er ization ▁and ▁dis pro port ion ation , ▁forming ▁element al ▁lead ▁in ▁the ▁process . ▁ ▁Pl um by len es ▁can ▁be ▁stabil ized ▁as ▁mon om ers ▁by ▁the ▁use ▁of ▁ster ically ▁bul ky ▁lig ands ▁( kin etic ▁stabil ization ) ▁or ▁heter o atom - cont aining ▁subst itu ents ▁that ▁can ▁don ate ▁electron ▁density ▁into ▁the ▁vac ant ▁ 6 p ▁orb ital ▁( ther mod ynamic ▁stabil ization ). ▁ ▁D imer ization ▁▁ ▁Pl um by len es ▁are ▁able ▁to ▁under go ▁dim er ization ▁in ▁two ▁ways : ▁either ▁through ▁the ▁formation ▁of ▁a ▁P b = P b ▁double ▁bond ▁to ▁form ▁a ▁formal ▁di pl umb ene , ▁or ▁through ▁brid ging ▁hal ide ▁interactions . ▁Un hal ogen ated ▁pl um by len es ▁tend ▁to ▁exist ▁in ▁an ▁equilibrium ▁between ▁the ▁mon omer ic ▁and ▁dim er ic ▁form ▁in ▁solution , ▁and , ▁due ▁to ▁the ▁low ▁dim er ization ▁energy , ▁as ▁either ▁mon om ers ▁or ▁dim ers ▁in ▁the ▁solid ▁state , ▁depending ▁on ▁the ▁ster ic ▁bulk ▁of ▁subst itu ents . ▁However , ▁increasing ▁the ▁ster ic ▁bulk ▁of ▁lead - bound ▁subst itu ents ▁can ▁prevent ▁the ▁close ▁association ▁of ▁pl um by l ene ▁mole cules ▁and ▁allow ▁the ▁pl um by l ene ▁to ▁exist ▁exclus ively ▁as ▁mon om ers ▁in ▁solution ▁or ▁even ▁in ▁the ▁solid ▁state . ▁ ▁The ▁driving ▁force ▁for ▁dim er