The longitudinal accordion motion of polymethylene chains has been studied fornthinsp;equals;thinsp;5ndash;36liquids and solids via laserhyphen;vibrational scattering. Unlike the fully extended,transchains of the solids, the abundance of thetransconformation in the liquids is vanishingly small fornthinsp;ge;thinsp;9, in favor of chain shortened forms. This is indicated by the variation of the primary accordion mode frequencies, which approach a limiting value. A gradual intensity dimunition and broadening of the primary longitudinal band, accompanied by an increase of continuum intensity, with increasingn, indicates an approach towards conformational randomness.
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