Dataset for Modelling Reaction Mechanisms Using Density Functional Theory: Mechanism of ortho-Hydroxylation by High-Valent Iron-Oxo Species

Modelling reaction mechanisms using density functional theory is one of the popular routes to underpin the course of a chemical reaction. Although numerous publications have come out in this area, the pitfall of modelling such reactions and explicitly publishing the entire data set (structures, energies, coordinates, spin densities, etc.) which lead to the conclusions are scarce. Here we have attempted to set a trend wherein all the computed data to underpin the reaction mechanism of ortho-hydroxylation of aromatic compounds by high-valent iron-oxo complexes (FeIII–OOH, FeIV=O, and FeV=O) are collected. Since the structure, energetics and other details of the calculations can be employed in future to probe/understand the reactivity pattern of such species, establishing the data set is justified. Here by analysing the presented results we also discuss in brief the presented results

Effect of a behaviour-change intervention on handwashing with soap in India (SuperAmma): a cluster-randomised trial.

BACKGROUND: Diarrhoea and respiratory infections are the two biggest causes of child death globally. Handwashing with soap could substantially reduce diarrhoea and respiratory infections, but prevalence of adequate handwashing is low. We tested whether a scalable village-level intervention based on emotional drivers of behaviour, rather than knowledge, could improve handwashing behaviour in rural India. METHODS: The study was done in Chittoor district in southern Andhra Pradesh, India, between May 24, 2011, and Sept 10, 2012. Eligible villages had a population of 700-2000 people, a state-run primary school for children aged 8-13 years, and a preschool for children younger than 5 years. 14 villages (clusters) were selected, stratified by population size (1200), and randomly assigned in a 1:1 ratio to intervention or control (no intervention). Clusters were enrolled by the study manager. Random allocation was done by the study statistician using a random number generator. The intervention included community and school-based events incorporating an animated film, skits, and public pledging ceremonies. Outcomes were measured by direct observation in 20-25 households per village at baseline and at three follow-up visits (6 weeks, 6 months, and 12 months after the intervention). Observers had no connection with the intervention and observers and participant households were told that the study was about domestic water use to reduce the risk of bias. No other masking was possible. The primary outcome was the proportion of handwashing with soap at key events (after defecation, after cleaning a child's bottom, before food preparation, and before eating) at all follow-up visits. The control villages received a shortened version of the intervention before the final follow-up round. Outcome data are presented as village-level means. FINDINGS: Handwashing with soap at key events was rare at baseline in both the intervention and control groups (1% [SD 1] vs 2% [1]). At 6 weeks' follow-up, handwashing with soap at key events was more common in the intervention group than in the control group (19% [SD 21] vs 4% [2]; difference 15%, p=0·005). At the 6-month follow-up visit, the proportion handwashing with soap was 37% (SD 7) in the intervention group versus 6% (3) in the control group (difference 31%; p=0·02). At the 12-month follow-up visit, after the control villages had received the shortened intervention, the proportion handwashing with soap was 29% (SD 9) in the intervention group and 29% (13) in the control group. INTERPRETATION: This study shows that substantial increases in handwashing with soap can be achieved using a scalable intervention based on emotional drivers. FUNDING: Wellcome Trust, SHARE

Chemical and in silico tuning of the magnetisation reversal barrier in pentagonal bipyramidal Dy(III) single-ion magnets

Two new air-stable axial Dy(III) Single-Ion Magnets, [Dy(H2O)5(HMPA)2]Cl3·HMPA·H2O (1) and [Dy(H2O)5(HMPA)2]I3 ·2HMPA (2) (HMPA = hexamethylphosphoramide), exhibit magnetic hysteresis which remains open up to 9 K for 1@Y and 10 K for 2@Y, respectively. Ab initio calculations, using step-by-step elimination of fragments to generate a series of model complexes, reveal that the secondary coordination sphere plays a key role in controlling the magnetisation reversal barrier and predict that the removal of outer-sphere molecules and anions will enhance the barrier further

Magnetic properties of a family of [MnIII4LnIII4] wheel complexes: an experimental and theoretical study

The chelating ligand 1,3-bis(tris(hydroxymethyl)methylamino)propane (H6L) has been used to synthesize a family of octanuclear heterometallic complexes with the formula (NMe4)3[Mn4Ln4(H2L)3(H3L)(NO3)12] (Ln = La (1), Ce (2), Pr (3), Nd (4)). Encapsulation by the ligand causes the Mn(III) centers to lie in an unusually distorted (∼C2v) environment, which is shown by density functional theory and complete active space self-consistent field calculations to impact on the magnetic anisotropy of the Mn(III) ion. The theoretical study also supports the experimental observation of a ferromagnetic superexchange interaction between the Mn(III) ions in 1, despite the ions being separated by the diamagnetic La(III) ion. The optical properties of the compounds show that the distortion of the Mn(III) ions leads to three broad absorption bands originating from the transition metal ion, while the Nd(III) containing complex also displays some weak sharp features arising from the lanthanide f–f transitions

Engineering macrocyclic high performance pentagonal bipyramidal Dy(iii) single-ion magnets

We generate a new air-stable pseudo-D5h Dy(III) Single-Molecule Magnet (Ueff = 1108 K, TB = 14 K) by combining a weak equatorial ligand field from a macrocyclic LN5 ligand with a strong axial ligand field. Based on our synthetic blueprint, we use ab initio calculations to show the vast scope for macrocyclic engineering of magnetic anisotropy

Enhancement of TbIII-CuII single-molecule magnet performance through structural modification

We report a series of 3d–4f complexes {Ln2Cu3(H3L)2Xn} (X=OAc−, Ln=Gd, Tb or X=NO3−, Ln=Gd, Tb, Dy, Ho, Er) using the 2,2′-(propane-1,3-diyldiimino)bis[2-(hydroxylmethyl)propane-1,3-diol] (H6L) pro-ligand. All complexes, except that in which Ln=Gd, show slow magnetic relaxation in zero applied dc field. A remarkable improvement of the energy barrier to reorientation of the magnetisation in the {Tb2Cu3(H3L)2Xn} complexes is seen by changing the auxiliary ligands (X=OAc− for NO3−). This leads to the largest reported relaxation barrier in zero applied dc field for a Tb/Cu-based single-molecule magnet. Ab initio CASSCF calculations performed on mononuclear TbIII models are employed to understand the increase in energy barrier and the calculations suggest that the difference stems from a change in the TbIII coordination environment (C4v versus Cs)

Investigation of the magnetic anisotropy in a series of trigonal bipyramidal Mn(II) complexes

Understanding how the magnetic anisotropy in simple coordination complexes can be manipulated is instrumental to the development of single-molecule magnets (SMMs). Clear strategies can then be designed to control both the axial and transverse contributions to the magnetic anisotropy in such compounds, and allow them to reach their full potential. Here we show a strategy for boosting the magnetic anisotropy in a series of trigonal bipyramidal Mn(II) complexes – [MnCl3(HDABCO)(DABCO)] (1), [MnCl3(MDABCO)2]·[ClO4] (2), and [MnCl3(H2O)(MDABCO)] (3). These have been successfully synthesised using the monodentate [DABCO] and [MDABCO]+ ligands. Through static (DC) magnetic measurements and detailed theoretical investigation using ab initio methods, the magnetic anisotropy of each system has been studied. The calculations reveal that the rhombic zero-field splitting (ZFS) term (E) can be tuned as the symmetry around the Mn(II) ion is changed. Furthermore, an in silico investigation reveals a strategy to increase the axial ZFS parameter (D) of trigonal bipyramidal Mn(II) by an order of magnitude

A large axial magnetic anisotropy in trigonal bipyramidal Fe(II)

The first trigonal bipyramidal Fe(II) complex to display slow relaxation of magnetisation has been isolated, with this behaviour found to arise through a combination of a large magnetic anisotropy (D = -27.5 cm-1) and a pseudo-D3h symmetry at the Fe(II) centre, as investigated through ab initio and magnetic studies

Enhancement of Tb^III-Cu^II Single-molecule magnet performance through structural modification

We report a series of 3d–4f complexes {Ln2Cu3(H3L)2Xn} (X=OAc¢, Ln=Gd, Tb or X=NO3 ¢, Ln=Gd, Tb, Dy, Ho, Er) using the 2,2’-(propane-1,3-diyldiimino)bis[2 (hydroxylmethyl)propane-1,3-diol] (H6L) pro-ligand. All complexes, except that in which Ln=Gd, show slow magneticrelaxation in zero applied dc field. A remarkable improvement of the energy barrier to reorientation of the magnetisationin the {Tb2Cu3(H3L)2Xn} complexes is seen by changing the auxiliary ligands (X=OAc¢ for NO3 ¢). This leads to thelargest reported relaxation barrier in zero applied dc field for a Tb/Cu-based single-molecule magnet. Ab initio CASSCF calculations performed on mononuclear TbIII models are employed to understand the increase in energy barrier and the calculations suggest that the difference stems from a change in the TbIII coordination environment (C4v versus Cs