S. Bambirra et al., Neutral and cationic yttrium alkyl complexes with linked 1,4,7-triazacyclononane-amide monoanionic ancillary ligands: synthesis and catalytic ethene polymerisation, CHEM COMMUN, (7), 2001, pp. 637-638
Yttrium dialkyl complexes [N,N'-R-2-tacn-N"-(CH2)(2)NBut]Y(CH2SiMe3)(2) (R=
Me, Pr-i; tacn=1,4,7-triazacyclononane) were prepared; when activated with
[PhNMe2H][B(C6F5)(4)] these complexes form cationic alkyl species that are
active ethene polymerisation catalysts.