## Conformers of Allyl Isothiocyanate: A Combined Microwave Spectroscopy and Computational Study

dataset

posted on 30.04.2020 by Joseph Stitsky, Weslley G. D. P. Silva, Wenhao Sun, Jennifer van Wijngaarden#### dataset

Datasets usually provide raw data for analysis. This raw data often comes in spreadsheet form, but can be any collection of data, on which analysis can be performed.

The
pure rotational spectrum of allyl isothiocyanate (CH

_{2}=CHCH_{2}–NCS) was collected from 4 to 26 GHz using Fourier transform microwave (FTMW) spectroscopy. Its analysis revealed the presence of two conformers that arise due to variation in the CCCN and CCNC dihedral angles. The observed spectrum is consistent with the accompanying potential energy surfaces derived using quantum chemical calculations at the B3LYP-D3(BJ) and MP2 levels of theory. Together, this experimental and theoretical study unequivocally identifies a new conformer (I) as the global minimum geometry. The spectral assignment of this new conformer is verified by the observation of transitions consistent with its^{34}S,^{13}C, and^{15}N isotopologues and with the characteristic^{14}N quadrupole hyperfine patterns. For conformer I, the substitution (*r*_{s}) and effective ground state (*r*_{0}) structures were derived and reveal contributions from a large amplitude motion in the CCNC angle. The remaining geometric parameters compare well with the equilibrium structure (*r*_{e}) from B3LYP-D3(BJ)/cc-pVQZ calculations. The derived CNC bond angle of 152.6(3)° for conformer I of allyl–NCS is found to be ∼15° larger than that of allyl–NCO (137.5(4)°), which is in line with a change in the hybridization at nitrogen from an orbital with more ∼sp character in allyl–NCS to ∼sp^{1.5}in allyl–NCO as determined via natural bond orbital analyses.#### Read the peer-reviewed publication

### Categories

### Keyword(s)

r eFTMWCCNC dihedral angles13 Cr 0conformer34 Sallyl isothiocyanateCHCH14 N quadrupoleequilibrium structureamplitude motion15 N isotopologues26 GHzenergy surfacesquantum chemical calculationsComputational StudyCH 2CCNC angleAllyl IsothiocyanateCNC bond angleground statespectrumMP 2 levelsB 3LYP calculationsMicrowave SpectroscopyB 3LYPCCCNspNCS

### History

### Licence

### Exports

#### Read the peer-reviewed publication

### Categories

### Keyword(s)

r eFTMWCCNC dihedral angles13 Cr 0conformer34 Sallyl isothiocyanateCHCH14 N quadrupoleequilibrium structureamplitude motion15 N isotopologues26 GHzenergy surfacesquantum chemical calculationsComputational StudyCH 2CCNC angleAllyl IsothiocyanateCNC bond angleground statespectrumMP 2 levelsB 3LYP calculationsMicrowave SpectroscopyB 3LYPCCCNspNCS