Eine 15N-NMR-untersuchung einiger trimethylstannylhydrazine / A15N-NMR study of some trimethylstannylhydrazines

1989 ◽  
Vol 44 (6) ◽  
pp. 653-658 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Theo Gasparis-Ebeling ◽  
Heinrich Nöth
Keyword(s):  
Nmr Spectroscopy ◽  
Lone Electron Pair ◽  
Electron Pair ◽  
Relative Magnitude ◽  
Coupling Constants ◽  
15N Nmr ◽  
Nmr Study ◽  
Geminal Coupling ◽  
In Cis ◽  
First Time

The trimethylstannylhydrazines (Me3Sn)2N-NMe2 (1), Me3Sn(Me)N-N(Me)SnMe3 (2), (Me3Sn)2N-N(Me)SnMe3 (3), and (M e3Sn)2N-N(Ph)SnMe3 (4) have been studied by δ15N NMR at natural abundance. A correlation between δ15N of hydrazines and δI5N of corresponding am ines (replacement of one N-atom by the CH-unit) is proposed in order to estimate δI5N values and to support the non-trivial assignment of 15N resonances of hydrazines. Geminal coupling constants 2J(119SnN 15N) have been observed for the first time. Their relative magnitude is related to the probability of the N-Sn bond being in cis-position with respect to the orientation of the lone electron pair at the 15N nucleus in the 119Sn-N-15N fragment. Treatment of 4 with phenylacetylene causes non-selective cleavage of the Sn-N bonds, leading to the trim ethylstannylhydrazines 5 and 6 which have been characterized by 119Sn and 15N NMR spectroscopy in solution

Synthese und Multikern-NMR-Spektroskopie einiger vier-und fünfgliedriger Zinn—Stickstoff-Heterocyclen / Synthesis and Multinuclear NMR Spectroscopy of Some Four-and Five-Membered Tin —Nitrogen Heterocycles

1988 ◽  
Vol 43 (6) ◽  
pp. 707-714 ◽  
Author(s):  
Carin Stader ◽  
Bernd Wrackmeyer ◽  
Dieter Schlosser
Keyword(s):  
Nmr Spectroscopy ◽  
Lone Electron Pair ◽  
Electron Pair ◽  
Chemical Shifts ◽  
Nitrogen Heterocycles ◽  
Spiro Compounds ◽  
Coupling Constants ◽  
Ring Size ◽  
Multinuclear Nmr Spectroscopy ◽  
Cyclic Compounds

Tin-nitrogen heterocycles [1,3,2,4λ2-diazasila- (1), -λ4-stannetidines (2), spiro-compounds (3, 4), 1,3,2λ4,4λ4-diazadistannetidines (5), 1,3,4,5,2λ2-diazadisila- (6) and -λ4-stannolidines (7)] have been characterized by 13C, 15N, 29Si and 119Sn NMR spectroscopy [chemical shifts δX and coupling constants nJ(119Sn-X) (n = 1, 2, 3; X = 13C, 15N, 29Si, 119Sn]. The influence of the ring size becomes apparent in particular by comparison of the various coupling constants. In the compounds 1 and 6 the presence of a two-coordinate tin atom is reflected by the extremely low shielding of the 119Sn nuclei and also by the reduced shielding of the 29Si nucleus. The comparison with δ(29Si) data for corresponding non-cyclic compounds indicates that the latter effect may be traced to intra-annular interactions in 1 and 6 which involve the lone electron pair at the tin atom.

14N Nuclear Quadrupole Coupling Constants of Acetamide and α-Fluoroacetamide

1993 ◽  
Vol 48 (7) ◽  
pp. 787-792 ◽  
Author(s):  
N. Heineking ◽  
H. Dreizler
Keyword(s):  
Lone Electron Pair ◽  
Electron Pair ◽  
Coupling Constants ◽  
Rotational Spectra ◽  
Quadrupole Coupling ◽  
Full Coupling ◽  
Nuclear Quadrupole ◽  
First Time ◽  
Hyperfine Structures ◽  
Nitrogen Lone Electron Pair

Abstract The 14N nuclear quadrupole hyperfine structures in the rotational spectra of acetamide, CH3CONH2 , and α-fluoroacetamide, FCH2CONH2 , have been resolved. From the observed patterns, the quadrupole coupling constants have been determined with high precision. The results provide evidence of considerable derealization of the nitrogen lone electron pair. For acetamide, the full coupling tensor has been determined from a combined analysis of the ground and first excited state of the methyl group internal rotation. The spectrum of α-fluoroacetamide-[15N] has been obtained for the first time, and a refined structure is proposed.

Notizen: 15N NMR Study of Tris(dimethylamino)phosphine Derivatives: (Me2N )3PSe, (Me2N)3PTe and (Me2N)3PBH3

1984 ◽  
Vol 39 (4) ◽  
pp. 533-534 ◽  
Author(s):  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectroscopy ◽  
Coupling Constants ◽  
15N Nmr ◽  
Dipolar Interactions ◽  
Nmr Study ◽  
Phosphine Derivatives

The title compounds have been studied by 11B, 15N, 31P, 77Se and 125Te NMR spectroscopy (δ-values, coupling, constants). The 15N relaxation is dominated by 15N-1H dipolar interactions whereas nuclear screening anisotropy controls the 125Te relaxation.

scholarly journals Homopiperazine (Hexahydro-1,4-diazepine)

Molbank ◽  
10.3390/m1200 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1200
Author(s):  
R. Alan Aitken ◽  
Dheirya K. Sonecha ◽  
Alexandra M. Z. Slawin
Keyword(s):  
13C Nmr ◽  
Title Compound ◽  
Coupling Constants ◽  
15N Nmr ◽  
Time Data ◽  
Nmr Spectrum ◽  
X Ray ◽  
First Time

The X-ray structure of the title compound has been determined for the first time. Data on its 1H–13C-NMR coupling constants and 15N-NMR spectrum are also given.

15N NMR study of amino-imino tautomerism in derivatives of 1,4-bis(substituted amino)-9,10-anthraquinones and 1,4-bis(substituted amino)-2,3-dihydro-9,10-anthraquinones

1987 ◽  
Vol 52 (3) ◽  
pp. 736-741 ◽  
Author(s):  
Antonín Lyčka ◽  
Libuše Havlíčková ◽  
Alois Koloničný ◽  
Josef Jirman
Keyword(s):  
Chemical Shifts ◽  
Coupling Constants ◽  
15N Nmr ◽  
Nmr Study ◽  
Derivatives Of ◽  
Tautomeric Mixture

The 15N chemical shifts and 1J(15N, H) coupling constants of 1,4-bis(substituted amino)-9,10-anthraquinones and 1,4-bis(substituted amino)-2,3-dihydro-9,10-anthraquinones indicate that these derivatives exist as true aminoderivatives except for 1,4-bis(phenylamino)-2,3-dihydro-9,10-anthraquinone which forms a tautomeric mixture of the amino and imino forms in deuteriochloroform and hexadeuteriodimethyl sulphoxide.

14N- und 15N-NMR-Spektroskopie von Diazaphospholen und die lineare Korrelation der chemischen Verschiebung von zweifach koordiniertem N und P / 14N and 15N NMR Spectroscopy of Diazaphospholes and the Linear Correlation of the Chemical Shift of Two-Coordinate N and P

1986 ◽  
Vol 41 (5) ◽  
pp. 553-559 ◽  
Author(s):  
Alfred Schmidpeter ◽  
Bernd Wrackmeyer
Keyword(s):  
Linear Correlation ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
15N Nmr ◽  
Ground State Structure ◽  
Nitrogen And Phosphorus ◽  
System A ◽  
Nmr Study ◽  
15N Nmr Spectroscopy ◽  
Scalar Relaxation

A systematic natural abundance 15N NMR study of diazaphospholes is presented for the first time, giving accurate values for chemical shifts, δN , and coupling constants J(31P15N), J(15N1H ). 14N NMR spectra can be used to predict the magnitude of 1J( 31P14N) if the broadening of the 31P resonance by scalar relaxation is known. The relaxation behaviour of the 14N nuclei corresponds to that found in azoles indicating a comparable electronic ground state structure. The comparison of the chemical shifts, δN, in the diazaphospholes with δN of corresponding triazoles reveals differences which can be traced to the N-P σ-bonds and to the influence o f the phosphorus atom on the π-system. A linear correlation δN/δP exists coordinate nitrogen and phosphorus, respectively.

Spatial dispersion of lone electron pairs? – Experimental charge density of cubic arsenic(iii) oxide

2015 ◽  
Vol 17 (16) ◽  
pp. 11020-11027 ◽  
Author(s):  
Piotr A. Guńka ◽  
Zygmunt Gontarz ◽  
Janusz Zachara
Keyword(s):  
Charge Density ◽  
Lone Electron Pair ◽  
Electron Pair ◽  
Spatial Dispersion ◽  
Electron Pairs ◽  
First Time ◽  
Experimental Charge Density

Lone electron pair dispersion into three separate domains in space is reported and discussed for the first time.

Metal Tetrahydroborates and Tetrahydroborato Metalates, 15 [1]. An 11B and 113Cd NMR Study of MBH4–CdCl2 Systems in Dimethylformamide and the X-Ray Structure of CdCl2 · 2 DMF

1990 ◽  
Vol 45 (11) ◽  
pp. 1463-1471 ◽  
Author(s):  
Gerald Linti ◽  
Heinrich Nöth ◽  
Martina Thomann
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Coordination Polymer ◽  
Ambient Temperature ◽  
Nmr Spectra ◽  
Carbonyl Oxygen ◽  
X Ray ◽  
Rapid Exchange ◽  
Nmr Study ◽  
In Cis

CdCl2 dissociates in dimethylformamide into the species Cd(DMF)62+, CdCl(DMF)5+ and CdCl3- as determined by 113Cd NMR spectroscopy. 11B and 113Cd NMR spectra of MBH4/CdCl2 solutions in this solvent show the presence of complexes [CdCl2-n(BH4)n+1]- with rapid exchange of BH4- and Cl- at ambient temperature. There is no evidence that Cd(BH4)2 is formed in a metathetical reaction.The crystal structure of CdCl2 · 2 DMF has been determined. It is a coordination polymer containing hexacoordinated Cd atoms with the DMF molecules in cis-position. Coordination of DMF occurs via the carbonyl oxygen atoms.

69/71Ga and 115In NMR Spectroscopy of Lithium Tetra(tert-butyl)gallate and -indate: Spin-Spin Coupling Constants 1J(69/71Ga,13C) and 1J(115In,13C)

2009 ◽  
Vol 64 (1) ◽  
pp. 41-46
Author(s):  
Bernd Wrackmeyer ◽  
Elena V. Klimkina
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Tert Butyl ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling ◽  
First Time

The 13C, 69/71Ga and 115In NMR spectra of lithium tetra(tert-butyl)gallate and -indate were measured under various conditions. It proved possible to determine for the first time the coupling constants 1J(69/71Ga,13C) = 182 Hz/232 Hz and 1J(115In,13C) = 310±10 Hz for these metallates under conditions for solvent-separated ions. DFT calculations [B3LYP/6-311+G(d,p)] were carried out for organogallium compounds such as tri(tert-butyl)gallium, trimethylgallium and tetramethylgallate in order to predict and confirm coupling constants 1J(Ga,13C).

Some Applications of Ultrahigh Resolution 15N NMR Spectroscopy

1998 ◽  
Vol 53 (4) ◽  
pp. 411-415 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Ēriks Kupče
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Absolute Magnitude ◽  
Natural Abundance ◽  
Coupling Constants ◽  
15N Nmr ◽  
Ultrahigh Resolution ◽  
Tert Butyl ◽  
15N Nmr Spectroscopy

Abstract Ultrahigh resolution 15N NMR spectra were measured for two nitroalkanes (MeNO2 la, tBuNO2 1c), two isocyanates (tBuNCO 2c, Me3SiNCO 2d), four isothiocyanates (MeNCS 3a, EtNCS 3b, tBuNCS 3c, Me3SiNCS 3d), one carbodiimide (Me3SiNCNSiMe3 4d), one keteneimine [Me3SiNCC(SiMe3)2 5d], two sulphinyl imides (tBuNSO 6c, Me3SiNSO 6d), and N-tert-butyl-pyrrole 7c, in order to determine coupling constants J(15N ,I3C) and isotope induced chemical shifts 1∆12/13C (15N) at the natural abundance of the isotopes. The values 1∆12/13C (15N) can be separated into two groups, one dealing with NC single and another one with NC double bonds. In each group (with few exceptions), the values 1∆12/13C (15N) become more negative with a decrease in the absolute magnitude of l1J(l5N ,13C)l. The corresponding values 1∆14/15N (13C) show a sim ilar behaviour. However, N-substituted pyrroles appear to be exceptional in this respect.

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