Chesapeake Energy Corp filed suit Tuesday alleging its founder and former chief executive, Aubrey K. McClendon, stole confidential company data during his last months on the job in order to launch his new oil and gas empire. McClendon, 55, “misappropriated highly sensitive trade secrets from Chesapeake” and “subsequently used these trade secrets for the benefit of” a company he founded in 2013, American Energy Partners LP, according to the civil complaint filed by Chesapeake(CHK.N) in Oklahoma County District Court.