Assessment of electrostatic discharge sensitivity of nitrogen-rich heterocyclic energetic compounds and their salts as high energy-density dangerous compounds:A study of structural variables

Nitrogen-rich heterocyclic energetic compounds(NRHECs)and their salts have witnessed widespread synthesis in recent years.The substantial energy-density content within these compounds can lead to potentially dangerous explosive reactions when subjected to external stimuli such as electrical discharge.Therefore,developing a reliable model for predicting their electrostatic discharge sensitivity(ESD)becomes imperative.This study proposes a novel and straightforward model based on the presence of specific groups(-NH_(2) or-NH-,-N=N^(+)-O^(-)and-NNO_(2),-ONO_(2) or-NO_(2))under certain conditions to assess the ESD of NRHECs and their salts,employing interpretable structural parameters.Utilizing a comprehensive dataset comprising 54 ESD measurements of NRHECs and their salts,divided into 49/5 training/test sets,the model achieves promising results.The Root Mean Square Error(RMSE),Mean Absolute Error(MAE),and Maximum Error for the training set are reported as 0.16 J,0.12 J,and 0.5 J,respectively.Notably,the ratios RMSE(training)/RMSE(test),MAE(training)/MAE(test),and Max Error(training)/Max Error(test)are all greater than 1.0,indicating the robust predictive capabilities of the model.The presented model demonstrates its efficacy in providing a reliable assessment of ESD for the targeted NRHECs and their salts,without the need for intricate computer codes or expert involvement.

A new heterocyclic compound from Cyathula officinalis Kuan

A new heterocyclic compound,named 5,5 -diisobutoxy-2,2 -bifuran(1),and four known compounds(2-5) were isolated from the roots of Cyathula officinalis Kuan.Their structures were elucidated by spectroscopic methods.Among these compounds,5,5 - dibutoxy-2,2 -bifuran(2) was isolated for the first time from this plant.

A Reduced Mechanism for Flame Inhibition by Phosphorus-containing Compounds Based on Level of Importance Analysis

A reduced mechanism for propane/air combustion and its flame inhibition by phosphorus-containing compounds (PCCs) is constructed with the level of importance (LOI) method. The analysis is performed on solutions of freely propagating premixed flames with detailed chemical kinetics involving 121 species and 682 reactions proposed by Jayaweera et al. For the non-homogeneous reaction-diffusion system, the chemical lifetime of each species is weighted by its diffusion timescale, and the characteristic flame timescale is used to normalize the chemical lifetime. The definition of sensitivity in LOI is extended so that multi-parameters can be used as sensitivity targets. Propane, oxygen, dimethyl methylphosphonate (DMMP), and flame speed are selected to be perturbed for sensitivity analysis, the species with low LOI index are removed, and reactions involving the redundant species are excluded from the mechanism. A skeletal mechanism is obtained, which consists of 57 species and 268 elementary reactions. Calculations for laminar flame speeds, key flame radicals and catalytic cycles using the skeletal mechanism are in good agreement with those by using the detailed mechanism over a wide range of equivalence ratio undoped and doped with DMMP.

A Novel Eleven-membered Heterocyclic Compound from Algae Sargassum Vachell

A novel eleven-membered heterocyclic compound with high nitrogen has been isolated from the marine alga Sargassum vachell collected from the South China Sea. Its structure has been established by verity of spectroscopic techniques such as IR. EIMS. ID NMR. H-1-(HCOSY)-H-1. HMQC, HMBC.

Physical and chemical effects of phosphorus-containing compounds on laminar premixed flame

Phosphorus-containing compounds are the promising halon alternatives for flame inhibitions. However, some literatures suggested that the phosphorus-related inhibitors may behave as the unfavorable ones that will increase the burning velocity under lean-burn conditions, and this indeed posed potential threats to the fire prevention and fighting. To seek deeper insights into the reaction process, a numerical investigation was actualized to study the phosphorus-related effects on methane-air flames. By replacing a phosphorus-related inhibitor with the corresponding decomposed molecules, the detailed promoting and inhibiting effects of combustion were separated from the general chemical effect. A comparative study was carried out to identify the interaction between the two effects under different combustion conditions. It is observed that the promoting effect becomes the dominant factor during the reaction process when the equivalence ratio is smaller than 0.60. In this lean-burn condition, the exothermic reactions were faster than the others within the reaction chains due to the reduction of radical recombination in hydrocarbon oxidation. The results are believed to be useful for the further application and improvement of flame inhibitors.

^(31)P NMR Study on Some Phosphorus-Containing Compounds

31P NMR has become a widely applied spectroscopic probe of the structure of phosphorus-containing compounds. Meanwhile, the application of 31P NMR has been rapidly expanded to biochemistry and medicinal chemistry of phosphorus-containing compounds because the growing importance of the phosphorus compounds is now widely realized. We report here the results of 31P NMR study on some phosphorus-containing compounds, namely, O-alkyl O-4-nitrophenyl methyl phosphonates with different alkyl chain-length (MePO-n), 4-nitrophenyl alkylphenylphosphinates with different alkyl chain-length (PhP-n), diethyl phosphono- acetonitrile anion and diethyl phosphite anion . Our results indicate that 31P NMR can not only be applied to not only the study of the hydrolytic reactions of MePO-8 and PhP-8 but also be applied to the study of the presence of the anions of diethylphosphonoacetonitrile and diethyl phosphite in nucleophilic reactions.

Ab Initio Study of the Mechanism of Forming a Spiro-Si-heterocyclic Ring Compound Involving Ge from Cl_2Ge=Si:and Formaldehyde

The X2Ge=Si： （X = H, Me, F, reaction is a new area for the study of silylene between singlet CI2Ge=Si： and formaldehyde CI, Br, Ph, At...） is a new species. Its cycloaddition chemistry. The mechanism of cycloaddition reaction has been investigated with CCSD（T）//MP2/6-31G＊ method. From the potential energy profile, it can be predicted that the reaction has two competitive dominant reaction pathways. The reaction rule presented is that the two reactants firstly form a four-membered Ge-heterocyclic ring silylene through the [2＋2] cycloaddition reaction. Owing to the 3p unoccupied orbital of Si： atom in the four-membered Ge-heterocyclic ring silylene and the π orbital of formaldehyde forming a π-p donor-acceptor bond, the four-membered Ge-heterocyclic ring silylene further combines with formaldehyde to form an intermediate. Because the Si： atom in intermediate shows sp3 hybridization after transition state, the intermediate isomerizes to a spiro-Si-heterocyclic ring compound involving Ge via a transition state. Simultaneously, the ring strain of the four-membered Ge-heterocyclic ring silylene makes it isomerize to a twisted four-membered ring product. The research result indicates the laws of cycloaddition reaction between X2Ge=Si： （X = H, Me, F, C1, Br, Ph, Ar...） and the asymmetric g-bonded compounds, which are significant for the synthesis of small-ring and spiro-Si-heterocyclic ring compound involving Ge The study extends the research area and enriches the research content of silvlene chemistrv.

α-Oxo Ketene Dithioacetals Chemistry-A Facile Route to the Synthesis of Fused Heterocyclic Compounds

The fused heterocyclic compounds 2 : imidazo [1.2-a] pyriding 2a-c and pyrido [ 1 .2-a] pyrimidine 2d were obtained from the reaction of α-cinnamoyl ketene dibenzylthio acetals 1 with diamine. When α-cinnamoyl -a'-benzoyl ketene N. N-acetals 3a-b were treated by t-BuONa/t- BuOH Solution. 8- benzoyl-pyrido[1.2-a] pyrimidine 4 was produced.

Ab Initio Study of Mechanism of Forming a Si-heterocyclic Spiro-Sn-heterocyclic Ring Compound by Cycloaddition Reaction of Cl2Si=Sn: and Ethylene

X2Si=Sn:(X = H, Me, F, Cl, Br, Ph, Ar…) are new species of chemistry. The cycloaddition reaction of X2Si=Sn: is a new study field of stannylene chemistry. To explore the rules of cycloaddition reaction between X2Si=Sn: and the symmetric p-bonded compounds, the cycloaddition reactions of Cl2Si=Sn: and ethylene were selected as model reactions in this paper.The mechanism of cycloaddition reaction between singlet Cl2Si=Sn: and ethylene has been first investigated with the MP2/GENECP(C, H, Cl, Si in 6-311++G**;Sn in LanL2dz) method in this paper. From the potential energy profile, it could be predicted that the reaction has one dominant reaction channel. The reaction rule presented is that the 5p unoccupied orbital of Sn in Cl2Si=Sn: and the π orbital of ethylene forming a p→p donor-acceptor bond, resulting in the formation of an intermediate. Instability of the intermediate makes it isomerize to a four-membered Si-heterocyclic ring stannylene. Because the 5p unoccupied orbital of Sn atom in the four-membered Si-heterocyclic ring stannylene and the π orbital of ethylene form a p→p donor-acceptor bond, the four-membered Si-heterocyclic ring stannylene further combines with ethene to form another intermediate. Because the Sn atom in the intermediate shows sp3 hybridization after transition state, the intermediate isomerizes to a Si-heterocyclic spiro-Sn-heterocyclic ring compound. The research result indicates the laws of cycloaddition reaction between X2Si=Sn: and the symmetric π-bonded compounds. The study opens up a new research field for stannylene chemistry.

Ab Initio Study of the Mechanism of Forming a Spiro-Ge-heterocyclic Ring Compound Involving Si from Me_2Si=Ge: and Formaldehyde

X2Si=Ge： （X = H, Me, F, CI, Br, Ph, Ar...） is a new species. Its cycloaddition reaction is a new area for the study of germylene chemistry. The mechanism of cycloaddition reaction between singlet state Me2Si=Ge： and formaldehyde has been investigated with the CCSD（T）//MP2/cc-pvtz method. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule presented is that the two reactants first form a four-membered Si-heterocyclic ring germylene through the [2＋2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge： atom in the four-membered Si-heterocyclic ring germylene and the π orbital of formaldehyde form a π→p donor-acceptor bond, the four-membered Si-heterocyclic ring germylene further combines with formaldehyde to form an intermediate. Because the Ge atom in the intermediate undergoes sp^3 hybridization after transition state, then the intermediate isomerizes to a spiro-Ge-heterocyclic ring compound involving Si via a transition state. The research result indicates the laws of cycloaddition reaction between HzSi=Ge： and formaldehyde. It has important reference value for the cycloaddition reaction between X2Si=Ge： （X = H, Me, F, CI, Br, Ph, Ar…） and asymmetric to-bonded compounds, which is significant for the synthesis of small-ring and spiro-Ge-heterocyclic compounds involving Si. The study extends research area and enriches the research content of germylene chemistry.

CATALYTIC LABELLING AND ~3H NMR ANALYSES OF SOME AROMATIC AND HETEROCYCLIC COMPOUNDS

This paper described the ~3H NMR determination of the positions and content of 24 tritium labeled aromatic and heterocyclic compounds prepared by catalytic tritiation derivatives, pyrrole, 1,2,4-triazole, thiazole, benzothiazole, purine and derivatives, indole, indanol, piperidine and derivative, diphenylamine, N- phenylanthranilic acid, 8- OH- quinoline, naphthol, diphenylether have been tritiated by catalytic exchange method using tritiated water and platinum catalyst (from the dioxide and sodium borohydride), and the pattern of labelling has been assigned by ~3H NMR spectroscopy. The results show that this exchange process can give general labelling compounds at various time and temperatures. For 4-Br-diphenylether, Raney nickel was used instead of Pt as a catalyst.

Syntheses and Characterization of Heterocyclic Compounds of Zirconium ( Ⅳ )

The Zr-H bond of zirconocene hydridochloride was heterolyzed at room temperature by five compounds containing nitrogen and hydroxyl group to give Cp(Q)2ZrCl(1) (Cp = cyclopentadienyl and Q = 8-quinolinoyl ) , Cp (Q-Me )2ZrCl (2) , Cp(5,7-Br2Q)2ZrCl(3), Cp2(2-pyridoyl)ZrCl(4) , and Cp(2-aminoethanoyl)2ZrCl(5), which were characterized by elemental analysis, IR, and 1H NMR spectroscopy. The molecular structure of 1 was confirmed by X-ray diffraction determination. The crystal of 1 crystallized monoclinically, space group P21/n a= 0.9004(2), b=1.3961(2), c = 1. 6056(2) nm, β=99. 48(1)°? V=1. 9906 nm3, Z = 4, and Dc=1. 582 g/cm3. The coordination polyhedron around the Zr atom can be described as a distorted octahedron. The Zr-N bonds of 0. 2364(3) and 0. 2377(4) nm suggest that they are coordination bonds. The two planar 8-quinolinoyl groups as bidentate ligands chelate with Zr atom, forming a dihedral angle of 108. 4(1)°?

SYNTHESIS OF FUSED PHOSPHORUS HETEROCYCLIC COMPOUNDS(II)

Using cation exchange resin(D72,Amberlyst-15) as catalyst, Mannich-type reaction of 5-amino-1,2,4-triazole 1, containing guanidine substructure, provides an efficient synthesis of a new kind of bicyclic P- and N-containing compounds, 6-phospha-4,5,6-trihydroimidazolo [2,3-e] 1,2,4-triazole 4.

SYNTHESIS OF 6,7-METHYLENEDIOXY-3-THIA-1(2H,4H)ACRIDONE AND THE RELATED THIA-ACRIDINE-PUSED HETEROCYCLIC COMPOUNDS

6,7-Methylenedioxy-3-thia-1(2H,4H)acridone and the related acridine-fused quinolines and pyridines,and also their flavylium-perchlorates were synthesized.The structures of all these compounds prepared are characterized by elemental analysis.IR and H-NMR spectra.

CHARACTERIZATION OF SOME SCHIFF BASES OF HETEROCYCLIC COMPOUNDS AND THEIR TRANSITION METAL COMPLEXES

Some new Schiff bases were synthesized by the condensation of equimolar quantities of salicylaldehyde and 2-amino-5-phenylazo-pyridine or its derivatives in dry benzene(1):Metal complexes of the type ML_2and M'L_3 where M=Cu^(2+),Co^(2+),Ni^(2+),Mn^(2+)Pd^(2+),M'=Fe^(3+)and L=different newly synthesized monobasic Schiff bases were prepared in absolute ethanolic medium(2)and characterized by elementary analysis,conductance measurements,infrared spectra,electronic spectra,magnetic moments studies.

Electrophysiological and Inotropic Effects of Iodium-Heterocyclic Compound on lsolated Guinea Pig Papillary Muscles

The effects of iodium-heterocyclic compound（3,6-di-[dimethytamino]-dibcnzopyrodoniun formate,IHC-64）on the action potentials and contractile force of the isolatedguinca pig papillary muscles were investigatad.50 μmol/L IHC-64 only inhibited contractile forceand had no effect on APA,dv/dt max,APD50 and APD90 of fast action potentials in Tyrode’s so-lution.All of these parametres were depressed by further increasing concentration of IHC-64.InK-rich Tyrodc’s solution,the depressive action of IHC-64 on slow action potentials andcontractile force could be antagonized by incrcased extracellular calcium.These results suggesr thatIHC-64 inhibit not only slow calcium influx but also fast sodium influx,and it may.（?）new calci-urn channd blockcr.

Bright Blue Light-emitting Diodes Based on a Novel Fluorescent Dye Containing Heterocyclic Groups

Novel molecular material, 1-benzotlliazoly-3 -phenyl --pyrazoline (BTPP) was found to function as bright blue light emitting dye in organic electroluminescent device, and its optical and electric characteristics were investigated. This heterocyclic compound exhibited good characteristics of blue photoluminescence and electroluminescence, which had the emission peak at 450 nm. The single layer light-emitting devices using BTPP as light-emitting material dispersed in poly(N- vinylcarbazole) (PVK) and double layer ones using PBD as hole block layer above the light-emitting layer were fabricated using conventional spin-casting and vaccum vapour deposition methods. The introduction of PBD has enhanced electron injection and luminance efficiency, compared with the single layer LEDs.

Synthesis of 2-methoxy-6-oxo-1, 4, 2-diazaphosphorinane-2-oxide, A New Potential Antitumor Phosphorus Heterocycle Compound

2-methoxy-6-oxo-1, 4, 2-diazaphosphorinane-2-oxide 8, phosphorus counterpart of 2, 6-dioxopiperazine, was synthesized as antitumor agent. The new phosphorus heterocycle compound 8 is the key intermediate in the synthesis of phosphorus counterpart of bisdioxopiperazine.

基于福井函数方法的芳杂环化合物亲电取代反应位点预测及图形可视化教学应用

基于福井函数方法,利用Gaussian和Multiwfn软件预测了常见芳杂环化合物及取代芳杂环化合物的亲电取代反应位点,使之以可视化图像形式展现并应用于基础有机化学的教学实践。