Charge-transfer complexes: halogen-doped anthracene as a case of study
We present a rational and easy guide which allows to foresee the effective charge transfer co-crystal production and that is based on the comparison of the frontier molecular orbital (MO) energies of a donor and acceptor couple. For the sake of comparison, theoretical calculations have been carried out by using the cheap and fast PM6 semiempirical Hamiltonian and pure HF/cc-pVTZ level of the theory. The results are then compared with experimental results obtained both by chemical (bromine and iodine were used as the acceptor) and electrochemical doping (exploiting an original experimental set-up by this laboratory: the ele...
Source: Chemistry - April 23, 2024 Category: Chemistry Authors: Simone Gilioli Roberto Giovanardi Andrea Gemelli Andrea Severini Fabrizio Roncaglia Alberta Carella Francesco Rossella Davide Vanossi Andrea Marchetti Raanan Carmieli Claudio Fontanesi Luca Pasquali Monica Montecchi Camilla Ferrari Source Type: research
Optical Upconversion in Mononuclear Lanthanide Co-crystal Assemblies
Chemistry. 2024 Apr 23:e202400911. doi: 10.1002/chem.202400911. Online ahead of print.ABSTRACTIn this work, we developed two kinds of co-crystal assemblies systems, consisting of discrete mononuclear Yb3+ and Er3+ and mononuclear Yb3+ and Pr3+, which can achieve Er3+ and Pr3+ upconversion luminescence, respectively, by Yb3+ sensitization under 980 nm excitation. The structure and composition of two co-crystal assemblies were determined by single crystal X-ray diffraction. By investigation of the series of two assemblies, respectively, it is found that the strongest upconversion luminescence is both obtained when the molar ...
Source: Chemistry - April 23, 2024 Category: Chemistry Authors: Yuxin Wang Guotao Sun Qichen Su Yao Xie Feifei Xing Hongjie Zhang Lining Sun Source Type: research
Dual Basicity and Nucleophilicity of Organosodium Reagents in Benzylic C-H Additions of Toluenes to Diarylethenes and Ketones
Chemistry. 2024 Apr 23:e202400492. doi: 10.1002/chem.202400492. Online ahead of print.ABSTRACTProfiting from the dual high basicity and nucleophilicity of organosodium complexes, here we report the stepwise lateral metalation of a wide range of alkyl arenes (MeAr), mediated by hydrocarbon-soluble NaCH2SiMe3.PMDETA (PMDETA = N,N,N',N'',N''-pentamethyldiethylenetriamine), followed by nucleophilic addition to olenfins of the newly generated NaCH2Ar.PMDETA complexes. This method grants access to a range of functionalised hydrocarbons in excellent yields and can be upgraded to catalytic regimes when using trans-stilbene, a 10 m...
Source: Chemistry - April 23, 2024 Category: Chemistry Authors: David Anderson Alex Truong Eva Hevia Source Type: research
Electrophotocatalysis versus Indirect Electrolysis: Electrochemical Selenocyclization of 3-Aza-1,5-dienes Facilitated by Energy Transfer, Direct Photolysis or N-Hydroxyphthalimide
Chemistry. 2024 Apr 23:e202400280. doi: 10.1002/chem.202400280. Online ahead of print.ABSTRACTThree hybrid electrochemical protocols, which involve the energy transfer, direct photolysis and N-hydroxyphthalimide catalyst, respectively, are presented for the selenylation/cyclization of the fragile substrates of 3-aza-1,5-dienes with diorganyl diselenides to afford 3-selenomethyl-4-pyrrolin-2-ones. The two electrophotocatalytic reactions and the indirect electrolysis one are both regioselective and external-oxidant- and transition-metal-free, and are associated with a broad substrate scope and high Se-economy, and all three ...
Source: Chemistry - April 23, 2024 Category: Chemistry Authors: Dongyin Wang Li Zeng Jifu Shi Shulin Gao Lou Shi Shaoguang Sun Deqiang Liang Source Type: research
Detection and Characterization of Hydride Ligands in Copper Complexes by Hard X-ray Spectroscopy
This study employs synchrotron hard X-ray spectroscopy to gain insights into the geometric and electronic properties of copper hydrides as potential catalysts for CO2 hydrogenation. The potential of high energy resolution X-ray absorption near-edge structure (HERFD-XANES) and valence-to-core X-ray emission (VtC-XES) is demonstrated with measurement on Stryker's reagent (Cu6H6) and [Cu3(μ3-H)(dpmppe)2](PF6)2 (Cu3H), alongside a non-hydride copper compound (Cu-I). The XANES analysis reveals that coordination geometries strongly influence the spectra, providing only indirect details about hydride coordination. The VtC-XES an...
Source: Chemistry - April 23, 2024 Category: Chemistry Authors: Lorena Fritsch Pia Rehsies Wael Barakat Deven P Estes Matthias Bauer Source Type: research
Asymmetric 1,4-Addition of Diarylphosphine Oxides to α,β-Unsaturated 2-Acyl Imidazoles
Chemistry. 2024 Apr 23:e202401017. doi: 10.1002/chem.202401017. Online ahead of print.ABSTRACTHere we introduce a metal-free, catalytic and enantioselective strategy from α,β-unsaturated 2-acyl imidazoles to the chiral phosphorous 2-acyl imidazoles. Interestingly, this methodology was catalyzed by the classical and commercial oxazaborolidine under mild conditions. This strategy features a wide range of substrates scope with good yields and excellent enantioselectivities. The possible mechanism further suggests the key of this reaction through the cleavage of diarylphosphine oxides using Frustrated Lewis Pairs theory.PMID...
Source: Chemistry - April 23, 2024 Category: Chemistry Authors: Lirong Chen Guiyong Wang Xiufei Nong Wendi Shao Jiuling Li Yafei Guo Baomin Fan Source Type: research
Efficient Synthetic Access to Stable Isotope Labelled Pseudouridine Phosphoramidites for RNA NMR Spectroscopy
Chemistry. 2024 Apr 23:e202401193. doi: 10.1002/chem.202401193. Online ahead of print.ABSTRACTHere we report the efficient synthetic access to 13C/15N-labelled pseudouridine phosphoramidites, which were incorporated into a binary H/ACA box guide RNA/product complex comprising 77 nucleotides (nts) in total and into a 75 nt E. coli tRNAGly. The stable isotope (SI) labelled pseudouridines were produced via a highly efficient chemo-enzymatic synthesis. 13C/15N labelled uracils were produced via chemical synthesis and enzymatically converted to 5'-monophosphate pseudouridine (ΨMP) by using YeiN, a Ψ-5'-monophosphate C-glycosi...
Source: Chemistry - April 23, 2024 Category: Chemistry Authors: David Gl änzer Martin Pfeiffer Andrej Ribar Ricarda Zeindl Martin Tollinger Bernd Nidetzky Christoph Kreutz Source Type: research
Application of Mono and Trinuclear Cyclometalated Iridium (III) Complexes in Differential Bacterial Imaging and Antimicrobial Photodynamic therapy
Chemistry. 2024 Apr 23:e202400646. doi: 10.1002/chem.202400646. Online ahead of print.ABSTRACTThe application of transition metal complexes for antimicrobial photodynamic therapy (PDT) has emerged as an attractive alternative in mitigating a broad range of bacterial pathogens, including multidrug-resistant pathogens. In view of their photostability, long excited-state lifetimes, and tunable emission properties, transition metal complexes also contribute as bioimaging agents. In the present work, we designed mono and trinuclear cyclometalated iridium(III) complexes to explore their imaging application and antibacterial pote...
Source: Chemistry - April 23, 2024 Category: Chemistry Authors: Bishnu Das Prakash Biswas Amirul Islam Mallick Parna Gupta Source Type: research
Thermal Equilibrium between Quinoid/Biradical Forms Enhancing Electrochemical Amphotericity
Chemistry. 2024 Apr 21:e202400916. doi: 10.1002/chem.202400916. Online ahead of print.ABSTRACTUpon dibenzo annulation on Thiele's hydrocarbon (tetraphenyl-p-quinodimethane), the quinoid form and the biradical form adopt quite different geometries, and thus are no longer resonance structures. When these two forms can interconvert rapidly due to the small energy barrier (ΔG‡), the equilibrated mixture contains both forms in a ratio that is determined by the energy difference (ΔGo) between the two forms. For a series of tetrakis[5-(4-methoxyphenyl)-2-thienyl]-substituted derivatives, the more stable quinoid form and the m...
Source: Chemistry - April 22, 2024 Category: Chemistry Authors: Yusuke Ishigaki Shin-Ichi Mizuno Kazuma Sugawara Takumi Hashimoto Shuichi Suzuki Takanori Suzuki Source Type: research
TEMPO/O2 Synergistically Mediated BiBrO-Photocatalyzed Decarboxylative Phosphorylation of N-Arylglycines
Chemistry. 2024 Apr 21:e202304234. doi: 10.1002/chem.202304234. Online ahead of print.ABSTRACTWith both TEMPO and O2 (in air) as the homogeneous redox mediators, BiBrO as the heterogeneous semiconductor photocatalyst, the first example of semi-heterogeneous photocatalytic decarboxylative phosphorylation of N-arylglycines with diarylphosphine oxides was established. A series of α-amino phosphinoxides were efficiently synthesized.PMID:38644695 | DOI:10.1002/chem.202304234 (Source: Chemistry)
Source: Chemistry - April 22, 2024 Category: Chemistry Authors: Wen-Tao Ouyang Hong-Tao Ji Yuan-Yuan Liu Ting Li Yan-Fang Jiang Yu-Han Lu Jun Jiang Wei-Min He Source Type: research
Photo/mechanical/acidic multi-stimuli responses and information encryption design of acylhydrazone derivative
Chemistry. 2024 Apr 22:e202401171. doi: 10.1002/chem.202401171. Online ahead of print.ABSTRACTStimuli-responsive crystalline materials have received much attention for being potential candidates of smart materials. However, the occurrence of polymorphism-driven stimuli responses in crystalline materials remains interesting but rare. Herein, three polymorphs of an acylhydrazone derivative, N'-[(E)-(1-benzofuran-2-yl) methylidene] pyridine -4-carbohydrazide (BFMP) were prepared. Form-1 undergoes a photomechanical response via E→Z photoisomerization under UV irradiation, accompanied by a decrease in fluorescence intensity a...
Source: Chemistry - April 22, 2024 Category: Chemistry Authors: Yang Ye Dechen Wang Yaru Zhang Xiaomeng Zhou Haowen Du Sen Yang Ying Bao Hongxun Hao Chuang Xie Source Type: research
Improving Fatigue Resistance and Autonomous Switching of pH Responsive Hydrazones by Pulses of a Chemical Fuel
Chemistry. 2024 Apr 22:e202400328. doi: 10.1002/chem.202400328. Online ahead of print.ABSTRACTThe chemically triggered reversible switching of pH-responsive hydrazones involves rotary motion-induced configurational changes, serving as a prototype for constructing an array of molecular machines. Typically, the configurational isomerization of such switches into two distinct forms (E/Z) occurs through the alteration of the pH the medium, achieved by successive additions of acid and base stimuli. However, this process results in intermittent operation due to the concomitant accumulation of salt after each cycle, limiting swit...
Source: Chemistry - April 22, 2024 Category: Chemistry Authors: Pankaj Maity Harekrushna Pradhan Asesh Das Monotosh Dalapati Dipak Samanta Source Type: research
High-Intensity Circular Dichroism of Head-to-tail Regioregular Poly(1,4-phenylene)s in the Aggregated State
Chemistry. 2024 Apr 22:e202400706. doi: 10.1002/chem.202400706. Online ahead of print.ABSTRACTCircular dichroism (CD) studies on poly(1,4-phenylene)s bearing a chiral side chain in the aggregated conditions were carried out. Little CD was observed in a solution form, while addition of a poor solvent into the polyphenylene solution induced aggregation and a strong CD was observed, accordingly. Applying the controlled degree of polymerization (DP) of poly(1,4-phenylene) in the use of bidentate diphosphine Chiraphos as a ligand for the nickel catalyst, the relationship of DP with CD strength was studied to reveal to show the ...
Source: Chemistry - April 22, 2024 Category: Chemistry Authors: Rikuya Tanaka Seiha Yamaoka Shuichi Ikeda Kentaro Okano Masaki Horie Hideto Minami Nozomu Suzuki Atsunori Mori Source Type: research
Solution-State Structure of a Long-Loop G-quadruplex Formed within Promoters of Plasmodium falciparum B var Genes
We report the high-resolution NMR solution-state structure of an intramolecular G-quadruplex with a diagonal loop of ten nucleotides. The G-quadruplex is formed by a 34-nt DNA sequence, d[CAG3T2A2G3TATA2CT3AG4T2AG3T2], named UpsB-Q-1. This sequence is found within promoters of the var genes of Plasmodium falciparum, which play a key role in malaria pathogenesis and evasion of the immune system. The [3+1]-hybrid G-quadruplex formed under physiologically relevant conditions exhibits a unique equilibrium between two structures, both stabilized by base stacking and non-canonical hydrogen bonding. Unique equilibrium of the two ...
Source: Chemistry - April 22, 2024 Category: Chemistry Authors: Marina Juriba šić Kulcsár Val érie Gabelica Janez Plavec Source Type: research
A Case-Study on the Photophysics of Chalcogen-Substituted Zinc(II) Phthalocyanines
Chemistry. 2024 Apr 22:e202304083. doi: 10.1002/chem.202304083. Online ahead of print.ABSTRACTSinglet dioxygen has been widely applied in different disciplines such as medicine (photodynamic therapy or blood sterilization), remediation (wastewater treatment) or industrial processes (fine chemicals synthesis). Particularly, it can be conveniently generated by energy transfer between a photosensitizer's triplet state and triplet dioxygen upon irradiation with visible light. Among the best photosensitizers, substituted zinc(II) phthalocyanines are prominent due to their excellent photophysical properties, which can be tuned b...
Source: Chemistry - April 22, 2024 Category: Chemistry Authors: Sergio D Ezquerra Riega Mat ías E Gutierrez Suburu Hern án B Rodríguez Beatriz Lanta ño Martin Kleinschmidt Christel M Marian Cristian A Strassert Source Type: research
