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ABSTRACT Access to benzofuran‐2(3H)‐one derivatives from readily available substrates under mild conditions is crucial in the pharmaceutical and plastics industries. We identified (Z)‐3‐(2‐phenylhydrazineylidene)benzofuran‐2(3H)‐one (P) during the recrystallization of (E)‐2‐(2,2‐dichloro‐1‐(phenyldiazenyl)vinyl)phenol using a 96% ethanol solution. The mechanism of the unexpected substrate conversion leading toPis investigated using density functional calculations. The computations revealed that ethanol is required to initiate the reaction viaTS1E, which involves a concerted deprotonation of ethanol by the basic diaza group of the substrate and an ethoxy group attacking the electrophilic center (Cl₂C), with an energy barrier of 28.3 kcal/mol. The resulting intermediate (I1E) is calculated to be unstable and can yield a cyclic chloroacetal adduct with a lower energy barrier of 2.2 kcal/mol via the ring‐closure transition state (TS2E). In the absence of water, the next steps are impossible because water is required to cleave the ether bond, yieldingP. A small amount of water (4% of the recrystallization solvent) can promote further transformation ofI2Evia the transition statesTS3E(∆G^‡ = 11.1 kcal/mol) andTS4E(∆G^‡ = 10.5 kcal/mol). A comparison of the ethanol/water‐ and only water‐promoted free energy profiles shows that the presence of ethanol is crucial for lowering the energy barriers (by about 5 kcal/mol) for the initial two steps leading to the cyclic chloroacetal (I2E), whereas water is then required to initiate product formation. 

Abstract This computational study explores the copper (I) chloride catalyzed synthesis of (E)‐1‐(2,2‐dichloro‐1‐phenylvinyl)‐2‐phenyldiazene (2Cl‐VD) from readily available hydrazone derivative and carbon tetrachloride (CCl₄).2Cl‐VDhas been extensively utilized to synthesize variety of heterocyclic organic compounds in mild conditions. The present computational investigations primarily focus on understanding the role of copper (I) andN¹,N¹,N²,N²‐tetramethylethane‐1,2‐diamine (TMEDA) in this reaction, TMEDA often being considered a proton scavenger by experimentalists. Considering TMEDA as a ligand significantly alters the energy barrier. In fact, it is only 8.3 kcal/mol higher compared to the ligand‐free (LF) route for the removal of a chlorine atom to form the radical·CCl₃but the following steps are almost barrierless. This intermediate then participates in attacking the electrophilic carbon in the hydrazone. Crucially, the study reveals that the overall potential energy surface is thermodynamically favorable, and the theoretical turnover frequency (TOF) value is higher in the case of Cu(I)‐TMEDA complex catalyzed pathway. 

Abstract This Roadmap article provides a succinct, comprehensive overview of the state of electronic structure (ES) methods and software for molecular and materials simulations. Seventeen distinct sections collect insights by 51 leading scientists in the field. Each contribution addresses the status of a particular area, as well as current challenges and anticipated future advances, with a particular eye towards software related aspects and providing key references for further reading. Foundational sections cover density functional theory and its implementation in real-world simulation frameworks, Green’s function based many-body perturbation theory, wave-function based and stochastic ES approaches, relativistic effects and semiempirical ES theory approaches. Subsequent sections cover nuclear quantum effects, real-time propagation of the ES, challenges for computational spectroscopy simulations, and exploration of complex potential energy surfaces. The final sections summarize practical aspects, including computational workflows for complex simulation tasks, the impact of current and future high-performance computing architectures, software engineering practices, education and training to maintain and broaden the community, as well as the status of and needs for ES based modeling from the vantage point of industry environments. Overall, the field of ES software and method development continues to unlock immense opportunities for future scientific discovery, based on the growing ability of computations to reveal complex phenomena, processes and properties that are determined by the make-up of matter at the atomic scale, with high precision. 

Abstract The photophysical and chiroptical properties of a novel, chiral helicene‐NHC−Re(I) complex bearing anN‐(aza[6]helicenyl)‐benzimidazolylidene ligand are described, showing its ability to emit yellow circularly polarized luminescence. A comparative analysis of this new system with other helicene‐Re(I) complexes reported to date illustrates the impact of structural modifications on the emissive and absorptive properties. 

The properties of chiral donor–acceptor systems displaying CPL sign inversion are investigated in solvents of different polarity. The solvent enables control of their deexcitation pathways favoring either locally excited or charge-transfer states.