IR and NMR studies of symmetrically and unsymmetrically bonded N,N‐dialkyldithiocarbamates

Abstract

In order to find characteristic differences between symmetrically and unsymmetrically bonded N,N‐dialkyldithiocarbamates, their IR and 1H NMR spectra have been examined. The IR data firmly underline a previously reported infrared criterion which makes it possible to distinguish the two types of bonding. In the spectra of the unsymmetrical N,N‐diethyldithiocarbamates a band at 1000 cm−1 is assigned to the CS stretching mode. Although the rotation around the S2C‐NR2, bond in several dithiocarbamato complexes will be strongly hindered at low temperatures, no splitting of the NMR signals of the N‐alkyl groups could be observed. This may be attributed to an extremely small difference in magnetic environment of the N‐alkyl moieties in the rotamers.

The unique chemistry of thiuram polysulfides enables energy dense lithium batteries

“…The defining bands in the spectrum (Figure 3c) occur in the 1500-1400 cm -1 region corresponding to N-C bond vibrations, from 1170-1115 cm -1 for the C=S bond and from 1030-930 cm -1 for C(=S)-S bond. 29,36,37 On comparing the spectrum of the discharged state with that of the cathode we observe diminished intensity in the N-C band and for those of the C=S bond whereas, the C-S bond is still evident on discharge. This is caused by the prevalence of the Re-examination of S 2p XPS data in the discharged state and the half-charged state which is pertinent to inhibition of the polysulfide shuttle provides evidence to support this phenomenon.…”

“…The 0.39 eV increase between 4 and 2 aligns with plateau III occurring at 2.1 V. Additionally, it is interesting to note that 2 can alternatively exist in its mesomeric form 7 (Li2PMDTC + ) with a positive nitrogen center in the presence of excess Li + owing to the N-electron flow from nitrogen to sulfur through planar delocalized π-orbitals which will be discussed later. 29 As for PMTH, the pathway remains relatively unaltered ( see Figure S5, ESI) with the exception of higher order polysulfides formed in the penultimate step before the reduction to Li2S.…”

Preparation and Characterization of the Adducts of Bis(morpholinedithiocarbamato)copper(II) with Nitrogen and Oxygen Donor Ligands

“…There is a positive shift of 10-30 cm 1 in comparison to the corresponding band in the free ligands which indicates that the dithiocarbamate ligand coordinates with metal through sulfur atoms. A single absorption in the range 1035-992 cm 1 is indicative of bidentate nature of the dithiocarbamate ligand which is due to equivalent C-S stretching vibrations [21][22][23][24] . A band of medium to strong intensity, observed in the region 400-426 cm 1 , may be assigned to υ(Cu-S) stretching mode (Table 3).…”