The electronic and dynamic changes at the phase transition at T(c) = 2
72 K in the quasi one-dimensional organic conductor DMTM(TCNQ)2 have b
een investigated with H-1- and C-13-NMR on powder samples and single c
rystals. The TCNQ hyperfine coupling constants were calculated from th
e observed H-1- and C-13-Knight shift, and the charge redistribution a
t T(c) is determined by the C-13 single crystal measurements, The DMTM
cation dynamics have been studied with broadline H-1-NMR which indica
tes a slowing down of cation motion at T(c) as evidenced by the temper
ature dependence of the relaxation rates. The results support a tentat
ive explanation of the unusual phase transition, an ''inverted Peierls
'' transition, given by Visser et al. [1, 2].