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We here report the synthesis of the homoleptic iron(II) N-heterocyclic carbene (NHC) complex [Fe(miHpbmi)(2)](PF6)(4) (miHpbmi = 4-((3-methyl-1H-imidazolium-1-yl)pyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)) and its electrochemical and photophysical properties. The introduction of the pi-electron-withdrawing 3-methyl-1H-imidazol-3-ium-1-yl group into the NHC ligand framework resulted in stabilization of the metal-to-ligand charge transfer (MLCT) state and destabilization of the metal-centered (MC) states. This resulted in an improved excited-state lifetime of 16 ps compared to the 9 ps for the unsubstituted parent compound [Fe(pbmi)(2)](PF6)(2) (pbmi = (pyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)) as well as a stronger MLCT absorption band extending more toward the red spectral region. However, compared to the carboxylic acid derivative [Fe(cpbmi)(2)](PF6)(2) (cpbmi = 1,1 '-(4-carboxypyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)), the excited-state lifetime of [Fe(miHpbmi)(2)](PF6)(4) is the same, but both the extinction and the red shift are more pronounced for the former. Hence, this makes [Fe(miHpbmi)(2)](PF6)(4) a promising pH-insensitive analogue of [Fe(cpbmi)(2)](PF6)(2). Finally, the excited-state dynamics of the title compound [Fe(miHpbmi)(2)](PF6)(4) was investigated in solvents with different viscosities, however, showing very little dependency of the depopulation of the excited states on the properties of the solvent used.

Nature captures sunlight via light-absorbing molecules.Similarly, photosensitisers are used in applications of solar cells and artificial photosynthesis to absorb sunlight, and transfer the excited electron.Successful photosensitisers have in the past been based on a Ru polipyridyl scaffold, despite Ru being one of the scarcest elements in Earth's crust.This thesis work aims to replace Ru polipyridyl complexes by Fe carbene complexes, that by clever ligand design have approached suitable photosensitiser properties.One crucial property that is not yet competitive for Fe carbene photosensitisers is how long they stay in the excited state, i.e. their lifetime. This is controlled by the deactivation pathways of the molecule, dictated by the excited state landscape. Several Fe carbene photosensitisers were in this thesis investigated by spectroscopic and computational methods, to understand their deactivation pathways. For the Fe(II) carbene complexes investigated, small changes in the ligand structure influenced both what excited state (charge-transfer or metal-centred) that was mainly populated and the lifetime of the state.For the Fe(III) carbene complexes investigated, there was instead one dominating charge-transfer excited state that was rather unaffected by changes to the ligand. Furthermore, for the Fe(II) complexes metal-centred states played a large role in the deactivation pathway but for the Fe(III) complexes this was not the case.Also, one Co(III) carbene complex was investigated which displays remarkable long lifetime and emission from a metal-centred state.As a first step towards application, the electron-transfer properties of some of the photosensitisers were investigated.Fe(II) complexes with a push-pull design were able to transfer electrons to TiO2 in a solar cell configuration.The solar cell performance was however limited by an ultrafast recombination reaction, that brought a majority of the transferred electrons back to the photosensitiser.The Fe(I

The starting point of this examination paper was the aspects of how norms, values, emotions and culture develop and affect the people working in the youth institutional settings like the Swedish National Board of Institutional care (Statens institutionsstyrelse, SiS). Our paper is based on qualitative semi structured interviews with the aim to gather new perspectives with a main focus on descriptive details like; what, how, and why some phenomena in these environments appear. The collected answers have been analyzed through an abductive approach, where we from a theoretical point of view aim to understand our respondent’s answers and why they answer like they do and what perspective that their conception of the world comes from. To guide us through this abductive approach we have used Goffman's perspective on Total institutions and Hochschilds perspective on Emotional labor. Moreover, this study seeks to understand the peculiarities and difficulties of the workplace and how staff working at these secure units experience the environment. We present this through five different themes that we found stood out the most during our interviews. First, we have the complexity between on the one side delivering care and on the other side controlling the placed youths. Thereafter we describe how SiS is an emotional environment. We also address the importance of working with good and competent colleagues that you can share your experiences with, and what consequences lack of competence can entail. And last but not least, how SiS in some parts consists of work-related misconducts that lead to a destructive work environment.

Fe(III) complexes with N-heterocyclic carbene (NHC) ligands belong to the rare examples of Earth-abundant transition metal complexes with long-lived luminescent charge-transfer excited states that enable applications as photosensitizers for charge separation reactions. We report three new hexa-NHC complexes of this class: [Fe(brphtmeimb)2]PF6 (brphtmeimb = [(4-bromophenyl)tris(3-methylimidazol-2-ylidene)borate]–, [Fe(meophtmeimb)2]PF6 (meophtmeimb = [(4-methoxyphenyl)tris(3-methylimidazol-2-ylidene)borate]–, and [Fe(coohphtmeimb)2]PF6 (coohphtmeimb = [(4-carboxyphenyl)tris(3-methylimidazol-2-ylidene)borate]–. These were derived from the parent complex [Fe(phtmeimb)2]PF6 (phtmeimb = [phenyltris(3-methylimidazol-2-ylidene)borate]– by modification with electron-withdrawing and electron-donating substituents, respectively, at the 4-phenyl position of the ligand framework. All three Fe(III) hexa-NHC complexes were characterized by NMR spectroscopy, high-resolution mass spectroscopy, elemental analysis, single crystal X-ray diffraction analysis, electrochemistry, Mößbauer spectroscopy, electronic spectroscopy, magnetic susceptibility measurements, and quantum chemical calculations. Their ligand-to-metal charge-transfer (2LMCT) excited states feature nanosecond lifetimes (1.6–1.7 ns) and sizable emission quantum yields (1.7–1.9%) through spin-allowed transition to the doublet ground state (2GS), completely in line with the parent complex [Fe(phtmeimb)2]PF6 (2.0 ns and 2.1%). The integrity of the favorable excited state characteristics upon substitution of the ligand framework demonstrates the robustness of the scorpionate motif that tolerates modifications in the 4-phenyl position for applications such as the attachment in molecular or hybrid assemblies.

1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav

A new generation of octahedral iron(ii)-N-heterocyclic carbene (NHC) complexes, employing different tridentate C<^>N<^>C ligands, has been designed and synthesized as earth-abundant photosensitizers for dye sensitized solar cells (DSSCs) and related solar energy conversion applications. This work introduces a linearly aligned push-pull design principle that reaches from the ligand having nitrogen-based electron donors, over the Fe(ii) centre, to the ligand having an electron withdrawing carboxylic acid anchor group. A combination of spectroscopy, electrochemistry, and quantum chemical calculations demonstrate the improved molecular excited state properties in terms of a broader absorption spectrum compared to the reference complex, as well as directional charge-transfer displacement of the lowest excited state towards the semiconductor substrate in accordance with the push-pull design. Prototype DSSCs based on one of the new Fe NHC photosensitizers demonstrate a power conversion efficiency exceeding 1% already for a basic DSSC set-up using only the I-/I-3(-) redox mediator and standard operating conditions, outcompeting the corresponding DSSC based on the homoleptic reference complex. Transient photovoltage measurements confirmed that adding the co-sensitizer chenodeoxycholic acid helped in improving the efficiency by increasing the electron lifetime in TiO2. Time-resolved spectroscopy revealed spectral signatures for successful ultrafast (<100 fs) interfacial electron injection from the heteroleptic dyes to TiO2. However, an ultrafast recombination process results in undesirable fast charge recombination from TiO2 back to the oxidized dye, leaving only 5-10% of the initially excited dyes available to contribute to a current in the DSSC. On slower timescales, time-resolved spectroscopy also found that the recombination dynamics (longer than 40 mu s) were significantly slower than the regeneration of the oxidized dye by the redox mediator (6-8 mu s). T

Vid skapandet av Folkets hus i Sandviken var det viktigt för mig att utgå från behovet av mötesplatser och att göra vattnet tillgängligt för alla boende och besökande i området. Ångbåtsbryggan som Sandviken i sin tid växte fram utifrån fick bli utgångspunkt och en rektangulär mötesplats som sträcker sig ut i vattnet blev skapad med inramningen av sex huskroppar. Gestaltningen är utarbetad med inspiration från de gamla tegelbruken som fanns här tidigare, men även den fragmentariska bebyggelse som härskar i Sandviken på grund av den begränsande detaljplanen. Det var även viktigt för mig att inte skapa en för stor byggnad som skulle ta över det pittoreska utseendet på platsen, istället ville jag skapa möjlighet för besökarna att själva kunna använda vissa funktioner utan att huset är bemannat. Platsen mellan byggnaderna delas av den passerande bilvägen och bildar två torg för bygden att samlas kring och tillgängliggör och skapar på så sätt ett Sandviken där fler är välkomna., When creating the community house in Sandviken, it was important for me to start from the need of places to meet and to make the water available to all residents and visitors in the area. The steamboat pier, that Sandviken in its time was founded out from, became the starting point for the project and a rectangular meeting place that extends into the water was created with the framing of six house bodies. The design is made with inspiration from the old brickworks that existed in the region before, but also the fragmentary buildings that rule in Sandviken due to the restrictive detailed plan. It was also important for me not to create an oversized building that would take over the picturesque appearance of the place, instead I wanted to create the opportunity for visitors to be able to use certain functions themselves without the house being staffed. The space between the buildings is divided by the passing car road and forms two squares for the neighborhood to gather around and makes accessible and thus creates a Sandviken where more people are welcome.

Iron's abundance and rich coordination chemistry are potentially appealing features for photochemical applications. However, the photoexcitable charge-transfer states of most iron complexes are limited by picosecond or subpicosecond deactivation through low-lying metal-centered states, resulting in inefficient electron-transfer reactivity and complete lack of photoluminescence. In this study, we show that octahedral coordination of iron(Ill) by two mono-anionic facial tris-carbene ligands can markedly suppress such deactivation. The resulting complex [Fe(phtmeimb)(2)](+), where phtmeimb is {phenyl[tris(3-methylimidazol-1-ylidene)]borate}(-), exhibits strong, visible, room temperature photoluminescence with a 2.0-nanosecond lifetime and 2% quantum yield via spin-allowed transition from a doublet ligand-to-metal charge-transfer ((LMCT)-L-2) state to the doublet ground state. Reductive and oxidative electron-transfer reactions were observed for the (2)LMCTstate of [Fe(phtmeimb)(2)](+) in bimolecular quenching studies with methylviologen and diphenylamine.

In the hunt for fossile-free energy-harvesting techniques, solar cells constitute one of the most promising techniques. Today, silicon-based solar cells are the dominant technique on the market but even the Silicon solar cell has limitations which means that there is a motivation for developing new solutions. One of those techniques is the dye-sensitized solar cell. Just as in photosynthesis, the solar cell contains a dye molecule that when absorbing the light from the sun can separate an electron from an electron hole. The electron is injected into titania and from there extracted as current. In this Master's thesis, two new dye molecules called FeCAB26 and FeCABCN2 have been investigated by spectroscopic methods (absorption spectroscopy, emission spectroscopy and transient absorption spectroscopy), quantum-chemical calculations and electrical measurements with the purpose to investigate the potential for usage as sensitizers in dye-sensitized solar cells. The molecules are iron-carbene-complexes, synthesized by colleges at Lund University, which are at the frontier of this research field since many traditionally used sensitizers have been ruthenium-complexes. Both molecules were able to sensitize films of titania and absorb light in the visible part of the spectrum. Quantum-chemical calculations indicated that the molecules did excite an electron from metal-centred orbitals to ligand-centred orbitals upon absorption of light. The molecules did also inject electrons into titania via the excited metal-to-ligand charge transfer state. The excited states had lifetimes of 21 ps and 36 ps for the different molecules. When the dye molecules were used as sensitizers in solar cells, a photocurrent was measured upon illumination in a solar simulator for the molecule FeCABCN2. Without having optimized the fabrication process, the efficiency of the best solar cell was 0.13 %. This shows a proof of concept that FeCABCN2 could work as a sensitizer in DSSCs. The optical characte, I jakten på förnyelsebara energikällor är solceller en av de mest lovande teknikerna. Idag dominerar kisel-solcellen marknaden men även den har begränsningar och därför är det motiverat att utveckla andra sorters solceller. En solcellsteknik på utvecklingsstadiet som försöker efterlikna fotosyntesen är Grätzelsolcellen. Precis som i fotosyntesen är det en färgämnesmolekyl i solcellen som ska absorbera solens ljus och separera en elektron från ett elektronhål genom att elektronen skickas från färgämnesmolekylen till en titandioxid-elektrod och därifrån extraheras som elektrisk ström. I detta masterarbete har två nya färgämnesmolekyler kallade FeCAB26 och FeCABCN2 undersökts genom en rad spektroskopiska (absorptionsspektroskopi, emissionsspektroskopi, tidsupplöst laserspektroskopi), beräkningskemiska och elektriska mätmetoder med målet att bestämma deras fotofysiska egenskaper och bedöma dugligheten för bruk i Grätzelsolceller. Färgämnesmolekylerna är båda järnkarben-komplex, syntetiserade av kollegor vid Lunds universitet, vilka är i framkanten av forskningen inom detta fält där många metallbaserade färgämnesmolekyler annars varit rutenium-komplex. Båda molekylerna visade sig fästa till titandioxidytor och absorbera ljus i det synliga våglängdsområdet. De kvantkemiska beräkningarna indikerade att färgämnesmolekylerna vid absorption av ljus exciterade en elektron i en metall-centrerad orbital till ligand-centrerade orbitaler. De exciterade tillstånden hade livstider på 21 ps respektive 36 ps. Färgämnesmolekylerna visade sig även injicera elektroner i titandioxiden vid belysning. När färgämnesmolekylerna införlivades i solceller, så kunde en elektrisk ström mätas under belysning i solsimulator för FeCABCN2. Utan att ha optimerat tillverkningsprocessen var effekten för de bästa solcellerna med FeCABCN2 runt 0,13 %. Som ett första steg visar detta att FeCABCN2-färgämnet principiellt sett fungerar, även om fortsatt utveckling mot bättre solceller av denna typ kräver omfat, Solar energy is a renewable energy source harvested by solar cells. But even if there are functioning solar cells on the market, the hunt for even better ones are engaging many scientists. This project has contributed in the development of a solar cell inspired by nature, that is using simple compounds to form the versatile solar cell of tomorrow: a solar cell that is environmentally friendly, can have different colours and can be made bendable.