Struktur‐Reaktivitätsuntersuchungen mit heterosubstituierten Nitrilen—VII:¹³C‐, ¹⁴N‐ und ¹⁹F‐NMR‐Spektroskopische Untersuchungen an Verbindungen vom Typ ArXCN

Abstract

Abstract-The chemical shifts of aromatic nitriles of the general structure pnru-Y-C&-X-CN with X = 0, S, Se and N(CH3) have been investigated by the 13C NMR technique. For cyanates (X = 0) the 14N shifts and for Y = F the 19F shifts were likewise measured. The chemical shifts and the corresponding 13C shift increments A, have been found to correlate with the appropriate substituent constants uRo, oDo and oI, as well as with the n-electron densities calculated in the PPP approximation.Zusarnmenfassung-An aromatischen Ni trilverbindungen der allgemeinen Struktur pura-Y-C6H,-X-CN mit X = 0, S, Se und N(CH,) wurden die 13C-NMR-sowie fur X = 0 die 14N-NMRund fur Y = F die lSF-NMR-chemischenVerschiebungen bestimmt. Die Merjergebnisse wurden in Zusammenhang mit der elektronischen Struktur der Molekule (Substituentenkonstanten, TElektronendichten in PPP-Naherung) diskutiert.

Synthesis, spectroscopy and structure of CF3CH2OCN, CF3CH2NCO, and (CF3CH2O)2CNHElectronic supplementary information (ESI) available: Experimental and calculated infrared and Raman vibrational frequencies and intensities of CF3CH2OCN, (CF3CH2O)2CNH and CF3CH2NCO. See http://www.rsc.org/suppdata/cp/b2/b212777f/

“…17 Interestingly, covalent cyanates are hardly studied by NMR spectroscopy and we have not found 13 C-NMR data for alkyl cyanates in the literature. The 13 C chemical shift of the cyanato group in aryl cyanates, between 107.9 and 109.9, 22 is in agreement with the observed value of 111.2 ppm.…”

NMR chemical shifts in MNDO approximation: Parameters and results for H, C, N, and O

“…In this case, part of the error may be due to association effects in the neat phenylcyanate used in the experimental measurements. 118 Although MB3 reproduces variations in the 2 Ž chemical shifts of sp carbons fairly well 110 to . 220 ppm relative to methane; see Fig.…”

Isolation and Structure Elucidation of a Novel Glycoside Niazidin from the Pods of Moringa oleifera

“…The chemical shift (δ 110.05) is comparable to the reported values for cyanato compounds. 13 The presence of cyanoxythiocarbamate group justified the remaining three double bonds in the molecule. Moreover, the chemical shift of the NH proton (δ 7.95, t, J ) 5.0 Hz) revealed that this is cis to sulfur, and the molecule as a whole has a trans (E) stereochemistry as observed earlier in case of thiocarbamates.…”

“…The molecular formula C 15 H 18 N 2 O 6 S was determined through integration of 1 H-NMR spectrum (Table 1), 13 C-NMR data (broad band and DEPT) ( Table 1), and HREIMS, which showed diagnostic ions at m/z 147.0649 and m/z 207.0247 corresponding to the fragments a (C 6 H 11 O 4 ) and b (C 9 H 7 N 2 O 2 S), respectively.…”

“…The methyl ester has been isolated from a number of plants, while there is only one report for detection of the propyl ester. 30 4 The components of N-16, as characterized by its HREIMS, 1 H-NMR, 13 C-NMR, and 2D NMR spectra, are niazinin A, niazinin B, niazimicin A, and 4-(R-L-rhamnosyloxy)benzeneisothiocyanate 6 isolated earlier from M. oleifera. 6,8,10 These compounds exist in a ratio of 1:1: 1:3 as revealed by the proton integrals.…”