Optical and ESR studies of one-electron reduction of alkylcobaloximes in rigid matrixes

Unraveling a Single-Step Simultaneous Two-Electron Transfer Process from Semiconductor to Molecular Catalyst in a CoPy/CdS Hybrid System for Photocatalytic H2 Evolution under Strong Alkaline Conditions

“…Semi-in situ X-band EPR spectra (100 K) of CoPy/CdS hybrid systems under different pH conditions were measured by quenching the samples immediately in liquid nitrogen after 5–90 min photoirradiation. The reference EPR spectrum of Co­(II)­Py ( g ⊥ = 2.26; g ∥ = 2.14) generated by reducing Co­(III)­Py using NaBH 4 in alkaline condition is similar to that reported in the literature (Figure a) . Under the same pH conditions (pH 6.0, 10.0, and 13.5), CoPy/CdS hybrid systems showed similar EPR spectra in all cases during 5–90 min photoirradiation time (Figure S8).…”

“…The reference EPR spectrum of Co(II)Py (g ⊥ = 2.26; g ∥ = 2.14) generated by reducing Co(III)Py using NaBH 4 in alkaline condition is similar to that reported in the literature (Figure 3a). 24 Under the same pH conditions (pH 6.0, 10.0, and 13.5), CoPy/CdS hybrid systems showed similar EPR spectra in all cases during 5−90 min photoirradiation time (Figure S8). The typical EPR spectra of CoPy/CdS hybrid systems measured immediately after 90 min photoirradiation at pH 6.0, 10.0, and 13.5 are shown in Figure 3a.…”

Electron Transfer and Alkyl Transfer with Cobaloximes in Aqueous Solutions. Kinetic Studies by Pulse Radiolysis

“…The reduced product is found to exist predominantly in the monomeric form of (H20)(dmgH)2Cou (dinuclear Co11 complexes have been shown to form at low temperatures).24 Loss of the Ch ion is expected because of the neutral charge of the product and because Co11 is generally pentacoordinated, as has been reported before. 24 Exchange of water for the pyridine ligand is expected at low concentrations (ca. 10-4 mol L_1) based on the equilibrium constant K9= 128 L moh1.25 (H20)(dmgH)2CoiI + py py(dmgH)2Con + H20…”

“…species are generally four-coordinated [12][13][14][15][16][17][19][20][21][22][23][24][25][26][27][28][29] Radiolytic Formation of Alkyl-Co™ Complexes. Alkyl-Co™ complexes are generally formed by reaction of Co1 complexes with alkyl halides or by reaction of Co11 complexes with alkyl radicals and are stable in aerated solutions.7-Radiolysis of deoxygenated aqueous solutions containing 0.2 mM Cl(py)-dmgH)2Com, 10% 2-PrOH, and 2 mM benzyl chloride or 4-carboxybenzyl chloride led to the formation of CeHs-CH2(py)(dmgH)2Co™ or 4-H02CC6H4CH2(py)(dmgH)2Co™ according to the following reactions (where PhCH2 represents T h i s c o n t e n t i s o n l y l i c e n s e d f o r c o n s u i v i d u a l n o t d i r e c t l y a s s o c i a t e d w i t h s c i t e i s p r o h i b i t e d .…”

Transition Metal Complexes of Oxamide Oxime, 1. Synthesis and X-Ray Crystal Structure of Tris(oxamide oxime-N1,N1′)cobalt(III) Triiodide [Co(H2oxao)3]I3

“…The primary focus has been their structural morphology which makes them appear as the simplest models, outstandingly suited to mimic and, eventually, elucidate systematically the origin of the biological activity of cyanocobalamins or co enzyme vitamins of the B12 series [1,3]. Along these lines, we have recently published a number of co baloximatic systems based on ethanedial dioxime (or glyoxime) as the "pristine" ligand system of this series [4 -6 ].…”