@article{40984,
  abstract     = {{A two-step seeded-growth method was refined to synthesize Au@Pd core@shell nanoparticles with thin Pd shells, which were then deposited onto alumina to obtain a supported Au@Pd/Al2O3 catalyst active for prototypical CO oxidation. By the strict control of temperature and Pd/Au molar ratio and the use of l-ascorbic acid for making both Au cores and Pd shells, a 1.5 nm Pd layer is formed around the Au core, as evidenced by transmission electron microscopy and energy-dispersive spectroscopy. The core@shell structure and the Pd shell remain intact upon deposition onto alumina and after being used for CO oxidation, as revealed by additional X-ray diffraction and X-ray photoemission spectroscopy before and after the reaction. The Pd shell surface was characterized with in situ infrared (IR) spectroscopy using CO as a chemical probe during CO adsorption–desorption. The IR bands for CO ad-species on the Pd shell suggest that the shell exposes mostly low-index surfaces, likely Pd(111) as the majority facet. Generally, the IR bands are blue-shifted as compared to conventional Pd/alumina catalysts, which may be due to the different support materials for Pd, Au versus Al2O3, and/or less strain of the Pd shell. Frequencies obtained from density functional calculations suggest the latter to be significant. Further, the catalytic CO oxidation ignition-extinction processes were followed by in situ IR, which shows the common CO poisoning and kinetic behavior associated with competitive adsorption of CO and O2 that is typically observed for noble metal catalysts.}},
  author       = {{Feng, Yanyue and Schaefer, Andreas and Hellman, Anders and Di, Mengqiao and Härelind, Hanna and Bauer, Matthias and Carlsson, Per-Anders}},
  issn         = {{0743-7463}},
  journal      = {{Langmuir}},
  keywords     = {{Electrochemistry, Spectroscopy, Surfaces and Interfaces, Condensed Matter Physics, General Materials Science}},
  number       = {{42}},
  pages        = {{12859--12870}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Synthesis and Characterization of Catalytically Active Au Core─Pd Shell Nanoparticles Supported on Alumina}}},
  doi          = {{10.1021/acs.langmuir.2c01834}},
  volume       = {{38}},
  year         = {{2022}},
}

@article{40993,
  abstract     = {{Understanding high-temperature unconventional superconductivity has become a long-lasting problem in which the cuprates stand as central reference materials. Given this impasse, the recent discovery of superconductivity in analogous nickelate thin films represents a fundamental breakthrough calling for the identification of additional materials in this class. In particular, thermodynamically more robust systems are required to “upgrade” nickelate superconductors from thin films to bulk samples. Here, we contribute in this direction by reporting the synthesis of the new single-layer T′ Pr2NiO3F compound, assessing this synthesis in relation to the only previous T′ nickelate La2NiO3F, and analyzing the electronic properties across the R2NiO3F series (R = La–Lu) via first-principles calculations. We find that these mixed anion systems have a comparatively high degree of stability and their synthesis enables a fine-tuning of their composition as inferred from their characterization. Furthermore, we find that these unprecedented square-planar nickelates hold great promise as prospective superconductors due to their exceptional electronic structure.}},
  author       = {{Wissel, Kerstin and Bernardini, Fabio and Oh, Heesu and Vasala, Sami and Schoch, Roland and Blaschkowski, Björn and Glatzel, Pieter and Bauer, Matthias and Clemens, Oliver and Cano, Andrés}},
  issn         = {{0897-4756}},
  journal      = {{Chemistry of Materials}},
  keywords     = {{Materials Chemistry, General Chemical Engineering, General Chemistry}},
  number       = {{16}},
  pages        = {{7201--7209}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Single-Layer T′ Nickelates: Synthesis of the La and Pr Members and Electronic Properties across the Rare-Earth Series}}},
  doi          = {{10.1021/acs.chemmater.2c00726}},
  volume       = {{34}},
  year         = {{2022}},
}

@article{40985,
  author       = {{Moll, Johannes and Naumann, Robert and Sorge, Lukas and Förster, Christoph and Gessner, Niklas and Burkhardt, Lukas and Ugur, Naz and Nuernberger, Patrick and Seidel, Wolfram and Ramanan, Charusheela and Bauer, Matthias and Heinze, Katja}},
  issn         = {{0947-6539}},
  journal      = {{Chemistry – A European Journal}},
  keywords     = {{General Chemistry, Catalysis, Organic Chemistry}},
  number       = {{57}},
  publisher    = {{Wiley}},
  title        = {{{Pseudo‐Octahedral Iron(II) Complexes with Near‐Degenerate Charge Transfer and Ligand Field States at the Franck‐Condon Geometry}}},
  doi          = {{10.1002/chem.202201858}},
  volume       = {{28}},
  year         = {{2022}},
}

@phdthesis{41008,
  author       = {{Dierks, Philipp}},
  title        = {{{Synthesis and characterization of multichromophoric iron(II) complexes as novel photosensitizers}}},
  doi          = {{10.17619/UNIPB/1-1558}},
  year         = {{2022}},
}

@phdthesis{41014,
  author       = {{Huber-Gedert, Marina}},
  title        = {{{Base Metal Iron(II)-Cobalt(III) Dyads for Photocatalytic Hydrogen Evolution}}},
  year         = {{2022}},
}

@article{35707,
  abstract     = {{<jats:p>The proton conductivity of two coordination networks, [Mg(H<jats:sub>2</jats:sub>O)<jats:sub>2</jats:sub>(H<jats:sub>3</jats:sub>L)]·H<jats:sub>2</jats:sub>O and [Pb<jats:sub>2</jats:sub>(HL)]·H<jats:sub>2</jats:sub>O (H<jats:sub>5</jats:sub>L = (H<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>PCH<jats:sub>2</jats:sub>)<jats:sub>2</jats:sub>-NCH<jats:sub>2</jats:sub>-C<jats:sub>6</jats:sub>H<jats:sub>4</jats:sub>-SO<jats:sub>3</jats:sub>H), is investigated by AC impedance spectroscopy. Both materials contain the same phosphonato-sulfonate linker molecule, but have clearly different crystal structures, which has a strong effect on proton conductivity. In the Mg-based coordination network, dangling sulfonate groups are part of an extended hydrogen bonding network, facilitating a “proton hopping” with low activation energy; the material shows a moderate proton conductivity. In the Pb-based metal-organic framework, in contrast, no extended hydrogen bonding occurs, as the sulfonate groups coordinate to Pb<jats:sup>2+</jats:sup>, without forming hydrogen bonds; the proton conductivity is much lower in this material.</jats:p>}},
  author       = {{Javed, Ali and Steinke, Felix and Wöhlbrandt, Stephan and Bunzen, Hana and Stock, Norbert and Tiemann, Michael}},
  issn         = {{2190-4286}},
  journal      = {{Beilstein Journal of Nanotechnology}},
  keywords     = {{Electrical and Electronic Engineering, General Physics and Astronomy, General Materials Science}},
  pages        = {{437--443}},
  publisher    = {{Beilstein Institut}},
  title        = {{{The role of sulfonate groups and hydrogen bonding in the proton conductivity of two coordination networks}}},
  doi          = {{10.3762/bjnano.13.36}},
  volume       = {{13}},
  year         = {{2022}},
}

@article{33691,
  abstract     = {{Near ambient pressure XPS in nitrogen atmosphere was utilized to investigate gas-solid interactions within porous SiO2 films ranging from 30 to 75 nm thickness. The films were differentiated in terms of porosity and roughness. The XPS N1s core levels of the N2 gas in presence of the SiO2 samples showed variations in width, binding energy and line shape. The width correlated with the surface charge induced in the dielectric films upon X-ray irradiation. The observed different binding energies observed for the N1s peak can only partly be associated with intrinsic work function differences between the samples, opening the possibility that the effect of physisorption at room temperature could be detected by a shift in the measured binding energy. However, the signals also show an increasing asymmetry with rising surface charge. This might be associated with the formation of vertical electrical gradients within the dielectric porous thin films, which complicates the assignment of binding energy positions to specific surface-related effects. With the support of Monte Carlo and first principles density functional theory calculations, the observed shifts were discussed in terms of the possible formation of transitory dipoles upon N2 physisorption within the porous SiO2 films.}},
  author       = {{de los Arcos, Teresa and Weinberger, Christian and Zysk, Frederik and Raj Damerla, Varun and Kollmann, Sabrina and Vieth, Pascal and Tiemann, Michael and Kühne, Thomas and Grundmeier, Guido}},
  issn         = {{0169-4332}},
  journal      = {{Applied Surface Science}},
  keywords     = {{Surfaces, Coatings and Films, Condensed Matter Physics, Surfaces and Interfaces, General Physics and Astronomy, General Chemistry}},
  publisher    = {{Elsevier BV}},
  title        = {{{Challenges in the interpretation of gas core levels for the determination of gas-solid interactions within dielectric porous films by ambient pressure XPS}}},
  doi          = {{10.1016/j.apsusc.2022.154525}},
  volume       = {{604}},
  year         = {{2022}},
}

@article{33685,
  abstract     = {{In the spatial confinement of cylindrical mesopores with diameters of a few nanometers, water molecules experience restrictions in hydrogen bonding. This leads to a different behavior regarding the molecular orientational freedom (‘structure of water') compared to the bulk liquid state. In addition to the pore size, the behavior is also strongly affected by the strength of the pore wall-to-water interactions, that is, the pore wall polarity. In this work, this is studied both experimentally and theoretically. The surface polarity of mesoporous silica (SiO2) is modified by functionalization with trimethylsilyl moieties, resulting in a change from a hydrophilic (pristine) to a hydrophobic pore wall. The mesopore surface is characterized by N2 and H2O sorption experiments. Those results are combined with IR spectroscopy to investigate pore wall-to-water interactions leading to different structures of water in the mesopore. Furthermore, the water's structure is studied theoretically to gain deeper insight into the interfacial interactions. For this purpose, the structure of water is analyzed by pairing densities, coordination, and angular distributions with a novel adaptation of surface-specific sum-frequency generation calculation for pore environments.}},
  author       = {{Weinberger, Christian and Zysk, Frederik and Hartmann, Marc and Kaliannan, Naveen and Keil, Waldemar and Kühne, Thomas and Tiemann, Michael}},
  issn         = {{2196-7350}},
  journal      = {{Advanced Materials Interfaces}},
  keywords     = {{Mechanical Engineering, Mechanics of Materials}},
  number       = {{20}},
  publisher    = {{Wiley}},
  title        = {{{The Structure of Water in Silica Mesopores – Influence of the Pore Wall Polarity}}},
  doi          = {{10.1002/admi.202200245}},
  volume       = {{9}},
  year         = {{2022}},
}

@article{29376,
  abstract     = {{The electrochemical properties of carbonaceous materials produced by hydrothermal carbonization, referred to as hydrochar, can be substantially improved by post-carbonization via pyrolysis. Although these materials have been widely studied for a variety of applications, the mechanisms underlying the pyrolysis are yet poorly understood. This study provides a comprehensive temperature-resolved characterization of the chemical composition, morphology and crystallinity of sucrose-derived hydrochar during pyrolysis. Thermogravimetric analysis, differential scanning calorimetry, and elemental analysis have shown that the dry hydrochar loses about 41% of its dry mass due to the exothermic disintegration of oxygen-containing groups until the carbonization is completed at about 850 °C with a total carbon yield of 93%. The carbonization and aromatization of the initially furanic and keto-aliphatic structure were analyzed by 13C solid-state nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The transition from an amorphous to a nanocrystalline graphitic structure was analyzed using X-ray diffraction and Raman spectroscopy. The pore formation mechanism was examined by helium ion microscopy, transmission electron microscopy, and nitrogen adsorption measurements. The results indicate the formation of oxygen-rich nanoclusters up to 700 °C, which decompose up to 750 °C leaving behind equally sized pores, resulting in a surface area of up to 480 m2/g.}},
  author       = {{Wortmann, Martin and Keil, Waldemar and Brockhagen, Bennet and Biedinger, Jan and Westphal, Michael and Weinberger, Christian and Diestelhorst, Elise and Hachmann, Wiebke and Zhao, Yanjing and Tiemann, Michael and Reiss, Günter and Hüsgen, Bruno and Schmidt, Claudia and Sattler, Klaus and Frese, Natalie}},
  issn         = {{0165-2370}},
  journal      = {{Journal of Analytical and Applied Pyrolysis}},
  keywords     = {{Analytical Chemistry, Fuel Technology}},
  publisher    = {{Elsevier BV}},
  title        = {{{Pyrolysis of sucrose-derived hydrochar}}},
  doi          = {{10.1016/j.jaap.2021.105404}},
  volume       = {{161}},
  year         = {{2022}},
}

@article{28254,
  abstract     = {{With the rapid advances of functional dielectric metasurfaces and their integration on on-chip nanophotonic devices, the necessity of metasurfaces working in different environments, especially in biological applications, arose. However, the metasurfaces’ performance is tied to the unit cell’s efficiency and ultimately the surrounding environment it was designed for, thus reducing its applicability if exposed to altering refractive index media. Here, we report a method to increase a metasurface’s versatility by covering the high-index metasurface with a low index porous SiO2 film, protecting the metasurface from environmental changes while keeping the working efficiency unchanged. We show, that a covered metasurface retains its functionality even when exposed to fluidic environments.}},
  author       = {{Geromel, René and Weinberger, Christian and Brormann, Katja and Tiemann, Michael and Zentgraf, Thomas}},
  issn         = {{2159-3930}},
  journal      = {{Optical Materials Express}},
  number       = {{1}},
  pages        = {{13--21}},
  publisher    = {{Optica}},
  title        = {{{Porous SiO2 coated dielectric metasurface with consistent performance independent of environmental conditions}}},
  doi          = {{10.1364/ome.444264}},
  volume       = {{12}},
  year         = {{2022}},
}

@inproceedings{44376,
  author       = {{Tonbul, Güldeniz and Kappler, Julian  and Murugan, Saravanakumar  and Schoch, Roland  and Nowakowski, Michal  and Lange, Pia  and Bauer, Matthias and Buchmeiser, Michael R.}},
  location     = {{Edinburgh}},
  title        = {{{Development of Battery System Based on Na-S and Characterization Using X-ray Absorption Spectroscopy}}},
  year         = {{2022}},
}

@article{40987,
  abstract     = {{<The replacement of noble metal catalysts by abundant iron as an active compound in CO oxidation is of ecologic and economic interest. However, improvement of their catalytic performance to the same level as state-of-the-art noble metal catalysts requires an in depth understanding of their working principle on an atomic level. As a contribution to this aim, a series of iron oxide catalysts with varying Fe loadings from 1 to 20 wt% immobilized on a γ-Al2O3 support is presented here, and a multidimensional structure–activity correlation is established. The CO oxidation activity is correlated to structural details obtained by various spectroscopic, diffraction, and microscopic methods, such as PXRD, PDF analysis, DRUVS, Mössbauer spectroscopy, STEM-EDX, and XAS. Low Fe loadings lead to less agglomerated but high percentual amounts of isolated, tetrahedrally coordinated iron oxide species, while the absolute amount of isolated species reaches its maximum at high Fe loadings. Consequently, the highest CO oxidation activity in terms of turnover frequencies can be correlated to small, finely dispersed iron oxide species with a large amount of tetrahedrally oxygen coordinated iron sites, while the overall amount of isolated iron oxide species correlates with a lower light-off temperature.}},
  author       = {{Schlicher, Steffen and Prinz, Nils and Bürger, Julius and Omlor, Andreas and Singer, Christian and Zobel, Mirijam and Schoch, Roland and Lindner, Jörg K. N. and Schünemann, Volker and Kureti, Sven and Bauer, Matthias}},
  issn         = {{2073-4344}},
  journal      = {{Catalysts}},
  keywords     = {{Physical and Theoretical Chemistry, Catalysis, General Environmental Science, Key}},
  number       = {{6}},
  publisher    = {{MDPI AG}},
  title        = {{{Quality or Quantity? How Structural Parameters Affect Catalytic Activity of Iron Oxides for CO Oxidation}}},
  doi          = {{10.3390/catal12060675}},
  volume       = {{12}},
  year         = {{2022}},
}

@article{29790,
  abstract     = {{The free exciton transition (near-band-edge emission, NBE) of ZnO at ≈388 nm can be strongly enhanced and even stimulated by an underlying photonic structure. 1D Photonic crystals, so-called distributed Bragg reflectors, are utilized to suppress the deep-level emission of ZnO (DLE, ≈500–530 nm). The reflector stacks are fabricated in a layer-by-layer procedure by wet-chemical synthesis. They consist of low-ε porous SiO2 layers and high-ε TiO2 layers. Varying the thickness of the SiO2 layers allows tuning the optical bandgap in a wide range between ≈420 and 800 nm. A ZnO layer is deposited on top of the reflector stacks by sol–gel synthesis. The spontaneous photoluminescence (PL) emission of the ZnO film is modulated by the photonic structure. When the optical bandgap of the reflector is in resonance with the deep-level emission of ZnO (DLE, ≈500–530 nm), then this defect-related emission mode is suppressed. Strong NBE emission is observed even when the ZnO layer does not show any NBE emission (due to low crystallinity) in the absence of the photonic structure. With this cost-efficient synthesis method, emitters for, e.g., luminescent gas sensors can be fabricated.}},
  author       = {{Kothe, Linda and Albert, Maximilian and Meier, Cedrik and Wagner, Thorsten and Tiemann, Michael}},
  issn         = {{2196-7350}},
  journal      = {{Advanced Materials Interfaces}},
  keywords     = {{Mechanical Engineering, Mechanics of Materials}},
  publisher    = {{Wiley}},
  title        = {{{Stimulation and Enhancement of Near‐Band‐Edge Emission in Zinc Oxide by Distributed Bragg Reflectors}}},
  doi          = {{10.1002/admi.202102357}},
  volume       = {{9}},
  year         = {{2022}},
}

@article{41001,
  abstract     = {{For entropic reasons, the synthesis of macrocycles via olefin ring-closing metathesis (RCM) is impeded by competing acyclic diene metathesis (ADMET) oligomerization. With cationic molybdenum imido alkylidene N-heterocyclic carbene (NHC) complexes confined in tailored ordered mesoporous silica, RCM can be run with macrocyclization selectivities up to 98% and high substrate concentrations up to 0.1 M. Molecular dynamics simulations show that the high conversions are a direct result of the proximity between the surface-bound catalyst, proven by extended X-ray absorption spectroscopy, and the surface-located substrates. Back-diffusion of the macrocycles decreases with decreasing pore diameter of the silica and is responsible for the high macrocyclization efficiency. Also, Z-selectivity increases with decreasing pore diameter and increasing Tolman electronic parameter of the NHC. Running reactions at different concentrations allows for identifying the optimum substrate concentration for each material and substrate combination.}},
  author       = {{Ziegler, Felix and Kraus, Hamzeh and Benedikter, Mathis J. and Wang, Dongren and Bruckner, Johanna R. and Nowakowski, Michał and Weißer, Kilian and Solodenko, Helena and Schmitz, Guido and Bauer, Matthias and Hansen, Niels and Buchmeiser, Michael R.}},
  issn         = {{2155-5435}},
  journal      = {{ACS Catalysis}},
  keywords     = {{Catalysis, General Chemistry}},
  number       = {{18}},
  pages        = {{11570--11578}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Confinement Effects for Efficient Macrocyclization Reactions with Supported Cationic Molybdenum Imido Alkylidene <i>N</i>-Heterocyclic Carbene Complexes}}},
  doi          = {{10.1021/acscatal.1c03057}},
  volume       = {{11}},
  year         = {{2021}},
}

@article{40999,
  abstract     = {{Rh(I) NHC and Rh(III) Cp* NHC complexes (Cp*=pentamethylcyclopentadienyl, NHC=N-heterocyclic carbene=pyrid-2-ylimidazol-2-ylidene (Py−Im), thiophen-2-ylimidazol-2-ylidene) are presented. Selected catalysts were selectively immobilized inside the mesopores of SBA-15 with average pore diameters of 5.0 and 6.2 nm. Together with their homogenous progenitors, the immobilized catalysts were used in the hydrosilylation of terminal alkynes. For aromatic alkynes, both the neutral and cationic Rh(I) complexes showed excellent reactivity with exclusive formation of the β(E)-isomer. For aliphatic alkynes, however, selectivity of the Rh(I) complexes was low. By contrast, the neutral and cationic Rh(III) Cp* NHC complexes proved to be highly regio- and stereoselective catalysts, allowing for the formation of the thermodynamically less stable β-(Z)-vinylsilane isomers at room temperature. Notably, the SBA-15 immobilized Rh(I) catalysts, in which the pore walls provide an additional confinement, showed excellent β-(Z)-selectivity in the hydrosilylation of aliphatic alkynes, too. Also, in the case of 4-aminophenylacetylene, selective formation of the β(Z)-isomer was observed with a neutral SBA-15 supported Rh(III) Cp* NHC complex but not with its homogenous counterpart. These are the first examples of high β(Z)-selectivity in the hydrosilylation of alkynes by confinement generated upon immobilization inside mesoporous silica.}},
  author       = {{Panyam, Pradeep K. R. and Atwi, Boshra and Ziegler, Felix and Frey, Wolfgang and Nowakowski, Michał and Bauer, Matthias and Buchmeiser, Michael R.}},
  issn         = {{0947-6539}},
  journal      = {{Chemistry – A European Journal}},
  keywords     = {{General Chemistry, Catalysis, Organic Chemistry}},
  number       = {{68}},
  pages        = {{17220--17229}},
  publisher    = {{Wiley}},
  title        = {{{Rh(I)/(III)‐N‐Heterocyclic Carbene Complexes: Effect of Steric Confinement Upon Immobilization on Regio‐ and Stereoselectivity in the Hydrosilylation of Alkynes}}},
  doi          = {{10.1002/chem.202103099}},
  volume       = {{27}},
  year         = {{2021}},
}

@article{41009,
  abstract     = {{Platinum hydride species catalyze a number of interesting organic reactions. However, their reactions typically involve the use of high loadings of noble metal and are difficult to recycle, making them somewhat unsustainable. We have synthesized surface-immobilized Pt–H species via oxidative addition of surface OH groups to Pt(PtBu3)2 (1), a rarely used immobilization technique in surface organometallic chemistry. The hydride species thus made were characterized by infrared, magic-angle spinning nuclear magnetic resonance, and X-ray absorption spectroscopies and catalyzed both olefin isomerization and cycloisomerization of a 1,6 enyne (5) with a high selectivity and low Pt loading.}},
  author       = {{Maier, Sarah and Cronin, Steve P. and Vu Dinh, Manh-Anh and Li, Zheng and Dyballa, Michael and Nowakowski, Michał and Bauer, Matthias and Estes, Deven P.}},
  issn         = {{0276-7333}},
  journal      = {{Organometallics}},
  keywords     = {{Inorganic Chemistry, Organic Chemistry, Physical and Theoretical Chemistry}},
  number       = {{11}},
  pages        = {{1751--1757}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Immobilized Platinum Hydride Species as Catalysts for Olefin Isomerizations and Enyne Cycloisomerizations}}},
  doi          = {{10.1021/acs.organomet.1c00216}},
  volume       = {{40}},
  year         = {{2021}},
}

@article{30216,
  author       = {{Huber-Gedert, Marina and Nowakowski, Michał and Kertmen, Ahmet and Burkhardt, Lukas and Lindner, Natalia and Schoch, Roland and Herbst‐Irmer, Regine and Neuba, Adam and Schmitz, Lennart and Choi, Tae‐Kyu and Kubicki, Jacek and Gawelda, Wojciech and Bauer, Matthias}},
  issn         = {{0947-6539}},
  journal      = {{Chemistry – A European Journal}},
  keywords     = {{Photocatalytic Hydrogen Production, Catalysis, Inorganic Chemistry}},
  number       = {{38}},
  pages        = {{9905--9918}},
  publisher    = {{Wiley}},
  title        = {{{Fundamental Characterization, Photophysics and Photocatalysis of a Base Metal Iron(II)‐Cobalt(III) Dyad}}},
  doi          = {{10.1002/chem.202100766}},
  volume       = {{27}},
  year         = {{2021}},
}

@phdthesis{41006,
  author       = {{Schlicher, Steffen}},
  title        = {{{Iron oxide catalysts for CO oxidation : from basic structure-activity-correlation to an advanced preparation strategy for highly active catalysts}}},
  doi          = {{10.17619/UNIPB/1-1089}},
  year         = {{2021}},
}

@article{41002,
  abstract     = {{Homogeneous catalysts immobilized on metal oxides often have different catalytic properties than in homogeneous solution. This can be either activating or deactivating and is often attributed to interactions of catalyst species with the metal oxide surface. However, few studies have ever demonstrated the effect that close associations of active sites with surfaces have on the catalytic activity. In this paper, we immobilize H2Ru(PPh3)2(Ph2P)2N–C3H6–Si(OEt)3 (3) on SiO2, Al2O3, and ZnO and interrogate the relationship to the surface using IR, MAS NMR, 1H–31P HETCOR, and XAS spectroscopies. We found that while there are close contacts between the P atoms of the complex and all three metal oxide surfaces, the Ru–H bond only reacts with oxygen bridges on SiO2 and Al2O3, forming new Ru–O bonds. In contrast, complex 3 stays intact on ZnO. Comparison of the catalytic activities of our immobilized species for CO2 hydrogenation to ethyl formate showed that Lewis acidic metal oxides activate, rather than deactivate, complex 3 in the order Al2O3 > ZnO > SiO2. The Lewis acidic sites on the metal oxide surfaces most likely increase the productivity by increasing the rate of esterification of formate intermediates.}},
  author       = {{Nguyen, Hoang-Huy and Li, Zheng and Enenkel, Toni and Hildebrand, Joachim and Bauer, Matthias and Dyballa, Michael and Estes, Deven P.}},
  issn         = {{1932-7447}},
  journal      = {{The Journal of Physical Chemistry C}},
  keywords     = {{Surfaces, Coatings and Films, Physical and Theoretical Chemistry, General Energy, Electronic, Optical and Magnetic Materials}},
  number       = {{27}},
  pages        = {{14627--14635}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Probing the Interactions of Immobilized Ruthenium Dihydride Complexes with Metal Oxide Surfaces by MAS NMR: Effects on CO<sub>2</sub> Hydrogenation}}},
  doi          = {{10.1021/acs.jpcc.1c02074}},
  volume       = {{125}},
  year         = {{2021}},
}

@article{40998,
  abstract     = {{Covalent organic frameworks (COFs) offer vast structural and chemical diversity enabling a wide and growing range of applications. While COFs are well-established as heterogeneous catalysts, so far, their high and ordered porosity has scarcely been utilized to its full potential when it comes to spatially confined reactions in COF pores to alter the outcome of reactions. Here, we present a highly porous and crystalline, large-pore COF as catalytic support in α,ω-diene ring-closing metathesis reactions, leading to increased macrocyclization selectivity. COF pore-wall modification by immobilization of a Grubbs-Hoveyda-type catalyst via a mild silylation reaction provides a molecularly precise heterogeneous olefin metathesis catalyst. An increased macro(mono)cyclization (MMC) selectivity over oligomerization (O) for the heterogeneous COF-catalyst (MMC:O=1.35) of up to 51 % compared to the homogeneous catalyst (MMC:O=0.90) was observed along with a substrate-size dependency in selectivity, pointing to diffusion limitations induced by the pore confinement.}},
  author       = {{Emmerling, Sebastian T. and Ziegler, Felix and Fischer, Felix R. and Schoch, Roland and Bauer, Matthias and Plietker, Bernd and Buchmeiser, Michael R. and Lotsch, Bettina V.}},
  issn         = {{0947-6539}},
  journal      = {{Chemistry – A European Journal}},
  keywords     = {{General Chemistry, Catalysis, Organic Chemistry}},
  number       = {{8}},
  publisher    = {{Wiley}},
  title        = {{{Olefin Metathesis in Confinement: Towards Covalent Organic Framework Scaffolds for Increased Macrocyclization Selectivity}}},
  doi          = {{10.1002/chem.202104108}},
  volume       = {{28}},
  year         = {{2021}},
}