Di-''tert''-butylcyclopentadiene is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

with the formula (Me₃C)₂C₅H₄, where Me = methyl. It is a colorless liquid that is soluble in organic solvents. The compound is the

conjugate acid A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...

of the di-''tert''-butylcyclopentadienyl ligand, (Me₃C)₂C₅H₃⁻ (sometimes abbreviated Cp^‡⁻). Two regioisomers of di-''tert''-butylcyclopentadiene exist, depending on the relative location of the

double bonds In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

Synthesis and reactions

Di-''tert''-butylcyclopentadiene is prepared by alkylation of cyclopentadiene with ''tert''-butyl bromide under phase-transfer conditions. It is the precursor to many metal complexes, such as the olefin polymerization catalyst ((Me₃C)₂C₅H₃)TiCl₃.{{cite journal, doi=10.1021/OM980106R, title=Synthesis of Various Nonbridged Titanium(IV) Cyclopentadienyl−Aryloxy Complexes of the Type Cp′Ti(OAr)X₂ and Their Use in the Catalysis of Alkene Polymerization. Important Roles of Substituents on both Aryloxy and Cyclopentadienyl Groups, year=1998, last1=Nomura, first1=Kotohiro, last2=Naga, first2=Naofumi, last3=Miki, first3=Misao, last4=Yanagi, first4=Kazunori, last5=Imai, first5=Akio, journal=Organometallics, volume=17, issue=11, pages=2152–2154 The conjugate base of di-''tert''-butylcyclopentadiene reacts with a third equivalent of ''tert''-butyl bromide to give (Me₃C)₃C₅H₃: :(Me₃C)₂C₅H₄ + NaH → Na(Me₃C)₃C₅H₃ + H₂ :Na(Me₃C)₂C₅H₃ + Me₃CBr → (Me₃C)₃C₅H₃ + NaBr

References

Cyclopentadienes Ligands