M. Mohammad et al., MO CALCULATIONS TO INTERPRET OPTICAL-SPECTRA OF MV - AND RELATED SPECIES, Journal of the Chemical Society of Pakistan, 19(1), 1997, pp. 1-7
The higher reduction products of dications of methyl viologen (MV2+),
diquat (DQ(2+)) and n-butyl viologen (BV2+) i.e. MV; DO; and BV; respe
ctively were prepared and their spectra recorded. MO calculation have
been carried out to interpret the optical spectra of MV; and DQ:. A go
od agreement was obtained between experimental and predicted singlet t
ransitions for MV: while in case of DQ: the agreement for singlet rans
ition at longer wave length was at variance. In case of MV:(I) the obs
erved transition are 3.1307 and 3.3056 eV while calculated one are 3.1
352 (B-2u) and 3.4006 (B-3u) eV respectively where as in case of DQ: (
II) the observed transitions are 3.0228 and 3.1307 eV while the calcul
ated one are 2.6032 (B-1) and 3.0873 (A(1)) eV respectively.