Application of Reverse Two-Dimensional 1H{15N} NMR Spectroscopy to the Characterization of Two Inorganic Compounds:

1987 ◽  
Vol 42 (6) ◽  
pp. 703-706 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Klaus Schamel ◽  
Karlheinz Guldner ◽  
Max Herberhold
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shifts ◽  
Inorganic Compounds ◽  
Ring System ◽  
Coupling Constants ◽  
15N Nmr ◽  
Two Dimensional ◽  
Hydrogen Atoms ◽  
15N Nmr Spectroscopy

AbstractThe inorganic ring system linked to the [Cr(CO)5] fragment [R = tBu (1), NH2 (2)], has been studied by reverse two-dimensional, 2D, 1H{15N} NMR spectroscopy. In solution, the exchange of the N-H hydrogen atoms is slow on the NMR time scale. Chemical shifts δ(1H), δ(13C), δ(31P), δ(15N) and coupling constants 1J(31P1H), 2J(31P13C), 1J(31P15N) are reported. In the case of 2, the reduced coupling constants 2K(31PN1H) and 1K(31P15N) have the same sign.

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.

scholarly journals 15N—NMR-Spektroskopie bei Stickstoffwasserstoffsäure und Chlorazid / 15N NMR Spectroscopy at Hydrazoic Acid and Chlorine Azide

1978 ◽  
Vol 33 (9) ◽  
pp. 993-996 ◽  
Author(s):  
Joachim Müller
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
15N Nmr ◽  
Hydrazoic Acid ◽  
15N Nmr Spectroscopy

The 15N NMR spectra of HN3 and CIN3 solutions were recorded under triply labelled conditions. The chemical shifts and coupling constants are discussed with respect to the structure and in relation to other isoelectronic compounds.

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.

Anwendung der 15N-NMR-Spektroskopie zur Charakterisierung reaktiver, koordinativ ungesättigter Zinn-, Bleiund Phosphor-Stickstoff-Verbindungen / Application of 15N-NMR Spectroscopy to the Characterization of Reactive, Coordinatively Unsaturated Tin-, Lead- and Phosphorus-Nitrogen Compounds

1987 ◽  
Vol 42 (12) ◽  
pp. 1515-1519 ◽  
Author(s):  
Carin Stader ◽  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectra ◽  
Pulse Sequence ◽  
Coupling Constants ◽  
Spin Coupling ◽  
15N Nmr ◽  
Nmr Data ◽  
15N Nmr Spectroscopy ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

AbstractThe basic INEPT pulse sequence proved most useful for recording 15N NMR spectra at natural abundance of bis(amino)stannvlenes (1). -plumbylenes (2) and of imino-amino-λ2-phosphanes (3), where the nitrogen atoms carry bulky substituents like Me3Si-, t-Bu-, 2.4.4-trimethyl-2- pentyl-groups (t-Oct-groups) or are part of the 2.2.6.6-tetramethylpiperidinyl group. The sensitiv­ity of this technique is proved by the observation of 117/119Sn or 207Pb satellites owing to spin-spin coupling constants 1J(117/119Sn15N) and 1J(117/119Pb15N), respectively. NMR data of bis[bis(trimethylsilyl)methyl]tin (4) are reported in order to corroborate the arguments for the interpretation of the δ(15N) and 1J(119Sn15N) data. The 15N NMR data of the λ2-phosphanes (3) indicate a bonding situation similar to that in triazenes.

Cyclische Schwefeldiimide des Siliciums. 15N-NMR-Spektroskopie und die Röntgenstrukturanalyse des Achtrings tBu2Si(NSN)2SitBu2 / Cyclic Sulfur Diimides of Silicon. 15N NMR Spectroscopy and the X-Ray Analysis of the Eight-Membered Ring tBu2Si(NSN)2SitBu2

1993 ◽  
Vol 48 (8) ◽  
pp. 1041-1050 ◽  
Author(s):  
Max Herberhold ◽  
Silke Gerstmann ◽  
Wolfgang Milius ◽  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectroscopy ◽  
Pulse Sequences ◽  
Ring System ◽  
Membered Ring ◽  
Coupling Constants ◽  
Primary Amines ◽  
15N Nmr ◽  
Monoclinic Space Group ◽  
Small Magnitude ◽  
X Ray

Various six-membered cyclic sulfur diimides (3a—f) were prepared by aminolysis of the bis(chloro-dimethylsilyl)sulfur diimide (2) using NH3 (a) and primary amines RNH2 [R = Me (b), Et (c), nPr (d), nBu (e), iPr (f)]. Except for R = H, non-cyclic intermediates, the Si-monoamino- (7) and Si,Si′-diamino derivatives of 2 (8), were detetected for all groups R, including R = tBu (g). The reaction between R2SiCl2 and the sulfur diimide anion K[(NSN)SiMe3] gave non-cyclic silanes (9,10) and the eight-membered rings of the type R2Si(NSN)2SiR2 [R = Me (4), tBu (5)] of which 5 was studied by X-ray analysis (monoclinic, space group P21/c; planar ring system) and solid-state 15N and 29Si CP/MAS NMR spectroscopy. The ten-membered ring system 6 was obtained from the reaction between 1,2-dichlorotetramethyldisilane and bis(trimethylstannyl)sulfur diimide. All compounds were studied by 1H,13C, 15N and 29Si NMR. The δ15N NMR data proved useful to distinguish between fluxional systems with fast E/Z—Z/E isomerization (non-cyclic compounds 8 and the ten-membered cycle 6). Hahn-Echo-extended (HEED) polarization transfer (INEPT) pulse sequences served to measure coupling constants 1J(29Si15Namine) for the compounds 3 and 8. This also proved that the magnitude of 1J(29Si15NNSN) must be small (< 1 Hz). In the case of the compounds 3, the rather small magnitude of both 1J(29Si15Namine) and 1J(15N1H) (3a) indicated that the aminonitrogen atom adopts a pyramidal environment.

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