No abstract

Sodium metabisulfite-mediated elimination of formaldehyde from the ferrocene-derived hydroxymethylphosphine FcCH 2 P(CH 2 OH) 2 yields the primary phosphine FcCH 2 PH 2 , which has been fully characterised, including an X-ray crystal structure; the phosphine is completely airstable.

Despite decades of effort, around 2.8 billion people still rely on solid fuels to meet domestic energy needs. There is robust evidence this causes premature death and chronic disease, as well as wider economic, social, and environmental problems. Behavior change interventions are effective to reduce exposure to harm such as household air pollution, including those using health communications approaches. This article reports the findings of a project that reviewed the effectiveness of behavior change approaches in cleaner cooking interventions in resource-poor settings. The authors synthesized evidence of the use of behavior change techniques, along the cleaner cooking value chain, to bring positive health, economic, and environmental impacts. Forty-eight articles met the inclusion criteria, which documented 55 interventions carried out in 20 countries. The groupings of behavior change techniques most frequently used were shaping knowledge (n ¼ 47), rewards and threats (n ¼ 35), social support (n ¼ 35), and comparisons (n ¼ 16). A scorecard of behavior change effectiveness was developed to analyze a selection of case study interventions. Behavior change techniques have been used effectively as part of multilevel programs. Cooking demonstrations, the right product, and understanding of the barriers and benefits along the value chain have all played a role. Often absent are theories and models of behavior change adapted to the target audience and local context. Robust research methods are needed to track and evaluate behavior change and impact, not just technology disseminated. Behavior change approaches could then play a more prominent role as the ''special sauce'' in cleaner cooking interventions in resource poor settings.This article reports the findings of a review into the effectiveness of behavior change approaches in cleaner cooking interventions in resource-poor settings (Goodwin et al., 2014). The review produced evidence on the use of behavior change techniques (BCTs), a behavior change framework for clean cooking and a set of seven case studies, using a scorecard of effectiveness. The recommendations do not include an attempt to highlight or rank the most effective behavior change models or theories; rather, the review captures the key elements that make behavior change approaches more likely to succeed in ensuring the scale and sustainability of cleaner cooking interventions.

Functional monolayers containing ferrocenylphosphines have been assembled at silicon surfaces by reaction with the hydrogen-terminated layer.The hydrogen terminated silicon surface formed on etching with aqueous ammonium fluoride or hydrofluoric acid is an integral step in the fabrication of semiconductor devices. 1 Despite the fact that this surface has been very well characterised, it is only comparatively recently that studies examining its functional group reactivity have been reported. 2-9 However, to date, despite the variety of synthetic routes explored, the types of molecules that have been attached to silicon have generally been simple alkyl and aryl groups. The development of chemicallysensitive devices based on silicon requires chemical routes for the covalent attachment of molecules capable of various functions to the semiconductor surface. These may include redoxactive molecules, reactive groups and ligands. Towards this end we have previously shown that redox-active monolayers based on ferrocenyl derivatives can be assembled via a two-stage process involving initial formation of a reactive monolayer (terminated with an bromoalkyl headgroup) to which the ferrocenyl group was subsequently attached through alkylation of (dimethylaminomethyl)ferrocene. 6 We recently reported syntheses of the ferrocenyl(hydroxymethyl)phosphine, [Fe(η 5 -C 5 H 5 ){η 5 -C 5 H 4 CH 2 P(CH 2 OH) 2 }] 1 and its oxide, [Fe(η 5 -C 5 H 5 ){η 5 -C 5 H 4 CH 2 P(O)(CH 2 OH) 2 }] 2, and sulfide, [Fe(η 5 -C 5 H 5 ){η 5 -C 5 H 4 CH 2 P(S)(CH 2 OH) 2 }] 3; these derivatives combine a redox centre and ligating donor groups (P, S or O) coupled with a suitable functional group, OH, for attachment to H-terminated silicon surfaces in a single molecule. 10 In this report we demonstrate that covalently attached monolayers incorporating these functionalities can be formed in one step on either porous silicon or single-crystal wafers as a result of the reactivity of the hydrogen terminated silicon surface towards the PCH 2 OH group.A typical procedure for covalent modification involved refluxing a freshly etched piece of (100) oriented Si wafer in a dry acetonitrile solution of the ferrocenyl derivative (0.02 -0.07 , typically 95 mg in 5 ml solvent) for 3 h under nitrogen. Following this reaction, the wafers were washed repeatedly with dichloromethane and dried in a stream of nitrogen. For comparison ferrocenylmethanol-derived monolayers 6 were also prepared, in this case the solvent used was dry hexanes. After monolayer formation ohmic contact was made to the back of the wafers with an In-Ga eutectic and a copper contact wire attached with silver-loaded epoxy. The wafers were then sealed onto glass slides with a silicone rubber such that only the polished face was exposed to solution to enable characterisation by cyclic voltammetry.

No abstract