High Chloride Research Articles

A Severe Case of Hypokalemic Metabolic Alkalosis: A Quiz

A Severe Case of Hypokalemic Metabolic Alkalosis: A Quiz

Association between urinary chloride excretion and progression of coronary artery calcification in patients with nondialysis chronic kidney disease: results from the KNOW-CKD study.

Urine chloride has recently been suggested as a biomarker of renal tubule function in patients with nondialysis chronic kidney disease (CKD), as low urinary chloride concentration is associated with an increased risk of CKD progression. We investigate the association between urinary chloride excretion and the progression of coronary artery calcification (CAC). A total of 1,065 patients with nondialysis CKD were divided into tertiles by spot urine chloride-to-creatinine ratios. The 1st, 2nd, and 3rd tertiles were defined as low, moderate, and high urinary chloride excretion, respectively. The study outcome was CAC progression, which was defined as an increase in coronary artery calcium score of more than 200 Agatston units during the 4-year follow-up period. Compared to moderate urinary chloride excretion, high urinary chloride excretion was associated with decreased risk of CAC progression (adjusted odds ratio, 0.379; 95% confidence interval, 0.190-0.757), whereas low urinary chloride excretion was not associated with risk of CAC progression. Restricted cubic spine depicted an inverted J-shaped curve, with a significant reduction in the risk of CAC progression in subjects with high spot urine chloride-to-creatinine ratios. High urinary chloride excretion is associated with decreased risk of CAC progression in patients with nondialysis CKD.

Combination of sequencing batch reactor and vertical flow treatment wetlands: A full-scale experience for rum distillery wastewater treatment in a tropical climate

Distillery wastewater is a difficult type of wastewater to treat because of its low pH (pH = 3.3), high chloride and sulfate content, high organic matter concentrations (3.2 gTSS/L, 6.8 gBOD5/L and 14.6 gCOD/L). Moreover, the rum production is intermittent over the season (5 months per year). The acidity of this type of wastewater, combined with the relatively underbalanced nitrogen concentrations, requires the addition of specific chemicals such as soda solution and urea, when a biological treatment technology is envisioned. In this full scale experiment, located in a tropical zone (Martinique island), the objective was to demonstrate the ability of treatment chain composed of a sequencing batch reactor (SBR) followed by vertical flow treatment wetlands (VFTWs). The objective was to use VFTWs for treatment polishing as well as sludge/water separation and sludge treatment over years. The VFTWs are planted with Heliconia psittacorum and Cyperus papyrus. The monitoring occurred during three rum production seasons. The treatment chain allows an overall average removal of TSS of 92% and 96% for organic matter (COD and BOD5). The average annual load applied to the filter in operation was 32 kgTSS/m²/y, which is equivalent to 78 kgTSS/m²/y over the distillation period. The applied load was too high for the plants tested and lead to plant death and surface clogging of the filters. Nevertheless, this experiment allowed specifying the way to operate the whole treatment plant as well as acceptable daily loads that should be applied on the VFTWs. Even if the operation of the filters and the selection of plants in a tropical climate still need to be optimized, this combination of intensive and extensive processes is an effective and sustainable nature-based solution for rum distillery wastewater treatment.

Effect of wastewater as sustainable concrete material on concrete performance: A critical review

A massive amount of water has been consumed to produce concrete. The lack of sufficient water for drinking and other essential processes reduces the quantity of water that should be delivered to the people because of the high water consumption by concrete production. All the waste from commercial buildings, households, institutions, and hospitals are known as wastewater. Generally, the water demand is anticipated to increase considerably in the near future. Energy and industry production are expected to witness essential rises in water demand. The enormous quantities of water and generating large quantities of various wastewater from different treatment processes led to exploring different ideas to overcome these issues. One of these ideas is the utilization of wastewater in the construction industry, particularly in concrete mixtures and curing. In the literature, a lack of sufficient studies is obtainable for concrete production from wastewater. This study reviews the chemical composition and physical properties of wastewater and the durability properties of concrete. The treated wastewater from sewage treatment plants (STP) is utilized acceptably for particular utilization. Using treated effluent (TE) in concrete improves cement paste's setting time and compressive strength more than drinking water. The concrete samples containing wastewater recorded 7%–27% lower porosity than control concrete because of the hydration process of cement with time, in addition to the pozzolan reactions. In terms of rapid chloride penetration examination, the authors detected that the samples containing wastewater recorded higher Coulomb charges than that of the control concrete sample without wastewater at 28 curing days because of the high chloride ions in wastewater than that of tap water. The chloride ion penetration increased due to an increase in the domestic wastewater content. Consequently, there is a critical need to improve various processes to adopt and use wastewater in concrete mixtures. This study recommends using a high volume of wastewater to get sustainable concrete with high performance.

Footprints in compositions, PCDD/Fs and heavy metals in medical waste fly ash: Large-scale evidence from 17 medical waste thermochemical disposal facilities across China.

Chemical compositions, polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) profiles and heavy metals (HMs) leachability of medical waste fly ash (MWFA) from 17 thermochemical treatment facilities in eight Chinese provinces were first investigated. Large-scale and extended monitoring revealed high chloride and Zn contents and similar PCDD/Fs congener profiles in MWFA. Particularly, the PCDD/Fs and HMs concentrations implied greater toxicity than that observed for municipal solid waste incinerator fly ash (MSWIFA). The maximum international toxic equivalent value of PCDD/Fs in MWFA was 40 times that of MSWIFA, and the leaching concentrations of Zn and Hg were 15 and 4 times those of MSWIFA, respectively. Notably, MWFA characteristics suggest the possibility of recycling and sustainable disposal solutions owing to the high Cl and Zn content with good recovery instead of landfill disposal. Similarities in chemical composition, PCDD/Fs homolog distribution, and water-solubility of chloride salts allows co-processing of MWFA and MSWIFA via water-washing detoxification and thermal treatment, such as that used in cement kilns. This study supplements existing literature on the characteristics and risk management of MWFA.

Effect of Polytetrafluoroethylene (PTFE) Content on the Properties of Ni-Cu-P-PTFE Composite Coatings

Q235B mild steel has the advantages of good mechanical properties, welding properties, and low cost, and it is widely used in bridges, energy fields, and marine equipment. However, Q235B low-carbon steel is prone to serious pitting corrosion in urban water and sea water with high chloride ions (Cl-), which restricts its application and development. Herein, to explore the effects of different concentrations of polytetrafluoroethylene (PTFE) on the physical phase composition, the properties of Ni-Cu-P-PTFE composite coatings were studied. The Ni-Cu-P-PTFE composite coatings with PTFE concentrations of 10 mL/L, 15 mL/L, and 20 mL/L were prepared on the surface of Q235B mild steel by the chemical composite plating method. The surface morphology, elemental content distribution, phase composition, surface roughness, Vickers hardness, corrosion current density, and corrosion potential of the composite coatings were analyzed by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), three-dimensional profile, Vickers hardness, electrochemical impedance spectroscopy (EIS), and Tafel curve test methods. The electrochemical corrosion results showed that the corrosion current density of the composite coating with a PTFE concentration of 10 mL/L in 3.5 wt% NaCl solution was 7.255 × 10-6 A∙cm-2, and the corrosion voltage was -0.314 V. The corrosion current density of the 10 mL/L composite plating was the lowest, the corrosion voltage positive shift was the highest, and the EIS arc diameter of the 10 mL/L composite plating was also the largest, which indicated that the 10 mL/L composite plating had the best corrosion resistance. Ni-Cu-P-PTFE composite coating significantly enhanced the corrosion resistance of Q235B mild steel in 3.5 wt% NaCl solution. This work provides a feasible strategy for an anti-corrosion design of Q235B mild steel.

Chemical vectoring in continental geothermal systems: Composition of altered rocks and illite as guides to magmatic degassing

The Taupō Volcanic Zone, New Zealand, is one of the most voluminous volcanic regions on Earth. Over the last 1.8 Myr, bimodal volcanism in this rifted-arc setting has been dominated by voluminous rhyolite ignimbrite eruptions (>6000 km3 cumulative) and minor arc-type andesite and dacite, underpinned by basaltic intrusions. The combination of the magmatism and extensionally thinned arc crust with high heat flow has resulted in more than 23 active geothermal fields in the region. The fluids sampled in the geothermal systems are dominated by dilute meteoric fluids that are low in components such as acids, alkalis, and some trace metals commonly ascribed to magmatic sources but can contain large amounts of deep sourced magmatic volatiles such as CO2.This study was designed to assess the long-term (>20,000yr) fluid and metal input into two Taupō geothermal systems, and the amount and proportion of magmatic-derived components in these fluids. We collected major and trace element compositions of hydrothermal altered whole rocks and clay minerals from two active geothermal systems and compared them with hydrothermally altered rocks of the fossil (0.6 Ma) Ngatamariki magmatic-hydrothermal system, which has a demonstrated large magmatic contribution. The Ohaaki and Rotokawa geothermal systems have both been drilled to a depth of 3000 m, with sampled reservoir fluids containing low concentrations of chloride (∼1000 mg/kg) but high levels of gas (CO2, N2) that have previously been interpreted to reflect subduction components derived from arc-type magmas. Whole-rock samples lack enrichment in chloride-transported metals such as Cu, Pb or Zn but have minor anomalies of bisulfide-complexed Au, Sb, and As in the uppermost 1500 m of the geothermal reservoirs. Hydrothermal water-rock interactions in the deep reservoirs of both geothermal systems at temperatures between 220 and 300 °C produced assemblages of illite + albite + adularia + calcite + pyrite that are in equilibrium with the observed neutral to slightly acidic pH (6 ± 1) of the present-day fluids. In the lower temperature end of this range, Mg and Fe increasingly enter the illite crystal lattice via Tschermak-type (phengite) substitution, whereas a few high-temperature (>300 °C) samples contain scarce muscovite compositions. The illites commonly have low contents of most trace metals, although minor amounts of Cs, Li, Cu, Sb and Sn occur in near-surface samples. Based on these data, over the >20,000-year lifetime of the Ohaaki and Rotokawa geothermal systems, fluids were dominated by chloride-poor meteoric water and contained little magmatic contributions other than conducted heat, some gases (CO2 - N2 ± H2S), and a small fraction of the total H2O of geothermal waters. Therefore, the inferred magma bodies of intermediate to silicic composition that lie at shallow depth beneath these geothermal systems currently are not, and likely have not been for >20,000 years, degassing significant water and chloride despite the high water and chloride contents of the magmas. By inference, the intermediate to silicic magmas at depth have not transferred large amounts of volatiles to the geothermal systems over this period, and rather are storing them in the magmatic bodies to be released in volcanic eruptions that are commonly explosive and pyroclastic in nature and highly hazardous.

Community-based serum chloride abnormalities predict mortality risk.

This population-based study aimed to investigate the prognostic value of ambulatory serum chloride abnormalities, often ignored by physicians. The study population included all non-hospitalized adult patients, insured by "Clalit" Health Services in Israel's southern district, who underwent at least 3 serum chloride tests in community-based clinics during 2005-2016. For each patient, each period with low (≤97 mmol/l), high (≥107 mmol/l) or normal chloride levels were recorded. A Cox proportional hazards model was used to estimate the mortality risk of hypochloremia and hyperchloremia periods. 664,253 serum chloride tests from 105,655 subjects were analyzed. During a median follow up of 10.8 years, 11,694 patients died. Hypochloremia (≤ 97 mmol/l) was independently associated with elevated all-cause mortality risk after adjusting for age, co-morbidities, hyponatremia and eGFR (HR 2.41, 95%CI 2.16-2.69, p<0.001). Crude hyperchloremia (≥107 mmol/L) was not associated with all-cause mortality (HR 1.03, 95%CI 0.98-1.09 p = 0.231); as opposed to hyperchloremia ≥108 mmol/l (HR 1.14, 95%CI 1.06-1.21 p<0.001). Secondary analysis revealed a dose-dependent elevated mortality risk for chloride levels of 105 mmol/l and below, well within the "normal" range. In the outpatient setting, hypochloremia is independently associated with an increased mortality risk. This risk is dose-dependent where the lower the chloride level, the higher is the risk.

Add a dash of salt? Effects of road de-icing salt (NaCl) on benthic respiration and nutrient fluxes in freshwater sediments

Winter road salt applications are increasing chloride concentrations in many freshwater ecosystems. This trend is alarming, giv¬en chloride’s potential to impair aquatic ecosystems. Short- and long-term exposure to salt could affect ecosystem metabolism and nutrient cycles. Here, we examine connections between chloride concentrations, water quality conditions, benthic respi¬ration, and sediment-water nutrient flux throughout a large (722 km2) lake and its catchment. Aquatic locations experiencing high concentrations of chloride are indicators of anthropogenic activities and are often associated with additional pollutants. We used sediment core flow-through incubations under ambient and enriched chloride concentrations to determine the effects of road salt on benthic respiration and nutrient fluxes in stream, stormwater pond, and lake sites. Salt (as sodium chloride) ad¬ditions caused a significant overall increase in benthic respiration. Acute exposure to road salt caused the strongest increase in benthic respiration when water was warm and at sites that had low (&lt; 50 mg Cl-/L) or high (&gt; 400 mg Cl-/L) ambient chloride concentrations or when water was cold and sites had intermediate (100-400 mg Cl-/L) ambient chloride concentrations. Nitrate flux responded less uniformly to salt additions. Depending on waterbody type and season, ambient nitrate flux into the sediment was similar, increased, or decreased post-chloride addition. Dissolved phosphorus flux was not significantly impacted by salt additions. Across lake and stream sites, our results supported the hypothesis that chloride causes increased respiration while nutrient cycles were weakly and inconsistently altered under experimental pulse road salt additions.

Super-hydrophilic/super-aerophobic Ni2P/Co(PO3)2 heterostructure for high-efficiency and durable hydrogen evolution electrocatalysis at large current density in alkaline fresh water, alkaline seawater and industrial wastewater

Seawater electrolysis has become an efficient method which makes full use of natural resources to produce hydrogen. However, it suffers high energy cost and chloride corrosion. Herein, we first present a Ni2P/Co(PO3)2/NF heterostructure in which Co(PO3)2 with the nano-rose morphology in-situ grown on the rough Ni2P/NF. The unique 3D nano-rose structure and the optimized electronic structure of the heterostructure enable Ni2P/Co(PO3)2/NF super-hydrophilic and super-aerophobic characteristics, and highly facilitate hydrogen evolution reaction (HER) kinetics in alkaline fresh water, alkaline seawater and even industrial wastewater at large current density, which is rarely reported. Significantly, at large current densities, Ni2P/Co(PO3)2/NF only requires overpotentials of 217 and 307 mV for HER to achieve 1000 mA cm−2 in alkaline fresh water and alkaline seawater, respectively, and requires an overpotential of 469 mV for HER to deliver 500 mA cm−2 in industrial wastewater. Furthermore, the overall seawater splitting system in the two-electrode electrolyzer only requires voltage of 1.98 V to drive 1000 mA cm−2, which also demonstrates significant durability to keep 600 mA cm−2 for at least 60 h. This study opens a new avenue of designing high efficiency electrocatalysts for hydrogen production at large current densities in alkaline seawater and industrial wastewater.

Corrosion Effects on the Seismic Vulnerability Index of Reinforced Concrete Scholar Buildings

The Veracruz - Boca del Río metropolitan area in Mexico presents high temperatures and even high chloride ion concentrations, causing an aggressive environment with significant corrosion rates. Therefore, in reinforced concrete buildings in said area, their service life and integrity can compromise. Rapid Screening Methods (RSM) are used to determine their Seismic Vulnerability Index (SVI). The Benedetti-Petrini RSM can be used to determine the SVI of the corroded structures, adapting how the state of conservation is evaluated and weighted. To that end, the corrosion level and the crack width were correlated to estimate how their state of conservation can be deteriorated, reducing the service life. To test its usefulness, nine faculties, whose ages are close to 50 years, were analyzed, and the SVI of the original and modified methods were compared. Additionally, as expected, the buildings close to the coastline, and the faces exposed to wind direction, were the most damaged. The results indicate that the modified SVI provides rational decisions and improves the action management for each structure.

Assessment of groundwater hydrogeochemical characteristics and salinization intrusion in coastal arid area (South Gabes, South-East Tunisia)

In the southern region of Gabes, groundwater is experiencing a quality deterioration in relation to the increase in demand to meet the various sectors of economic and agricultural activities. Indeed, the degradation of quality generally results in high concentrations of total dissolved solids, ranging from 2.44 to 13.68 g/L, and waters contamination by nitrates. The determination of the groundwater salinity origin from Gabes, largely influenced by tectonics, was approached from the study of the evolution in the space of major chemical elements and by statistical treatment. Based on these methods, this work aims to demonstrate that the high waters’ salinity in this aquifer is explained by an interaction between its waters and the evaporitic levels of the aquifer formation, by the marine intrusion around the El Hajel Wadi, and by the return of irrigation water to the Mareth-Arram region. The hypothesis of marine intrusion is justified by the high chloride content due to the presence of reverse reactions of cation exchange. Geochemical interactions (reverse basic exchanges and precipitation/dissolution phenomena of minerals from the aquifer formation) show that these waters have poor to bad quality.

Co2Mo6S8 Catalyzes Nearly Exclusive Electrochemical Nitrate Conversion to Ammonia with Enzyme-like Activity.

Electrocatalytic nitrate to ammonia conversion is a key reaction for energy and environmental sustainability. This reaction involves complex multi electron and proton transfer steps, and is impeded by the lack of catalyst for promoting both reactivity and ammonia selectivity. Here, we demonstrate active motifs based on the Chevrel phase Co2Mo6S8 exhibit an enzyme-like high turnover frequency of ∼95.1 s-1 for nitrate electroreduction to ammonia. We reveal strong synergy of multiple binding sites on this catalyst, such that the ligand effect of Co steers Had* toward hydrogenation other than hydrogen evolution, the ensemble effect of Co, and the spatial confinement effect that promote the full hydrogenation of NOx to ammonia without N-N coupling. The catalyst exhibits almost exclusive ammonia conversion with a Faradaic efficiency of 97.1% and ammonia yielding rate of 115.5 mmol·gcat-1·h-1 in neutral electrolytes. The high activity was also confirmed in electrolytes with dilute nitrate and high chloride concentrations.

Boosting Hydroxyl Radical Yield via Synergistic Activation of Electrogenerated HOCl/H2O2 in Electro-Fenton-like Degradation of Contaminants under Chloride Conditions.

Hydroxyl radical production via catalytic activation of HOCl is a new type of Fenton-like process. However, metal-chlorocomplex formation under high chloride conditions could deactivate the catalyst and reduce the process efficiency. Herein, in situ electrogenerated HOCl was activated to •OH via a metal-free, B/N-codoped carbon nanofiber cathode for the first time to degrade contaminant under high chloride condition. The results show 98% degradation of rhodamine B (RhB) within 120 min (k = 0.036 min-1) under sulfate conditions, while complete degradation (k = 0.188 min-1) was obtained in only 30 min under chloride conditions. An enhanced degradation mechanism consists of an Adsorb & Shuttle process, wherein adsorption concentrates the pollutants at the cathode surface and they are subsequently oxidized by the large amount of •OH produced via activation of HOCl and H2O2 at the cathode. Density functional theory calculations verify the pyridinic N as the active site for the activation of HOCl and H2O2. The process efficiency was also evaluated by treating tetracycline and bisphenol A as well as high chloride-containing real secondary effluents from a pesticide manufacturing plant. High yields of •OH and HOCl allow continuous regeneration of the cathode for several cycles, limiting its fast deactivation, which is promising for real application.

High extracellular sodium chloride concentrations induce resistance to LPS signal in human dendritic cells.

Recent evidence showed that in response to elevated sodium dietary intakes, many body tissues retain Na+ ions for long periods of time and can reach concentrations up to 200mM. This could modulate the immune system and be responsible for several diseases. However, studies brought contrasted results and the effects of external sodium on human dendritic cell (DC) responses to danger signals remain largely unknown. Considering their central role in triggering T cell response, we tested how NaCl-enriched medium influences human DCs properties. We found that DCs submitted to high extracellular Na+ concentrations up to 200mM remain viable and maintain the expression of specific DC markers, however, their maturation, chemotaxis toward CCL19, production of pro-inflammatory cytokines and ROS in response to LPS were also partially inhibited. In line with these results, the T-cell allostimulatory capacity of DCs was also inhibited. Finally, our data indicate that high NaCl concentrations triggered the phosphorylation of SGK1 and ERK1/2 kinases. These results raised the possibility that the previously reported pro-inflammatory effects of high NaCl concentrations on T cells might be counterbalanced by a downregulation of DC activation.

CQDs improved the photoelectrocatalytic performance of plasma assembled WO3/TiO2-NRs for bisphenol A degradation.

Carbon quantum dots (CQDs) have been supported on WO3/TiO2-NRs using a hydrothermal method and a novel CQDs/WO3/TiO2-NRs composite formed via dielectric barrier discharge. The composite electrodes were characterized using morphology, structural, optical and electrochemical analysis. The CQDs were successfully prepared on the composite electrode with the highest photocurrent density reaching 2.51mA·cm-2 under UV-visible light irradiation (100mW·cm-2) and an applied voltage of 0.6V vs. Ag/AgCl. The CQDs/WO3/TiO2-NRs electrode exhibited a good degradation effect toward bisphenol A (BPA) (75.66 %) combined with the production of hydrogen (0.89mmol) in Na2SO4 system after 2h of the photoelectrocatalytic (PEC) reaction and the BPA degradation rate reached 100 % after 7min of reaction in both simulated and real seawater. The CQDs/WO3/TiO2-NRs exhibited excellent stability and efficient PEC performance in which the CQDs acted as electron reservoirs to capture and promote charge separation. Our analysis of intermediates of BPA degradation indicated the possible degradation pathways that mainly formed BPA polymers in the Na2SO4 system or chlorinated compounds in the high chloride salt system.

Failure analysis of S13Cr-110 telescopic tube used in an ultra-deep gas well

The failure reason and stress corrosion cracking mechanism of S13Cr-110 telescopic tube used in an ultra-deep gas well are discussed based on physical and chemical properties, operating conditions and construction processes. The results show that: stress corrosion cracking occurred in S13Cr-110 telescopic tube during acid fracturing, the crack initiated from the bottom of the corrosion pit in the inner wall of the telescopic tube and the crack propagation mode is inter-granular cracking. The reason for cracking is that S13Cr-110, the telescopic tube material, is exposed to high-chlorine-containing acid environment for a long time in the acid fracturing process, and the corrosion inhibitor used at the temperature of ultra-deep well has poor corrosion inhibition effect, resulting in inter-granular crack originated from the bottom of the corrosion pit on the inner wall of the telescopic tube. During the subsequent acidizing operations, the telescopic tube sustained a high circumferential tensile stress, stress corrosion occurs, and the stress corrosion cracks expand rapidly. It is suggested that the S13Cr-110 pipe string used in acidic environments with high chloride concentrations should be selected with appropriate corrosion inhibitor based on well depth and formation temperature.

Jungle juice causing pseudohypercholesterolaemia

Background: A twenty-one-year old female presented to the emergency department with cyanosed lips after consuming 3– 5mL of Jungle Juice (pentyl nitrite) with seven standard drinks of ethanol over the course of six hours. Her skin appeared grey suggesting progressive hypoxaemia, blood paracetamol level was undetectable and urine drug screen (Roche Cobas c501) was negative for cannabinoids, barbiturates, amphetamines and opiates. Methylene blue was commenced immediately and a follow-up venous blood gas fourr hours after admission (Radiometer ABL 800) showed pH: 7.35, pO2: 20.4 mmHg, pCO2: 46.0 mmHg, Na: 143 mmol/L, K: 4.2 mmol/L, Cl: 119 mmol/L, bicarbonate: 24.8 mmol/L, creatinine: 92 umol/L, ionised Ca: 1.18 mmol/L and glucose: 5.4 mmol/L. Paired peripheral venous sample performed on the Roche Cobas c501 for electrolytes gave similar results, but the chloride was significantly different: 104 mmol/L. The calculated anion gap (AG) resulting from the ABL 800 is falsely low 3 (7–17), compared to 22 (7–17) from the Roche Cobas c501. Conclusion: This illustrates that nitrate from the metabolism of pentyl nitrite may be preferentially selected by chloride electrodes impregnated with certain ionophores, causing falsely high chloride levels. In an unconscious patient, this presents a challenge to clinicians to determine the cause.

A Visible Light Driven Nickel Carbonylation Catalyst: The Synthesis of Acid Chlorides from Alkyl Halides.

We describe here the development of a visible light driven nickel carbonylation catalyst. The combination of the large bite-angle Xantphos ligand with nickel(0) generates a catalyst capable of activating alkyl halides toward carbonylation at ambient temperature in the presence of blue light irradiation, and the reductive elimination of high energy acid chloride products. Unlike classical carbonylations, where the coordination of carbon monoxide inhibits the reactivity of earth abundant nickel catalysts, a CO-associated nickel is found to be the active catalyst in the reaction. Coupling the build-up of acid chlorides with nucleophile addition can be used to access various amides, esters and thioesters, including those of sterically encumbered substrates or with metal-reactive functionalities.

A Visible Light Driven Nickel Carbonylation Catalyst: The Synthesis of Acid Chlorides from Alkyl Halides

AbstractWe describe here the development of a visible light driven nickel carbonylation catalyst. The combination of the large bite‐angle Xantphos ligand with nickel(0) generates a catalyst capable of activating alkyl halides toward carbonylation at ambient temperature in the presence of blue light irradiation, and the reductive elimination of high energy acid chloride products. Unlike classical carbonylations, where the coordination of carbon monoxide inhibits the reactivity of earth abundant nickel catalysts, a CO‐associated nickel is found to be the active catalyst in the reaction. Coupling the build‐up of acid chlorides with nucleophile addition can be used to access various amides, esters and thioesters, including those of sterically encumbered substrates or with metal‐reactive functionalities.