Senior chemical industry research leaders Thomas M. Connelly Jr. of DuPont and Andreas Kreimeyer of BASF plan to retire in the coming months. Connelly, 63, DuPont’s chief innovation officer, will retire effective Dec. 31 after 37 years with the firm. He presided over DuPont’s innovation center strategy and growing involvement in industrial biotechnology. Douglas W. Muzyka, 59, DuPont’s chief science and technology officer, will succeed Connelly as a member of the office of the chief executive. Kreimeyer, 59, executive research director at BASF for the past six years and a member of the company’s board, will retire on April 30, 2015. He joined BASF 28 years ago and has presided over an effort to expand BASF’s R&D presence beyond Europe. Fellow board member Martin Brudermüller, 53, will take on the research role after Kreimeyer’s retirement.