The introduction and changes of the substituents at the middle carbon atom of the preligand dipyrrolmethane have a significant impact on the reaction results. When the substituent at the C_sp³ atom is a methyl group, the reaction of the preligand with CoMe(PMe₃)₄ delivered cobalt(I) complex 2 as a C_sp³–H bond activation product. In the case of ethyl, propyl and pentyl groups, PCP pincer cobalt complexes 3–5 with cobaltacyclopropane moieties were formed via double C_sp³–H bond activation. With iso-propyl as the substituent, cobalt(I) complex 6 as C_sp²–H activation product was obtained.