scholarly journals Nitration of Chitin Monomer: From Glucosamine to Energetic Compound

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7531
Author(s):  
Hui Dou ◽  
Yuxuan Zheng ◽  
Manyi Qu ◽  
Peng Chen ◽  
Chunlin He ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Nitric Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Elemental Analysis ◽  
Specific Impulse ◽  
Solid Propellants ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energetic Compound

The nitration of chitin monomer in a mixture of nitric acid and acetic anhydride was conducted and a highly nitrated (3R,4R,6R)-3-acetamido-6-((nitrooxy)methyl)tetrahydro-2H-pyran-2,4,5-triyl trinitrate (1) was obtained. Its structure was fully characterized using infrared spectroscopy, NMR spectroscopy, elemental analysis, and X-ray diffraction. Compound 1 possesses good density (ρ: 1.721 g·cm−3) and has comparable detonation performance (Vd: 7717 m·s−1; P: 25.6 GPa) to that of nitrocellulose (NC: Vd: 7456 m·s−1; P: 23 GPa; Isp = 239 s) and microcrystalline nitrocellulose (MCNC; Vd: 7683 m·s−1; P: 25 GPa; Isp = 250 s). However, Compound 1 has much lower impact sensitivity (IS: 15 J) than the regular nitrocellulose (NC; IS: 3.2 J) and MCNC (IS: 2.8 J). Compound 1 was calculated to exhibit a good specific impulse (Isp: 240 s), which is comparable with NC (Isp: 239 s) and MCNC (Isp: 250 s). By replacing the nitrocellulose with Compound 1 in typical propellants JA2, M30, and M9, the specific impulse was improved by up to 4 s. These promising properties indicate that Compound 1 has a significant potential as an energetic component in solid propellants.

A novel octa-nuclear 32-membered zirconocene macrocycle based on the aromatic selenite

2017 ◽  
Vol 46 (2) ◽  
pp. 524-528 ◽  
Author(s):  
Nian-Tao Yao ◽  
Ru-Fen Zhang ◽  
Shao-Liang Zhang ◽  
Qian-Li Li ◽  
Chun-Lin Ma
Keyword(s):  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Esi Ms ◽  
Cyclopentadienyl Anion ◽  
C Nmr

A novel macrocyclic zirconocene(iv) aromatic selenite [(CpZr)8L16]·2(Cp4Zr2(μ-O)Cl2) (complex 1) (Cp = cyclopentadienyl anion; L = 4-fluorobenzeneseleninic acid) was prepared by the reaction of bis(cyclopentadienyl)zirconium dichloride with 4-fluorobenzeneseleninic acid and characterized by elemental analysis, infrared spectroscopy, 1H, 13C NMR spectroscopy, ESI-MS, XRD and X-ray diffraction.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

An Intramolecular Boron Nitrogen Lewis Acid Base Pair on a Rigid Naphthyl Backbone

2012 ◽  
Vol 67 (6) ◽  
pp. 589-593 ◽  
Author(s):  
Daniel Winkelhaus ◽  
Beate Neumann ◽  
Norbert W. Mitzel
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Lewis Acid ◽  
Elemental Analysis ◽  
Base Pair ◽  
Ring System ◽  
X Ray Diffraction ◽  
Acid Base ◽  
X Ray ◽  
Boron Nitrogen

The reaction of (C6F5)2BCl with 8-lithio-N,N-dimethyl-1-naphthylamine (1) afforded the fivemembered ring system 8-bis(pentafluorophenyl)boryl-N,N-dimethyl-1-naphthylamine (2) with an intramolecular dative B-N bond. The compound was characterised by elemental analysis, NMR spectroscopy and single-crystal X-ray diffraction.

scholarly journals Synthesis, Structure, and Properties of a Dinuclear Cu(II) Coordination Polymer Based on Quinoxaline and 3,3-Thiodipropionic Acid Ligands

2021 ◽  
Author(s):  
Adedibu Clement Tella ◽  
Samson Owalude ◽  
Vincent Adimula ◽  
Adetola Oladipo ◽  
Victoria Olayemi ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Nitrogen Atom ◽  
Coordination Polymer ◽  
Elemental Analysis ◽  
Catalytic Reduction ◽  
Copper Acetate ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr

Abstract The coordination polymer [Cu2(TDPH)4(QNX)].DMF, (QNX = Quinoxaline; TDPH = 3,3-thiodipropionic acid), has been prepared by reaction of copper acetate, TDPH, and quinoxaline. The compound was characterized by elemental analysis, FTIR spectroscopy, and single-crystal X-ray diffraction. The crystal is monoclinic with a P21/n space group and dimensions of a = 12.889(3) Å, b = 14.983(4) Å, c = 14.091(3) Å, α = 90 °, β = 90.200(11) °, γ = 90 °, V = 2721.18 (2) Å3, Z = 4. The ligands are hexagonally coordinated to the Cu(II) centre in the form of Cu2O4N with one nitrogen atom from the quinoxaline ligand, and four oxygen atoms from four TDPH molecules in a monodentate fashion. The Cu-Cu bond length was 2.642(1) and 2.629(1) Å for the Cu1----Cu1 and Cu2----Cu2 bonds. The QNX ligand bridged the two copper atoms. The catalytic reduction of 4-nitrophenol to 4-aminophenol using NaBH4 in the presence of [Cu2(TDPH)4(QNX)].DMF, as catalyst was completed within 11 minutes. The 4-aminophenol product was confirmed using 1H NMR spectroscopy.

Synthesis, Structure and Properties of Two-Dimensional Coordination Polymer Based on 3,5-di(benzimidazol-1-yl)pyridine

2020 ◽  
Vol 42 (2) ◽  
pp. 249-249
Author(s):  
Guo Jun Wu Guo Jun Wu
Keyword(s):  
Infrared Spectroscopy ◽  
Coordination Polymer ◽  
Single Crystal ◽  
Photocatalytic Degradation ◽  
Elemental Analysis ◽  
Solvothermal Reaction ◽  
Two Dimensional ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray

[Cu(L)(AIP)·1.5H2O]n (1) [L= 3,5-di(benzimidazol-1-yl)pyridine, H2AIP= 5-aminoisophthalic acid] was prepared by the solvothermal reaction, which was characterized by single-crystal X–ray diffraction, infrared spectroscopy, and elemental analysis. 1 exhibits an infinite two dimensional [Cu(AIP)]n sheet parallel to (0 1 1) crystal plane. Furthermore, complex 1 displays good photocatalytic degradation of methyl blue (MB).

Boron Carbide-Based Ceramics Via Polymer Route Synthesis

1991 ◽  
Vol 249 ◽  
Author(s):  
Haixing Zheng ◽  
Kevin Thorne ◽  
J.D. Mackenzie ◽  
Xiaoguang Yang ◽  
M.F. Hawthome
Keyword(s):  
Thermal Analysis ◽  
Infrared Spectroscopy ◽  
High Temperature ◽  
Nmr Spectroscopy ◽  
Physical Properties ◽  
Boron Carbide ◽  
X Ray Diffraction ◽  
Polymeric Precursors ◽  
X Ray ◽  
Crystalline Boron

ABSTRACTBoron carbide is a ceramic material with excellent high temperature physical properties. As compared to conventional techniques, the preparation of boron carbide from polymeric precursors is attractive as this technique offers a number of unique advantages. In this paper, the screening of polymeric precursors to boron carbide will be discussed. Two promising boron carbide, carborane containing polymeric precursors have resulted in 60-70 wt.% ceramic yields. The chemistry of polymer synthesis and the transformations from the polymer to amorphous and crystalline boron carbide were investigated with infrared spectroscopy, NMR spectroscopy, thermal analysis, and x ray diffraction.

Synthesis and Characterization of the nido-Platinaborane 7,7-(PPh3)2-7-PtB10H11-11-OC(O)Me

2011 ◽  
Vol 66 (4) ◽  
pp. 387-391
Author(s):  
Jinling Miao ◽  
Yong Nie ◽  
Haiyan Chen ◽  
Daqi Wang ◽  
Markus Enders ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Elemental Analysis ◽  
Chain Structure ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ir And Nmr Spectroscopy

The reaction of closo-B10H102− with PtCl2(PPh3)2 in the presence of MeCOSH afforded the title platinaborane nido-7,7-(PPh3)2-7-PtB10H11-11-OC(O)Me (1), which has been characterized by IR and NMR spectroscopy, MS, elemental analysis, and single-crystal X-ray diffraction. In contrast to the known products having exo-polyhedral Pt-S-C-O-B ring(s) from the same reaction with Ph- COSH, compound 1 has a B-acetoxy group on the open PtB4 face of the nido-PtB10 cluster. The structure of 1 features both intramolecular/intermolecular C-H· · ·O hydrogen bonds and intramolecular C-H· · ·H-B dihydrogen bonds, which link the molecules into a 1-D chain structure.

Synthesis of Sterically Demanding Bis(phosphinimine) Dibenzofuran Ligands and Subsequent Zinc Metalation

2015 ◽  
Vol 68 (3) ◽  
pp. 373 ◽  
Author(s):  
Matthew T. Zamora ◽  
Saif M. Zahir ◽  
Kevin R. D. Johnson ◽  
Clay J. Barnson ◽  
Craig A. Wheaton ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Ambient Temperature ◽  
Elemental Analysis ◽  
Elimination Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr ◽  
Sterically Demanding ◽  
Multinuclear Nmr Spectroscopy ◽  
Alkane Elimination

In light of previous success surrounding the use of bis(phosphinimine)dibenzofuran ligands for zinc-mediated lactide polymerization, a series of sterically demanding P=N pincer compounds have been prepared with important steric and electronic modifications at both P- and N-sites (L, 3a–d). These systems are highly crystalline and have been extensively characterized using multinuclear NMR spectroscopy, elemental analysis, and X-ray diffraction. The ligands can be transformed into their protonated analogues [HL][BArF4] (4a–d, [BArF4] = [B(m-(CF3)2-C6H3)4]) by reaction with Brookhart’s acid, and subsequently coordinated to zinc via an alkane elimination reaction with [ZnEt2] at ambient temperature to afford the corresponding [LZnEt][BArF4] cationic complexes 5a–d. In addition, an unusual chloridozinc species [LZnCl][BArF4] (5c′) has been isolated and structurally characterized, providing comparisons to previously established ligand sets with similar geometries.

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