Cr Bond Research Articles

Interaction characteristics and mechanism of Cr(VI)/Cr(III) with microplastics: Influence factor experiment and DFT calculation

The coexistence of highly toxic heavy metal chromium and new pollutants microplastics has been widely present, and the interaction behavior and mechanism of the two are crucial for their environmental effects in coexisting environments, which urgently need to be further explored. Firstly, the interaction characteristics of polyamide (PA) and polyethylene (PE) with Cr(VI)/Cr(III) were investigated, where PA exhibited higher adsorption capacity of both Cr(VI) and Cr(III) than PE among various environmental conditions. The higher adsorption energy of PA on Cr(VI)/Cr(III) was also achieved by DFT calculation, and the bending configuration of PA during the adsorption process may be beneficial for its interaction with Cr. Then, the combination of characterization analysis and DFT calculation showed that significant chemical bonding occurred in the interaction between CO bond of PA and Cr(III), weak chemical interactions occurred in the adsorption of PE with Cr(III) and PA with Cr(VI), while the adsorption of PE with Cr(VI) was mainly physical effects. This study provides theoretical support for pollution control of microplastics and chromium in co-existing environment.

Steric, Synergetic, Energetic Studies on the Impact of the Type of the Hybridized Polymers (Chitosan and β-Cyclodextrin) on the Adsorption Properties of Zeolite-A for Congo Red Dye.

Zeolite-A was synthesized successfully from kaolinite and hybridized with two species of biopolymers (chitosan (CH/Z) and β-cyclodextrin (CD/Z)). The obtained hybridized forms were assessed as potential adsorbents of Congo red synthetic dye (CR) with enhanced affinities and elimination capacities. The synthesized CD/Z and CH/Z hybrids demonstrated uptake capacities of 223.6 and 208.7 mg/g, which are significantly higher than single-phase zeolite-A (140.3 mg/g). The integrated polymers change the surface area, surface reactivity, and number of free active receptors that are already present. The classic isotherm investigations validate Langmuir equilibrium behavior for ZA and Freundlich properties for CD/Z and CH/Z. The steric parameters validate a strong increase in the existing active receptors after the incorporation of CD (CD/Z) to be 98.1 mg/g as compared to 83 mg/g for CH/Z and 60.6 mg/g for ZA, which illustrate the detected uptake behaviors. Moreover, the CR dye was adsorbed as several molecules per single site, reflecting the vertical uptake of these molecules by multimolecular mechanisms. The energetic assessment, considering both Gaussian energies and adsorption energies (<40 kJ/mol), validates the dominant impact of the physical mechanism during the sequestration of CR (dipole binding interactions (2-29 kJ/mol) and hydrogen bonds (<30 kJ/mol)), in addition to the considerable effect of ion exchange processes. Based on the thermodynamic parameters, the CR molecules were adsorbed by exothermic and spontaneous reactions.

Spin Glass Behavior in Amorphous Cr2 Ge2 Te6 Phase-Change Alloy.

The layered crystal structure of Cr2 Ge2 Te6 shows ferromagnetic ordering at the two-dimensional limit, which holds promise for spintronic applications. However, external voltage pulses can trigger amorphization of the material in nanoscale electronic devices, and it is unclear whether the loss of structural ordering leads to a change in magnetic properties. Here, it is demonstrated that Cr2 Ge2 Te6 preserves the spin-polarized nature in the amorphous phase, but undergoes a magnetic transition to a spin glass state below 20K. Quantum-mechanical computations reveal the microscopic origin of this transition in spin configuration: it is due to strong distortions of the CrTeCr bonds, connecting chromium-centered octahedra, and to the overall increase in disorder upon amorphization. The tunable magnetic properties of Cr2 Ge2 Te6 can be exploited for multifunctional, magnetic phase-change devices that switch between crystalline and amorphous states.

Cr2 Gen - (n = 15-20) clusters with two Cr atoms exhibited antiferromagnetic coupling.

In this work, we investigated the structural evolution, electronic and magnetic properties of Cr2 Gen - clusters for n = 15-20 by using density functional theory (DFT) calculations. Low-energy structures for these clusters were fully searched through a self-developed genetic algorithm code combined with DFT calculations. The calculations show that all the two Cr atoms prefer to stay together to form a strong CrCr bond, which-except for size 20-is shorter than the nearest neighbor distance in Cr bulk. Sizes 15 and 16 adopt a wheel-like structure as the structural motif with the extra Ge atoms capped on the top, while larger sizes (n = 17-20) prefer fullerene-like Cr2 @Ge12 motifs. From the results of the average binding energies of Cr2 Gen - , one can conclude that it is easier to form larger size clusters. In these lowest-lying isomers except for size 16, the two Cr atoms contribute opposite magnetic moments for the total magnetic moments of 1 μB , showing an antiferromagnetic state.

Pr2CrMnO6 double perovskite as new electrode material for electrochemical energy storage

Single phase double perovskite oxide (Pr2CrMnO6) based new electrode material was developed for supercapacitor applications. Structural studies reveal monoclinic structure with space group P21/n. The sample exhibit bond angle distortion in the form of octahedral tilt. A signature of distortion in Mn — O — Cr bond angles is visualized through delocalization of oxygen clouds around Cr and Mn atoms via electron density maps. Large octahedral tilt in vertical direction forms uniform chain of spherical particles of mean size ∼870 nm. Electrochemical studies were performed by a three-electrode set up in room temperature. Both the cyclic voltametric and galvanic charge-discharge studies reveal great retention with variation in scanning parameters as well as cycles. The chain-like spherical-shaped particles anticipate active sites for intercalation and deintercalation of electrolyte ions that contributed towards diffusion-controlled capacitance. A significant value of specific capacitance (177.4 F/g) was achieved at current density of 2 A/g and it is found to be better than Ni–Mn based double perovskite oxides.

Preparation of a novel metal-free polypyrrole-red phosphorus adsorbent for efficient removal of Cr(VI) from aqueous solution

The toxicity and carcinogenicity of Cr(VI) makes it a major threat to the health of animals and people. However, how to efficiently remove Cr(VI) still faces important challenges. In this study, a new metal-free polypyrrole-red phosphorus (PPy-RP) composite is successfully synthesized by in-situ oxidation polymerization for Cr(VI) removal from wastewater. The maximum adsorption capacity (qm) of Cr(VI) on PPy-RP-1 is 513.2 mg/g when the pH value is 2, which is far superior to RP nanosheets (207.8 mg/g) and PPy (294.9 mg/g). The improved qm can be ascribe to the good dispersion and increased specific surface area of PPy-RP adsorbent. Encouragingly, PPy-RP adsorbent still exhibits excellent stability after 7 cycles tests without a significant decline in removal efficiency, and remain above 81.4%. Based on the fittings of adsorption isotherms and kinetics, the process conforms to the pseudo-first-order kinetic model and the single-layer adsorption of the Langmuir model with an R2 value of 0.98533. The adsorption process is chemical and monolayer. The experimental result demonstrates that the PPy-RP can efficient removal Cr(VI) by electrostatic attraction and complexation reaction (formation of N–Cr(VI) bond) through the PPy on the surface. The results of this study indicate that PPy-RP is a promising adsorbent to remove the Cr(IV).

Trimorphic TaCrP – A diffraction and 31P solid state NMR spectroscopic study

Abstract The metal-rich phosphide TaCrP forms from the elements by step-wise solid state reaction in an alumina crucible (maximum annealing temperature 1180 K). TaCrP is trimorphic. The structural data of the hexagonal ZrNiAl high-temperature phase (space group P 6 ‾ 2 m $P\overline{6}2m$ ) was deduced from a Rietveld refinement. At room temperature TaCrP crystallizes with the TiNiSi type (Pnma, a = 623.86(5), b = 349.12(3), c = 736.78(6) pm, wR = 0.0419, 401 F 2 values, 20 variables) and shows a Peierls type transition below ca. 280 K to the monoclinic low-temperature modification (P121/c1, a = 630.09(3), b = 740.3(4), c = 928.94(4) pm, β = 132.589(5)°, wR = 0.0580, 1378 F 2 values, 57 variables). The latter phase transition is driven by pairwise Cr–Cr bond formation out of an equidistant chain in o-TaCrP. The phase transition was monitored via different analytical tools: differential scanning calorimetry, powder synchrotron X-ray diffraction, magnetic susceptibility measurements and 31P solid state NMR spectroscopy.

Development of hydrothermal corrosion model and BWR metal coating for CVD SiC in light water reactors

SiC/SiC fiber composites with CVD SiC overcoats are potential candidates for light water reactor advanced accident tolerant cladding materials. Understanding its corrosion kinetics in Light Water Reactor (LWR) conditions is essential to evaluate the concept's viability. Existing models only account for the temperature and oxygen concentration effect on the hydrothermal corrosion behavior applicable to LWR operating conditions. However, the development of a general corrosion rate for CVD SiC that accounts for the impact of irradiated microstructure, flow rate, electrical resistivity, pH, and surface roughness is critical for the practical realization of SiC/SiC-based cladding concepts. After a rigorous experimental campaign, this work updates the existing hydrothermal corrosion model to predict hydrothermal corrosion in LWRs. Numerical radiation and coolant chemistry analysis for LWRs conducted based on the updated corrosion kinetic models suggests that CVD SiC is likely a viable environmental barrier coating for Pressurized Water Reactors while questionable for Boiling Water Reactors (BWR) when the effect of irradiation damage on SiC corrosion is considered. An effective mitigation strategy for the double-layer metal coating is proposed for BWR applications. The double-layer metal coating comprising a FeCrAl overcoat with an intermediate Cr bond coating was observed to provide a stable protective barrier against SiC dissolution in BWR conditions. The proposed metal coating was also fully adherent following quench and burst tests.

Swelled Mechanism of Crumb Rubber and Technical Properties of Crumb Rubber Modified Bitumen.

Crumb rubber modified bitumen (CRMB) has excellent high-temperature performance and fatigue resistance, and is widely used in asphalt pavement to cope with increasing traffic axle load and changing climate. Under conventional preparation conditions, the swelling degree of CR can directly impact the comprehensive properties of CRMB; however, physical and chemical properties research on swelling crumb rubber (SCR) and crumb rubber recycled bitumen (CRRB) in CRMB is relatively lacking. In this paper, the working performance of CRMB and CRRB in high-temperature and low-temperature conditions were studied through physical and working performance testing of bitumen. The CR and SCR were tested by scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), gel permeation chromatography (GPC), and particle size distribution (PSD) tests to study the physicochemical behavior and microscopic effects before and after CR swelling. The results showed that CR dosage was in the range of 10%, 15%, and 20%, as well as that CR dosages have a positive effect on the high- and low-temperature performance, storage stability, and elastic recovery of bitumen. The high-temperature PG grades of bitumen were directly improved by four grades, and the elastic recovery rate increased by 339.9%. CR improved the ultra-low temperature crack resistance of bitumen. Due to the absorption of lighter components by CR, the relative content of the heavy component of bitumen increased; however, its low-temperature performance decreased significantly. After swelling, the CR particle size increased and the range became wider, the surface complexity of CR became higher, and the specific surface area was larger. At the same time, CR carried out the transformation process from large and medium molecules to small molecules. During the swelling process, a new benzene ring structure appeared in the CR, and the C-C bond and C-S bond of CR broke, forming part of the C=C bond.

Strain tuning of Néel temperature in YCrO3 epitaxial thin films

Epitaxial strain is a useful handle to engineer the physical properties of perovskite oxide materials. Here, we apply it to orthorhombic chromites that are a family of antiferromagnets showing fruitful functionalities as well as strong spin–lattice coupling via antisymmetric exchange interaction along Cr–O–Cr bonds. Using pulsed laser deposition, we grow YCrO3 thin films on various substrates imposing strain levels in the range from −1.8% to +0.3%. The films are stoichiometric with a 3+ valence for Cr both within the films and at their surface. They display an antiferromagnetic spin order below their Néel temperature, which we show can be strongly tuned by epitaxial strain with a slope of −8.54 K/%. A dimensionless figure of merit (defined as the slope normalized by the Néel temperature of bulk) is determined to be 6.1, which is larger than that of other perovskites, such as manganites (5.5), ferrites (2.3), or nickelates (4.6). Density functional theory simulations bring insight into the role of Cr–O bond lengths and oxygen octahedral rotations on the observed behavior. Our results shed light on orthorhombic chromites that may offer an energy-efficient piezo-spintronic operation.

Study of phosphate glasses containing iron, sodium and chromium : 30Fe2O3–3Cr2O3–12Na2O–55P2O5

In this research work, the authors devoted their efforts to study the physical and chemical properties of the glassy systm 30Fe2O3–3Cr2O3–12Na2O–55P2O5. The bulk glassy sample were prepared using the known melt quenching method. X-ray diffraction examination showed that sample was deposited in the amorphous state, where no discrete sharp diffraction peaks were formed. Energy dispersive X-ray spectroscopy exhibited also that there is a good agreement between the experimental results and the selected elemental composition ratios for obtaind sample. Differential Scanning Calorimetry (DSC) have provided good information on the correlation between the chemical composition of the sample and its characteristic parameters. It reflect a good mechanical, chemical and thermal resistance, a strengthening of the glass network explained by the formation of P – O – Cr bonds, as well as a good thermal stability. The structural analysis has been performed using FTIR techniques and RAMAN spectroscopy. The hyperfine parameters from the Mössbauer spectrum indicates that iron mainly exists as Fe3+ ions and in octahedral coordination.The proportion of transition oxides in the studied glass ensure the glass thermal stability, the relatively low melting temperature, and a high chemical durability, with potential application in nuclear waste immobilization.

Analysis of spectator chemical bonds in SN2@C and @Si reaction mechanisms in the gas phase

In this work, Cl−+AR3Cl reactions (with A = C and Si, and R = H, Me, Et, Cl, and F) were investigated to evaluate the A–R spectator bond properties at the ω-B97X-D/SPK-TZP level of theory, applying the Quantum Theory of Atoms in Molecules, the Overlap Model, and Local Vibrational Mode theory. The different chemical bond analyses converge to the conclusion (in line with current literature) that the steric hindrance experienced by Cl− in SN2@C reactions can be viewed as a consequence of the greater covalent nature of CR bonds that concentrate density in bond region more efficiently than SiR.

Theoretical Studies on the Structures of Metal String Complexes Crn(L)4Cl2 (n = 3, 5, 7; L = Oligo-α-Pyridylamide) under the Effect of an Electric Field.

To study the electronic structures and properties of [Crn(L)4Cl2] (n = 3, L = dpa: di(2-pyridyl)amido; n = 5, L = tpda: tripyridyldiamido; n = 7, L = teptra: tetrapyridyltriamine) metal string complexes, the BP86 method was used by considering the influence of the electric field (EF) applied parallel to the metal axis. As the EF increases, the migration of more positively charged Crodd is more significant than that of Creven, which results in alternating long-short Cr-Cr bonds. This happens because of the natural charges on the Crodd of 1-3, which are more electropositive than those on Creven. The electrons are pulled to the Cr and Cl(r) atoms at the high-potential side from Cl(l) at the low-potential side by the EF, which leads to asymmetrical FMOs. After the critical electric field (Ec), the configuration turns into a remarkably asymmetric one with alternating Cr-Cr quadruple bonds and weak interactions. The electrons are transferred from equatorial ligands (L) to metal chains. In the meantime, the asymmetry of the FMOs increases and the delocalization is further reduced, which affects the conductivity. Especially for [Cr7(teptra)4Cl2], the delocalized electrons of HOMO are completely transformed into a localized model after the critical electric field. It is observed that this supports the electric switching phenomenon ascribed to the conformations of delocalized and localized electrons. In addition, the longer the length of the metal chain, the smaller the Ec and the easier is for the complexes to be polarized by the EF.

Reactive molecular dynamics study of the oxidation behavior of iron‐based alloy in supercritical water

AbstractA theoretical study of the oxidation behavior of iron‐based alloy in the supercritical water (SCW) has been carried out based on ReaxFF force‐field molecular dynamics simulation. An atomic model has been proposed to simulate the initial chemisorption reactions and atoms diffusion behavior across the oxide layer. Simulation results imply that Cr addition has an important effect on the oxidation behavior of iron‐based alloy. In the initial stage of oxidation, H2O prefers to adsorb on the Cr atom, and some species in the form of Cr(OH)4 are observed on the FeCr alloy surface. Once an initial oxide layer is formed, further oxidation is controlled by the migration of vacancy. The O vacancies are formed at the oxide/FeCr alloy interface and migrate toward the steam, whereas Fe vacancies are formed at the oxide/steam interface and migrate toward the FeCr alloy. Attributed to the stronger binding energy of O–Cr bond than O–Fe bond, the Cr diffusivity in the oxide is less than Fe atoms. Thus, double oxide layers, including the inner Fe–Cr–O layer and outer Fe–O layer, are formed on the FeCr alloy, which is in good agreement with previous experimental observation.

Two-dimensional intrinsic ferromagnetic monolayer transition metal oxyhydroxide

Using density functional theory within the generalized gradient approximation, we predict that monolayer vanadium oxyhydroxide (VOOH) and chromium oxyhydroxide (CrOOH) are two-dimensional (2D) ferromagnetic semiconductors. These two kinds of oxyhydroxides possess excellent thermal and dynamical stability as the free-standing 2D monolayer films. Our results show that the monolayer VOOH and CrOOH remain ferromagnetic ordering with the critical temperature up to $\ensuremath{\sim}100\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, and the ferromagnetic ordering is due to a superexchange interaction in the near-${90}^{\ensuremath{\circ}}$ V(Cr)-O-V(Cr) bonds in monolayer VOOH(CrOOH). However, the different occupancy of $d$ electrons between the ${\mathrm{V}}^{3+}$ and ${\mathrm{Cr}}^{3+}$ ions gives rise to the different axes or planes of easy magnetization and the different magnetic anisotropy energies between the monolayer VOOH and CrOOH. Our study demonstrates that monolayer transition metal oxyhydroxides could be one category of testing ground for the investigation of 2D ferromagnets.

Structure-property correlations and scaling in the magnetic and magnetocaloric properties of GdCrO3 particles

The structure, magnetic, and magnetocaloric (MC) properties of orthorhombic nanocrystalline GdCrO3 with six particle sizes: ⟨d⟩ = 87, 103, 145, 224, 318, and 352 nm are reported. The particle size was tailored by annealing under different temperatures and estimated by scanning electron microscopy. With increase in ⟨d⟩, Goldschmidt tolerance factor t, orthorhombic strain s, and out-of-plane Cr–O1–Cr bond angle first decrease, reaching minimum values for ⟨d⟩ = 224 nm, and then increase for sample with ⟨d⟩ = 318 nm and 352 nm, thus showing a V-shaped variation. Temperature dependence of the magnetization (M) reveals an antiferromagnetic transition at K for ⟨d⟩ ⩾ 224 nm and K for ⟨d⟩ < 224 nm and an essentially d-independent spin-reorientation at T SR = 9 K. M measured at 5 K and 7 T first increases with increase in ⟨d⟩, reaching maximum value for sample with ⟨d⟩ = 224 nm, and then decreases for samples with ⟨d⟩ = 318 nm and 352 nm, showing an inverted-V variation with ⟨d⟩. Similar ⟨d⟩-dependence is observed for the magnetic entropy change (MEC) and relative cooling power (RCP) showing a close relationship between the structural and magnetic properties of GdCrO3 nanoparticles investigated here. The 224 nm sample with the minimum values of t, s, and Cr–O1–Cr bond angle exhibits the maximum value of MEC (−ΔS) = 37.8 J kg−1 K−1 at 5 K under a field variation (ΔH) of 7 T and its large estimated RCP of 623.6 J Kg−1 is comparable with those of typical MC materials. Both (−ΔS) and RCP are shown to scale with the saturation magnetization M S, suggesting that M S is the crucial factor controlling their magnitudes. Assuming (−ΔS) ∼ (ΔH) n , the temperature dependence of n for the six samples are determined, n varying between 1.3 at 5 K to n = 2.2 at 130 K in line with its expected magnitudes based on mean-field theory. These results on structure-property correlations and scaling in GdCrO3 suggest that its MC properties are tunable for potential low-temperature magnetic refrigeration applications.

Utilizing the weak P−Cr bond in [{Cp*Cr(CO)3}2(μ,η1:1−P4)] for the generation of different P4 butterfly compounds

AbstractA novel reactivity of [{Cp*Cr(CO)3}2(μ,η1:1−P4)] (Cp*=C5Me5; 1) is reported, which utilizes the selective cleavage of the two P−Cr bonds and subsequently initiates a substituent exchange yielding P4 butterfly compounds. By means of NMR and IR spectroscopy studies, the successful implementation of 1 to obtain [{Cp′′′Fe(CO)2}2(μ,η1:1−P4)] (Cp′′′=C5H2tBu3; 2) and Cp′′′2P4 (3) could be confirmed, by reacting 1 with 2.0 eq. of K[Cp′′′Fe(CO)2] or NaCp′′′, respectively. Hereby, a quantitative conversion could be detected alongside the formation of 2.0 eq. of the [Cp*Cr(CO)3]− anion. Moreover, various syntheses of novel organometallic and organo‐P4 butterfly compounds were examined and first results show that the generation of different compounds should be possible. However, the isolation and stabilization of these sensitive molecules proves to be a major challenge.

Chemical interaction and electronic structure in a compositionally complex alloy: A case study by means of X-ray absorption and X-ray photoelectron spectroscopy

Chemical interaction and changes in local electronic structure of Cr, Fe, Co, Ni and Cu transition metals (TMs) upon formation of an Al8Co17Cr17Cu8Fe17Ni33 compositionally complex alloy (CCA) have been studied by X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. It was found that upon CCA formation, occupancy of the Cr, Co and Ni 3d states changes and the maximum of the occupied and empty Ni 3d states density shifts away from Fermi level (Ef) by 0.5 and 0.6 eV, respectively, whereas the Cr 3d empty states maximum shifts towards Ef by 0.3 eV, compared to the corresponding pure metals. The absence of significant charge transfer between the elements was established, pointing to the balancing of the 3d states occupancy change by involvement of delocalized 4s and 4p states into the charge redistribution. Despite the expected formation of strong Al–TMs covalent bonds, the Al role in the transformation of the TMs 3d electronic states is negligible. The work demonstrates a decisive role of Cr in the Ni local electronic structure transformation and suggests formation of directional Ni–Cr bonds with covalent character. These findings can be helpful for tuning deformation properties and phase stability of the CCA.

Experimental Investigation on the DLC Film Coating Technology in Scroll Compressors of Automobile Air Conditioning

The friction of the orbiting scroll leads to large power consumption and low energy efficiency of the scroll compressor. The common methods to solve this problem are high cost and a complex process. Considering special structures and operating principles to apply the coating technology on the scroll compressor is a new subject. Given the material of the orbiting scroll being aluminum alloy, the unbalanced magnetron sputtering technology for the orbiting scroll of the scroll compressor was chosen and the Cr transition layer was coated to enhance the bonding strength. Moreover, we innovatively performed an experiment to verify the feasibility of unbalanced magnetron sputtering film coating technology for the diamond-like carbon film coated in the scroll compressor. This article elaborates the parameter test methods of the film properties before and after experiments and the experimental system components. The results showed that the diamond-like carbon film has low coefficient and high bonding strength, which renders it a good wear-reducing effect and an excellent self-lubricating property. Due to the thin film layer and high operating temperature, the thickness should be increased to raise the abrasion resistance. The refrigeration system with the scroll compressor coated with the diamond-like carbon film can satisfy the national standard conditions with low Vickers hardness. Its performance was improved at low speed. Therefore, the unbalanced magnetron sputtering with increased Cr bond layer is a feasible and appropriate technology for coating diamond-like carbon film.

Regiospecific Synthesis and Structural Studies of 3,5-Dihydro-4H-pyrido[2,3-b][1,4]diazepin-4-ones and Comparison with 1,3-Dihydro-2H-benzo[b][1,4]diazepin-2-ones.

Nine 3,5-dihydro-4H-pyrido[2,3-b][1,4]diazepin-4-ones (17–25), some of which contain fluoro-substituents, have been regiospecifically prepared by reaction of 2,3-diaminopyridines with ethyl aroylacetates. In two cases, open intermediates have been isolated and these are related to the reaction pathway. The X-ray crystal structure of 1-methyl-4-phenyl-3,5-dihydro-4H-pyrido[2,3-b][1,4]diazepin-4-one (23) has been solved (formula, C15H13N3O; crystal system, monoclinic; space group, C2/c). This is an asymmetric unit constituted by a single nonplanar molecule and its conformational enantiomer due to the presence of the seven-membered diazepin-2-one moiety, which introduces a certain degree of torsion in the adjacent pyridine ring. The 1H, 13C, 15N, and 19F NMR spectra were obtained and the chemical shifts, together with those of the previously published 1,3-dihydro-2H-benzo[b][1,4]diazepin-2-ones (1–16), i.e., a total of 544 values, were successfully compared with the chemical shifts calculated at the gauge invariant atomic orbital (GIAO)/Becke, three-parameter, Lee–Yang–Parr (B3LYP)/6-311++G(d,p) level. The seven-membered ring inversion barrier in 5-benzyl-2-phenyl-3,5-dihydro-4H-pyrido[2,3-b][1,4]diazepin-4-one (25) was determined and, in conjunction with the data from the literature, compared with the B3LYP/6-311++G(d,p) computed values. This allowed the determination of several structural effects. The rotation about the exocyclic N1–CR bond was also calculated and its dynamic properties were discussed.