Fixing Carbon Dioxide with Copper:  Crystal Structure of [LCu(μ-C₂O₄)CuL][Ph₄B]₂ (L = N,N‘,N‘ ‘-Triallyl-1,4,7-triazacyclononane)

A copper(II)–oxalate compound resulting from the fixation of carbon dioxide: μ-oxalato-bis[bis(1-benzyl-1H-pyrazole)(trifluoromethanesulfonato)copper(II)]

“…As part of our continuing interest in the chemistry of Cucontaining complexes (Stibrany et al, 2002(Stibrany et al, , 2003(Stibrany et al, , 2004, we attempted to prepare a tris(N-benzylpyrazole) complex of Cu I and obtained instead the oxalate-containing title compound, (I), in which the oxalate ion appears to have been formed by the reductive coupling of adventitious CO 2 . Reductive coupling of CO 2 , induced by metal complexes, to afford oxalate is rare, and we are aware of only one such example, the salt -oxalato-1 2 O 1 ,O 2 :2 2 O 1 0 ,O 2 0 -bis(triallyl-1,4,7-triazacyclononane)copper(II) bis(tetraphenylborate), (II), in which a Cu I complex served as the reducing agent (Farrugia et al, 2001). In that case also, the product was originally obtained serendipitously.…”

Controlling selectivity in the reductive activation of CO2 by mixed sandwich uranium(iii) complexes

“…15 Whilst the reductive coupling of CO 2 to the oxalate dianion may be achieved by reaction of CO 2 with molten alkali metals or their amalgams, 16 well defined molecular systems that will undergo this reaction are very rare. 17,18 Indeed, the best known example of clean, reductive coupling of CO 2 to the oxalate dianion remains that first reported by Evans several years ago using the divalent lanthanide complex Sm(η 5 -Cp * ) 2 (THF) 2 , 19,20 and later extended to other lanthanide metal centres. 21 To the best of our knowledge such a transformation has not been previously reported using uranium or indeed any actinide metal centre.…”

Synthesizing High‐Volume Chemicals from CO2 without Direct H2 Input

“…Oxalic acid produced from CO 2 can be used as an intermediate to synthesize high‐volume bulk chemicals such as ethylene glycol (20000 ktpa) [21] . CO 2 dimerization to oxalic acid is almost entirely performed using homogeneous [160] or heterogeneous electrochemical systems [161] . One potential way of avoiding direct hydrogen input is to use hydrogen generated through biomass reforming at the anode.…”