kˈoʊbɐltˌoʊsiːn hɐz nˈaɪntiːn vˈeɪləns ᵻlˈɛktɹɑːnz, wˈʌn mˈoːɹ ðɐn jˈuːʒuːəli fˈaʊnd ɪn ɔːɹɡˌænoʊtɹænsˈɪʃən mˈɛɾəl kˈɑːmplɛksᵻz, sˈʌtʃ ɐz ɪts vˈɛɹi stˈeɪbəl ɹˈɛlətˌɪv, fˈɛɹoʊsˌiːn, ɪn ɐkˈoːɹdəns wɪððɪ ˈeɪtiːnᵻlˈɛktɹɑːn ɹˈuːl.
Cobaltocene has 19 valence electrons, one more than usually found in organotransition metal complexes, such as its very stable relative, ferrocene, in accordance with the 18-electron rule.