Second‐Sphere Biomimetic Multipoint Hydrogen‐Bonding Patterns to Boost CO₂ Reduction of Iron Porphyrins

Abstract

CO2‐Reduktion Harnstoffgruppen in einem Eisenporphyrinkatalysator führen zu einer mehrfachen Stabilisierung von CO2 durch Wasserstoffbrücken. Wie Z. Halime, A. Aukauloo et al. in ihrer Zuschrift auf S. 4552 zeigen, hat der Katalysator eine hohe Aktivität in der CO2‐Reduktion.

Tuning coordination chemistry through the second sphere in designed metallocoiled coils

“…Our original design, which featured an Ile as the second sphere residue generates a highly hydrated site with three waters bound to the Tb 3+ . 15 Replacing the relatively bulky Ile with the sterically undemanding Ala, did not increase the hydration state, as may have been expected. 8,9 This suggests when the double AsnAsp binding site is presented, that the maximum Tb 3+ hydration state is three.…”

“…Though we previously found evidence of 3.6 waters bound when only the Asp layer is available. 15 When the second sphere residue is Phe, the Tb 3+ hydration state is reduced to two bound waters, which could be due to greater sterics of the benzyl side chain. On incorporation of Tyr, the data is consistent with only one bound water.…”

“…14 This profound change in coordination chemistry should be mirrored by the MRI properties of the Gd 3+ complex. 15 The longitudinal (r 1 ) and transverse (r 2 ) relaxivity of the Gd(MB1-1(2W)) 3 complex at 7 T (Fig, S10 (ESI †) and Table 2; r 1 = 3.9 AE 0.4 mM À1 s À1 and r 2 = 24.2 AE 2.4 mM À1 s À1 ) are the same within error to those reported previously for Gd(MB1-2) 3 ( Table 2), 15 consistent with no bound water molecules ( Table 2). 15 Merely changing the non-coordinating second sphere residue directly above the Gd 3+ binding site, Ile -Trp, leads to an almost four-fold reduction in transverse relaxivity.…”

Unexpected Effect of Intramolecular Phenolic Group on Electrocatalytic CO2 Reduction

“…Fe porphyrins have received considerable attention among these catalysts . They show high activity and stability for the selective CO 2 ‐to‐CO conversion, and they provide an ideal platform to investigate various structural effects on CO 2 RR, because the meso ‐substituents of the porphyrin ring can be systematically modified to introduce different acid/base groups and positively/negatively charged moieties .…”

Thermal Reactivity in Metal Organic Materials (MOMs): From Single-Crystal-to-Single-Crystal Reactions and Beyond

“…For instance, in biochemistry [49,50], second sphere interactions were successfully used to determine activity and selectivity of certain metalloenzymes, and also in homogenous catalysis with the scope of replicating active sites found in enzymes [51]. Also, CO 2 reduction using outer sphere biomimetic hydrogen bonds were applied in iron porphyrins [52]. In the solid-state second sphere coordination has been applied to study selective gold separation [53], gas adsorption [54], ferromagnetic behavior [55], and to build 3D and 2D perovskites as optically active materials [56].…”