Application Effect of Comprehensive Noise Reduction Technology in Outpatients with Vitiligo: A Retrospective Study.

OBJECTIVE: Noise is a kind of perceived public nuisance that is closely related to people's subjective feelings and lives. This study explores the clinical application effect of comprehensive noise reduction technology in outpatients with vitiligo. METHODS: A total of 76 patients with vitiligo were selected in the Department of Dermatology at Baoding No. 2 Central Hospital from January 2020 to January 2021, as the control group (CG), receiving 5S management mode, and 80 patients with vitiligo from February 2021 to October 2022 were selected as the study group (SG), receiving comprehensive noise reduction technology combined with the 5S management mode for this retrospective study. The effects of different management modes on these patients were observed. RESULTS: SG had higher nursing quality scores in service attitude, service initiative, communication skills, environmental management and item management and overtly a lower noise level than CG (all P < 0.001). The Hamilton Anxiety Scale (HAMA) scores of the two groups at the end of treatment were significantly lower than those on admission (P < 0.05), with SG showing a lower score than CG (P < 0.001). Correlation analysis showed that noise levels and HAMA scores had a positive correlation (r = 0.423, P < 0.001). Patients with negative feelings about medical treatment caused by various noise sources in SG were obviously less than those in CG (P < 0.05). Both the groups had a statistical difference in overall satisfaction (P < 0.05). CONCLUSION: The investigation and data analysis demonstrated that comprehensive noise reduction in outpatients with vitiligo had a considerable effect. This technology can standardise the behaviour of medical staff, enhance nursing quality, reduce noise levels and alleviate patients' anxiety and improve their satisfaction. It has great benefits for the outpatient environment and patients.

A Conjugated Phenylene Nanocage with a Guest-Adaptive Deformable Cavity.

The highly strained, phenylene-derived organic cages are typically regarded as very rigid entities, yet their deformation potential and supramolecular properties remain underexplored. Herein, we report a pliable conjugated phenylene nanocage by synergistically merging rigid and flexible building blocks. The anisotropic cage molecule contains branched phenylene chains capped by a calix[6]arene moiety, the delicate conformational changes of which endow the cage with a remarkably deformable cavity. When complexing with fullerene guests, the cage showcases excellent guest-adaptivity, with its cavity volume capable of swelling by as much as 85 %.

Macrocycle-Induced Modulation of Internuclear Interactions in Homobimetallic Complexes.

A synthetic route has been developed for a series of 3d homobimetallic complexes of Mn, Fe, Co, Ni, and Cu using three different pyridyldiimine and pyridyldialdimine macrocyclic ligands with ring sizes of 18, 20, and 22 atoms. Crystallographic analyses indicate that while the distances between the metals can be modulated by the size of the macrocycle pocket, the flexibility in the alkyl linkers used to construct the macrocycles enables the ligand to adjust the orientation of the PD(A)I fragments in response to the geometry of the [M2(µ-Cl)2]2+ core, particularly with respect to Jahn-Teller distortions. Analyses by UV-vis spectroscopy and SQUID magnetometry revealed deviations in the properties [M2(µ-Cl)2]2+-containing complexes bound by standard mononucleating ligands, highlighting the ability of macrocycles to use ring size to control the magnetic interactions of pseudo-octahedral, high-spin metal centers.

A Conjugated Figure-of-Eight Oligoparaphenylene Nanohoop with Adaptive Cavities Derived from Cyclooctatetrathiophene Core.

A fully conjugated figure-of-eight nanohoop is presented with facile synthesis. The molecule's lemniscular skeleton features the combination of two strained oligoparaphenylene loops and a flexible cyclooctatetrathiophene core. Its rigid yet guest-adaptive cavities enable the formation of the peanut-like 1:2 host-guest complexes with C60 or C70 , which have been confirmed by X-ray crystallography and characterized in solution. Further computational studies suggest notable geometric variations and non-covalent interactions of the cavities upon binding with different fullerenes, as well as overall conjugation comparable to cycloparaphenylenes.

Selective Electrochemical Oxidation of Functionalized Pyrrolidines.

A method for the selective electrochemical aminoxyl-mediated Shono-type oxidation of pyrrolidines to pyrrolidinones is described. These transformations show the high selectivity and functional group compatibility. This chemistry also demonstrates the use of an operationally simple ElectraSyn 2.0 and cost-effective stainless-steel electrode for the electrochemical oxidation of functionalized pyrrolidines.

Biocatalytic oxidation of alcohols using galactose oxidase and a manganese(III) activator for the synthesis of islatravir.

Galactose oxidase (GOase) is a Cu-dependent metalloenzyme that catalyzes the oxidation of alcohols to aldehydes. An evolved GOase variant was recently shown to catalyze a desymmetrizing oxidation as the first enzymatic step in the biocatalytic synthesis of islatravir. Horseradish peroxidase (HRP) is required to activate the GOase, introducing cost and protein burden to the process. Herein we describe that complexes of earth-abundant Mn(iii) (e.g. Mn(OAc)3) can be used at low loadings (2 mol%) as small molecule alternatives to HRP, providing similar yields and purity profiles. While an induction period is observed when using Mn(OAc)3 as the activator, employment of alternative Mn(iii) sources, such as Mn(acac)3 and K3[Mn(C2O4)3], eliminates the induction period and provides higher conversions to product. We demonstrate that use of the Mn(OAc)3 additive is also compatible with subsequent biocatalytic steps in the islatravir-forming cascade. Finally, to exhibit the wider utility of Mn(OAc)3, we show that Mn(OAc)3 functions as a suitable activator for several commercially available variants of GOase with a series of alcohol substrates.

Reversible nickel-metallacycle formation with a phosphinimine-based pincer ligand.

Pincer ligands have a remarkable ability to impart control over small molecule activation chemistry and catalytic activity; therefore, the design of new pincer ligands and the exploration of their reactivity profiles continues to be a frontier in synthetic inorganic chemistry. In this work, a novel, monoanionic NNN pincer ligand containing two phosphinimine donors was used to create a series of mononuclear Ni complexes. Ligand metallation in the presence of NaOPh yielded a nickel phenoxide complex that was used to form a mononuclear hydride complex on treatment with pinacolborane. Attempts at ligand metallation with NaN(SiMe3)2 resulted in the activation of both phosphinimine methyl groups to yield an anionic, cis-dialkyl product, in which dissociation of one phosphinimine nitrogen leads to retention of a square planar coordination environment about Ni. Protonolysis of this dialkyl species generated a monoalkyl product that retained the 4-membered metallacycle. The insertion of 2,6-dimethylphenyl isocyanide (xylNC) into this nickel metallacycle, followed by proton transfer, generated a new five-membered nickel metallacycle. Kinetic studies suggested rate-limiting proton transfer (KIE ≥ 3.9 ± 0.5) from the α-methylene unit of the putative iminoacyl intermediate.

N-H Bond Formation at a Diiron Bridging Nitride.

Despite their connection to ammonia synthesis, little is known about the ability of iron-bound, bridging nitrides to form N-H bonds. Herein we report a linear diiron bridging nitride complex supported by a redox-active macrocycle. The unique ability of the ligand scaffold to adapt to the geometric preference of the bridging species was found to facilitate the formation of N-H bonds via proton-coupled electron transfer to generate a µ-amide product. The structurally analogous µ-silyl- and µ-borylamide complexes were shown to form from the net insertion of the nitride into the E-H bonds (E=B, Si). Protonation of the parent bridging amide produced ammonia in high yield, and treatment of the nitride with PhSH was found to liberate NH3 in high yield through a reaction that engages the redox-activity of the ligand during PCET.

Interdependent Metal-Metal Bonding and Ligand Redox-Activity in a Series of Dinuclear Macrocyclic Complexes of Iron, Cobalt, and Nickel.

This report describes an isostructural series of dinuclear iron, cobalt, and nickel complexes bound by a redox-active macrocyclic ligand. The series spans five redox levels (34-38 e-/cluster core), allowing for a detailed investigation into both the degree of metal-metal interaction and the extent of ligand-based redox-activity. Magnetometry, electrochemistry, UV-vis-NIR absorption spectroscopy, and crystallography were used in conjunction with DFT computational analyses to extract the electronic structures of the six homodinuclear complexes. The isoelectronic, 34 e- species [(3PDI2)Fe2(PMe3)2(µ-Cl)](OTf) and [(3PDI2)Co2(PMe3)2(µ-Cl)](OTf)3 exhibit metal-metal single bonds, with varying amounts of electron density delocalization into the ligand as a function of the effective nuclear charge of the metal ions. One- and two-electron reductions of [(3PDI2)Co2(PMe3)2(µ-Cl)](OTf)3 lead to isolable products, which show successive increases in both the Co-Co distances and the extent of reduction of the ligand manifold. This trend results from reduction of a Co-Co σ* orbital, which was found to be heavily mixed with the redox-active manifold of the 3PDI2 ligand. A similar trend was observed in the 37 and 38 e- dinickel complexes [(3PDI2)Ni2(PMe3)2(µ-Cl)](OTf)2 and [(3PDI2)Ni2(PMe3)2(µ-Cl)](OTf); however, their higher electron counts lead to high-spin ground states that result from occupation of a high-lying δ/δ* manifold with significant Ni-NPDI σ* character. This change in ground state configuration reforms a M-M bonding interaction in the 37 e- complex, but formation of the 38 e- species again disrupts the M-M bond alongside the transfer of electron density to the ligand.

Tuning Metal-Metal Interactions through Reversible Ligand Folding in a Series of Dinuclear Iron Complexes.

A dinucleating macrocyclic ligand with two redox-active, pyridyldiimine components was shown to undergo reversible ligand folding to accommodate various substitution patterns, metal ion spin states, and degrees of Fe-Fe bonding within the cluster. An unfolded-ligand geometry with a rectangular Fe2(µ-Cl)2 core and an Fe-Fe distance of 3.3262(5) Å served as a direct precursor to two different folded-ligand complexes. Chemical reduction in the presence of PPh3 resulted in a diamagnetic, folded ligand complex with an Fe-Fe bonding interaction (dFe-Fe = 2.7096(17) Å) between two intermediate spin (SFe = 1) Fe(II) centers. Ligand folding was also induced through anion exchange on the unfolded-ligand species, producing a complex with three PhS- ligands and a temperature-dependent Fe-Fe distance. In this latter example, the weak ligand field of the thiolate ligands led to a product with weakly coupled, high-spin Fe(II) ions (SFe = 2; J = -50.1 cm-1) that form a bonding interaction in the ground state and a nonbonding interaction in the excited state(s), as determined by SQUID magnetometry and variable temperature crystallography. Finally, both folded-ligand complexes were shown to reform an unfolded-ligand geometry through convergent syntheses of a complex with an Fe-Fe bonded Fe2(µ-SPh)2 core (dFe-Fe = 2.7320(11) Å). Experimentally validated DFT calculations were used to investigate the electronic structures of all species as a way to understand the origin of Fe-Fe bonding interactions, the extent of ligand reduction, and the nature of the spin systems that result from multiple, weakly interacting spin centers.

Reversible Heterolytic Cleavage of the H-H Bond by Molybdenum Complexes: Controlling the Dynamics of Exchange Between Proton and Hydride.

Controlling the heterolytic cleavage of the H-H bond of dihydrogen is critically important in catalytic hydrogenations and in the catalytic oxidation of H2. We show how the rate of reversible heterolytic cleavage of H2 can be controlled, spanning 4 orders of magnitude at 25 °C, from 2.1 × 103 s-1 to ≥107 s-1. Bifunctional Mo complexes, [CpMo(CO)(κ3-P2N2)]+ (P2N2 = 1,5-diaza-3,7-diphosphacyclooctane diphosphine ligand with alkyl/aryl groups on N and P), have been developed for heterolytic cleavage of H2 into a proton and a hydride, akin to frustrated Lewis pairs. The H-H bond cleavage is enabled by the basic amine in the second coordination sphere. The products of heterolytic cleavage of H2, Mo hydride complexes bearing protonated amines, [CpMo(H)(CO)(P2N2H)]+, were characterized by spectroscopic studies and by X-ray crystallography. Variable-temperature 1H, 15N, and 2-D 1H-1H ROESY NMR spectra indicated rapid exchange of the proton and hydride. The exchange rates are in the order [CpMo(H)(CO)(PPh2NPh2H)]+ > [CpMo(H)(CO)(PtBu2NPh2H)]+ > [CpMo(H)(CO)(PPh2NBn2H)]+ > [CpMo(H)(CO)(PtBu2NBn2H)]+ > [CpMo(H)(CO)(PtBu2NtBu2H)]+. The pKa values determined in acetonitrile range from 9.3 to 17.7 and show a linear correlation with the logarithm of the exchange rates. This correlation likely results from the exchange process involving key intermediates that differ by an intramolecular proton transfer. Specifically, the proton-hydride exchange appears to occur by formation of a molybdenum dihydride or dihydrogen complex, resulting from proton transfer from the pendant amine to the metal hydride. The exchange dynamics are controlled by the relative acidity of the [CpMo(H)(CO)(P2N2H)]+ and [CpMo(H2)(CO)(P2N2)]+ isomers, providing a design principle for controlling heterolytic cleavage of H2.

Facile P-C/C-H Bond-Cleavage Reactivity of Nickel Bis(diphosphine) Complexes.

Unusual cleavage of P-C and C-H bonds of the P2 N2 ligand, in heteroleptic [Ni(P2 N2 )(diphosphine)](2+) complexes under mild conditions, results in the formation of an iminium formyl nickelate featuring a C,P,P-tridentate coordination mode. The structures of both the heteroleptic [Ni(P2 N2 )(diphosphine)](2+) complexes and the resulting iminium formyl nickelate have been characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Density functional theory (DFT) calculations were employed to investigate the mechanism of the P-C/C-H bond cleavage, which involves C-H bond cleavage, hydride rotation, Ni-C/P-H bond formation, and P-C bond cleavage.

Semibullvalene and diazasemibullvalene: recent advances in the synthesis, reaction chemistry, and synthetic applications.

Semibullvalene (SBV) and its aza analogue 2,6-diazasemibullvalene (NSBV) are theoretically interesting and experimentally challenging organic molecules because of four unique features: highly strained ring systems, intramolecular skeletal rearrangement, extremely rapid degenerate (aza-)Cope rearrangement, and the predicted existence of neutral homoaromatic delocalized structures. SBV has received much attention in the past 50 years. In contrast, after NSBV was predicted in 1971 and the first in situ synthesis was realized in 1982, no progress on NSBV chemistry was made until our results in 2012. We have been interested in the reaction chemistry of 1,4-dilithio-1,3-butadienes (dilithio reagents for short), especially for their applications in the synthesis of SBV and NSBV, because (i) the cyclodimerization of dilithio reagents could provide the potential eight-carbon skeleton of SBV from four-carbon butadiene units and (ii) the insertion reaction of dilithio reagents with C≡N bonds of two nitriles could provide a 6C + 2N skeleton that might be a good precursor for the synthesis of NSBV. Therefore, we initiated a journey into the synthesis and reaction chemistry of SBV and NSBV starting from dilithio reagents that has been ongoing since 2006. In this Account, we outline mainly our recent achievements in the synthesis, structural characterization, reaction chemistry, synthetic application, and theoretical/computational analysis of NSBV. Two efficient strategies for the synthesis of NSBV from dilithio reagents and nitriles via oxidant-induced C-N bond formation are described. Structural investigations of NSBV, including X-ray crystal structure analysis, determination of the activation barrier for the aza-Cope rearrangement, and theoretical analysis, show that the localized structure of NSBV is the predominant form and that the homoaromatic delocalized structure exists as a minor component in the equilibrium. We also discuss the reaction chemistry and synthetic applications of NSBV. Several novel reaction patterns have been explored, including thermolysis, C-N bond insertion, rearrangement-cycloaddition, oxidation, and nucleophilic ring-opening reactions. Diverse and interesting N-containing polycyclic skeletons can be constructed, such as nickelaazetidine, 1,5-diazatriquinacenes, and triazabrexadienes, which are not available by other means. Our results show that NSBV not only features a rapid aza-Cope rearrangement with a low activation barrier but also acts as unique synthetic reagent that is significantly different from aziridine. The strained rigid ring systems as a whole can be involved in the reactions. Our achievements highlight two significant advances: (i) the well-established efficient synthesis and isolation of NSBV has greatly accelerated the development of NSBV chemistry, and (ii) the previously unattainable molecules have become "normal" and routine starting materials for the synthesis of otherwise unavailable but interesting structures. We expect that our pursuits will inspire and help direct future chemical and physical research on NSBV.

Molybdenum Hydride and Dihydride Complexes Bearing Diphosphine Ligands with a Pendant Amine: Formation of Complexes with Bound Amines.

CpMo(CO)(PNP)H complexes (PNP = (R2PCH2)2NMe, R = Et or Ph) were synthesized by displacement of two CO ligands of CpMo(CO)3H by the PNP ligand; these complexes were characterized by IR and variable temperature (1)H and (31)P NMR spectroscopy. CpMo(CO)(PNP)H complexes are formed as mixture of cis- and trans-isomers. The structures of both cis-CpMo(CO)(P(Et)N(Me)P(Et))H and trans-CpMo(CO)(P(Ph)N(Me)P(Ph))H were determined by single crystal X-ray diffraction. Electrochemical oxidation of CpMo(CO)(P(Et)N(Me)P(Et))H and CpMo(CO)(P(Ph)N(Me)P(Ph))H in CH3CN are both irreversible at slow scan rates and quasireversible at higher scan rates, with E1/2 = -0.36 V (vs Cp2Fe(+/0)) for CpMo(CO)(P(Et)N(Me)P(Et))H and E1/2 = -0.18 V for CpMo(CO)(P(Ph)N(Me)P(Ph))H. Hydride abstraction from CpMo(CO)(PNP)H with [Ph3C](+)[A](-) (A = B(C6F5)4 or BAr(F)4; [Ar(F) = 3,5-bis(trifluoromethyl)phenyl]) afforded "tuck-in" [CpMo(CO)(κ(3)-PNP)](+) complexes that feature the amine bound to the metal. Displacement of the κ(3) Mo-N bond by CD3CN gives [CpMo(CO)(PNP)(CD3CN)](+). The kinetics of this reaction were studied by (31)P{(1)H} NMR spectroscopy for [CpMo(CO)(κ(3)-P(Et)N(Me)P(Et))](+), providing the activation parameters ΔH(⧧) = 21.6 ± 2.8 kcal/mol, ΔS(⧧) = -0.3 ± 9.8 cal/(mol K), Ea = 22.1 ± 2.8 kcal/mol. Protonation of CpMo(CO)(P(Et)N(Me)P(Et))H affords the Mo dihydride complex [CpMo(CO)(κ(2)-P(Et)N(Me)P(Et))(H)2](+), which loses H2 to generate [CpMo(CO)(κ(3)-P(Et)N(Me)P(Et))](+) at room temperature. Our results show that the pendant amine has a strong driving force to form stable "tuck-in" [CpMo(CO)(κ(3)-PNP)](+) complexes, and also promotes hydrogen elimination from [CpMo(CO)(PNP)(H)2](+) complexes by formation of a Mo-N dative bond. CpMo(CO)(dppp)H (dppp = 1,3-bis(diphenylphosphino)propane) was studied as a Mo diphosphine analogue without a pendant amine, and the product of protonation of this complex gives [CpMo(CO)(dppp)(H)2](+).

Synthesis of α,α,α',α'-tetrachloro-Δ1-bipyrrolines and 4,8-dichloro-2,6-diazasemibuvallenes.

A series of 4,8-dichloro-2,6-diazasemibullvalenes were synthesized and isolated from the reaction of α,α,α',α'-tetrachloro-Δ(1)-bipyrrolines with lithium via C-N bond formation. All those dichlorodiazasemibullvalene derivatives demonstrated extremely rapid aza-Cope rearrangement in solution. An unprecedented skeletal rearrangement of 4,8-dichloro-2,6-diazasemibullvalene derivatives took place, resulting in the formation of a new bipyrroline skeleton.

Efficient synthesis of aza-triquinacene derivatives via cycloaddition of 2,6-diazasemibullvalenes with nitroso compounds.

The reaction between 2,6-diazasemibullvalenes and nitroso compounds was investigated. Aza-triquinacene derivatives of interesting structural and synthetic chemistry were generated highly selectively in good to excellent isolated yields. This reaction, which was rarely found between common aziridine derivatives and nitroso compounds, could be attributed to the rigid polycyclic ring system and the substitution patterns of 2,6-diazasemibullvalenes. Δ(1) -Bipyrroline derivatives were formed in excellent yields when these aza-triquinacene derivatives were treated with SmI2 .

Diastereoselective nucleophilic ring-opening reactions of 2,6-diazasemibullvalenes for the synthesis of diverse functionalized δ(1) -bipyrroline derivatives.

Nucleophilic ring-opening reactions of 2,6-diazasemibullvalenes (NSBVs) were investigated. Different types of nucleophile (alcohols, phenols, thiols, carboxylic acids, water, enols, amines, indoles, metal-halide salts, sodium azide, organozinc compounds, lithium alkynethiolate, and sulfoxonium ylides) were used to afford diverse functionalized Δ(1) -bipyrroline derivatives in good yields with high regio- and diastereoselectivity. Most of the reactions featured milder conditions and higher reactivity relative to those for common aziridine derivatives, probably because of the rigid ring system and substitution patterns of NSBVs.

Diazo compounds as electrophiles to react with 1,4-dilithio-1,3-dienes: efficient synthesis of 1-imino-pyrrole derivatives.

1-Imino-pyrrole and indole derivatives were synthesized in high yields from the reaction of diaryl diazomethanes with 1,4-dilithio-1,3-dienes. Diaryl diazomethanes reacted as electrophiles in this reaction. An unprecedented Zn-complex was formed via transmetalation of the above reaction intermediate with ZnCl2 and was structurally characterized. The trans-µ2-η(1):η(1) coordination mode in the solid state for this azaallylzinc compound was observed.

Very-low speed control of PMSM based on EKF estimation with closed loop optimized parameters.

When calculating the speed from the position of permanent magnet synchronous motor (PMSM), the accuracy and real-time are limited by the precision of the sensor. This problem causes crawling and jitter at very-low speed. Using the angle from the position sensor, an extended Kalman filter (EKF) designed in dq-coordinate is presented to solve this problem. The usage of position sensor simplifies the model and improves the accuracy of speed estimation. Specially, a closed loop optimal (CLO) method is devised to overcome the difficulty to adjust the parameters of the EKF. The EKF is the feedback link of speed control, CLO method is derived from the perspective of the speed step response to optimize the measurement covariance matrix and the system covariance matrix of EKF. Simulation and experimental results, comparing the low-speed performance of the EKF and sensor feedback methods, prove the effectiveness of the method to adjust the parameters of EKF and the advantages in eliminating the low speed jitter.

Oxidation of C-H bonds to C=O bonds by O2 only or N-oxides and DMSO: synthesis of Δ(1)-bipyrrolinones and pyrrolino[3,2-b]pyrrolinones from 2,6-diazasemibullvalenes.

2,6-Diazasemibullvalenes (NSBVs) readily reacted with oxygen under mild conditions, affording Δ(1)-bipyrrolinones via C-N bond cleavage and C-H bond oxidation. Pyrrolino[3,2-b]pyrrolinone derivatives were efficiently generated when NSBVs were treated with N-oxides in the presence of Lewis acids. Δ(1)-Bipyrrolinones thus obtained could be readily transformed into other heterocycles.