Acta Phys. -Chim. Sin. ›› 1987, Vol. 3 ›› Issue (02): 141-145.doi: 10.3866/PKU.WHXB19870207

• ARTICLE • Previous Articles     Next Articles


Chen Min; Wang Zongming; Lu Wanzhen   

  1. Research Institute of Petroleum Processing; Beijing
  • Received:1985-10-30 Revised:1986-04-17 Published:1987-04-15
  • Contact: Lu Wanzhen

Abstract: Infrared and Raman spectra of W_6O_(19)~(2-) were measured, and the normal coordi- nate analysis was performed for the W_6O_(19)~(2-) anion by using general valence force field (GVFF), Urey-Bradley force field (UBFF) and modified Urey-Bradley force field (MUBFF). The later is the best one,and the result is given. The sym- metrical coordinates consisted of 132 internal coordinates were used, in order to split the secular equations into blocks and assign the symmetrical species of the vibrations. For the terminal oxygen exhibit stronger electric negativity, repulsive forces among them were considered in MUBFF, and an improved result was obtained at high wavenumbers. Although the central oxygen atom exhibits ion character, the contributions of the internal coordinates associated with it should not be ignored. However, these coordinates only show an effect on IR active bands, and so Raman active bands 230 cm~(-1) (A_(1g)) and 122 cm~(-1) (E_g) can′t be assigned as W-O_c stretching. Moreover, the Raman band 122 cm~(-1) assigned as F_(2g) was found following the prediction of the calculation.