Unlike the organolithium compounds, the organometallic compounds of the heavier alkali metals are predominantly ionic.
ʌnlˈaɪk ðɪ ɔːɹɡˌænoʊlˈɪθiəm kˈɑːmpaʊndz, ðɪ ɔːɹɡˌænoʊmətˈælɪk kˈɑːmpaʊndz ʌvðə hˈɛviɚɹ ˈælkəlˌaɪ mˈɛɾəlz ɑːɹ pɹɪdˈɑːmɪnəntli aɪˈɑːnɪk.