Article
Chemistry, Physical
Clayton J. Dahlman, Rhys M. Kennard, Piotr Paluch, Naveen R. Venkatesan, Michael L. Chabinyc, G. N. Manjunatha Reddy
Summary: Layered hybrid organic-inorganic perovskites, such as the lead halide Ruddlesden-Popper (RP) series, exhibit tunable optoelectronic properties due to dynamic interactions between the ionic perovskite substructure and organic spacer cations. Solid-state NMR spectroscopy was used to characterize the static and dynamic structures of linear alkylammonium and aromatic spacers in lead iodide RP phases, revealing different site-specific rigidity trends for short and long spacers. The study highlights the interplay between spacer interactions with lead iodide octahedra and van der Waals forces in contributing to a variety of site-specific dynamics and structural distortions at intermediate time scales.
CHEMISTRY OF MATERIALS
(2021)
Article
Plant Sciences
Maria Laura Bellone, Cesar Munoz Camero, Maria Giovanna Chini, Fabrizio Dal Piaz, Vanessa Hernandez, Giuseppe Bifulco, Nunziatina De Tommasi, Alessandra Braca
Summary: Nine new limonoids were isolated from Guarea guidonia and Cedrela odorata, including three A2,B,D-seco-type limonoids, a mexicanolide, three nomilin-type limonoids, and two limonol derivatives. Among them, chisomicine D demonstrated the highest affinity as a type of client-selective Hsp90 inhibitor through biochemical and cellular assays, and molecular docking. The study also utilized a DFT/NMR procedure to define the relative configurations of certain limonoids.
JOURNAL OF NATURAL PRODUCTS
(2021)
Article
Geosciences, Multidisciplinary
Jocelyn A. Richardson, Sascha Roest-Ellis, Brian L. Phillips, Justin Strauss, Samuel M. Webb, Nicholas J. Tosca
Summary: Constraints on marine phosphate availability and cycling are crucial for our understanding of long-term biological evolution. This study demonstrates that well-preserved shallow marine inorganic carbonate precipitates contain phosphate sourced from seawater, indicating the potential for an unaltered archive of marine phosphate concentration over geologic time.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Engineering, Environmental
Dongxu Xing, Xunzhou Li, Yi Wang, Shenggui Deng, Chunji Jin, Yangguo Zhao, Liang Guo
Summary: Understanding the impact of phosphorus sources on microalgae growth is crucial for cultivating microalgae. Both inorganic phosphorus and organic phosphorus can be absorbed and utilized by Chlorella pyrenoidosa. The maximum dry cell weight was achieved when the IP/OP ratio was 1:3, which was higher than other combinations. The increase in OP proportion was beneficial for microalgae growth but disadvantageous for lipid accumulation. The use of 31P NMR spectroscopy provided valuable insights into phosphorus metabolism and transformation in microalgae.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Robin Rothfelder, Verena Streitferdt, Ulrich Lennert, Jose Cammarata, Daniel J. Scott, Kirsten Zeitler, Ruth M. Gschwind, Robert Wolf
Summary: Detailed P-31{H-1} NMR spectroscopic investigations provide deeper insight into the mechanisms involved in the photocatalytic arylation of white phosphorus, revealing previously unrecognized side products and the unexpected behavior of the terminal reductant Et3N. The different rate of formation of these products explains the performance discrepancies of two effective catalysts, while the observation of PH3 as a minor intermediate led to the development of a new catalytic procedure for the arylation of white phosphorus. This method yields valuable triarylphosphines or tetraarylphosphonium salts depending on aryl substituents' steric profiles.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Jelte P. Nimoth, Thomas Mueller
Summary: Hydrogen-bridged oligosilanylsilyl borates and diborates were prepared through hydride transfer. Their structures and properties were characterized using low temperature NMR spectroscopy and density functional calculations.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Mehdi Elsayed Moussa, Tobias Kahoun, Christian Marquardt, Matthias T. Ackermann, Oliver Hegen, Michael Seidl, Alexey Y. Timoshkin, Alexander V. Virovets, Michael Bodensteiner, Manfred Scheer
Summary: This article reports an unprecedented family of substituted anionic derivatives of pnictogenylboranes. By reacting various combinations of H2E'-BH2-NMe3 (E'=P, As) with pnictogen-based nucleophiles MER1R2 (E=P, As; R1=H, R2=Bu-t; R1=R2=Ph; M=Na, K), unsymmetrical and symmetrical products were isolated. Furthermore, the thermodynamics of the reaction pathways were evaluated by quantum chemical computations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Letter
Chemistry, Multidisciplinary
Irene Casademont-Reig, Luis Soriano-Agueda, Eloy Ramos-Cordoba, Miquel Torrent-Sucarrat, Eduard Matito
Summary: This article challenges our conclusions on the aromaticity of a six-porphyrin nanoring linked by a butadiyne, based on experimental H-1-NMR data and calculations using the BLYP35 functional. The authors caution against relying solely on BLYP35 and argue that the indirect evidence of ring current from experimental H-1-NMR data is not a definitive proof of aromaticity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Marcel Krug, Nina Frohlich, Dominik Fehn, Alexander Vogel, Frank Rominger, Karsten Meyer, Timothy Clark, Milan Kivala, Dirk M. Guldi
Summary: Three linear dimers containing two redox-active planarized triphenylamines were synthesized and their structures verified by X-ray crystallography. Investigation of their radical cations using various techniques revealed the significance of using redox centers with low internal reorganization energies. Distance-dependence attenuation factor of the super-exchange mechanisms remained similar when compared with non-planarized nitrogen-centered building blocks.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Environmental Sciences
Mary R. Arenberg, Yuji Arai
Summary: The study demonstrated that the carbon composition of plant leaf residue can affect phosphorus reaction dynamics in floodplain soils under different soil organic carbon to phosphorus ratios. Residues with low aromaticity promoted phosphorus mineralization, while residues with high aromaticity and hydrophobicity caused phosphorus immobilization.
Article
Biochemistry & Molecular Biology
Sulejman Alihodzic, Hana Cipcic Paljetak, Ana Cikos, Ivaylo Jivkov Elenkov
Summary: This study utilized an unprecedented tandem reaction to prepare novel bicyclic azalides, and NMR spectroscopy was used to determine the structure and investigate the effect of the rigid bicyclic modification on the molecule's conformation. Some prepared compounds exhibited antibacterial activity similar to azithromycin.
Article
Chemistry, Organic
Akihiko Ishii, Ryota Ebina, Norio Nakata
Summary: In this study, a 1,2,5-triphenylpentadienyl cation fused with a dibenzobarrelene skeleton was synthesized and characterized by NMR spectroscopy. The persistent nature and reaction properties of the cation were investigated, revealing its absorption and emission characteristics through experimental and computational methods.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Ritu Yadav, Bindusagar Das, Ashi Singh, Ankita Anmol, Ankita Sharma, Chinmoy Majumder
Summary: In this study, the synthesis and characterization of bicyclic (alkyl)(amino)carbene (BICAAC)-stabilized phosphinidenes were reported. The compounds were obtained through reactions between trihalophosphine and BICAAC, and their structures were confirmed by X-ray crystallography and NMR spectroscopy. Theoretical calculations revealed the presence of predominant C(carbene)-P double bond characteristic in these compounds.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Ritu Yadav, Bindusagar Das, Ashi Singh, Ankita Anmol, Ankita Sharma, Chinmoy Majumder
Summary: This study reports the synthesis and characterization of BICAAC-stabilized phosphinidenes. X-ray crystallography and NMR spectroscopy were used to characterize the compounds, and theoretical calculations indicated the presence of characteristic double bonds.
DALTON TRANSACTIONS
(2023)
Article
Biochemistry & Molecular Biology
Kseniya N. Sedenkova, Kristian S. Andriasov, Marina G. Eremenko, Yuri K. Grishin, Vera A. Alferova, Anna A. Baranova, Nikolay A. Zefirov, Olga N. Zefirova, Vladimir V. Zarubaev, Yulia A. Gracheva, Elena R. Milaeva, Elena B. Averina
Summary: The application of non-planar scaffolds in drug design allows for the enlargement of chemical space and the construction of more effective molecules. The study on derivatives active against resistant viral strains has achieved significant progress.
Article
Chemistry, Inorganic & Nuclear
Stephan Ludwig, Friederike M. Hamann, Kai Helmdach, Alexander Villinger, Wolfram W. Seidel
Summary: Eleven complexes bearing the general formula [Tp*W(CO)L{η(2)-C-2(PPh2)(2)}](n+) have been synthesized and fully characterized. The oxidation process and spectroscopic properties of the complexes are influenced by the electron character of the central metal. The basicity of the phosphine groups in the alkyne complexes is estimated. The coordination of PdCl2 affects the redox potentials and catalytic activity. X-ray diffraction analysis shows the flexibility of the alkyne complex moiety.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Yannic Pilopp, Jonas Bresien, Daniel T. Gschwind, Alexander Villinger, Dirk Michalik, Axel Schulz
Summary: Differently substituted phenyl isonitriles and naphthyl isonitriles reacted with the cyclic biradical [P-*(mu-N-Ter)(2)P-*] (1) to form cyclic five-membered biradicals [P-*(NTer)2C(R)P-*] (2R, R= phenyl, naphthyl). C-H activation at the aryl substituent led to the formation of novel azaphospholes (5R), which were fully characterized. The addition of a second equivalent of isonitrile prevented the formation of azaphospholes by blocking the radical centers in 2R through adduct formation (3R). Quantum mechanical calculations revealed an increase in aromaticity as one of the driving forces for the activation process.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Liesa Eickhoff, Pascal Kramer, Jonas Bresien, Dirk Michalik, Alexander Villinger, Axel Schulz
Summary: In the solution, Pacman chlorophosphane (2Cl) demonstrates rapid exchange of the endo/exo-orientation of the two P-Cl bonds in the molecule, which shows cooperativity. Experimental and quantum mechanical investigations confirm the crucial role of chloride ions in this dynamic process. Homologous Pacman halogen-phosphanes 2X were prepared through halogen exchange reactions (X = F, Br, and I) to validate the results, revealing accelerated dynamic behavior for heavier analogues and significant differences in the molecular structure, including the formation of an endo-endo substituted Pacman fluorophosphane as well as dicationic species by phosphorus halogen bond dissociation.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Lilian Sophie Szych, Karsten Paul Ludtke, Alexander Villinger, Dirk Bockfeld, Matthias Tamm, Axel Schulz
Summary: The synthesis of sterically demanding 2,6-bis-(2,4,6-trimethylphenyl)-phenyl (Ter)-stabilized and H-substituted diphosphanes via conversion of phosphide with secondary chlorophosphanes is described. The resulting potassium phosphinophosphides can be further functionalized and selectively used to synthesize Si-substituted diphosphanes or triphosphanes.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Ricardo Molenda, Jonas Polkaehn, Miguel Andre Argueello Cordero, Alexander Villinger, Peter Ehlers, Stefan Lochbrunner, Peter Langer
Summary: Thieno[2 ',3 ',4 ':4,5]naphtho[1,8-cd]pyridines, S,N-doped pyrene analogs, were synthesized by combination of Pd catalyzed cross-coupling reactions and acid-mediated cycloisomerization. The modular synthesis approach allowed for the preparation of various functionalized derivatives. The photophysical properties were extensively studied using steady-state and femtosecond transient absorption along with cyclic voltammetry and (TD)-DFT calculations. The introduction of a five-membered thiophene into the 2-azapyrene scaffold resulted in redshifted emission and significant effects on excited state dynamics, such as quantum yield, lifetime, decay rates, and ISC ability, which could be further controlled by the substitution pattern of the heterocyclic scaffold.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Aleksandra Khomutetckaia, Peter Ehlers, Alexander Villinger, Peter Langer
Summary: Benzo[h]imidazo[1,2-a]quinolines and1,2a-diazadibenzo[cd,f]azulenes were synthesized via regioselectivecycloisomerization reactions starting from a common intermediate. The choice of Bronsted acid and solvent significantly influenced the selectivity of the reactions. The optical and electrochemical properties of the products were characterized using UV/vis, fluorescence, and cyclovoltammetric measurements, which were further supported by density functional theory calculations.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Edgar Zander, Jonas Bresien, Vladimir V. Zhivonitko, Johannes Fessler, Alexander Villinger, Dirk Michalik, Axel Schulz
Summary: In this study, a persistent phosphorus-centered tetraradical was isolated and found to be capable of activating small molecules. Quantum mechanical calculations were used to compare its properties and aromaticity with other known tetraradicals and biradicals.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Chemistry, Multidisciplinary
Alexander Hinz, Jonas Bresien, Frank Breher, Axel Schulz
Summary: Heteroatom-centered diradical(oid)s have been the focus of molecular main group chemistry for the past 30 years, with a shift towards rational design for specific applications. Theoretical considerations and examples are presented to highlight the design of diradical(oid)s, including ligand choice, steric, symmetry, electronic situation, element choice, and reactivity. The review also discusses heteroatom-centered diradical reactions, their comparison with closed-shell reactions, and the application of diradical(oid)s in small molecule activation and molecular switches. Lastly, recent developments in spectroscopy and the study of heteroatom-centered diradical(oid)s and tetraradical(oid)s published since 2013 are summarized.
Article
Chemistry, Organic
Arpine Vardanyan, Alexander Villinger, Peter Ehlers, Peter Langer
Summary: A new and convenient method for synthesizing aryl-substituted naphtho[2,1-a]azulenes by combining Suzuki-Miyaura, Sonogashira, and cycloisomerization reactions is reported. This methodology was used to synthesize previously unknown azuleno[1,2-h]quinolines, cyclohepta[1,2]indeno[4,5-b]thiophenes, and cyclohepta[1,2]indeno[4,5-c]thiophenes. The impact of different fused heterocyclic rings on the photophysical and electrochemical properties of these azulene derivatives was studied using experimental and theoretical methods, providing a rationale for the preparation of novel azulene derivatives with improved properties for organic material applications.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Sophie Janke, Sebastian Boldt, Pascal Nakielski, Alexander Villinger, Peter Ehlers, Peter Langer
Summary: 5-Azaullazines, indolizino[6,5,4,3-ija][1,5]naphthyridines, and their benzo-fused analogues were synthesized in three steps using Pd catalyzed cross-coupling reactions and Bronsted acid mediated cycloisomerisations. The reaction exhibited tolerance towards various substitution patterns and functional groups, resulting in high yields. The optical and electrochemical properties of selected products were experimentally studied and also characterized by DFT calculations.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Rajesh Dasi, Alexander Villinger, Malte Brasholz
Summary: 2-Cyanochromone (1) undergoes visible light-induced photocycloadditions with various alkenes using (Ir[dF(CF3)ppy](2)(dtbpy))PF6 as the photosensitizer. Mono-, di-, and trisubstituted styrenes and acrylonitriles produce [2 + 2] cycloadducts with excellent regiocontrol and high diastereoselectivity. Trialkyl-substituted alkenes yield cyclopentenone-fused chromones through a [3 + 2] cycloaddition process in moderate yields.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Erich Ammon, Paul Heine, Miguel Andre Argueello Cordero, Stefan Lochbrunner, Alexander Villinger, Peter Langer, Peter Langer
Summary: Dibenzo[a,j] acridines and regioisomeric dibenzo[c,h]acridines were synthesized from 2,3,5,6-tetrachloropyridine using site-selective cross-coupling and alkyne-carbonyl metathesis reactions. The two regioisomeric series were obtained by changing the order of Sonogashira and Suzuki-Miyaura reactions. The optical and electronic properties of the products were studied using spectroscopy and DFT calculations.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Leon Ohms, Liesa Eickhoff, Pascal Kramer, Alexander Villinger, Jonas Bresien, Axel Schulz
Summary: We have extended the functionality of Pacman ligands by modifying them into bidentate phosphane ligands, allowing them to bind metals in a sterically protected cavity. The coordination of coinage metals demonstrates the ligand's ability to adopt various coordination modes, with some modes including the imine nitrogen atoms as well. Furthermore, the type of coordination is influenced by the substitution on the phosphorus atoms.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
T. Taeufer, F. Dankert, D. Michalik, J. Pospech, J. Bresien, C. Hering-Junghans
Summary: The reactivity of Cp*Ga (Cp* = C5Me5) towards phosphanylidenephosphoranes was investigated. Under irradiation at 405 nm at low temperatures, phosphagallenes (Dip)TerP = GaCp* (1a) and (Tip)TerP = GaCp* (1b) were formed, accompanied by release of PMe3. Reformation of (Ar)TerP(PMe3) and Cp*Ga was observed upon warming the reaction mixture to ambient temperatures without irradiation. 1a and 1b were isolated and found to react cleanly with CO2 and H2O to afford (Dip)TerPCO (3) and (Dip)TerPH(2) (4), respectively.
