Terje Grønås

• Samdal, Svein; Grønås, Terje; Møllendal, Harald & Guillemin, Jean-Claude (2014). Microwave Spectrum and Conformational Properties of 4-Isocyano-1-butene (H2C=CHCH2CH2N≡C). Journal of Physical Chemistry A.  ISSN 1089-5639.  118(8), s 1413- 1419 . doi: 10.1021/jp4122134 Show summary

  The microwave spectrum of 4-isocyano-1-butene (H2C=CHCH2CH2NC) has been investigated in the 35 – 80 GHz spectral region. Selected measurements have also been made outside this spectral range. Rotation about the ‒CH‒CH2‒ and ‒CH2‒CH2‒ single bonds may produce rotational isomerism resulting in five conformers. The spectra of three of them, denoted I, III, and IV, have been assigned. In conformer I, the C=C‒C‒C link of atoms is +anticlinal and the C‒C‒C‒N chain is antiperiplanar. In III, the two links of atoms are +anticlinal and +synclinal, whereas in IV, the two chains are synperiplanar and antiperiplanar, respectively. Conformer I was found to have the lowest energy of the three forms by relative intensity measurements. These measurements yielded EIII – EI = 1.1(7) kJ/mol, and EIV – EI = 2.9(7) kJ/mol for the internal energy differences. The microwave study was augmented by quantum chemical calculations at the CCSD/cc-pVQZ and MP2/cc-pVTZ levels of theory. Good agreement between experimental and theoretical results was seen in most cases.

• Samdal, Svein; Grønås, Terje; Møllendal, Harald & Guillemin, Jean-Claude (2013). Microwave Spectrum and Conformational Properties of 4-Isocyano-1-butyne (HC≡CHCH2CH2N≡C). Journal of Physical Chemistry A.  ISSN 1089-5639.  117(40), s 10304- 10310 . doi: 10.1021/jp407126x Show summary

  The microwave spectrum of 4-isocyano-1-butyne (HC≡CCH2CH2N≡C) has been investigated in the 12.4 – 77.6 GHz spectral region. The spectra of two rotamers denoted ap and sc were assigned. ap has an antiperiplanar arrangement for the C‒C‒C‒N chain of atoms, whereas sc has synclinal conformation for this link. The ground state spectrum and three vibrationally excited state spectra of the lowest torsional vibration were assigned for ap, while the ground vibrational state spectrum was assigned for sc. The C‒C‒C‒N dihedral angle was found to be 64.5(30)º in sc and exactly 180º in ap. ap was determined to be 2.9(6) kJ/mol lower in energy than sc from relative intensity measurements. The microwave study has been augmented with ab initio and DFT calculations employing the CCSD(T), MP2, and B3LYP methods with the cc-pVTZ basis set. A Natural Bond Order analysis has also been performed. Most, but not all, of the quantum chemical predictions agree satisfactorily with the experimental results.

• Haraldseth, Olav; Grønås, Terje; Southon, Timothy; Thommessen, Line; Borchgrevink, Grethe; Jynge, Per; Gisvold, Sven Erik & Unsgård, Geirmund (1992). The effect of brain temperature on temporary global ischaemia in rat brain. A 31-phosphorous NMR spectroscopy study. Acta Anaesthesiologica Scandinavica.  ISSN 0001-5172.  36, s 393- 399

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