The transmetalation of phenylcopper yields thesolvent-separated cuprate [(thf)3Ca(G SRC="/images/entities/mgr.gif">-Ph)3Ca(thf)3]+[Ph-Cu-Ph]-. This derivative extends the known classes of organiccalcium compounds by an organometallic complex cation, inaddition to the already well-known neutral diarylcalcium andtrialkylcalciate anions.