Exploiting reduced-symmetry ligands with pyridyl and imidazole donors to construct a second-generation stimuli-responsive heterobimetallic [PdPtL4]4+ cage.

A new sequential metalation strategy that enables the assembly of a new more robust reduced symmetry heterobimetallic [PdPtL4]4+ cage C is reported. By exploiting a low-symmetry ditopic ligand (L) that features imidazole and pyridine donor units we were able to selectively form a [Pt(L)4]2+ "open-cage" complex. When this was treated with Pd(ii) ions the cage C assembled. 1H and DOSY nuclear magnetic resonance (NMR) spectroscopy and electrospray ionisation mass spectrometry (ESIMS) data were consistent with the quantitative formation of the cage and the heterobimetallic structure was confirmed by single crystal X-ray crystallography. The cage C was shown to bind anionic guest molecules. NMR studies suggested that these guests interacted with the cavity of the cage in a specific orientation and this was confirmed for the mesylate ion (MsO-) : C host-guest adduct using X-ray crystallography. In addition, the system was shown to be stimulus-responsive and could be opened and closed on demand when treated with appropriate stimuli. If a guest molecule was bound within the cage, the opening and closing was accompanied by the release and re-uptake of the guest molecule.

Implementation of e-cigarette regulation through the EU Tobacco Products Directive (2016) in Wales, Scotland and England from the perspectives of stakeholders involved in policy introduction and enforcement.

INTRODUCTION: From May 2016, the European Union introduced the Tobacco Products Directive (TPD) regulations, which included restrictions to advertising and new safety and labeling standards for e-cigarette products. This represented the first supranational policy regulating e-cigarette sales and marketing. This study explores perceptions of TPD and its implementation in Wales, Scotland and England, from perspectives of stakeholders involved in tobacco and e-cigarette policy and implementation in each nation. METHODS: Semi-structured qualitative interviews were completed with 12 stakeholders from government and third sector organizations in the UK involved in tobacco control policy-making processes, and Trading Standards Officers from 13 UK local authorities. Data were analyzed thematically and a sub-sample double-coded. RESULTS: Stakeholders held varying views of e-cigarettes, recognizing potential benefits and harms of both the products and the new policy actions. Nevertheless, most perceived TPD to be a positive step in introducing regulation for e-cigarettes. Compliance was perceived as high across nations, although stakeholders highlighted product adaptations to circumvent restrictions, and absence of controls on non-nicotine products. Budgetary and staffing limitations also meant that capacity to communicate new measures, and enforce change, was limited. This led to a gap occupied by industry representatives, who played a substantial role in preparing retailers for adoption of new measures. CONCLUSIONS: TPD policy roll-out was largely perceived positively and as having been effectively implemented. However, contribution of industry to communication of new measures and absence of resourcing for effective communication perhaps introduced widespread innovations within regulations. While largely viewed positively, some refinements to device regulations were proposed.