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The escalating concentration of carbon dioxide in the atmosphere is a pressing environmental concern, necessitating the development of efficient technologies for CO 2 reduction and utilization. In this context, metal-organic frameworks (MOFs) emerge as promising catalysts due to their tunable structures and unique chemical properties. This study focuses on the synthesis, characterization, and evaluation of amino-functionalized MOFs with cobalt and nickel nodes for the electrochemical reduction of CO 2 . Electrochemical investigations reveal that a cobalt-based MOF primarily facilitates the production of methane, demonstrating high selectivity and efficiency under controlled conditions. In contrast, a nickel-based MOF exhibits a broader array of reduction products, including methane, CO, and ethanol, with a significant conversion efficiency. These differences underscore the impact of the central metal node on the catalytic activity and product distribution. This comprehensive study not only advances our understanding of MOF-based catalysts for CO 2 reduction but also underscores the significance of molecular engineering in enhancing the selectivity and efficiency of these processes. By demonstrating the potential of amino-functionalized MOFs with specific metal nodes, we contribute to the development of sustainable solutions for carbon capture and utilization, aligning with global efforts to mitigate climate changes and foster a green chemical industry.

The structure of the two intramolecular hydrogen-bonded motifs within ferrocene-1,1'-diyl-bisphosphinic acid, a cyclic dimer and a homoconjugated anion, has been experimentally revealed by NMR spectroscopy for a solution in a low-freezing polar aprotic CDF 3 /CDF 2 Cl medium at 100 K. Structure elucidation was achieved with the help of the H/D isotope effects on the 1 H, 2 H and, for the first time, 31 P NMR chemical shifts. The questions of bridging hydron localization and origins of opposite signs of H/D isotope effects on the 31 P NMR chemical shifts in the cyclic dimer and homoconjugated anion have also been addressed by DFT calculations, including numerical solution of the Schrödinger equation for proton and deuteron vibrations in the anharmonic double well potentials.

This paper illustrates how the size and type of substituent R in the phosphinate group of ferrocenyl bisphosphinic acids can affect conformational possibilities and coordination packing. It also demonstrates that H -phosphinate plays a key role in variational mobility, while Me- or Ph- substituents of the phosphinate group can only lead to 0D complexes or 1D coordination polymer. Overall, this paper provides valuable insights into the design and construction of coordination polymers based on ferrocene-contained linkers. It sheds light on how different reaction conditions and substituents can affect conformational possibilities and coordination packing, which could have significant implications for developing new polymers with unique properties.

Heteroleptic 2,3,4,5-tetraphenyl-1-monophosphaferrocene [FeCp(η 5 -PC 4 Ph 4 )] was obtained at a 62% yield through the reaction of lithium 2,3,4,5-tetraphenyl-1-monophosphacyclopentadienide Li(PC 4 Ph 4 ) ( 1 ) with [FeCp(η 6 -C 6 H 5 CH 3 )][PF 6 ]. The structure of 1-monophosphaferrocene 2 and its W(CO) 5 -complex 3 were confirmed by multinuclear NMR and single-crystal X-ray diffraction study and further supported by DFT calculations. Cyclic voltammetry demonstrated that [FeCp(η 5 -PC 4 Ph 4 )] 2 has a quasi-reversible oxidation wave. The comparison of the properties of phosphaferrocene 2 with those of W(CO) 5 -complex 3 shows the possibility of changing the coordination type during oxidation.

Racemic and enantiopure ferrocene-based P -chiral amidophosphinates have been simply and stereoselectively synthesized by ortho -lithiation of rac - or ( R )-Ugi's amine and further reaction with amidochlorophenylphosphinate Cl-P(O)(Ph)NEt 2 . This is the first example of an asymmetric reaction of ortho -lithiated Ugi's amine with tetracoordinated phosphorus(V) chlorides. The structures of rac - and ( R )-Ugi's amine ferrocenyl(phenyl)phosphinic acid N , N -diethylamide have been extensively studied experimentally (NMR, X-ray analysis, electrochemistry). The CV first peak refers to the oxidation of the amine fragment, which is clearly seen when ( R )-Ugi's amine ferrocenyl(phenyl)phosphinic acid N , N -diethylamide reacts with anhydrous acid. The addition of two equivalents of CF 3 COOH leads to the protonation of nitrogen atoms, and a classical reversible wave of oxidation of Fe(II) to Fe(III) is observed.

A coordination polymer has been synthesized using ferrocene-based ligand-bearing phosphinic groups of 1,1'-ferrocene-diyl-bis( H -phosphinic acid)), and samarium (III). The coordination polymer's structure was studied by both single-crystal and powder XRD, TG, IR, and Raman analyses. For the first time, the Mössbauer effect studies were performed on ferrocenyl phosphinate and the polymer based on it. Additionally, the obtained polymer was studied by the method of cyclic and differential pulse voltammetry. It is shown that it has the most positive potential known among ferrocenyl phosphinate-based coordination polymers and metal-organic frameworks. Using the values of the oxidation potential, the polymer was oxidized and the ESR method verified the oxidized Fe(III) form in the solid state. Additionally, the effect of the size of the phosphorus atom substituent of the phosphinate group on the dimension of the resulting coordination compounds is shown.

A triferrocenyl trithiophosphite was studied by X-ray single-crystal diffraction. Triferrocenyl trithiophosphite has nine axes of internal rotation: three P-S bonds, three C-S bonds and three Fe-cyclopentadienyl axes. Rotation around the P-S bonds results in a totally asymmetric structure with three ferrocenylthio groups exhibiting different orientations towards the phosphorus lone electron pair (LEP). A comparison of DFT calculations and X-ray diffraction data is presented, herein we show which conformations are preferred for a given ligand., (Copyright © 2022, Shekurov et al.)

The reaction between aryl substituted sodium 1,2,3-triphospholides or disodium bis(1,2,3-triphospholide) and [Fe(η6-(C6H5CH3)Cp]+[PF6]- in boiling diglyme results in pure 1,2,3-triphosphaferrocenes 1-3 or bis(1,2,3-triphosphaferrocene) 4, respectively, in good yields. The structure of all obtained 1,2,3-triphosphaferrocenes 1-4 has been extensively studied experimentally (NMR, UV-Vis spectroscopy, and X-ray analysis for 1 and 4) and quantum chemically. The electrochemical properties of 1,2,3-triphosphaferrocenes 1-4 in the solid state were studied for the first time and a reversible one-electron oxidation (E1/2 = 0.52-0.92 V vs. Fc+/Fc) was demonstrated for 1, 3, and 4. In the case of 1,4-bis(5-phenyl-4-(1,2,3-triphospaferrocenyl))benzene 4, consecutive oxidation in the solid state is observed in contrast to other 1,2,3-triphosphaferrocenes 1-3. According to the ESR data, the g-factor of the oxidized bis(1,2,3-triphosphaferrocene), 4 (g = 2.12) is different from the g-factors of oxidized 1,2,3-triphosphaferrocenes 1-3 (g = 2.01). This is the first example of multi(ferrocenyl) systems based on the phosphaferrocene motif, which in turn opens up a new fundamental platform for the preparation of compounds with stimuli-responsive properties.