1,2,3,4,5-Pentakis(4-butylphenyl)-1,3-cyclopentadiene is an organochemical compound from the diene group and a cyclopentadiene derivative. The anion of this compound is used as a sterically demanding ligand, often abbreviated as Cp[BIG], in the organometallic chemistry of sandwich compounds.
Preparation
1,2,3,4,5-Pentakis(4-butylphenyl)-1,3-cyclopentadiene can be prepared in a one-step reaction by the palladium-catalyzed reaction of Zirconocene dichloride with 4-n-butylbenzene bromide.[1]
Reactions
1,2,3,4,5-Pentakis(4-butylphenyl)-1,3-cyclopentadiene reacts directly with a range of organometallic compounds or in reduced form as a sodium or potassium compound with the salts of main-group and transition metals. The resulting metallocenes, in contrast to the unsubstituted Pentaphenylcyclopentadienyl complexes are in various solvents readily soluble.[2] The perarylated metallocenes, such as samarium, sometimes exhibit unusual stability. This is likely to be explained by hydrogen bonds between the substituents.[3] The reaction of 1,2,3,4,5-pentakis(4-butylphenyl)-1,3-cyclopentadiene with strong basic strontium and barium compounds provides the corresponding coplanar sandwich compounds.[4]
References
^Dyker, Gerald; Heiermann, Jörg; Miura, Masahiro; Inoh, Jun-Ichi; Pivsa-Art, Sommai; Satoh, Tetsuya; Nomura, Masakatsu (2000). "Palladium-Catalyzed Arylation of Cyclopentadienes". Chemistry - A European Journal. 6 (18): 3426–3433. doi:10.1002/1521-3765(20000915)6:18<3426::AID-CHEM3426>3.0.CO;2-B. PMID11039536.