Hyperconjugative Interactions Research Articles

Molecular docking, experimental FT-IR spectra, UV–Vis spectra, vibrational analysis, electronic properties, Fukui function analysis of a potential bioactive agent – Proflavine

Proflavine, having the molecular formula C13H11N3, is a well-known urinary antiseptic and anticancer medication (3,6-diaminoacridine). In this communication, Quantum chemical computations of Proflavine's geometry have been performed and examined in the ground state. The optimized structure and wavenumbers of the molecule's vibrational bands were investigated using the DFT/B3LYP method and 6–311G (d, p) as the basis set. The calculated vibrational frequencies are compared to experimental IR spectra. The link between thermodynamic characteristics and temperature has been studied. The computed IR frequencies correlate well with the experiments, as indicated by the correlation factor (R2 = 0.99). The UV spectra of the title molecule are calculated by using Time Dependent Density Functional Theory (TD-DFT). The molecule's interactions with other species were described using an analysis of a HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital). Natural bond orbitals (NBO) analysis was used to investigate intramolecular and intermolecular hydrogen bonding and their second-order stabilization energies and conjugative and hyperconjugative interactions. By computing the first hyperpolarizability, nonlinear optical (NLO) analysis was utilized to explore the molecule's nonlinear optical properties.

Synthesis and Structural Characterization of β-Turn Mimics Containing (Z)-Chloroalkene Dipeptide Isosteres.

Described here is the synthetic, spectroscopic, crystallographic, and computational analysis of a series of peptidomimetics containing l-Xaa-d-Yaa-type (Z)-chloroalkene dipeptide isosteres (CADIs) that were measured in an investigation of the β-turn mimicry of this peptide bond surrogate. We found that the 1,3-allylic strain across the chloroalkene moiety engenders the hyperconjugative interactions between the chloroalkene moiety and the C-H bonding or antibonding orbitals of the C-H bonds in allylic positions. These effects contribute significantly to the stabilization of β-turn structures.

Synthesis, spectral property, IEF-PCM solvation, anti-microbial evaluation and molecular docking studies of 6 amino-2-(4 nitrophenyl)-1H-benzimidazole

6-amino-2-(4-nitrophenyl)-1H-benzimidazole (6A2NHB) was synthesized and characterized by FT-IR, UV visible spectroscopy. The optimized structure, geometry parameters and wavenumbers of the title compound were calculated using the basis sets of Hartree Fock and DFT (B3LYP/ B3PW91) methods with 6–311 G (d, p) and 6–311++ G (d, p) and analyzed with experimental data. Electronic absorption spectra and 1H–13C NMR studies have been computed in gas and solvents (DMSO, chloroform, water) by using TD-DFT (IEF-PCM). To know the stability, hyper conjugative interaction and delocalization NBO study has been executed. Molecular electrostatic potential reveals the chemical reactivity sites for the reaction. Antimicrobial activity reveals the synthesized compound biological activity.

Structural, Electronic, Vibrational and Pharmacological Investigations of Highly Functionalized Diarylmethane Molecules Using DFT Calculations, Molecular Dynamics and Molecular Docking

Present work describes the UV–Visible and FT-IR spectral behavior of highly functionalized diarylmethanes via theoretical investigations. Analyses of both theoretical and experimental UV data were in good agreement with the assigned bands. In addition, calculations pertaining to natural bond orbitals (NBOs) and mapped molecular electrostatic potential surface (MEPS) were also performed, revealing that the strongest hyperconjugative intramolecular interactions involves the π ⟶ π∗, LP ⟶ σ∗ and transitions in the D and A rings. Further, the theoretical vibrational analysis revealed several characteristic vibrations that may be used as a diagnostic tool for other diarylmethanes and also indicated that the experimental bands related to the nitrile group occur in regions lower than usual, which confirms high conjugation of the triple bond with the aromatic system. Molecular dynamics (MD) and molecular docking calculations were performed in order to evaluate the behavior of such molecules in aqueous medium and the pharmacological potential. Another interesting observation in this study is the HOMO–LUMO analysis, which showed that the global reactivity values changed according to the type of substituent groups.

Spectroscopic analysis, DFT studies and molecular docking of 2,3‐dichloro‐benzylidine‐(2‐trifluoromethyl‐phenol)‐amine

Abstract2,3‐dichloro‐benzylidine‐(2‐trifluoromethyl‐phenol)‐amine (2DBTP) has been synthesized and characterized by various spectroscopic techniques including FT‐IR, FT‐Raman, UV‐Vis and 1H, 13C NMR spectroscopy. The equilibrium geometry and harmonic vibrational frequencies were investigated by density functional theory (DFT) at B3LYP/6‐311++G(d,p) basis set. The vibrational wavenumber assignments were made on the basis of total energy distribution (TED) calculations using Veda 4 program. The harmonic wavenumbers calculated at DFT were in line with the experimental values. The non‐linear optical properties (NLO) were calculated. Stability of the molecule arises from hyperconjugative interactions and charge delocalization was analyzed by natural bond orbital (NBO) analysis. Molecular electrostatic potential (MEP), mulliken atomic charges were also calculated. The energy gap of the molecule was found by HOMO and LUMO calculation. TD‐DFT calculations have been carried out on the optimized geometry to further understand the electronic transitions in the UV‐Vis spectrum of the compound. In addition, the 1H and 13C NMR chemical shift values of 2DBTP in the ground state were also calculated using Gauge invariant atomic orbital (GIAO) method. The molecular docking solved the binding mode of 2XCT complex with the ligand. The investigated molecule revealed the inhibition activity of the ligand against anti‐bacterial protein topoisomerase DNA gyrase enzyme (PDB ID: 2XCT).

Chalcogen Bonding in the Molecular Dimers of WCh2 (Ch = S, Se, Te): On the Basic Understanding of the Local Interfacial and Interlayer Bonding Environment in 2D Layered Tungsten Dichalcogenides.

Layered two-dimensional transition metal dichalcogenides and their heterostructures are of current interest, owing to the diversity of their applications in many areas of materials nanoscience and technologies. With this in mind, we have examined the three molecular dimers of the tungsten dichalcogenide series, (WCh2)2 (Ch = S, Se, Te), using density functional theory to provide insight into which interactions, and their specific characteristics, are responsible for the interfacial/interlayer region in the room temperature 2H phase of WCh2 crystals. Our calculations at various levels of theory suggested that the Te···Te chalcogen bonding in (WTe2)2 is weak, whereas the Se···Se and S···S bonding interactions in (WSe2)2 and (WS2)2, respectively, are of the van der Waals type. The presence and character of Ch···Ch chalcogen bonding interactions in the dimers of (WCh2)2 are examined with a number of theoretical approaches and discussed, including charge-density-based approaches, such as the quantum theory of atoms in molecules, interaction region indicator, independent gradient model, and reduced density gradient non-covalent index approaches. The charge-density-based topological features are shown to be concordant with the results that originate from the extrema of potential on the electrostatic surfaces of WCh2 monomers. A natural bond orbital analysis has enabled us to suggest a number of weak hyperconjugative charge transfer interactions between the interacting monomers that are responsible for the geometry of the (WCh2)2 dimers at equilibrium. In addition to other features, we demonstrate that there is no so-called van der Waals gap between the monolayers in two-dimensional layered transition metal tungsten dichalcogenides, which are gapless, and that the (WCh2)2 dimers may be prototypes for a basic understanding of the physical chemistry of the chemical bonding environments associated with the local interfacial/interlayer regions in layered 2H-WCh2 nanoscale systems.

Evaluation of Vibrational, Electronic, Topology, Reactivity, Bioactivity, Bioavailability and Blood-Brain Barrier Score of 1-(2,6-dimethylphenoxy)propan-2-amine-A DFT, Spectro-scopic and Molecular Docking Approach

Density functional theory (DFT) has become an integral technique when it comes to the arena of quantum mechanical calculations. Its credibility and effectiveness have been established, especially for organic compounds. Here, the vibrational and electronic characteristics of 1-(2,6-dimethylphenoxy)propan-2-amine are evaluated using density functional theory (DFT). Vibrational assignment for the entire range of theoretical frequencies was carried out and the PED percentage was reported. Frontier molecular orbital analysis was carried out and various properties such as band gap, ionisation potential, electron affinity, chemical softness, hardness, electronegativity, electrophilicity index were accounted for. Further, TD-DFT method was employed to evaluate the electronic properties. Natural Bond Orbital analysis was done in order to evaluate the hyper conjugative interaction. Topology analysis was carried out using MEP, ELF and LOL. Bonding interactions and the percentage contribution of each group to each orbital was analysed using TDOS and PDOS respectively. Employing Lipinski’s rule of five, drug likeness of the compound was determined and the Blood-Brain Barrier (BBB) score was reported. Molecular docking studies were carried out to comprehend the interaction between protein (6EUB) and Ligand (title compound) as a vital part of this work.

Exploring intermolecular interactions in some halogen substituted formyl coumarins and their DFT studies

The present manuscript describes an in-depth analysis of various interactions present in the crystal structure of formyl coumarins using Crystal explorer 17.0. Element based interactions were quantified by the decomposition of generated 3D surfaces into 2D fingerprint regions. DFT methods were used to explore electrostatic parameters, global and local reactivity descriptors. Electrophilicity based charge transfer (ECT) analysis was done to explore the probability of charge transfer between formyl coumarins and DNA base pairs. The reactivity and selectivity of different formyl coumarins have been accessed using Fukui functions in their reduced form. Non-bonding orbital (NBO) analysis revealed the presence of various hyperconjugative interactions and their stabilization energy in formyl coumarins. Non-linear optical properties are presented in terms of first order hyperpolarizibility (β0), where maximum β0 is observed for C4 (1.64 × 10-30esu.) which is found to be 2 times greater than that of p-nitroaniline. Molecular electrostatic potential (MEP) plots are mapped in terms of electron density.

Role of O-H⋯O/S conventional hydrogen bonds in considerable Csp2 -H blue-shift in the binary systems of acetaldehyde and thioacetaldehyde with substituted carboxylic and thiocarboxylic acids.

Stable binary complexes of RCZOH⋯CH3CHZ (R = CH3, H, F; Z = O, S) are due to contributions from the O-H⋯O/S and Csp2 -H⋯O/S hydrogen bonds. The strength of Csp2 /O-H⋯O is 1.5 to 2 times greater than that of the Csp2 /O-H⋯S bond. The substitution of H(Csp2 ) of HCZOH by CH3 causes a decrease in complex stability, while the opposite trend occurs for the F atom. A very large red shift of the O-H stretching frequency in O-H⋯O/S bonds was observed. A surprising Csp2 -H blue shift up to 104.5 cm-1 was observed for the first time. It is found that the presence of O-H⋯O/S hydrogen bonds and a decisive role of intramolecular hyperconjugation interactions in the complex cause a significant blue shift of the Csp2 -H covalent bonds. A striking role of O compared to the S atom in determining the blue shift of Csp2 -H stretching vibration and stability of binary complexes is proposed. The obtained results show that the ratio of deprotonation enthalpy and proton affinity could be considered as an index for the classification of the non-conventional hydrogen bond. SAPT2+ results show that the strength of RCSOH⋯CH3CHS complexes is dominated by electrostatic and induction energies, while a larger contribution to the stability of remaining complexes is detected for the electrostatic component.

Molecular Docking and Quantum Chemical Computations of 4-Chloro-2-[(furan-2-ylmethyl)amino]-5-sulfamoylbenzoic Acid Based on Density Functional Theory

Quantum computational calculations of energies and geometries of 4-chloro-2-[(furan-2-ylmethyl)amino]-5-sulfamoylbenzoic acid have been performed by DFT level of theory using B3LYP/6-31G(d,p) basis set. The solid phase FT-Raman and FT-IR spectra of the Furosemide compound were recorded in the region 4000 cm−1 to 400 cm−1 and 4000 cm−1 to 400 cm−1 respectively. The molecular geometry, harmonic vibrational frequencies and bonding features of 4-chloro-2-[(furan-2-ylmethyl)amino]-5-sulfamoylbenzoic acid in the ground state have been calculated by using density functional theory (DFT) B3LYP method with standard 6–31 G(d,p) basis set. The scaled theoretical wavenumber showed very good agreement with the experimental values. The vibrational assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes. Stability associated with molecule as a result of hyperconjugative interactions, charge delocalization has been analyzed utilizing Natural Bond Orbital (NBO) analysis through the use of B3LYP/6-31G(d,p) technique. The outcomes reveal that electron density (ED) within the σ* and π* orbitals which are antibonding second-order delocalization energies E (2) confirm the occurrence of intramolecular charge transfer (ICT) inside the molecule. Hirshfield surface analysis and Fukui functions calculation were also performed. From the calculations the first order hyperpolarisability was found to be 3.136 × 10−30esu. The molecule orbital contributions have been analyzed utilizing the total (TDOS), partial (PDOS), and overlap population (OPDOS) density of states. A molecular docking study has supported the anticonvulsant activity of the Furosemide molecule.

Synthesis of novel hybrid quinoxaline containing triazole and acetamide moieties by azide-alkyne click chemistry: Experimental and theoretical characterization

Heterocyclic compounds bearing triazole and quinoxaline possess significant pharmacological activities. Herein, a new quinoxaline derivative containing 1,2,3-triazole moiety was synthesis using a copper-catalyzed azide−alkyne cycloaddition (CuAAC) “click” procedure. The solid state crystal structures of 2-azido-N-(4-methoxyphenyl)acetamide (AMA) and N-(4-methoxyphenyl)-2-(4-((3-methyl-2-oxoquinoxalin-1(2H)-yl)methyl)-1H-1,2,3-triazol-1-yl)acetamide (QTA) were determined by X-ray structure analysis. Density Functional Theory (DFT) computations were performed using DFT/B3LYP with 6–311++G(d,p) basis set in the gas phase to get the optimized geometry of both molecules and detailed insights into the molecular and chemical properties that are inaccessible by experimental ways like global reactivity descriptors and Fukui functions. DFT calculations at the same level of theory, with the POP=NBO keyword, were used to evaluate charge delocalization and hyperconjugative interactions through Natural Bond orbital (NBO) analysis. In the title molecule, C21H20N6O3, the quinoxaline moiety is essentially planar while the whole molecule adopts an approximate "U" shape. In the crystal, the molecules form inversion dimers through slightly slipped π-stacking interactions between quinoxaline units. These form chains extending along the a-axis direction by a combination of additional π-stacking interactions as well as N—H···N and C—O···O hydrogen bonds and C—H···π(ring) interactions. The chains are connected by C—H···O and C—H···N hydrogen bonds. In the azide compound an intramolecular C—H···O hydrogen bond helps to establish the rotational orientation of the acetamide group. In the crystal, a stepped arrangements of ribbons approximately parallel to (10¯ 1) is formed by a combination of N—H···O, C—H···O and C—H···N hydrogen bonds. Furthermore, to evaluate the chemical reactivity and charge distribution on molecules, molecular electrostatic potential (MEP) maps and atomic charges, computed by NBO theory were determined. Additionally, local reactive properties of AMA and QTA were determined using Fukui functions and dual descriptor calculations.

DFT/TDDFT studies of the structural, electronic, NBO and non-linear optical proper-ties of triphenylamine functionalized tetrathiafulvalene

In this paper, we present a theoretical analysis of the molecular structure of a conjugated molecule TTPA-TTF at the DFT level using the B3LYP method and the 6-31G (d) basis set. The TTPA-TTF mole-cule presented a twisted configuration, which gave it good solubility in different organic solvents. The Partial atomic charge, molecular electrostatic potential (MEP) map, and global reactivity descriptors highlight the reactive sites of the molecule with the possible prediction of its reactivity. Moreover, a clear image of the intra- and intermolecular interactions illustrates hyperconjugative interactions based on the charge delocalization that emerges from the natural bond orbital analysis. The non-linear optical proper-ties of the TTPA-TTF molecule can also be calculated by determining their first hyperpolarizabilities. The time-dependent density theory method TD-DFT-B3LYP 6-31G (d) was used for the study of absorption. The obtained results show a broad spectrum in the visible range favorable to harvest solar light.

Exploration of Photophysical and Nonlinear Properties of Salicylaldehyde-Based Functionalized Materials: A Facile Synthetic and DFT Approach.

The current research presents the synthesis of novel salicylaldehyde thiosemicarbazones (1–6) and their spectroscopic characterization employing UV–visible, Fourier transform infrared spectroscopy, and NMR techniques. Experimental results are compared and validated with the results obtained theoretically by employing density functional theory at the M06 level with the 6-311G (d,p) basis set. Further, various parameters [natural bond orbital (NBO)], linear and nonlinear optical (NLO) properties, and global reactivity parameters (GRPs) are computationally calculated. The NBO approach has confirmed the stability of compounds on account of charge delocalization and hyper conjugative interaction network. Frontier molecular orbital analysis has explained the charge transfer and chemical reactivity capability, while GRPs have led to the analysis of kinetic stability of the studied molecules. Further, the probability of being NLO-active has been theoretically proved by the HOMO/LUMO energy difference (4.133–4.186 eV) and β values (192.778–501.709 a.u). These findings suggest that the studied compounds possess potential NLO applications as they have shown larger NLO values in comparison with that of the urea molecule, and such distinct properties prove their technological importance.

Spectroscopic studies, quantum chemical investigations, and in silico and in vitro scrutiny of the diuretic drug trichlormethiazide adsorbed on AuNPs.

Experimental and theoretical study was employed to study the adsorption of the diuretic drug, trichlormethiazide (TCM) molecule on AuNPs (TCMA). The stereoelectronic properties of the molecular structure of most stable conformers of TCM and TCMA were studied using DFT/B3LYP-6-311++G (d, p) together with LANL2DZ methodology. The Fourier transform Raman and Infrared spectra of TCM were recorded and analyzed. Quantum chemical calculations of TCM and TCMA molecules were used to evaluate the stability of the molecule, hyper-conjugative interactions, electron delocalization, and binding interactions. The calculated and experimentally observed vibrational frequencies of the molecule were assigned and compared. The shifting and intensity enhancement of the CCl2 band manifests the back-donation and conjugation effect, which are the result of the presence of nitrogen atom adjoining the dichloromethyl groups and the oxygen in the sulfur dioxide group attached among the amino group and the chlorophenyl ring, respectively, which enhances bioactivity. Anticancer activity was examined based on molecular docking analysis, and it was identified that TCM and TCMA molecules act as good inhibitors against lung cancer. SERS analysis and MTT assay confirmed the molecular docking analysis results.

Spectroscopic (UV and fluorescence), biological, DFT and molecular docking studies of 3,5‐diethyl‐2r,6c‐di(4‐fluorophenyl)piperidin‐4‐one picrate

AbstractThe spectroscopic investigations of 3,5‐diethyl‐2r,6c‐di(4‐fluorophenyl)piperidin‐4‐one picrate (3,5‐DEDFPP) are evaluated by UV–Vis and fluorescence techniques. At the B3LYP/6‐311++G(d,p) level of theory, the DFT approach was utilized to optimize the molecular structure. The dipole moment, polarizability, and hyperpolarizability values are calculated at same level of theory. NBO analysis was used to calculate the hyperconjugative interaction energy (E(2)) and electron densities of donor (i) and acceptor (j) bonds. The molecule's energy gap was discovered using HOMO and LUMO calculation. The Mulliken atomic charges of the carbon, nitrogen and oxygen atoms were calculated and using at the same level. The thermodynamic properties of the title compound were calculated at different temperatures in gas phase. The 3,5‐DEDFPP's bacterial activity was evaluated against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Vibreo cholerae, and Pseudomonas aeruginosa, as well as fungal strains such as Candida albicans, Aspergillus niger, Aspergillus flavus, and Trichophyton rubrum. The interaction of the title compound to bind to a target protein was studied using molecular docking analysis.

Probing into the Outcome of Charge Transfer Interactions and Hyperconjugative Effect on the Antibacterial Molecule 4-dimethylaminopyridine using Spectroscopic Elucidations and DFT Calculations

The prospective compound 4-dimethylaminopyridine was probed using FT-IR, FT-Raman, UV-Visible spectra and quantum chemical computations. Vibrational assignments pertaining to different modes of vibration with potential energy distribution have been augmented by normal coordinate analysis. Electronic stability of the compound arising from hyper conjugative interactions and charge delocalization is scrutinized using natural bond orbital analysis. The frontier molecular orbital energy gap probably indicates a compound's strong chemical reactivity and enables eventual charge transfer inside the molecule. The molecular electrostatic potential map and Fukui functions reveal that electronegative nitrogen and electropositive hydrogen atoms can be attacked by electrophiles and nucleophiles. The molecule's electron-hole distribution showed a charge transfer within the molecule, and the chemical implications of the molecule were described using electron localization function and localized orbital locator. Antibacterial activity of the compound with different bacterial strains was validated by agar well diffusion method. Ligand–protein interaction was explored by using molecular docking studies, while the pharmacokinetic aspects of the compound were probed using drug likeness and Absorption, Distribution, Metabolism, Excretion, and Toxicity properties.

Experimental, spectroscopic and theoretical investigation of (+)-(R)-5-[1-(Benzenesulfonamido)-2-phenylethyl]-4-phenethyl-2,4-dihydro-3H-1,2,4-triazole-3-thione

In this study, an enantiomerically pure triazole derivative, namely, (+)-(R)-5-[1-(benzenesulfonamido)-2-phenylethyl]-4-phenethyl-2,4-dihydro-3H-1,2,4-triazole-3-thione was successfully synthesized in high yield and characterized by spectroscopic techniques (FT-IR and UV–Vis) and single crystal X-ray diffraction analysis. Hirshfeld surface (HS) analysis revealed the nature of intermolecular contacts, the fingerprint plots, and molecular surface contours. All theoretical computations were calculated using density functional theory (DFT) B3LYP method with the help of 6–311G(d,p) basis set. Chemical activity descriptors were studied for global (HOMO, LUMO, hardness, and softness parameters) and local (MEP, Fukui function, net charges). The stability of the molecule arising from hyper conjugative interactions, charge delocalization was analyzed by using natural bond orbital analysis (NBO) and in the continuation of the study, nonlinear optical properties were examined.

Synthesis, in vitro and in silico antitumor evaluation of 3-(2,6-dichlorophenyl)-1,5-diphenylpentane-1,5‑dione: Structure, spectroscopic, RDG, Hirshfeld and DFT based analyses

New bischalcone derivative 3-(2,6-dichlorophenyl)-1,5-diphenylpentane-1,5‑dione (C23H18Cl2O2) has been efficiently synthesized and the solid state formation of the grown crystals was characterized by X-ray crystallographic diffraction (XRD)analysis at 296 K. The single crystal XRD results show that the title compound belongs to triclinic system with unit cell dimensions, a = 9.4104 (12) (Å), b = 10.2951(13) (Å), c = 10.9411(15) (Å) and V = 980.9(Å3). The key contributor intermolecular interactions C‒O···H/H···O‒C were explored by Hirshfeld surface analysis. The active functional group interpretations have been carried using FT-IR and FT-Raman spectroscopies with the assistance of energy distributions. Density functional theory (DFT) calculations of the synthesized compound carried out for better understanding of molecular futures. Hyperconjugative interactions present in the molecule were also quantified using natural bond orbitals (NBO). Reactivity and stability of the title molecule assessed utilizing global reactivity descriptors. The condensed Fukui functions explored the available electrophile and nucleophile regions in the form of local based descriptors. The reduced density gradient (RDG) isosurfaces reveals the dominance of non-bonded interactions of the title compound. MTT assay revealed that the title compound had potentiate antitumor activity against human lung cancer A549 cells with 40.71 µg/mL IC50 value. Moreover the capability of the compound to be interconnected within the key amino acids of lung cancer receptor binding sites was detected by molecular docking. Antibacterial and antifungal efficacy of the title compound studied using Kirby-Bauer disc diffusion technique.

Stabilization of Reactive Nitrene by Silylenes without Using a Reducing Metal.

Herein, we report the stabilization of nitrene reagents as the source of a nitrogen atom to synthesize nitrogen‐incorporated R1LSi‐N←SiLR2 (1) [L=PhC(NtBu)2; R1=NTMS2, R2=NTMS]. Compound 1 is synthesized by reacting LSi(I)‐SiIL with 3.1 equivalents of Me3SiN3 at low temperature to afford a triene‐like structural framework. Whereas the reaction of the LSi(I)‐SiIL with 2.1 equivalents of Me3SiN3 at room temperature produced silaimine 2 with a central four‐membered Si2N2 ring which is accompanied by a silylene LSi and a cleaved silylene fragment. 1 further reacts with AgOTf at room temperature to yield compound 3 which shows coordination of nitrene to silver with the triflate salt. The compounds 1 and 2 were fully characterized by NMR, mass spectrometry, and X‐ray crystallographic analysis. The quantum mechanical calculations reveal that compounds 1 and 2 have dicoordinated monovalent N atoms having two active lone pairs of electrons. These lone pairs are stabilized by hyperconjugative interactions.

Stabilization of Reactive Nitrene by Silylenes without Using a Reducing Metal

AbstractHerein, we report the stabilization of nitrene reagents as the source of a nitrogen atom to synthesize nitrogen‐incorporated R1LSi‐N←SiLR2 (1) [L=PhC(NtBu)2; R1=NTMS2, R2=NTMS]. Compound 1 is synthesized by reacting LSi(I)‐SiIL with 3.1 equivalents of Me3SiN3 at low temperature to afford a triene‐like structural framework. Whereas the reaction of the LSi(I)‐SiIL with 2.1 equivalents of Me3SiN3 at room temperature produced silaimine 2 with a central four‐membered Si2N2 ring which is accompanied by a silylene LSi and a cleaved silylene fragment. 1 further reacts with AgOTf at room temperature to yield compound 3 which shows coordination of nitrene to silver with the triflate salt. The compounds 1 and 2 were fully characterized by NMR, mass spectrometry, and X‐ray crystallographic analysis. The quantum mechanical calculations reveal that compounds 1 and 2 have dicoordinated monovalent N atoms having two active lone pairs of electrons. These lone pairs are stabilized by hyperconjugative interactions.