VIBRATIONAL-SPECTRA OF 2-PHENYL-INDANE-1,3-DIONE, ITS ISOTOPIC LABELED 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 c orresponding carbanions have also been measured in DMSO-d(6) solutions in the 2000-1100 cm(-1) frequency range. The assignment of the spectr a of the neutral compounds is performed using the group vibrational co ncept and the isotopic shifts of the normal modes. The assignment of t he bands in the IR and Raman spectra of the corresponding carbanions i s made on the basis of isotopic shifts and the spectral changes accomp anying the conversion of the neutral compounds into carbanions. The co nversion of the parent beta-diketone into carbanion causes a ca. 160 c m(-1) decrease in the frequency of the anti-phase nu(C infinity O) ban ds; this results is explained by the high mobility of the carbanionic charge. (C) 1998 Elsevier Science B.V. All rights reserved.