No, it cannot. Each core runs at 1.1GHz as the BASE frequency. Burst frequency is 2.5GHz when pushed to its limits. I am not sure if it will do all 4 cores simultaneously or not at 2.5, though.
Cores are not additive in speed. They run in parallel. If you get 4 identical cars that have a max speed of 100MPH, and get four drivers to drive them down a 4 lane highway, they do not get the ability to run at 400MPH.