The redox processes associated with BODIPY analogues are studied by electrochemical and spectroscopic methods revealing a characteristic profile for the persistent BODIPY radical and quenching of fluorescence upon reduction.

No abstract

Purpose – This paper aims to evaluate internships in terms of governance structures. Internships are being promoted as a European Union policy lever to address high youth unemployment. However, concerns exist that internships often have few developmental opportunities and poor employment outcomes, something this conceptual paper examines. Design/methodology/approach – The authors develop a conceptual framework for distinguishing between different types of internships based on “dimensions of governance” (contract, agreed duration and partnership). A distinction is made between “open market”, “educational” and “active labour market policy” internships, drawing on examples and evidence from Spain and Portugal. Findings – The authors argue that “governed” internships, linked to educational programmes or genuine active labour market policies, are much more likely to have beneficial outcomes than “open market internships”. This is because they provide the positive governance conditions relating to contract, duration and partnership arrangements under which employers, interns and third parties understand how they can benefit from the internship and what their responsibilities are. Research limitations/implications – The strength of the paper lies in outlining an analytical framework for future research. The evidence presented from Spain and Portugal provides support for the conceptual framework; future comparative internship research should further test the propositions made across a range of countries and contexts. Social implications – By increasing understanding of internship governance, employers, policymakers and educationalists will be in a better position to design successful internships. Originality/value – The paper broadens the focus beyond educational internships alone and proposes a conceptual framework for future research.

Five new metal-organic frameworks prepared from the ligand 5-bis(3-(1-imidazolyl)propylcarbamoyl)terephthalate (bipta(2-)) and transition metal salts, Zn(2+) (1), Co(2+) (2), Mn(2+) (3, 4) and Cu(2+) (5), are reported. Single crystal X-ray studies reveal that the bipta(2-) ligand acts as a tetradentate ligand and combines with four-coordinate cationic metal nodes to give four-connected framework structures. Whilst reaction of bipta(2-) with Zn(II) gives rise to a framework of diamondoid topology 1, the analogous frameworks with Co(II), Mn(II) and Cu(II) afford frameworks that incorporate square-planar nodes. Whereas 2 and 5 form frameworks of Cd(SO(4)) (cds) and square 4(4) nets (sql), respectively, reaction of Mn(II) with bipta(2-) forms two supramolecular isomers of topology cds for 3 and sql for 4.

Two single molecule magnets based on the dodecamanganese (III, IV) cluster with either benzoate or terphenyl-4-carboxylate ligands, have been studied on the Au(111) and rutile TiO2(110) surfaces. We have used in situ electrospray deposition to produce a series of surface coverages from a fraction of a monolayer to multilayer films in both cases. X-ray absorption spectroscopy measured at the Mn L-edge (Mn 2p) has been used to study the effect of adsorption on the oxidation states of the manganese atoms in the core. In the case of the benzoate-functionalised complex reduction of the manganese metal centres is observed due to the interaction of the manganese core with the underlying surface. In the case of terphenyl-4-carboxylate, the presence of this much larger ligand prevents the magnetic core from interacting with either the gold or the titanium dioxide surfaces and the characteristic Mn(3+) and Mn(4+) oxidation states necessary for magnetic behaviour are preserved.

The synthesis, structural and magnetic characterisation of trinuclear manganese cluster, [Mn(3)O(O(2)C-anth)(6)(HOCH(3))(3)] 1 (where O(2)C-anth = 9-anthracenecarboxylate), with crystallographic three-fold (C(3)) symmetry, are described. The cluster was prepared by a carboxylate exchange reaction between HO(2)C-anth and [Mn(12)O(12)(O(2)CMe)(16)(H(2)O)(4)] with concomitant fragmentation of the dodecanuclear Mn core of the starting material to form a trinuclear Mn(3)(μ(3)-O) cluster capped by six carboxylate ligands. Bond valence sum calculations and SQUID magnetometric measurements establish the oxidation states of the metal ions as Mn(II)·2 Mn(III) which are antiferromagnetically coupled.

No abstract

Organic materials are highly sensitive to electron beam irradiation and thus easily damaged upon imaging by electron microscopy. Now, low-dose aberration-corrected high resolution transmission electron microscopy allows for less invasive near-atomic-scale imaging of a two-dimensional polymer.