Co(II)(l-proline)2(H2O)2 solid complex: Characterization, magnetic properties, and DFT computations. Preliminary studies of its use as oxygen scavenger in packaging films

L‐Proline/CoCl2‐Catalyzed Highly Diastereo‐ and Enantioselective Direct Aldol Reactions

“…It has been established that metal(II) ions interact with amino acids in a 1:2 ratio, [12] moreover, a crystal structure of ZnCl 2 (l-proline) 2 has already been described by Lutz and Bakker under neutral conditions. [14] In analogy, we therefore propose that initially two molecules of proline are bound through the carboxylate groups to cobalt(II), giving rise to 10 (Scheme 2).…”

“…[12] Consequently, we screened a variety of readily available 1:2 metal(II) chloride/proline complexes, which were prepared in situ, for the aldol reaction between cyclohexanone (1 a) and 4-nitrobenzaldehyde (2 a) in DMSO; the latter being the optimum solvent for this reaction with proline as catalyst.…”

Toward New Polymeric Oxygen Scavenging Systems: Formation of Poly(vinyl alcohol) Oxygen Scavenger Film

“…The Co( l ‐Thr) 2 (OH 2 ) 2 solid complex synthesis was already described in details elsewhere, and only a brief description will be presented here. The oxygen scavenger complex was prepared in a glove box under inert N 2 atmosphere (O 2 < 1 vpm) by mixing cobalt chloride salt dissolved in outgassed water and l ‐threonine ( l ‐Thr) dissolved in an outgassed solution of KOH 1 M (molar conditions: 1 : 2 : 2).…”

Speciation studies of Co(II), Ni(II) and Cu(II) complexes of L-valine in acetonitrile–water mixtures

“…In aqueous solutions metal ions are coordinated by six water molecules. Amino acids replace water molecules and form metal-amino acid complexes (Chen et al, 2000a,b;Damaj et al, 2009;Patil et al, 2009) nitrogen can associate with hydrogen ions in physiological pH ranges. Hence, there is often significant competition between hydrogen and metal ion for this donor site and it results in the formation of protonated species.…”