Formamide Research Articles

Perovskite grain fusion strategy via controlled methylamine gas release for efficient and stable formamide-based perovskite solar cells

The effectiveness of post-treatment on formamide (FA)-based perovskites by applying methylammonium (MA) has not been reported so far, due to the formation of fatal δ-phase. Herein, we select a series of carboxyl compounds to form their MA salts, utilizing the volatile nature of MA+, so as to control the release of MA gas via an MA-gas-releasing secondary grain growth (MGR-SGG) technique, stabilizing FA-based perovskite while inhibiting the formation of photo-inactive δ-phase. After such a treatment, perovskite grains fuse into larger ones, forming perovskites with better crystallinity, while the remaining compounds, including the carboxyl molecules and the undecomposed MA salts left on the perovskite surface, present passivation effect. The synergetic effects are tuned by varying the carboxyl acid backbones, and the moderate OPEM exhibits suitable MA gas release rate and strong interaction with perovskite, therefore sufficiently diminish defect density, contributing to increased open-circuit voltages by more than 20 mV, and enhanced maximum power conversion efficiency from 21.3% (untreated cells) to 22.4% (MGR-SGG treated cells), along with promoted device stability.

Exploring the amide coupling of carboxylic acids with amines using green solvent limonene

Limonene was identified as green media for amide formation through quantum chemistry calculation. An environmentally benign and sustainable protocol for amide formation was developed with simple filtration without the need for extensive isolation and purification. Additionally, the scope and general compatibility of the proposed method were explored with aromatic and aliphatic substrates, giving moderate to excellent yields, and a gram-scale synthesis of SHP1 activator 3a-18 were easily performed for further biological evaluation.

An amide based polyvinyl alcohol / protic ionic liquid (PVA / PIL) gel electrolyte for supercapacitor applications

An aqueous gel based on polyvinyl alcohol (PVA) and a mixture of two nitrate salts, namely lithium nitrate (LiNO3) and pyrrolidinium nitrate, PIL (PyrrNO3) was prepared and used as an electrolyte. The gel electrolyte shows a high conductivity in the presence of formamide (FMD), which was studied as an organic additive in the gel at 5–400 % with respect to the salt content. Their electrochemical behaviors were examined by cyclic voltammetry, galvanostatic charge-discharge and an impedance technique at room temperature (17 °C). The 100 % of amide in the gel has shown a maximum ionic conductivity of 33 × 10−3 and 11.2 × 10−3 Scm−1 at 17 °C and −20 °C respectively. A two electrode supercapacitor (SC) was assembled and analyzed. The cycle life is improved by the additive over the bare gel, as evidenced by the galvanostatic cycling. The specific discharge capacitance of SC based on the 100 % of amide can be used for delivering 34.2, 27.3 and 21 Fg−1 at 1.5 V under a constant current density of 50, 100 and 500 mAg−1 respectively. Moreover, the SC efficiency was maintained at 95 %, and above as well as the capacity loss was minimized in the presence of the additive. This quasi solid-state supercapacitor will be capable of delivering an energy density of 12–13 Whkg−1and maximum power density of 0.60 kWkg−1 at 2 V. The results confirm that the capacitive enhancement is at the lower limit of the FMD.

Molecularly designed and synthesized of bright blue nitrogen-doped lignin-derived carbon dots applied in printable anti-counterfeiting

With the increased demand for green and sustainable development, the research of advanced biomass-based carbon dots (CDs) has drawn growing attention. Herein, a one-step green solvent integration strategy-assisted solvothermal method to preparing CDs from hydrolyzed lignin and ethylenediamine (EDA) in formamide (FA) was developed. The Schiff reaction between FA and EDA contributes to the formation of -C-N groups, further inducing the high photoluminescence quantum yield (up to 42.69 %)，obviously higher than NCDs prepared in H2O, EtOH and DMF systems (corresponding to H-NCDs, E-NCDs and D-NCDs, respectively). The analysis of structure, composition, photoluminescence (PL) behaviors and DFT calculations showed that F-NCDs have main blue fluorescent emission peak from 410 to 455 nm under 330–390 nm excitation due to the small sp2 structure in carbon core, and the large sp2 conjugated clusters and CO group related surface states leaded to the long wavelength emission. The F-NCDs with excellent optical properties was further used for preparing fluorescent film and invisible anti-counterfeiting ink, which exhibited outstanding fluorescence even at different temperatures and aging times. We provided a facile way for green facile preparation of lignin-based CDs and their sustainable anti-counterfeiting application.

Synthesis of Mono and Bis-Substituted Compounds 1-(2-hydroxybenzylidene) Carbonohydrazide and 1, 5-bis(2-Hydroxybenzaldehyde) Carbohydrazone: Study Spectroscopy and X-ray Diffraction

The unsymmetric monocarbonohydrazide Schiff base (H5L1) (1) and the symmetric dicarbonohydrazone (H4L2) (2) were prepared from a monocondensation reaction between carbonohydrazide and 2-hydroxybenzaldehyde, respectively, in 1/1 and 1/2 ratio. The compounds were characterized by elemental analysis, 1H and 13C NMR and FTIR spectroscopy. The NMR and FTIR data analysis revealed that compounds (1) and (2) are in the amide form in the solid state as well as in DMSO solution. The molecular structure of each Schiff base compound has been elucidated by single crystal X-ray diffraction analysis. Compound H5L1 (1) crystallizes in the monoclinic system in P21/c space group with cell parameters: a = 17.0790(2) Å, b = 11.07410(10) Å, c = 10.56110(10) Å, b = 106.5730(10) °, V = 1914.49(3) Å3 , Z = 4, R1 = 0.0432, wR2 = 0.1275 . The compound H4L2 (2) crystallizes in the orthorhombic system in C2221 space group with cell parameters; a = 4.5494 (1) Å, b = 12.2213 (2) Å, c = 27.4001 (6) Å, V = 1523.43 (5) Å3 , Z = 4, R1 = 0.039 , wR2 = 0.125 . Both compounds exhibit inter and intramolecular hydrogen bonds which consolidate the structures into three-dimensional networks.

Detection of H2O2 using Carbon Nanotubes Covalently Attached to Nanostructured Au Electrode

Detection of hydrogen peroxide (H2O2) has practical significance in various fields, including pharmaceutical, clinical and food industries. The enzyme based H2O2 biosensors allow for the detection at lower potentials, thus avoiding possible interference from reducing agents. However, this type of sensors is inherently less stable, difficult to fabricate and more expensive. Due to high electroactive surface area and electrocatalytic properties, gold nanoparticles and their combination with carbon nanotubes (CNTs) are commonly used in H2O2 sensor design.To avoid fabrication inconveniences and improve stability of a H2O2 sensor, we designed a new hybrid material in which CNTs are covalently attached to a gold surface. First, a highly homogeneous nanostructured gold surface was formed on top of the SiO2 substrate with an intermediate layer of Ti, using E-beam evaporation technique. The average height of the gold nanostructures was 3.9 nm. The gold surface was then electrochemically grafted with aminophenyl groups. Further, plasma-functionalized densified CNT film made from CNT array was attached to the gold surface via amide formation reaction. An introduction of CNTs led to a 40-fold increase in current response. Formation of nanostructured gold surface without actual attachment of nanoparticles to the substrate, as well as covalent bonding of CNTs to the surface, provide a very high stability of the fabricated material, which, in turn, improves the repeatability of measurements.A designed electrode was used for non-enzymatic H2O2 detection. Under optimized parameters of square wave voltammetry and optimum pH, analysis of H2O2 can be performed using 5 independent oxidation peaks. The presence of multiple peaks is due to oxidation of gold, CNTs and H2O2 itself. All peaks increase when H2O2 is added in solution, because of chemical reduction of CNT and gold surfaces, and their consecutive electrochemical oxidation. Using the peak at -0.6 V allows for the H2O2 detection at very low potential, that can minimize interference from various reducing agents. For the -0.6 V peak, the limit of detection was 1.4 mM. Using the peak at -0.05 V allows for much higher sensitivity with the limit of detection of 500 nM.Almost no signal deterioration was observed after 200 measurements, proving high stability of the fabricated electrodes.

Dynamic structural analysis-based epitope prediction of Exendin-4 in aqueous solution.

The study of epitopes has a broad range of applications in drug discovery, vaccine design, and immunotherapy. In this study, an epitope prediction method was developed based on the dynamic structure of protein antigens. Solvent accessible surface area, charge, and root mean square fluctuation were introduced as the key residue property parameters. The epitope prediction algorithm was established by constructing a three-parameter complex metrics of seven-peptide groups. The method was applied to predict the epitopes of Exendin-4, an effective antidiabetic drug. The epitopes of both the natural and C-terminal amidated forms of Exendin-4 were predicted and compared in their folded and intermediate states. In the folded state, the epitopes of natural Exendin-4 (His1-Phe6 and Asp9-Val19) were found to be nearly identical to the epitopes of C-terminal aminated Exendin-4 (His1-Thr7 and Asp9-Val19). In the intermediate state, however, the epitopes of natural Exendin-4 (His1-Gly4, Phe6 and Lys12-Arg20) covered fewer amino acids than the epitopes of C-terminal aminated Exendin-4 (His1-Gly4, Phe6, Asp9-Val19 and Trp25-Lys27). The comparison with the results from other prediction tools demonstrates the reliability of our predicted epitopes of Exendin-4.

N-Acetylcysteine Amide against Aβ-Induced Alzheimer's-like Pathology in Rats.

Oxidative stress with a depletion of glutathione is a key factor in the initiation and progression of Alzheimer's disease (AD). N-Acetylcysteine (NAC), a glutathione precursor, provides neuroprotective effects in AD animal models. Its amide form, N-Acetylcysteine amide (NACA), has an extended bioavailability compared to NAC. This study evaluates the neuroprotective effects of NACA against Aβ1-42 peptide-induced AD-like pathology in rats. Male Wistar rats (2.5 months old) were divided into five groups: Normal Control (NC), Sham (SH), Aβ, Aβ + NACA and NACA + Aβ + NACA (n = 8 in all groups). AD-like pathology was induced by the intracerebroventricular infusion of Aβ1-42 peptide into the lateral ventricle. NACA (75 mg/kg) was administered either as a restorative (i.e., injection of NACA for 7 consecutive days after inducing AD-like pathology (Aβ + N group)), or as prophylactic (for 7 days before and 7 days after inducing the pathology (N + Aβ + N group)). Learning and memory, neurogenesis, expression of AD pathology markers, antioxidant parameters, neuroprotection, astrogliosis and microgliosis were studied in the hippocampus and the prefrontal cortex. All data were analyzed with a one-way ANOVA test followed by Bonferroni's multiple comparison test. NACA treatment reversed the cognitive deficits and reduced oxidative stress in the hippocampus and prefrontal cortex. Western blot analysis for Tau, Synaptophysin and Aβ, as well as a histopathological evaluation through immunostaining for neurogenesis, the expression of neurofibrillary tangles, β-amyloid peptide, synaptophysin, neuronal morphology and gliosis, showed a neuroprotective effect of NACA. In conclusion, this study demonstrates the neuroprotective effects of NACA against β-amyloid induced AD-like pathology.

Diisocyanate‐based chain extension via Mg(II) catalyzed amide formation to high‐molecular‐weight poly(lactic acid)

AbstractA simple chain‐extension reaction using diisocyanate as a chain extender was adopted to increase the molecular weight of low‐molecular‐weight (LMW) poly(lactic acid) (PLA) synthesized via direct polycondensation and to recover the molecular weight of commercial PLA after service life. The slow reaction between diisocyanate and the carboxylic acid terminus of PLA was successfully accelerated using a Mg(II) catalyst, affording a linear chain‐extended PLA (cePLA) connected through amide bonds. To increase the number of amide bonds, which exhibit higher thermal stability than the urethane bonds that are formed in the more common chain‐extension reactions between isocyanates and the hydroxy terminus of PLA, a telechelic LMW‐PLA having carboxylic acid groups at both termini was prepared. Subsequent reaction of this LMW‐PLA with diisocyanate in the presence of a Mg(II) catalyst afforded a cePLA with high molecular weight (Mw > 180 × 103 g/mol) and enhanced stability against thermal degradation, while showing identical mechanical properties and biodegradability as commercial PLA.

Exploring the Crystal Structure Landscape of Sulfasalazine through Various Multicomponent Crystals.

Sulfasalazine is used as an anti-inflammatory drug to treat large intestine diseases and atrophic arthritis. In the solid state, two tautomers are known: an amide tautomer (triclinic polymorph) and an imide tautomer (monoclinic polymorph). Crystallization of six new multicomponent solids of sulfasalazine with three cocrystal formers and three salt formers has been achieved by slurry, liquid-assisted grinding and slow evaporation methods. All of the solid forms are characterized by X-ray diffraction techniques, thermal analysis, and Fourier transform infrared spectroscopy. The crystal structural analysis reveals that two sulfasalazine molecules or anions arrange in a head-to-head fashion involving their pyridyl, amide, and sulfonyl groups in an R22(7):R22(8):R22(7) motif. This is the key structural unit appearing in both sulfasalazine imide polymorph and all six multicomponent crystals. In addition, sulfasalazine exists in the amide form in all unsolvated multicomponent crystals obtained in this work and adopts the imide tautomer in the solvated cocrystals and salt. Hirshfeld surface analysis and the associated two-dimensional (2D) fingerprint plots demonstrate that sulfasalazine has significant hydrogen bond donor capability when cocrystallized and is a significant hydrogen bond acceptor in the salts. The frontier molecular orbital analysis indicates that sulfasalazine cocrystals are chemically more stable than the salts.

1,5,7-Triazabicyclo[4.4.0]dec-5-ene: An Effective Catalyst for Amide Formation by Lactone Aminolysis.

The amide is one of the most prevalent functional groups throughout natural and engineered chemical space. Among various methods of constructing amide bonds, lactone aminolysis remains one of the most atom economical. Herein, we report 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as an effective catalyst for lactone aminolysis under mild conditions. This methodology is compatible with a wide range of lactones and amines (>50 examples), including various natural products and pharmaceuticals, and applicable to the synthesis of bioactive molecules. Detailed mechanistic studies under synthetically relevant conditions, including reaction progress kinetic analysis and variable time normalization analysis, reveal a likely mechanism for this reaction involving acyl-TBD as the reactive intermediate.

Enhancement of the Catalytic Activity of Lithium Amide towards Ammonia Decomposition by Addition of Transition Metals

The catalytic decomposition of ammonia to hydrogen is a vital process in the use of ammonia as a zero-carbon energy store. However, the viability of current catalyst systems in terms of operating conditions, versatility, and cost efficiency has proven an issue. Catalytic and gravimetric studies were conducted considering mechanistic uncertainty surrounding the enhanced catalytic activity reported for lithium amide and imide composited with transition metals (Cr, Mn, Fe). Gas flow in excess of ammonia decomposition was quantified and used to differentiate the extent of formation of non-stoichiometric lithium imide amide from other competing processes. This analysis showed the initial compositional transition from lithium amide to an imide-rich phase was reduced in temperature by compositing with Mn and Cr, but not with Fe. The system is, therefore, best considered as promoted lithium imide, with Cr and Mn acting to reduce the formation temperature of the active imide-rich phase such that the catalytic activity is enhanced.

The effect of gamma-irradiation on absorption spectrum of fluorescein dye

In this study, the fluorescein dye was dissolved in the solvent Dimethyl Form amide (DMF). Weighed equivalent to 0.0664, 0.0996 and 0.132 gm from the material. Using 5mM of solvent, each weight of the substance was dissolved separately to obtain the concentration 60 and 80 mM respectively. The effects of both concentration and gamma radiation on optical spectrum of all samples were investigated at room temperature. After irradiation and within the different concentration percentage at fix dose (4.7 KGy), where the results showed increase absorbance with increase concentration (40, 60 and 80 mM). Also, it is found that the decrease absorbance spectrums at wavelength 460 and 487 nm with increase dose and the good stability absorbance spectrum with time. Because of this, the structures in question are regarded as an efficient material for carrying out real-time gamma radiation dosimetry at ambient temperature.

One-step synthesis of novel carbon dots through cross amide formation of benzene-1,3,5-triamine and trimethyl 1,3,5-benzenetricarboxylate for fluorescence Hg2+ detection

Herein, we rationally designed and synthesized novel green-emitting fluorescent carbon dots (CDs) through cross amide formation of two precursors, benzene-1,3,5-triamine trihydrochloride and trimethyl 1,3,5-benzenetricarboxylate, under hydrothermal treatment. The average particle size of the CDs was ∼2.7 nm with graphitic carbon structures. The obtained CDs showed good photoluminescent properties with a quantum yield of up to 11.2%. The carbon dots showed good fluorescence sensitivity and selectivity for Hg2+, and the LOD and LOQ values were 17.5 pM and 58.3 pM in the range of 0.1–0.8 μM, which could be successfully applied to Hg2+ detection in real water samples as well as intracellular Hg2+ fluorescence detection.

A facile approach for sulphur and nitrogen co-doped carbon nanodots to improve photothermal eradication of drug-resistant bacteria

In this study, we produced S, N co-doped CNDs (SN@CNDs) by using dimethyl sulfoxide (DMSO) and formamide (FA) as single sources of S and N, respectively. We varied the S/N ratios by adjusting the volume ratios of DMSO and FA and investigated their effect on the red-shift of the CNDs' absorption peak. Our findings demonstrate that SN@CNDs synthesized using a volume ratio of 5:6 between DMSO and FA exhibit the most significant absorption peak redshift and enhanced near-infrared absorption performance. Based on comparative analysis of the particle size, surface charge, and fluorescence spectrum of the S@CNDs, N@CNDs, and SN@CNDs, we propose a possible mechanism to explain the change of optical properties of CNDs due to S, N doping. Co-doping creates a more uniform and smaller band gap, resulting in a shift of the Fermi level and a change in energy dissipation from radioactive to non-radiative decay. Importantly, the as-prepared SN@CNDs exhibited a photothermal conversion efficiency of 51.36% at 808 nm and demonstrated exceptional photokilling effects against drug-resistant bacteria in both in vitro and in vivo experiments. Our facile method for synthesizing S and N co-doped CNDs can be extended to the preparation of other S and N co-doped nanomaterials, potentially improving their performance.

Sodium Nitrate/Formamide Deep Eutectic Solvent as Flame‐Retardant and Anticorrosive Electrolyte Enabling 2.6 V Safe Supercapacitors with Long Cyclic Stability

Safe operation of electrochemical capacitors (supercapacitors) is hindered by the flammability of commercial organic electrolytes. Non‐flammable Water‐in‐Salt (WIS) electrolytes are promising alternatives; however, they are plagued by the limited operation voltage window (typically ≤2.3 V) and inherent corrosion of current collectors. Herein, a novel deep eutectic solvent (DES)‐based electrolyte which uses formamide (FMD) as hydrogen‐bond donor and sodium nitrate (NaNO3) as hydrogen‐bond acceptor is demonstrated. The electrolyte exhibits the wide electrochemical stability window (3.14 V), high electrical conductivity (14.01 mS cm−1), good flame‐retardance, anticorrosive property, and ultralow cost (7% of the commercial electrolyte and 2% of WIS). Raman spectroscopy and Density Functional Theory calculations reveal that the hydrogen bonds between the FMD molecules and ions are primarily responsible for the superior stability and conductivity. The developed NaNO3/FMD‐based coin cell supercapacitor is among the best‐performing state‐of‐art DES and WIS devices, evidenced by the high voltage window (2.6 V), outstanding energy and power densities (22.77 Wh kg−1 at 630 W kg−1 and 17.37 kW kg−1 at 12.55 Wh kg−1), ultralong cyclic stability (86% after 30 000 cycles), and negligible current collector corrosion. The NaNO3/FMD industry adoption potential is demonstrated by fabricating 100 F pouch cell supercapacitors using commercial aluminum current collectors.

Highly Conductive Inkjet-Printed PEDOT:PSS Film under Cyclic Stretching.

Inkjet-printed conductive polymer PEDOT:PSS films have provided a new developing direction for realizing the stretchable transparent electrodes in optoelectronic devices. However, their conductivity and stretchability are limited as the presence of insulating PSS chains, rigid PEDOT conjugated backbone, and stronger inter-chain interactions in the pristine polymer, respectively. Here, we report a PEDOT:PSS film with preferable electrical and mechanical performances by inkjet-printing the formulated printable ink containing PEDOT:PSS, formamide (FA), d-sorbitol (SOR), sodium dodecyl benzene sulfonate (DBSS), and ethylene glycol (EG). The inkjet-printed uniform PEDOT:PSS film exhibits a high conductivity of 1050 S/cm and sheet resistance of less than 145 Ω/sq on both rigid and flexible substrates. Moreover, the resistance can remain stable after 200 cycles of stretching at 55% strain. The film also presents good stability during repetitive stretching-releasing cycles. The significantly enhanced conductivity of the film lies on the conformational transition of the backbone by secondary doping and post-treatment with FA as well as removing the excess PSS components after phase separation between PEDOT and PSS. Meanwhile, SOR serves as a plasticizer to break the original hydrogen bonds between PSSH chains and provides larger free volume for polymer chain extension, which gives the PEDOT:PSS film the ability to tolerant cyclic tension. This is one of the optimal performances currently reported for inkjet-printed stretchable PEDOT:PSS films. The inkjet-printed PEDOT:PSS film with high conductivity, stretching properties, as well as good biocompatibility exhibits promising prospects as anodes on optoelectronic devices.

Waste-Derived Iron Nanoparticles for Solvent-Free Single-Step Reductive Acetylation of Nitroarenes

A simple and single-step synthetic protocol is reported here for synthesizing medicinally important amide compounds such as acetanilide (N-phenylacetamide) and its derivatives (including paracetamol and phenacetin). Compared to the existing reports used for a single-step amidation that requires multiple reagents, herein, waste-derived iron nanoparticles (FeOx-NPs) isolated from the “free-of-cost available iron dust/powder” were used for the same single-step amidation reaction without using any external reagents and high pressure, resulting in the cost-effective viable reported procedure. The Soxhlet-purified iron dust is subjected to high-temperature heating at ∼800 °C in a muffle furnace to achieve its heterogeneously active form (Fe3O4-type moieties on its surface). The as-prepared catalyst (FeOx-NPs) has been used to synthesize 17 acetanilide derivatives including two essential antipyretic drugs, paracetamol and phenacetin, on a gram scale, and one industrially important dye/pigment precursor (2-nitroacetanilide). Based on the X-ray photoelectron spectroscopy and vibrating sample magnetometry results, a possible mechanism has been proposed. The sustainability associated with the whole process is the direct amide formation using a magnetically separable waste-derived metal catalyst in solvent-free conditions, which provides a possible way to utilize large-scale industrial waste, thus directly reducing some environmental stress.

Synthesis and Characterization of Multi-Reducing-End Polysaccharides.

Site-specific modification is a great challenge for polysaccharide scientists. Chemo- and regioselective modification of polysaccharide chains can provide many useful natural-based materials and help us illuminate fundamental structure-property relationships of polysaccharide derivatives. The hemiacetal reducing end of a polysaccharide is in equilibrium with its ring-opened aldehyde form, making it the most uniquely reactive site on the polysaccharide molecule, ideal for regioselective decoration such as imine formation. However, all natural polysaccharides, whether they are branched or not, have only one reducing end per chain, which means that only one aldehyde-reactive substituent can be added. We introduce a new approach to selective functionalization of polysaccharides as an entrée to useful materials, appending multiple reducing ends to each polysaccharide molecule. Herein, we reduce the approach to practice using amide formation. Amine groups on monosaccharides such as glucosamine or galactosamine can react with carboxyl groups of polysaccharides, whether natural uronic acids like alginates, or derivatives with carboxyl-containing substituents such as carboxymethyl cellulose (CMC) or carboxymethyl dextran (CMD). Amide formation is assisted using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM). By linking the C2 amines of monosaccharides to polysaccharides in this way, a new class of polysaccharide derivatives possessing many reducing ends can be obtained. We refer to this class of derivatives as multi-reducing-end polysaccharides (MREPs). This new family of derivatives creates the potential for designing polysaccharide-based materials with many potential applications, including in hydrogels, block copolymers, prodrugs, and as reactive intermediates for other derivatives.

Effect of Sodium on the Evolution of Nitrogen Functionalities During Coal Pyrolysis : A Quantitative Experimental and Theoretical Investigation

ABSTRACT Understanding the migration and transformation of nitrogen during high-alkali coal pyrolysis and the influence of sodium on the nitrogen-containing components of coal is of great significance for the clean and efficient utilization of coal. In this study, gas chromatography-mass spectrometry (GC-MS), X-ray photoelectron spectroscopy (XPS) and ultraviolet visible spectroscopy (UV-Vis) were used to analyze the conversion of tar-N, char-N and gas-N during coal pyrolysis and the effect of sodium on the nitrogen-containing pyrolysis products of coal. The experimental results were combined with density functional theory (DFT) calculations to investigate the effect of sodium on the internal conversion process of char-N. The results revealed that a large amount of Na (2.5 wt.%, 3.5 wt.%) can reduce the nitrogen content in coal pyrolysis char, promote the formation of amine and amide in tar-N and inhibit the release of gaseous nitrogen. A small amount of Na (0.5 wt.%, 1.5 wt.%) retains nitrogen in char, reducing the total amount of nitrogen-containing species in the gas phase and tar, which is an effective means to inhibit the transformation of nitrogen to volatile matter. In addition, a large amount of Na promotes the conversion of pyrrole nitrogen (N-5) and pyridine nitrogen (N-6) in char to heterocyclic N in tar. A small amount of sodium promotes the hydrogenation and ring opening of heterocyclic-N in tar to HCN. Na promotes the conversion of N-5 and N-6 in char. DFT calculations further confirmed that the addition of Na significantly reduced the energy barrier of the rate determining step by about 36.6 kJ/mol.