The direct electrochemical reduction of nicotinamide adenine dinucleotide (NAD⁺) results in various products, complicating the regeneration of the crucial 1,4‐NADH cofactor for enzymatic reactions. Previous research primarily focused on steady–state polarization to examine potential impacts on product selectivity. However, this study explores the influence of dynamic conditions on the selectivity of NAD⁺ reduction products by comparing two dynamic profiles with steady‐state conditions. Our findings reveal that the main products, including 1,4‐NADH, several dimers, and ADP‐ribose, remained consistent across all conditions. A minor by–product, 1,6‐NADH, was also identified. The product distribution varied depending on the experimental conditions (steady state vs. dynamic) and the concentration of NAD⁺, with higher concentrations and overpotentials promoting dimerization. The optimal yield of 1,4‐NADH was achieved under steady–state conditions with low overpotential and NAD⁺ concentrations. While dynamic conditions enhanced the 1,4‐NADH yield at shorter reaction times, they also resulted in a significant amount of unidentified products. Furthermore, this study assessed the potential of using pulsed electrochemical regeneration of 1,4‐NADH with enoate reductase (XenB) for cyclohexenone reduction.

Two new main group element carboranylamidinates were synthesized using a bottom-up approach starting from o-carborane, ortho-C₂B₁₀H₁₂ (1, = 1,2-dicarba-closo-dodecaborane). The first divalent germanium carboranylamidinate, GeCl[HL^Cy] (3, [HL^Cy]⁻ = [o-C₂B₁₀H₁₀C(NCy)(NHCy)]⁻, Cy = cyclohexyl), was synthesized by treatment of GeCl₂(dioxane) with 1 equiv. of in situ-prepared Li[HL^Cy] (2a) in THF and isolated in 47% yield. In a similar manner, the first antimony(III) carboranylamidinate, SbCl₂[HL^iPr] (4, [HL^iPr]⁻ = [o-C₂B₁₀H₁₀C(NⁱPr)(NHⁱPr)]⁻), was obtained from a reaction of SbCl₃ with 1 equiv. of Li[HL^iPr] in THF (56% yield). The title compounds were fully characterized by analytical and spectroscopic methods as well as single-crystal X-ray diffraction. Both compounds 3 and 4 are monomeric species in the solid state, and the molecular geometries are governed by a stereo-active lone pair at the metal centers.

Treatment of N,N′-diisopropylcarbodiimide with sodium cyclopentadienide (NaCp) in a molar ratio of 1:1 in THF solution resulted in formation of the unexpected dinuclear sodium half-sandwich complex [NaC₅H₃{C(NHⁱPr)(=NⁱPr)}₂-1,2]₂ (1) as colorless crystals in low yield. The newly formed ligand, which belongs to the group of 6-aminofulvene-2-aldiminate ligands, coordinates to sodium in an η⁵-coordination mode via the cyclopentadienyl ring. Dimerization occurs through additional chelating κN,N′-coordination of the amidine substituents. The NMR data of 1 indicated a slow dimer/monomer equilibrium in solution. A serendipitously isolated hydrolysis product, {µ-(ⁱPrNH)₂C=O}₂[NaC₅H₃{C(NHⁱPr)(=NⁱPr)}₂-1,2]₂ (2), contains the new 6-aminofulvene-2-aldiminate ligand in the N,N′-chelating coordination mode with the cyclopentadiene ring being uncoordinated. In this case, dimerization occurs through the presence of two bridging neutral N,N′-diisopropylurea ligands. Both compounds have been structurally characterized by single-crystal X-ray diffraction.