FG Metallorganische Chemie und Anorganische Materialien

52 Items

Recent Submissions
Isolierbare Silicium‐basierte Polykationen mit Lewis‐Superacidität

Hermannsdorfer, André ; Driess, Matthias (2020-10-15)

Molekulare Silicium‐Polykationen des Typs R2Si2+ und RSi3+ (R=H, organische Gruppe) sind Lewis‐Supersäuren und bisher in kondensierter Phase unbekannt. Wir berichten über die Synthese einer Reihe isolierbarer Terpyridinkomplexe von R2Si2+ und RSi3+, [R2Si(terpy)]2+ (R=Ph 12+; R2=C12H8 22+, (CH2)3 32+) und [RSi(terpy)]3+ (R=Ph 43+, C6H11 53+, m‐Xylyl 63+) in Form ihrer Triflat‐Salze. Die Stabili...

Intermetallic Fe6Ge5 formation and decay of a core–shell structure during the oxygen evolution reaction

Hausmann, J. Niklas ; Khalaniya, Roman A. ; Das, Chittaranjan ; Remy-Speckmann, Ina ; Berendts, Stefan ; Shevelkov, Andrei V. ; Driess, Matthias ; Menezes, Prashanth W. (2021-01-22)

Herein, we report on intermetallic iron germanide (Fe6Ge5) as a novel oxygen evolution reaction (OER) precatalyst with a Tafel slope of 32 mV dec−1 and an overpotential of 272 mV at 100 mA cm−2 in alkaline media. Furthermore, we uncover the in situ formation of a core–shell like structure that slowly collapses under OER conditions.

Promoting Photocatalytic Hydrogen Evolution Activity of Graphitic Carbon Nitride with Hole‐Transfer Agents

Indra, Arindam ; Beltrán‐Suito, Rodrigo ; Müller, Marco ; Sivasankaran, Ramesh P. ; Schwarze, Michael ; Acharjya, Amitava ; Pradhan, Bapi ; Hofkens, Johan ; Brückner, Angelika ; Thomas, Arne ; Menezes, Prashanth W. ; Driess, Matthias (2020-11-27)

Visible light‐driven photocatalytic reduction of protons to H2 is considered a promising way of solar‐to‐chemical energy conversion. Effective transfer of the photogenerated electrons and holes to the surface of the photocatalyst by minimizing their recombination is essential for achieving a high photocatalytic activity. In general, a sacrificial electron donor is used as a hole scavenger to re...

Bis(silylene)‐Stabilized Monovalent Nitrogen Complexes

Yao, Shenglai ; Szilvási, Tibor ; Xiong, Yun ; Lorent, Christian ; Ruzicka, Ales ; Driess, Matthias (2020-09-28)

The first series of bis(silylene)‐stabilized nitrogen(I) compounds is described. Starting from the 1,2‐bis(N‐heterocyclic silylenyl) 1,2‐dicarba‐closo‐dedocaborane(12) scaffold 1, [1,2‐(LSi)2C2B10H10; L=PhC(NtBu)2], reaction with adamantyl azide (AdN3) affords the terminal N‐μ2‐bridged zwitterionic carborane‐1,2‐bis(silylium) AdN3 adduct 2 with an open‐cage dianionic nido‐C2B10 cluster core. Re...

A Low‐Temperature Molecular Precursor Approach to Copper‐Based Nano‐Sized Digenite Mineral for Efficient Electrocatalytic Oxygen Evolution Reaction

Chakraborty, Biswarup ; Kalra, Shweta ; Beltrán‐Suito, Rodrigo ; Das, Chittaranjan ; Hellmann, Tim ; Menezes, Prashanth W. ; Driess, Matthias (2020-02-20)

In the urge of designing noble metal‐free and sustainable electrocatalysts for oxygen evolution reaction (OER), herein, a mineral Digenite Cu9S5 has been prepared from a molecular copper(I) precursor, [{(PyHS)2CuI(PyHS)}2](OTf)2 (1), and utilized as an anode material in electrocatalytic OER for the first time. A hot injection of 1 yielded a pure phase and highly crystalline Cu9S5, which was the...

Crystalline Copper Selenide as a Reliable Non‐Noble Electro(pre)catalyst for Overall Water Splitting

Chakraborty, Biswarup ; Beltrán‐Suito, Rodrigo ; Hlukhyy, Viktor ; Schmidt, Johannes ; Menezes, Prashanth W. ; Driess, Matthias (2020-05-07)

Electrochemical water splitting remains a frontier research topic in the quest to develop artificial photosynthetic systems by using noble metal‐free and sustainable catalysts. Herein, a highly crystalline CuSe has been employed as active electrodes for overall water splitting (OWS) in alkaline media. The pure‐phase klockmannite CuSe deposited on highly conducting nickel foam (NF) electrodes by...

An Isolable Bis(Silanone–Borane) Adduct

Luecke, Marcel‐Philip ; Pens, Elron ; Yao, Shenglai ; Driess, Matthias (2020-03-11)

The reaction of bis(silylenyl)‐substituted ferrocene 1 with two molar equivalents of BPh3 yields the corresponding bis(silylene–borane) Lewis adduct 2. The latter is capable to activate CO2 to furnish the borane‐stabilized bis(silanone) 3 through mono‐oxygenation of the dative SiII→B silicon centers under release of CO. Removal of BPh3 from 3 with PMe3 affords the corresponding 1,3,2,4‐cyclodis...

A Systems Approach to a One‐Pot Electrochemical Wittig Olefination Avoiding the Use of Chemical Reductant or Sacrificial Electrode

Chakraborty, Biswarup ; Kostenko, Arseni ; Menezes, Prashanth W. ; Driess, Matthias (2020-08-13)

An unprecedented one‐pot fully electrochemically driven Wittig olefination reaction system without employing a chemical reductant or sacrificial electrode material to regenerate triphenylphosphine (TPP) from triphenylphosphine oxide (TPPO) and base‐free in situ formation of Wittig ylides, is reported. Starting from TPPO, the initial step of the phosphoryl P=O bond activation proceeds through al...

Enabling Iron‐Based Highly Effective Electrochemical Water‐Splitting and Selective Oxygenation of Organic Substrates through In Situ Surface Modification of Intermetallic Iron Stannide Precatalyst

Chakraborty, Biswarup ; Beltrán‐Suito, Rodrigo ; Hausmann, J. Niklas ; Garai, Somenath ; Driess, Matthias ; Menezes, Prashanth W. (2020-06-24)

A strategy to overcome the unsatisfying catalytic performance and the durability of monometallic iron‐based materials for the electrochemical oxygen evolution reaction (OER) is provided by heterobimetallic iron–metal systems. Monometallic Fe catalysts show limited performance mostly due to poor conductivity and stability. Here, by taking advantage of the structurally ordered and highly conducti...

Understanding the formation of bulk- and surface-active layered (oxy)hydroxides for water oxidation starting from a cobalt selenite precursor

Hausmann, Jan Niklas ; Mebs, Stefan ; Laun, Konstantin ; Zebger, Ingo ; Dau, Holger ; Menezes, Prashanth W. ; Drieß, Matthias (2020-09-04)

The urgent need for a stable, efficient, and affordable oxygen evolution reaction (OER) catalyst has led to the investigation of a vast amount of transition metal materials with multiple different anions. In situ and post catalytic characterization shows that most materials transform during the harsh OER conditions to layered (oxy)hydroxides (LOH). Several open questions concerning these in sit...

Plasma‐Assisted Immobilization of a Phosphonium Salt and Its Use as a Catalyst in the Valorization of CO2

Hu, Yuya ; Peglow, Sandra ; Longwitz, Lars ; Frank, Marcus ; Epping, Jan Dirk ; Brüser, Volker ; Werner, Thomas (2020-03-17)

The first plasma‐assisted immobilization of an organocatalyst, namely a bifunctional phosphonium salt in an amorphous hydrogenated carbon coating, is reported. This method makes the requirement for prefunctionalized supports redundant. The immobilized catalyst was characterized by solid‐state 13C and 31P NMR spectroscopy, SEM, and energy‐dispersive X‐ray spectroscopy. The immobilized catalyst (...

Nanocatalysts Unravel the Selective State of Ag

Lamoth, Maximilian ; Jones, Travis ; Plodinec, Milivoj ; Machoke, Albert ; Wrabetz, Sabine ; Krämer, Michael ; Karpov, Andrey ; Rosowski, Frank ; Piccinin, Simone ; Schlögl, Robert ; Frei, Elias (2020-05-07)

In the present work, we report on a comparative study of model catalysts during ethylene epoxidation reaction under industrially relevant conditions. The catalysts consist of Ag nanoparticles <6 nm and a reference sample ∼100 nm. Combining catalytic data with transmission electron microscopy, thermal desorption spectroscopy, and density functional theory allows us to show that catalytic perform...

Beiträge zur Chemie von Bis(silylenen) für die Aktivierung kleiner Moleküle

Lücke, Marcel-Philip (2020)

Die Chemie der niedervalenten-Hauptgruppenchemie gehört zu den attraktivsten Forschungsfeldern in der metallorganischen Chemie. Besonders N heterocyclische Silylene (NHSis) mit einem niedervalenten, neutralen Siliciumatom in der Oxidationsstufe II sind von großem Interesse, da sie als starke σ Donorliganden in der homogenen Katalyse fungieren und in der Lage sind, unreaktive chemische Bindunge...

Where silylene–silicon centres matter in the activation of small molecules

Shan, Changkai ; Yao, Shenglai ; Drieß, Matthias (2020-08-19)

Small molecules such as H2, N2, CO, NH3, O2 are ubiquitous stable species and their activation and role in the formation of value-added products are of fundamental importance in nature and industry. The last few decades have witnessed significant advances in the chemistry of heavy low-coordinate main-group elements, with a plethora of newly synthesised functional compounds, behaving like transi...

Precise Orbit and Clock Products of Galileo, BDS and QZSS from MGEX Since 2018: Comparison and PPP Validation

Li, Xingxing ; Zhu, Yiting ; Zheng, Kai ; Yuan, Yongqiang ; Liu, Gege ; Xiong, Yun (2020-04-30)

In recent years, the development of new constellations including Galileo, BeiDou Navigation Satellite System (BDS) and Quasi-Zenith Satellite System (QZSS) have undergone dramatic changes. Since January 2018, about 30 satellites of the new constellations have been launched and most of the new satellites have been included in the precise orbit and clock products provided by the Multi Global Navi...

Enhancing of catalytic properties of vanadia via surface doping with phosphorus using atomic layer deposition

Strempel, Verena E. ; Löffler, Daniel ; Kröhnert, Jutta ; Skorupska, Katarzyna ; Johnson, Benjamin ; Naumann d’Alnoncourt, Raoul ; Drieß, Matthias ; Rosowski, Frank (2015-12-11)

Atomic layer deposition is mainly used to deposit thin films on flat substrates. Here, the authors deposit a submonolayer of phosphorus on V2O5 in the form of catalyst powder. The goal is to prepare a model catalyst related to the vanadyl pyrophosphate catalyst (VO)2P2O7 industrially used for the oxidation of n-butane to maleic anhydride. The oxidation state of vanadium in vanadyl pyrophosphate...

Atomic layer deposition on porous powders with in situ gravimetric monitoring in a modular fixed bed reactor setup

Strempel, Verena E. ; Naumann d’Alnoncourt, Raoul ; Drieß, Matthias ; Rosowski, Frank (2017-07-19)

A modular setup for Atomic Layer Deposition (ALD) on high-surface powder substrates in fixed bed reactors with a gravimetric in situ monitoring was developed. The design and operation are described in detail. An integrated magnetically suspended balance records mass changes during ALD. The highly versatile setup consists of three modular main units: a dosing unit, a reactor unit, and a downstre...

Detecting structural transformation of cobalt phosphonate to active bifunctional catalysts for electrochemical water-splitting

Indra, Arindam ; Menezes, Prashanth W. ; Zaharieva, Ivelina ; Dau, Holger ; Drieß, Matthias (2020-01-07)

In recent years, several cobalt-based catalysts have been developed for water splitting because of their promising activity, stability and structural motifs. Here, we report that cobalt phosphonate represents a novel class of bifunctional single-source precursors for highly efficient alkaline electrochemical O2 evolution (OER) and H2 evolution reaction (HER). Inspired by its favorable catalytic...

Beiträge zur Wasseroxidationskatalyse

Walter, Carsten (2020)

Die elektrochemische Wasserstoffentwicklung (HER = hydrogen evolution reaction) durch Wasserspaltung gilt als vielversprechende Technologie für eine „grüne“, erneuerbare und nachhaltige Energieversorgung. Hierbei gilt die Sauerstoffentwicklungsreaktion (OER = oxygen evolution reaction) als Engpass des vierstufigen Mechanismus mit gekoppelten Elektronen-Protonen-Transferreaktionen und hochenerge...

Stannites – a new promising class of durable electrocatalysts for efficient water oxidation

Hausmann, Jan Niklas ; Heppke, Eva Maria ; Beltrán-Suito, Rodrigo ; Schmidt, Johannes ; Mühlbauer, Martin ; Lerch, Martin ; Menezes, Prashanth Wilfried ; Drieß, Matthias (2020-01-09)

The oxygen evolution reaction (OER) through water oxidation is a key process for multiple energy storage technologies required for a sustainable energy economy such as the formation of the fuel hydrogen from water and electricity, or metal‐air batteries. Herein, we investigate the suitability of Cu2FeSnS4 for the OER and demonstrate its superiority over iron sulfide, iron (oxy)hydroxides and be...