Mass spectra and molecular structure. Part I. Correlation studies and metastable transitions

1968 ◽  
pp. 93 ◽  
Author(s):  
H. C. Hill ◽  
R. I. Reed ◽  
M. T. Robert-Lopes
Keyword(s):  
Molecular Structure ◽  
Mass Spectra ◽  
Correlation Studies

Molecular structure, Vibrational assignment, HOMO-LUMO and Mulliken analysis of 2-[4-amino-2-(4-methylphenylamino) thiazol-5-oyl]benzothiazole(AMPATOB)

2016 ◽  
Vol 2 (1) ◽  
pp. 38
Author(s):  
Dr A Yardily
Keyword(s):  
Molecular Structure ◽  
Mass Spectra ◽  
Density Functional ◽  
Dft Method ◽  
Dihedral Angles ◽  
Atomic Charges ◽  
Vibrational Assignment ◽  
Functional Theory ◽  
Wave Numbers ◽  
Homo Lumo

The compound 2-[4-amino-2-(4-methylphenylamino) thiazol-5-oyl]benzothiazole (AMPATOB) was prepared from 1-(4-methylphenyl)-3-(N-nitroamidino)thiourea and 2-(2-bromoacetyl)benzothiazole in the presence of triethylamine and characterised  by FTIR, NMR and mass spectra. The geometry of the molecule was investigated and optimized with the help of B3LYP/ 6-31G density functional theory (DFT) method using Gaussian 09 software package.The calculated geometries such as bond lengths, bond angles, dihedral angles, atomic charges, harmonic vibrational wave numbers and intensities of vibrational bonds of the titled compound were investigated. The experimental 1H NMR and IR spectrum was compared with theoretical value. The molecule consists of three ring systems, all are lying in one plane.

scholarly journals Searching molecular structure databases with tandem mass spectra using CSI:FingerID

2015 ◽  
Vol 112 (41) ◽  
pp. 12580-12585 ◽  
Author(s):  
Kai Dührkop ◽  
Huibin Shen ◽  
Marvin Meusel ◽  
Juho Rousu ◽  
Sebastian Böcker
Keyword(s):  
Molecular Structure ◽  
Mass Spectra ◽  
Metabolite Identification ◽  
Tandem Ms ◽  
Unknown Compound ◽  
Tandem Mass Spectra ◽  
Structure Database ◽  
Fragmentation Spectrum ◽  
Structure Databases ◽  
Fragmentation Tree

Metabolites provide a direct functional signature of cellular state. Untargeted metabolomics experiments usually rely on tandem MS to identify the thousands of compounds in a biological sample. Today, the vast majority of metabolites remain unknown. We present a method for searching molecular structure databases using tandem MS data of small molecules. Our method computes a fragmentation tree that best explains the fragmentation spectrum of an unknown molecule. We use the fragmentation tree to predict the molecular structure fingerprint of the unknown compound using machine learning. This fingerprint is then used to search a molecular structure database such as PubChem. Our method is shown to improve on the competing methods for computational metabolite identification by a considerable margin.

Relationship Between Radiation Stability and Molecular Structure of Nitramine Explosives

1992 ◽  
Vol 296 ◽  
Author(s):  
James J. Pinto
Keyword(s):  
Molecular Structure ◽  
Binding Energy ◽  
Mass Spectra ◽  
Bond Distance ◽  
Radiation Stability ◽  
Photoelectron Spectra ◽  
X Rays ◽  
First Order ◽  
First Order Kinetics ◽  
Cyclotrimethylene Trinitramine

AbstractThe radiation stabilities of the nitramine explosives 1,4-dinitroglycolurile (DINGU), 1,4-dimethyl-2,5-dinitroglycolurile (DMD) and hexanitrohexaazaisowurtzitane (HNIW) have been determined using XPS. Samples were exposed to x-rays for times up to eight hours while photoelectron spectra were recorded in the carbon, oxygen, and nitrogen Is energy regions and mass spectra were recorded of gases evolved during the decomposition process. These data are compared to the previously determined stabilities for cyclotrimethylene trinitramine (RDX) and cyclotetramethylene tetranitramine (HlMX). The N1s spectra of the irradiated materials show the NO2 peak decreases relative to the total nitrogen signal while low binding energy peaks grow. The rate of loss of the NO2 peak was fit to first order kinetics and the rate constants obtained show some correlation with the N-N bond strength as measured by the average N-N bond distance and the average NO2 asymetric stretch frequency. Despite the differences in structure of these molecules (DINGU and DMD are bicyclic rings, RDX and HMX are rings and HNIW is a cage) the radiation stability appears to be controlled by the strength of the N-N bond.

Reactions of Ru3(CO)12 with Ethyne: Molecular Structure of Ru2(µ-h1,h4:h1,h4-C8H8)(CO)4

1999 ◽  
Vol 52 (5) ◽  
pp. 413 ◽  
Author(s):  
Michael I. Bruce ◽  
Brian W. Skelton ◽  
Natasha N. Zaitseva ◽  
Allan H. White
Keyword(s):  
Molecular Structure ◽  
Mass Spectra ◽  
Ruthenium Complexes ◽  
The Other ◽  
Binuclear Complexes ◽  
X Ray ◽  
X Ray Crystallography

The reaction between Ru3(CO)12 and ethyne (refluxing tetrahydrofuran, 2 h) produced four binuclear complexes, Ru2(CO)m(C2H2)n [m = 4,n= 4 (1); m = 5,n= 4 (3); m = 7,n= 2 (2), 4 (4)], in low yield. The molecular structure of (1) has been determined by X-ray crystallography and consists of an Ru2(CO)4 group bridged by a C8H8 chain, attached in the µ−η1 ,η4 :η1 ,η4 mode. Structures for the other three complexes are suggested on the basis of their i.r. and mass spectra and similarities with analogous ruthenium complexes obtained from other alkynes.

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