Compounds Cp Pentamethylcyclopentadienyl

Structure of the ring-opened product of the reaction between SmCL and NaCp in THF. 

When [SmCp 3] was eventually isolated, it was found to be [Sm() -C5Me5)3] (Eig-ure 6.10) and also that three of these bulky ligands fit round samarium with an increase in bond length from the usual 2.75 A to 2.82 A. 

Apart from the novel ring-opening reaction with THF, [SmCp 3] inserts RNC and CO and is an ethene polymerization catalyst. Another reaction uncharacteristic of [LnCp3] systems 

Similarly, reactions of LiR with LnCp2Cl which, strictly, should be written to give the product [Cp2Ln(/r-Cl)2LnCp2] resulted in the synthesis of LnCp2R (R, e.g., Bu , Bu, CH2SiMe3, p-C6H4Me, etc.) for later lanthanides  

When this reaction is carried out in TFIF, a solvent that can coordinate well, the product is LnCp2R(THF). 

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Scheme 6-1 All-carbon and all-phosphorus cage compounds. Cp, pentamethylcyclopentadienyl.

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