Two quanta of the aldehyde H-wag vrbratronal mode are observed with relatrvely constant activrty in the vtbra-horn11 structure of 3A"(nn*) -+ 1 A' phosphorescence spectra of benzaidehyde, deutcrated benzaldehydes. pyridme aldehydes, p-methylbenzaldehyde, p-fluorobenzaldehyde, and p-chlorobenzaldehyde at 4 2°K m a methylcycI* hexane polycr~stalhne envrronment The fundamental IS erther missmg or very weak Crlntrasted to the aIdehyde Hwag mode, higher quanta of the CHO torsmnal mode are observed in the phosphorescence of the-e moIecuIcs wrth vannble rntensrty and progression length These results are mterpreted rn terms of a static (I e , vaIence) drstortron of the 3nn potential surface along the aldehyde H-waggmg coordmate. and pseudo-Jahn-Teller dlstortron along the CHO torsronal coordmate The valence drstortron IS analogous to a drstortron found for the 3n%:c state m propynal and rts orrgm probably hes rn excess electron densrty at the carbonyl carbon rn the exerted state The dynamical Jahn-Teller drsrortron IS ascrrbed to vrbronrc mteractron between 3A"(nn) and the nearest 3A'(s;~*) states Smce Walsh postulated for valence reasons nonplanar lT3A2(nrr*) (or more properly lp3A") exerted Stlales SF 53i~Fil&k..~i3~ 5 3) the pX!jEtT~ Gf the eX-* I e , the Fermr correlatron energy, 2Kn,* tn moieclllar orbrtal thesry, IS expected to strongly increax as the molecule bends * Se+ also ref [4], pp 524,614 and 516.