The present invention is directed to novel compounds that can serve as highly efficient initiators for controlled radical (co)polymerization processes including atom transfer radical (co)polymerization processes. These compounds include di-(trimethylolpropane)-tetra-(2-haloisobutyrate) compounds. The present invention also is directed to controlled radical (co)polymerization processes in which novel (co)polymers are prepared using the novel compounds, as well as to the novel (co)polymer products of the process.