A 15N, 13C, and 1H NMR study of reaction products from arylguanidines and chloroformate esters

1991 ◽  
Vol 56 (7) ◽  
pp. 1505-1511 ◽  
Author(s):  
Antonín Lyčka ◽  
Karel Palát
Keyword(s):  
1H Nmr ◽  
H Nmr ◽  

The 15N, 13C, and 1H NMR spectra of the reaction products from arylguanidines with two mols of chloroformate esters have been measured. With application of the corresponding 15N isotopomer it has been proved that the reaction products have the structures IIIa-IIIc.

1977 ◽  
Vol 32 (9) ◽  
pp. 1033-1037 ◽  
Author(s):  
Anton Lerf ◽  
Paul Burkert ◽  
Jürgen O. Besenhard ◽  
Robert Schöllhorn

H NMR spectra of different hydration stages show that the water molecules in hydrated layered niobium sulfides A0.5(H2O)y[NbS2] are rather mobile at room temperature. A structural scheme of water arrangement in the interlayer space is proposed with the C2-axis of the H2O molecules parallel to the basal planes of the NbS2 layer units.


1996 ◽  
Vol 51 (5) ◽  
pp. 691-697 ◽  
Author(s):  
W. Lübbe ◽  
W. Preetz

By reaction of [B6H6]2- with ω,ω′-dibromo-o-xylene in acetonitrile the 1,2-xylylenepentahydro-closo-hexaborat, cis-[B6H5(CH2)2C6H4]- , is formed. The new ansa compound has been separated from excess [B6H6]2- and other reaction products by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structures of cis-[P(C6H5)4][B6H5(CH2)2C6H4] (I) and as-[(n-C4H9)4N][B6H5(CH2)2C6H4] (II) have been determined by single crystal X-ray diffraction analysis: I is monoclinic, space group P 21/n with a = 13.715(5), b = 11.118(1) and c = 19.702(2) Å, β = 103.47(2)°; II is orthorhombic with a = 10.204(7), b = 13.352(4) and c = 20.824(8) Å. The 11B NMR spectrum confirms the structure with a hetero disubstituted octahedral B6 cage with local C2v symmetry. The 13C and 1H NMR spectra have been assigned in term of such a configuration. The IR and Raman spectra exhibit characteristic CH, BH, BC, B6 and arene vibrations.


1982 ◽  
Vol 47 (2) ◽  
pp. 384-391 ◽  
Author(s):  
Otomar Kříž ◽  
František Mareš ◽  
Bohuslav Čásenský

Sodium tetraamidoaluminate reacts with alcohols and aromatic amines under formation of sodium alkoxyimidoaluminates or amido(arylamido)aluminates, respectively. The corresponding sodium amido(alkylamido)aluminates were prepared from sodium tetraamidoaluminate and sodium tetrakis(alkylamido)aluminates in 1,2-dimethoxyethane or pyridine solution. 1H NMR spectra and in some cases also the cryoscopic molecular weights of the prepared compounds were measured.


1998 ◽  
Vol 63 (7) ◽  
pp. 977-989 ◽  
Author(s):  
Aleš Růžička ◽  
Vladimír Pejchal ◽  
Jaroslav Holeček ◽  
Antonín Lyčka ◽  
Klaus Jacob

119Sn, 15N, 13C, and 1H NMR spectra were studied for [2-(dimethylaminomethyl)phenyl]stannanes, R1R2R3R4Sn or R1R2R24Sn, where R1, R2, and R3 are 1-butyl, Cl or Br, the same or different, and R4 is 2-(dimethylaminomethyl)phenyl. The occurrence of intramolecular interaction between the nitrogen and tin atoms was demonstrated based on changes in the characteristic values of the NMR parameters of these nuclides (δ(15N), δ(119Sn), J(119Sn,15N), and their interrelations, as well as on the relatively high values of the coupling constants 3J(119Sn,13C(CH2)).


1995 ◽  
Vol 60 (2) ◽  
pp. 251-256
Author(s):  
Karel Nálepa ◽  
Aleš Halama ◽  
Taťjana Nevěčná ◽  
Vojtěch Bekárek

1H NMR spectra have been measured of seven 3,5-disubstituted 6-oxo-1,6-dihydro-1,2,4-triazines, and tautomerism of these compounds has been evaluated in connection with the nature of substituents, medium, and temperature. The title compounds exist in their benzyl or benzylidene forms or as a mixture of both forms. Thermodynamic characteristics of the transition between the two forms have been determined from the temperature dependence of NMR spectra of three derivatives.


1997 ◽  
Vol 13 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Fadhil S. Kamounah ◽  
Salam J. Titinchi

The abundance1H-NMR spectra of some new mono- and diacetyl compounds derived from 2,2′-dimethyl-, 3,3′-dimethyl-, and 4,4′-dimethylbiphenyls were recorded. Unambiguous signal assignment of the methyl groups of the aromatic biphenyl rings were made for the structure elucidation.


1997 ◽  
Vol 62 (8) ◽  
pp. 1169-1176 ◽  
Author(s):  
Antonín Lyčka ◽  
Jaroslav Holeček ◽  
David Micák

The 119Sn, 13C and 1H NMR spectra of tris(1-butyl)stannyl D-glucuronate have been measured in hexadeuteriodimethyl sulfoxide, tetradeuteriomethanol and deuteriochloroform. The chemical shift values have been assigned unambiguously with the help of H,H-COSY, TOCSY, H,C-COSY and 1H-13C HMQC-RELAY. From the analysis of parameters of 119Sn, 13C and 1H NMR spectra of the title compound and their comparison with the corresponding spectra of tris(1-butyl)stannyl acetate and other carboxylates it follows that in solutions of non-coordinating solvents (deuteriochloroform) the title compound is present in the form of more or less isolated individual molecules with pseudotetrahedral environment around the central tin atom and with monodentately bound carboxylic group. The interaction of tin atom with oxygen atoms of carbonyl group and hydroxyl groups of the saccharide residue - if they are present at all - are very weak. In solutions in coordinating solvents (hexadeuteriodimethyl sulfoxide or tetradeuteriomethanol), the title compound forms complexes with one molecule of the solvent. Particles of these complexes have a shape of trigonal bipyramid with the 1-butyl substituents in equatorial plane and the oxygen atoms of monodentate carboxylic group and coordinating solvent in axial positions.


1999 ◽  
Vol 23 (1) ◽  
pp. 48-49
Author(s):  
Martín A. Iglesias Arteaga ◽  
Carlos S. Pérez Martinez ◽  
Roxana Pérez Gil ◽  
Francisco Coll Manchado

The assignment of 13C and 1H NMR signals of synthetic (25 R)-5α-spirostanes is presented; the main effects on chemical shifts due to substitution at C-23 are briefly discussed.


1989 ◽  
Vol 44 (9) ◽  
pp. 1117-1123 ◽  
Author(s):  
Jasmin Jakupovic ◽  
Siegfried Huneck

The 1H NMR spectra of the following lichen substances have been correlated by NOE difference spectroscopy: atranorin, barbatic acid, diffractaic acid, nephroarctin, perlatolic acid, planaic acid methyl ester, pseudocyphellarin A, sphaerophorin (depsides), hypoprotocetraric acid, lobaric acid, pannarin, physodalic acid, psoromic acid, stictic acid (depsidones), picrolichenic acid (depsone), di-O-methyl-pannaric acid dimethylester, pannaric acid, porphyrilic acid, schizopeltic acid, strepsilin, and usnic acid (dibenzofurans).


2008 ◽  
Vol 3 (5) ◽  
pp. 1934578X0800300
Author(s):  
Dongmin Su ◽  
Jinglan Han ◽  
Shishan Yu ◽  
Hailin Qin

The 1H NMR fingerprints of fractionated non-polar extracts (CSPD A) from the roots of Angelica sinensis of six different specimens were assigned by comparison with the 1H NMR spectra of the isolated pure compounds. The 1H NMR fingerprints showed exclusively characteristic resonance signals of the major constituents of the plant. The 1H NMR fingerprint established for an authentic sample of A. sinensis can be used for authenticating A. sinensis species.


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