Raman study of order-disorder phase transitions in polydialkylmetallanes of the type [R2M]n -: organometallic polymers with the main chain consisting entirely of either Si, or Ge, or Sn atoms

Variable-temperature Raman studies were carried out for some representatives of a novel class of industrially promising sigma-conjugated polymers - polymetallanes of the type [R2M](n), M=Si, Ge, Sn. Electronic-conformational nature of the thermochromic phase transitions of order-disorder type exhibited by some of these polymers was investigated. The applicability of Shorygin's semiclassical approach to the pre-resonant Raman intensity enhancement was confirmed experimentally by the example of polysilanes.