This account details the author's work with reactive intermediates and unusual molecules, starting with amateur rocket propellants like zinc dust and sulfur followed by experiments with highly sensitive compounds, nitrogen trichloride, and fulminating gold. Research on alkyl and aryl cyanates, ROCN, the inorganic and organic fulminates, XCNO, and the CHNO and CRNO isomers lead to detailed chemical and spectroscopic (IR, UV, ESR, MS, MW, and PES) investigations of reactive intermediates generated by flash vacuum pyrolysis, matrix isolation, and matrix photolysis, in particular nitrenes and carbenes from azides, diazo compounds, triazoles, tetrazoles, and sydnones, as well as nitrile imines, ylides, and oxides, imidoylnitrenes, carbodiimides, cyanocyclopentadiene, fulvenallene, numerous ketenes, propadienones, iminopropadienones, sulfur compounds like SCCS, N2S, and RCNS, the HCN dimers CH2NCN and HNCHCN, and numerous other compounds. Along the way, equipment for flash vacuum pyrolysis in conjunction with IR, UV, and ESR spectroscopies and mass spectrometry was developed.

Abstract The Reformatsky reaction is a well-established method for the synthesis of β-hydroxyesters, a structural motif commonly found in natural products. While continuous-flow adaptations of the traditional Reformatsky reaction, which offer improved safety and efficiency, have been reported, related transformations using γ-bromocrotonate esters have not yet been explored in flow chemistry. Under batch conditions, the corresponding organozinc reagent can yield both γ- and α-adducts, depending on the metal employed and the specific reaction parameters. In this study, we report the first Reformatsky-type reaction in continuous flow using ethyl γ-bromocrotonate, with conditions optimized to favor γ-selectivity and the synthesis of homoallylic alcohols. Zinc dust was utilized as the reagent, and the reaction scope was demonstrated with a variety of carbonyl compounds, including in a four-step synthesis of piperine. Furthermore, the synthesis of ethyl γ-bromocrotonate was efficiently accomplished under continuous-flow conditions on a multigram scale via a Wohl–Ziegler bromination.

Study on the recovery of zinc in high zinc dust by one-step reduction distillation

This paper presents a brief review of the results previously obtained by the authors in their studies of the chemical and granulometric composition of zinc‑containing dispersed waste (zinc dust) generated during the galvanizing of pipes and subsequent steam blowing. It also examines the influence of technological parameters such as the mixture composition and the temperature of thermodiffusion galvanizing on the thickness, structure, and properties of zinc coatings produced using thermodiffusion galvanizing in saturating mixtures based on zinc‑containing waste. Since the primary function of zinc coatings is corrosion protection, samples of zinc coatings based on both standard zinc powder and production waste were fabricated ina rotating container unit for comparative corrosion resistance testing in a salt spray chamber. It is well known that to enhance corrosion resistance, zinc coatings are commonly passivated and coated with paint materials. Some of the zinc‑coated samples were also subjected to additional treatments. The comparative salt spray chamber testing (ongoing at the time of writing) revealed that after 300 hours of exposure, the coatings produced from zinc‑containing waste only slightly underperformed in terms of protective properties compared to those made with standard zinc powder. Additional treatments, specifically passivation, nearly eliminated white rust formation. Furthermore, the use of a combined paint coating system (passivation + painting) ensured complete corrosion resistance for no less than 300 hours in the salt spray chamber.

A simple manually rotated paper-based analytical device with electrochemical sensors for the determination of nitrite and nitrate.

Lead and zinc distribution in chloridizing sintering of zinc dust obtained after processing of different kinds of raw materials in the iron and steel industry

Influence of Sulfur Morphology on Arsenic Removal from Zinc Dust

Abstract The organometallic multicomponent Manich reaction of secondary benzylzinc compounds is described. These organometallic reagents were efficiently prepared by direct metalation of (1‐bromoethyl)benzenes in tetrahydrofuran with zinc dust. Their subsequent multicomponent Mannich coupling with amines and aldehydes allowed the straightforward preparation of a large variety of α,β‐disubstituted β‐arylethylamines in yields ranging from 13% to 79%. This reaction was found to require the use of a heated mixture of tetrahydrofuran and acetonitrile, tetrahydrofuran being essential to reach good yields and acetonitrile ensuring reproducibility.

A novel Zn-mediated preparation of propiolonitriles using electrophilic cyanation of alkynyl bromides with N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS) has been achieved here. The zinc dust was firstly used to activate the C(sp)–Br bond in the presence of tetrabutylammonium iodide (TBAI) to form an alkynyl zinc reagent in situ, which would undergo a nucleophilic addition with NCTS at the cyano group to afford an imine. Finally the propiolonitrile product was obtained after the elimination of the zinc complex. According to this new protocol, various phenylpropiolonitriles have been prepared from alkynyl bromides in moderate to excellent yields (51–95%), and could also be generated from the combination of inactive alkynyl chlorides with tetrabutylammonium bromide (TBAB) in lower yields (23–70%).

Abstract This article presents a simple and efficient method for synthesizing the key fragment of lifitegrast, benzofuran‐6‐carboxylic acid. The synthetic pathway involves two key conversions such as intramolecular cross‐coupling and oxidative dehydrogenation reactions to obtain the target compound. The first key reaction, the cross‐coupling reaction, proceeds smoothly with the use of 1.2 equivalents of zinc dust in a dimethylacetamide medium at 60 ° C. The second key reaction, the oxidative dehydrogenation of dihydrobenzofuran occurs comfortably with the catalytic amount of DDQ along with 6 equivalents of MnO 2 in a chlorbenzene medium to generate the benzofuran moiety in good yield. We also discussed in‐detail about the impurity formation and its control by adjusting the pH, reagent quantity, solvent quality etc. The proposed synthetic route has been scaled up to a multi‐gram scale.The proposed approach offers several advantages, including scalability and cost‐effectiveness by utilizing inexpensive and readily available raw materials.

This paper presents the results of a study on thermodiffusion zinc coatings obtained using a technology where zinc dust – waste from hot‑dip galvanizing created during the air blowing of pipes post‑galvanization – is used as the zinc component on steel products, including those with threaded surfaces. The technology involves applying zinc coatings to steel products, including threaded surfaces, through thermodiffusion saturation in a stationary container with a powder mixture consisting of 40 % Znwaste, 59 % Al2O3, and 1 % NH4Cl. This method yields coatings with good appearance, and the desired coating thickness, ensuring compatibility for threading, can be controlled by adjusting the exposure time.

The article focuses on researching the technology of cementation purification of zinc sulfate solutions from impurities that adversely affect the electrolysis of zinc. The purpose of this work is to explore new approaches for deep cementation purification of solutions, aimed at reducing the consumption of zinc dust and activating additives (antimony and copper compounds) in the technological process, while improving the quality of the purified solution by decreasing the content of cobalt, nickel, and cadmium in the solution supplied for zinc electrolysis. In this study, a new technology for the cementation purification of industrial solutions was developed, which includes the following stages of impurity removal using zinc dust: preliminary purification stage to remove copper to a concentration of 90–110 mg/L; co-precipitation of copper, cadmium, cobalt, and nickel with the addition of antimony trioxide; deep purification of the solutions from all impurities remaining after the first stage. The purification process was conducted under the following conditions: the preliminary deposition took place at a temperature of 50 °C, with a duration of 30 min and a zinc dust consumption of 0.2–0.4 g/L; the first purification stage occurred at a temperature of 80 °C, for a duration of 1 h, with a zinc dust consumption of 2–3 g/L, and an antimony dosage of 3–6 mg/L; the second purification stage was carried out at a temperature of 75–80 °C, for a duration of 1 h, with a zinc dust consumption of 2–3 g/L, and dosages of copper sulfate and antimony at 50 mg/L and 2–3 mg/L, respectively.

This research is part of a continuing effort to synthesize copper and zinc arsenates(III) to use as a zinc dust activator in zinc sulphate solution purification. In this paper, the feasibility of synthesizing crystalline, mono-phase zinc and copper arsenates(III) were investigated. Copper and zinc arsenates(III) were prepared by adding their sulphate solutions into arsenious solution obtained by dissolving As2O3 in NaOH aqueous solution. The structure and crystal lattice of the products and amount of the elements in precipitations were characterized by X-ray diffraction(XRD) and Atomic Absorption Spectrometry(AAS), respectively. Based on the results of XRD in the conditions of NaOH concentration = 1 mol/L, n(OH–)/n(As) = 1:1, n(Cu)/n(As) = 1:2, reaction temperature 90°C and reaction time 8h, a mono-phase crystalline copper arsenate(III) with the chemical composition of Cu(AsO2)2 and tetragonal crystal lattice was synthesized. In these conditions, the yields of arsenic and copper precipitation from the solution were 93.81% and 97.68%, respectively. Based on the XRD results in the conditions of NaOH concentration = 1 L, n(OH–)/n(As) = 1:1, n(Zn)/n(As) = 1:2, reaction temperature 80°C, reaction time 2h and washing pH = 6, a mono-phase crystalline zinc arsenate (III) with the chemical composition of Zn(AsO2)2 and monoclinic crystal lattice was synthesized. In these conditions, the yields of arsenic and zinc extraction from the solution were 77.70% and 46.37%, respectively.

The use of alkylzinc bromides in the multicomponent Mannich reaction is described. Heteroleptic organozinc compounds were obtained in THF or 2-MeTHF by direct insertion of zinc dust into the C-Br bond of alkyl bromides. It was found that the presence of a stoichiometric amount of LiCl was essential for the efficiency of the subsequent three-component coupling with aldehydes and amines. A variety of primary, secondary, and tertiary organozinc reagents as well as secondary amines and aromatic aldehydes could be used for the straightforward preparation of α-branched amines. Interestingly, whereas previously reported work describing the preparation and reaction of organozinc iodides in acetonitrile showed higher reactivity of secondary organozinc reagents over primary ones, reactions in THF in the presence of LiCl led to opposite results, with higher reactivity of primary organozinc reagents.

Simple and robust method for the synthesis of Metopimazine by utilising smile’s rearrangement. Elimination of genotoxic impurities via derivatization

Within this study, the influence of particles of different types, natures, and sizes on the mechanical and corrosion resistance of pigmented systems containing spherical zinc was studied. For this study, prominent representatives from the group of transition metal dichalcogenides (MoS2, WS2), layered transition metal oxides (MoO3, WO3), and other semiconductor materials (ZnS and ZnO) were used. The layered ultra-thin structure of these particles was predisposed to provide enhanced mechanical and anti-corrosion performance. The mechanical properties of the studied coatings were tested using standardized mechanical tests, while the anti-corrosion performance of these coatings was studied using standardized cyclic corrosion tests and the linear polarization electrochemical technique. The results of the experimental techniques bring completely original knowledge about the action of these pigments in paint systems pigmented with zinc. The results of experimental techniques have shown enhancement and an increase in both mechanical and anti-corrosion performance when using these special types of inorganic pigments. In particular, with organic coatings pigmented with MoO3, there was an increase in mechanical resistance mainly due to its morphology and layered structure. In addition, a significant enhancement of the anti-corrosion efficiency was noted for this type of organic coating due to the enhancement of individual types of action mechanisms typical and proven for zinc-pigmented systems. These original findings can be used in the search for possibilities to reduce the zinc content in zinc-pigmented organic coatings. This partial replacement of zinc particles leads not only to a reduction in the zinc content in the system but also to a significant strengthening of the mechanical resistance and an increase in the corrosion efficiency of the system.

Abstract This work presents artificial neural network (ANN) models to determine explosion severity parameters (e.g., maximum explosion pressure and maximum rate of pressure rise) of given dust samples. ANN‐based models for explosibility parameters are presented for carbon black, zinc, urea, and oat grain flour dust samples based on data generated in a 20‐L explosion chamber. The optimal hyper‐parameters of the models have been explored using the Broyden–Fletcher–Goldfarb–Shanno, stochastic gradient descent, and Adam solvers. A hazard and operability study has also been conducted for each of the following to diagnose issues at different stages in developing the ANN‐based dust explosibility models: dust testing, model selection, parameter learning, and evaluation. Using different guidewords, the deviation of numerous factors from their design intent, causes, consequences, and specific safeguards have been provided for enabling optimal performance. This can be helpful in understanding, evaluating, and analyzing dust explosions for safer operation of industrial activities handling combustible dusts.

In this study, an array of environmentally friendly and heavy-duty anticorrosion composite coatings were prepared. The synthesis involved amine-capped aniline trimer (ACAT) produced by an oxidative coupling reaction and graphene oxide (GO) prepared based on Hummer's method, and later, the waterborne epoxy thermoset composite (WETC) coatings were prepared by thermal ring-opening polymerization of EP 147w, a commercial waterborne epoxy resin, in the presence of ACAT and/or GO with zinc dust (ZD). A synergistic effect was observed by replacing a significant amount of the ZD loading in the WETC by simultaneously incorporating a small amount of ACAT and GO. The electrochemical corrosion measurements of the as-prepared WETC coatings indicated that incorporating 5% w/w ACAT or 0.5% w/w GO separately replaced approximately 30% w/w or 15% w/w of the ZD, respectively. Moreover, the WETC coatings containing 5% w/w ACAT and 0.5% w/w GO simultaneously were found to replace 45% w/w of the ZD. A salt spray test based on ASTM B-117 also showed a consistent trend with the electrochemical results. Incorporating small amounts of ACAT and GO in WETC coatings instead of ZD not only maintains the anticorrosion performance but also enhances adhesion and abrasion resistance, as demonstrated by the adhesion and abrasion tests.

Recovery of high-grade cobalt oxide from zinc plant residue (ZPR) generated at zinc processing plants

This article presents the findings of research on the impact of thermal diffusion galvanizing duration and the particle size of zinc dust waste in the galvanizing mixture on the properties and structure of the zinc coating. The study focuses on coating characteristics, such as microstructure and particle distribution.