We
report the synthesis of long narrow gold nanocrystals and the
study of their vibrational dynamics using inelastic light-scattering
measurements. Rich experimental spectra are obtained for monodomain
gold nanorods and pentagonal twinned bipyramids. Their assignment
involves diameter-dependent nontotally symmetric vibrations which
are modeled in the framework of continuum elasticity by taking into
account simultaneously the size, shape, and crystallinity of the nanocrystals.
Light scattering by vibrations with angular momenta larger than 2
is reported. It is shown to increase with the ratio of the nanocrystals
diameter to the interparticle separation. It originates from the plasmonic
coupling due to the self-assembly of the nanocrystals after deposition.