mimicking the above biological systems, e.g. with iron, 8 cadmium, 9 molybdenum, 10 manganese, 11 vanadium 12 and nickel, 13 by spectroscopic techniques including electrospray mass spectrometry (ESMS).…”