Homochiral self-sorted and emissive IrIII metallo-cryptophanes

We thank the EPSRC (DTG award 1238852, EP/K039202/1, EP/M02105X/1, EP/J001325/1), Leverhulme Trust (RPG-2014-148), University of St Andrews, and the MEXT/JSPS Grants in Aid for Scientific Research (JP25102005 and JP25102001) for funding; Simon Barrett for assistance with NMR; Martin Huscroft for assistance with HPLC, and Stephen Boyer for elemental analysis measurements.The racemic ligands (±)-tris(isonicotinoyl)-cyclotriguaiacylene (L1), or (±)-tris(4-pyridyl-methyl)-cyclotriguaiacylene (L2) assemblewith racemic (Λ, Δ)- [Ir(ppy)2(MeCN)2]+, in which ppy = 2-phenylpyridinato to form [{Ir(ppy)2}3(L)2]3+ metallo-cryptophane cages. The crystal structure of [{Ir(ppy)2}3(L1)2]∙3BF4 has MM-ΛΛΛ nd PP-ΔΔΔ isomers, and homochiral self-sorting occurs in solution, a processaccelerated by a chiral guest. Self-recognition between L1 and L2 within cagesdoes not occur, and cages show very slow ligand-exchange. Both cages are phosphorescent,with [{Ir(ppy)2}3(L2)2]3+ havingenhanced and blue-shifted emission when compared with [{Ir(ppy)2}3(L1)2]3+ .PostprintPeer reviewe

O Santuário Ecológico de Ilhabela como área marinha protegida a ser incorporada ao SNUC: panorama atual e próximos passos

O Santuário Ecológico de Ilhabela foi criado mediante decreto municipal em 1992, apresentando desde aquela época evidências de degradação ambiental devido a atividades humanas. Com a criação do Sistema Nacional de Unidades de Conservação, a categoria “Santuário Ecológico” passou a não ter mais validade, havendo necessidade de recategorização a uma das categorias presentes na Lei. Ilhabela é um município que tem como principal fonte de renda atividades relacionadas ao turismo, que, se mal planejadas, podem levar a impactos sociais, ambientais e econômicos. A região do Canal de São Sebastião em que o Santuário está localizado possui rica fauna marinha, mas também sofre grande pressão antrópica, fator que pode colocar em risco, inclusive, a saúde e bem-estar de moradores, turistas e da fauna marinha local. Nos últ­imos anos, grupos vêm buscando apresentar dados que justifiquem a proposta de recategorização da área, até o presente momento sem sucesso. Este artigo tem por objetivo contextualizar a atual situação do Santuário Ecológico de Ilhabela, apresentar subsídios que justifiquem sua recategorização e indicar caminhos para a continuidade do processo.Ilhabela Ecological Sanctuary is a marine protected area created through a municipal decree in 1992. Since that time it was possible to identify evidences of environmental degradation caused by human activities in the area. According to the most recent law of protected areas in Brazil (SNUC), the category "Ecological Sanctuary" is no longer valid, demanding the area to be reclassified within the new law. The tourism and correlated services are the main sources of income for Ilhabela. However, if poorly planned, tourism activities can lead to social, environmental and economic impacts. The Ecological Sanctuary is placed in a region that houses a rich marine fauna, the São Sebastião Channel. This area, however, also suffers with great anthropic pressure, which may endanger the health and well-being of residents, tourists and local marine fauna. In the last years groups have presented data to attempt the reclassification of the Sanctuary, with no success to the present moment. This article aims to contextualize the current situation of Ilhabela Ecological Sanctuary, present subsidies that justify its reclassification and indicate ways to continue the process

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

In this work we showcase the emitter DICzTRZ in which we employed a twin-emitter design of our previously reported material, ICzTRZ. This new system presented a red-shifted emission at 488 nm compared to that of ICzTRZ at 475 nm and showed a comparable photoluminescence quantum yield of 57.1% in a 20 wt % CzSi film versus 63.3% for ICzTRZ. The emitter was then incorporated within a solution-processed organic light-emitting diode that showed a maximum external quantum efficiency of 8.4%, with Commission Internationale de l’Éclairage coordinate of (0.22, 0.47), at 1 mA cm$^{-2}

Exploring the self-assembly and energy transfer of dynamic supramolecular iridium-porphyrin systems

EZ-C acknowledges the University of St Andrews for financial support. IDWS acknowledges support from EPSRC (EP/J009016) and the European Research Council (grant 321305). IDWS also acknowledges support from a Royal Society Wolfson research merit award. DJ acknowledges the European Research Council (grant: 278845) and the RFI Lumomat for financial support.We present the first examples of dynamic supramolecular systems composed of cyclometalated Ir(III) complexes of the form of [Ir(C^N)2(N^N)]PF6 (where C^N is mesppy = 2-phenyl-4-mesitylpyridinato and dFmesppy = 2-(4,6-difluorophenyl)-4-mesitylpyridinato and N^N is 4,4':2',2'':4'',4'''-quaterpyridine, qpy) and zinc tetraphenylporphyrin (ZnTPP), assembled through non-covalent interactions between the distal pyridine moieties of the qpy ligand located on the iridium complex and the zinc of the ZnTPP. The assemblies have been comprehensively characterized by a series of analytical techniques (1H NMR titration experiments, 2D COSY and HETCOR NMR spectra and low temperature 1H NMR spectroscopy) and the crystal structures have been elucidated by X-ray diffraction. The optoelectronic properties of the assemblies and the electronic interaction between the iridium and porphyrin chromophoric units have been explored with detailed photophysical measurements, supported by time-dependent density functional theory (TD-DFT) calculations.PostprintPeer reviewe

In the dedicated pursuit of dedicated capital: restoring an indigenous investment ethic to British capitalism

Tony Blair’s landslide electoral victory on May 1 (New Labour Day?) presents the party in power with a rare, perhaps even unprecedented, opportunity to revitalise and modernise Britain’s ailing and antiquated manufacturing economy.* If it is to do so, it must remain true to its long-standing (indeed, historic) commitment to restore an indigenous investment ethic to British capitalism. In this paper we argue that this in turn requires that the party reject the very neo-liberal orthodoxies which it offered to the electorate as evidence of its competence, moderation and ‘modernisation’, which is has internalised, and which it apparently now views as circumscribing the parameters of the politically and economically possible

Protection of Domestic bank Ownership in France and Germany: The Functional Equivalency of Institutional Diversity in Takeovers

We investigate the character of the market for corporate control (i.e. takeovers) in French and German banking. The key feature of this character is the marked ability of French and German banks to resist unsolicited takeover bids, especially – although not exclusively– those from foreign competitors. We present an institutional perspective to account for the restrained character of takeovers in French and German banking. Our perspective is composed of two elements. First, institutional arrangements are important since they structure power relations among firm stakeholders by providing opportunities, as well as imposing constraints, to influence the decision-making process in which takeover transactions take place. Second, institutional arrangements provide firm stakeholders with several potential opportunities, not just one, to block unsolicited bids since takeover contests are composed of sequences of decisions for which approval is needed at each stage. French and German banks have used different mixes of institutional arrangements, themselves located at different stages of takeover transactions, to secure restrained markets for corporate control. Our institutional analysis, in turn, also illustrates an important shortcoming of banking sector protectionism, namely the contribution of protection from unsolicited takeover bids to the building of banks carrying systemic risks

Using the Mechanical Bond to Tune the Performance of a Thermally Activated Delayed Fluorescence Emitter**

We report the characterization of rotaxanes based on a carbazole-benzophenone thermally activated delayed fluorescence luminophore. We find that the mechanical bond leads to an improvement in key photophysical properties of the emitter, notably an increase in photoluminescence quantum yield and a decrease in the energy difference between singlet and triplet states, as well as fine tuning of the emission wavelength, a feat that is difficult to achieve when using covalently bound substituents. Computational simulations, supported by X-ray crystallography, suggest that this tuning of properties occurs due to weak interactions between the axle and the macrocycle that are enforced by the mechanical bond. This work highlights the benefits of using the mechanical bond to refine existing luminophores, providing a new avenue for emitter optimization that can ultimately increase the performance of these molecules

A Boron, Nitrogen, and Oxygen Doped π-Extended Helical Pure Blue Multiresonant Thermally Activated Delayed Fluorescent Emitter for Organic Light Emitting Diodes That Shows Fast kRISC Without the Use of Heavy Atoms

Narrowband emissive multiresonant thermally activated delayed fluorescence (MR-TADF) emitters are a promising solution to achieve the current industry-targeted color standard, Rec. BT.2020-2, for blue color without using optical filters, aiming for high-efficiency organic light-emitting diodes (OLEDs). However, their long triplet lifetimes, largely affected by their slow reverse intersystem crossing rates, adversely affect device stability. In this study, a helical MR-TADF emitter (f-DOABNA) is designed and synthesized. Owing to its π-delocalized structure, f-DOABNA possesses a small singlet-triplet gap, ΔEST, and displays simultaneously an exceptionally faster reverse intersystem crossing rate constant, kRISC, of up to 2 × 10⁶ s⁻¹ and a very high photoluminescence quantum yield, ΦPL, of over 90% in both solution and doped films. The OLED with f-DOABNA as the emitter achieved a narrow deep-blue emission at 445 nm (full width at half-maximum of 24 nm) associated with Commission Internationale de l'Éclairage (CIE) coordinates of (0.150, 0.041), and showed a high maximum external quantum efficiency, EQEmax, of ≈20%

A Deep-Blue-Emitting Heteroatom-Doped MR-TADF Nonacene for High-Performance Organic Light-Emitting Diodes

We present a p- and n-doped nonacene compound, NOBNacene, that represents a rare example of a linearly extended ladder-type multiresonant thermally activated delayed fluorescence (MR-TADF) emitter. This compound shows efficient narrow deep blue emission, with a λPL of 410 nm, full width at half maximum, FWHM, of 38 nm, photoluminescence quantum yield, ФPL of 71%, and a delayed lifetime, τd of 1.18 ms in 1.5 wt% TSPO1 thin film. The organic light-emitting diode (OLED) using this compound as the emitter shows a comparable electroluminescence spectrum peaked at 409 nm (FWHM = 37 nm) and a maximum external quantum efficiency (EQEmax) of 8.5% at Commission Internationale de l'Éclairage (CIE) coordinates of (0.173, 0.055). The EQEmax values were increased to 11.2% at 3 wt% doping of the emitter within the emissive layer of the device. At this concentration, the electroluminescence spectrum broadened slightly, leading to CIE coordinates of (0.176, 0.068)