Various compositions encompassing polymers containing acidic pendent groups in combination with one or more reactive olefinic compounds and a photoacid generators form self-imagable negative tone films. Examples of such polymers include polymers and copolymers containing norbornene-type repeating units having acidic pendent groups, ring opened maleic anhydride polymers, polyacrylic acid, polyhydroxystyrene polymers, and the like. The films formed from such compositions provide self imagable, low-k, thermally stable layers for use in microelectronic and optoelectronic devices, among other applications.