Final answer:
PBr3 and SOCl2 are not suitable for converting tertiary alcohols to alkyl halides due to steric hindrance in SN2 mechanisms; tertiary alcohols often undergo SN1 or elimination reactions instead.
Step-by-step explanation:
PBr3 and SOCl2 are commonly used for the conversion of primary and secondary alcohols to alkyl halides, primarily through SN2 mechanisms. However, tertiary alcohols are generally resistant to these reagents because tertiary alcohols do not undergo SN2 reactions due to steric hindrance. They are more likely to undergo SN1 reactions or elimination reactions. The conversion of tertiary alcohols to alkyl halides is therefore not favorable with PBr3 and SOCl2, and alternative methods like using strong acids (HCl, HBr, or HI) or other reagents that promote SN1 or elimination might be considered for converting tertiary alcohols to their corresponding halides.