Diversity in weakly coordinating anions. mono- and polynuclear halo(perfluoroaryl)metalates as cocatalysts for stereospecific olefin polymerization: Synthesis, structure, and reactivity

Ming Chou Chen, John A.S. Roberts, Afif M. Seyam, Liting Li, Cristiano Zuccaccia, Nicholas G. Stahl, Tobin Jay Marks*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

54 Scopus citations

Abstract

A series of mononuclear and polynuclear trityl (perfluoroaryl)borate, -aluminate, and -gallate reagents, potential cocatalysts/activators for metallocene-mediated olefin polymerization, have been synthesized via fluoride abstraction from trityl fluoride (Ph 3CF) by the organo Lewis acid reagents B(C 6F 5) 3 (1), B(o-C 6F 5C 6F 4) 3 (2), and Al(C 6F 5) 3 (3), by derivatization of Ph 3C +FAl(o-C 6F 5C 6F 4) 3 - (4), and by reaction of trityl fluoride with in situ generated Ga(C 6F 5) 3 (5). Reaction of trityl fluoride with the tris(perfluoroaryl)-boranes 1 and 2 yields the trityl tris(perfluoroaryl)fluoroborates Ph 3C +FB(C 6F 5) 3 - (6) and Ph 3C +FB(o-C 6F 5C 6F 4) 3 - (7), respectively. The three trityl tris(perfluorophenyl)fluoroaluminates (Ph 3C +F x[Al(C 6F 5) 3] y x- (x = 1, y = 1, 8; x = 1, y = 2, 9; x = 2, y = 3, 10) can be isolated from the reaction of trityl fluoride with the tris(perfluoroaryl)alane 3 in the appropriate molar ratios. Reaction of the trityl tris(perfluoroaryl)- fluoroaluminate 4 with 3 affords the asymmetric fluoro-bridged trityl bis[tris(perfluoroaryl)]aluminate Ph 3C +(C 6F 5) 3AlFAl(o-C 6F 5C 6F 4) 3 - (11), while reaction of the trityl halides Ph 3CCl and Ph 3CBr with 3 gives the corresponding trityl tris(perfluorophenyl)haloaluminates Ph 3C +XAl(C 6F 5) 3 - (X = Cl, 12; X = Br, 13). The isolable, symmetric fluoro-bridged trityl bis[tris(perfluoroaryl)]gallate Ph 3C +F[Ga(C 6F 5) 3] 2 - (14) is derived from a "one-pot" reaction of trityl fluoride with Ga(C 6F 5) 3, generated in situ from 4 + Ga(CH 3) 3. Of these new species, compounds 7 and 10-14 were characterized by single-crystal X-ray diffraction. Trityl salts 6-13 react with the C s-symmetric metallocene precatalyst Me 2C(Cp)(Flu) ZrMe 2 (15: Cp = C 5H 4; Flu = C 13H 8, fluorenyl) to form isolable ion-pair complexes or characterizable mixtures. Species 6 reacts with 15 to generate the known ion pair Me 2C(Cp)(Flu)ZrMe +MeB(C 6F 5) 3 - (16), and reaction of 7 with 15 gives the fluoro-bridged dimeric diastereomers [Me 2C(Cp)(Flu)ZrMe] 2(μ-F) +FB-(o-C 6F 5C 6F 4) 3 - (17). The trityl tris(perfluorophenyl)fluoroaluminates 8-10 all react with 15 to afford mixtures of Me 2C(Cp)(Flu)ZrMe +FAl(C 6F 5) 3 - (18) and diastereomeric [Me 2C(Cp)(Flu)ZrMe] 2(w-Me) +-(C 6F 5) 3AlFAl(C 6F 5) 3 - (19). Asymmetric, species 11 cleanly affords the diastereomeric [Me 2C(Cp)(Flu)-ZrMe] 2(M-Me) +(C fF 5) 3AlFAl((o-C 6F 5C 6F 4) 3 -- (20) in reaction with the metallocene 15. Adducts of 12 and 13 with the metallocene 15 afford the decomposition products Me 2C(Cp)(Flu)ZrCl(C 6F 5) (21) and [Me 2C-(Cp)(Flu)Zr(μ 2-Br)] 2 2+[Al(C 6F 5) 4 -] 2 (22), respectively. Complexes 17-22 were characterized by single-crystal X-ray diffraction.

Original languageEnglish (US)
Pages (from-to)2833-2850
Number of pages18
JournalOrganometallics
Volume25
Issue number11
DOIs
StatePublished - May 22 2006

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

Fingerprint

Dive into the research topics of 'Diversity in weakly coordinating anions. mono- and polynuclear halo(perfluoroaryl)metalates as cocatalysts for stereospecific olefin polymerization: Synthesis, structure, and reactivity'. Together they form a unique fingerprint.

Cite this