Vibrational spectra of 2-phenyl-indane-1,3-dione, its isotopic labelled derivatives and the corresponding carbanions

IR and Raman spectra of 2-phenyl-indane-1,3-dione d(0), d(4), d(5), d(10), and O-18 have been measured in both the solid state and solution in the 4000-100 cm(-1) frequency region. IR and Raman spectra of the corresponding carbanions have also been measured in DMSO-d(6) solutions in the 2000-1100 cm(-1) frequency range. The assignment of the spectra of the neutral compounds is performed using the group vibrational concept and the isotopic shifts of the normal modes. The assignment of the bands in the IR and Raman spectra of the corresponding carbanions is made on the basis of isotopic shifts and the spectral changes accompanying the conversion of the neutral compounds into carbanions. The conversion of the parent beta-diketone into carbanion causes a ca. 160 cm(-1) decrease in the frequency of the anti-phase nu(C infinity O) bands; this results is explained by the high mobility of the carbanionic charge. (C) 1998 Elsevier Science B.V. All rights reserved.