Knowledge Bank

The IR absorption spectrum of monolayer acetylene on a single crystal of NaC1 was obtained in $3200cm-1$ region. From results using $Es$ and $Ep$ polarized light, the molecular axis of acetylene was determined to lie parallel to the substrate surface. Results were found to be consistent with a monolayer made up of a series of hydrogen-bonded chains in which half of the acetylene molecules act as proton acceptors and half act as proton donors. This monolayer structure is directly analogous to the T-shaped gas phase dimer