Children learn through play, and they learn more than adults might expect. Science experiments are a great way to spark their curiosity, get their minds active, and encourage them to do something that doesn’t involve a screen. 12150-46-8, C34H28FeP2. A document type is Article, introducing its new discovery., Quality Control of: 1,1-Bis(diphenylphosphino)ferrocene
Heating the 50-electron cluster [Fe3(CO)9 (mu3-Te)2] (1) with the diphosphines Ph2P-R-PPh2 [R = -CH2CH2- (dppe), Z-CH=CH- (dppv), 1,2-C6H4 (dppb), -CH2CH2CH2- (dpp), ferrocenyl (dppf), naphthalenyl (dppbn)] in benzene affords the 52-electron diphosphine-containing tellurium-capped triiron clusters [Fe3(CO)8 (mu3-Te)2 (kappa2-diphosphine)] (diphosphine = dppe, dppv, dppb, dpp, dppf, dppnd) (2?7) in moderate yields, resulting from both phosphine addition and carbonyl loss. With 1,2-bis(diphenylphosphino)benzene (dppb) a second product is the cubane cluster [Fe4(CO)10(mu3-Te)4 (kappa2-dppb)] (8). Cyclic voltammetry measurements on 2?7 reveal that all clusters show irreversible reductive behaviour at ca. ?1.85 V with a series of associated small back oxidation waves, suggesting that reduction leads to significant structural change but that this can be reversed chemically. Oxidation occurs at relatively low potentials and is diphosphine-dependent. The first oxidation appears at ca. +0.35 V for 2?6 with a small degree of reversibility but is as low as +0.14 V for the bis(diphenylphosphino)naphthalene derivative 7 and in some cases is followed by further closely-spaced oxidation. Addition of [Cp2Fe][PF6] to 2?7 results in the formation of new clusters formulated as [Fe3(CO)8(mu3-Te)2(kappa2-diphosphine)]+, with their IR spectra suggesting oxidation at the diiron centre. This is supported by computational studies (DFT) of the bis(diphenylphosphino)propane cluster 5 showing that the HOMO is the Fe?Fe sigma-bonding orbital, while the LUMO is centered on the diphosphine-substituted iron atom and has significant Fe?Te sigma?-anti-bonding character consistent with the irreversible nature of the reduction. Complexes 2?7 have been examined as proton reduction catalysts in the presence of para-toluenesulfonic acid (TsOH). All are active at their first reduction potential, with a second catalytic process being observed at slightly higher potentials. While their overall electrocatalytic behaviour is similar to that noted for [Fe2(CO)6{mu-E(CH2)3E}] (E = S, Se, Te), the DFT results suggest that as the added electron is localised on the unique iron atom. The mechanistic aspects of hydrogen formation are likely to be quite different from the more widely studied diiron models.
Interested yet? Keep reading other articles of 12150-46-8!, Quality Control of: 1,1-Bis(diphenylphosphino)ferrocene
Reference:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate