429-42-5Relevant articles and documents
Electrochemical studies of the nickel catecholate complexes for detection of sulphur dioxide gas
Tembwe, Inonge,Ngila, J. Catherine,Kgarebe, Boitumelo,Darkwa, James,Iwuoha, Emmanuel
, p. 4314 - 4318 (2010)
Nickel catecholate complexes, bis(diphenylphosphino)ethanenickelcatecholate [(dppe)NiO2C6H34-R1] R1 = CH3 (1), C(CH3)3 (2), H (3) and F (4)] were studied using CV and
Controlling Metal-to-Oxygen Ratios via M=O Bond Cleavage in Polyoxovanadate Alkoxide Clusters
Petel, Brittney E.,Fertig, Alex A.,Maiola, Michela L.,Brennessel, William W.,Matson, Ellen M.
, p. 10462 - 10471 (2019)
In this manuscript, we further investigate the use of Lindqvist polyoxovanadate alkoxide (POV-alkoxide) clusters as homogeneous molecular models of reducible metal oxides (RMO), focusing on the structural and electronic consequences of forming one or two oxygen-deficient sites. We demonstrate the reactivity of a neutral POV-alkoxide cluster, [V6O7(OCH3)12]0, with a reductant, revealing routes for controlling metal-to-oxygen ratios in self-assembled polynuclear ensembles through post-synthetic modification. The outlook of this science is bolstered by the fact that, in both cases, O-atom removal reveals reduced V ions at the surface of the cluster. Extending our entry into small-molecule activation mediated by surface defect sites, we report the reactivity of mono- and divacant clusters with a model substrate, tert-butyl isocyanide, demonstrating the electronic consequences of small-molecule coordination to reduced ions in RMO materials.
Assessing the Electrocatalytic Properties of the (Cp*RhIII)2+-Polyoxometalate Derivative [H2PW11O39(RhIIICp*(OH2))]3- towards CO2 Reduction
Girardi, Marcelo,Platzer, Dominique,Griveau, Sophie,Bedioui, Fethi,Alves, Sandra,Proust, Anna,Blanchard, Sébastien
, (2018)
Storage of electricity produced intermittently by renewable energy sources is a societal issue. Besides the use of batteries and supercapacitors, conversion of excess electricity into chemical energy is also actively investigated. The conversion of CO2 to fuel or fuel precursors is an option that requires the use of a catalyst to overcome the high activation energy barrier. Of molecular catalysts, metal complexes with polypyridyl ligands are well represented, among which the [Cp*Rh(bpy)Cl]+ and [M(bpy)(CO)3X] (M = Re, Mn) complexes. As redox non-innocent ligand, the bipyridine ligand is generally involved in the reduction mechanisms. It is thus tempting to replace it by other redox non-innocent ligands such as vacant polyoxometalates (POMs). We have thus prepared [α-H2PW11O39(RhIIICp*(OH2))]3- which is closely related to [Cp*RhIII(bpy)Cl]+ by substitution of the monovacant [PW11O39]7- Keggin-type POM for the bipyridine ligand. Its activity towards CO2 reduction has been assessed in acetonitrile in the presence of water. Compared to [Cp*Rh(bpy)Cl]+ that produces formate selectively over CO and H2, the POM derived catalyst favors proton reduction over CO2 reduction.
Stereoelectronic and Resonance Effects on the Rate of Ring Opening of N-Cyclopropyl-Based Single Electron Transfer Probes
Grimm, Michelle L.,Suleman, N. Kamrudin,Hancock, Amber N.,Spencer, Jared N.,Dudding, Travis,Rowshanpour, Rozhin,Castagnoli, Neal,Tanko, James M.
supporting information, p. 2640 - 2652 (2020/02/18)
N-Cyclopropyl-N-methylaniline (5) is a poor probe for single electron transfer (SET) because the corresponding radical cation undergoes cyclopropane ring opening with a rate constant of only 4.1 × 104 s-1, too slow to compete with other processes such as radical cation deprotonation. The sluggish rate of ring opening can be attributed to either (i) a resonance effect in which the spin and charge of the radical cation in the ring-closed form is delocalized into the phenyl ring, and/or (ii) the lowest energy conformation of the SET product (5a¢+) does not meet the stereoelectronic requirements for cyclopropane ring opening. To resolve this issue, a new series of N-cyclopropylanilines were designed to lock the cyclopropyl group into the required bisected conformation for ring opening. The results reveal that the rate constant for ring opening of radical cations derived from 1′-methyl-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-quinoline] (6) and 6′-chloro-1′-methyl-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-quinoline] (7) are 3.5 × 102 s-1 and 4.1 × 102 s-1, effectively ruling out the stereoelectronic argument. In contrast, the radical cation derived from 4-chloro-N-methyl-N-(2-phenylcyclopropyl)aniline (8) undergoes cyclopropane ring opening with a rate constant of 1.7 × 108 s-1, demonstrating that loss of the resonance energy associated with the ring-closed form of these N-cyclopropylanilines can be amply compensated by incorporation of a radical-stabilizing phenyl substituent on the cyclopropyl group. Product studies were performed, including a unique application of EC-ESI/MS (Electrochemistry/ElectroSpray Ionization Mass Spectrometry) in the presence of 18O2 and H218O to elucidate the mechanism of ring opening of 7a¢+ and trapping of the resulting distonic radical cation.
Charge-Assisted phosph(v)azane anion receptors
Bond, Andrew D.,Goodman, Jonathan M.,Lee, Sanha,Plajer, Alex J.,Wright, Dominic S.
, p. 3403 - 3407 (2020/04/02)
Coordination of Cu(i) or Pd(ii) to seleno-cyclodiphosph(v)azanes of the type [RNH(Se)P(μ-NtBu)]2 results in positively charged anion receptor units which have increased anion affinity over the neutral seleno-phosph(v)azanes, due to the increase in electrostatic interactions between the receptor and the guest anions. The same effect is produced by replacement of one of the PSe units by a P-Me+ unit.