156278-75-0

Basic information

• Product Name: Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3)⁽¹⁺⁾*B(C₆H₅)4^(1-)=(Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3))(B(C₆H₅)4)
• Synonyms: Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3)⁽¹⁺⁾*B(C₆H₅)4^(1-)=(Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3))(B(C₆H₅)4)
• CAS NO: 156278-75-0
• Molecular Weight: 901.376
• Mol File: 156278-75-0.mol
• Article Data: 1

Chemical Properties

• CAS DataBase Reference: Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3)⁽¹⁺⁾*B(C₆H₅)4^(1-)=(Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3))(B(C₆H₅)4)(CAS DataBase Reference)
• NIST Chemistry Reference: Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3)⁽¹⁺⁾*B(C₆H₅)4^(1-)=(Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3))(B(C₆H₅)4)(156278-75-0)
• EPA Substance Registry System: Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3)⁽¹⁺⁾*B(C₆H₅)4^(1-)=(Hf(C₅(CH₃)5)2(CH₂CH(CH₃)2)(P(CH₃)3))(B(C₆H₅)4)(156278-75-0)

Safety Data

• Hazardous Substances Data: 156278-75-0(Hazardous Substances Data)

Upstream product

• 105931-10-0 Hf(C₅(CH₃)5)2(CH₂CH(CH₃)CH₂) 
• 64167-39-1 tri(n-butyl)ammonium tetraphenylborate 

Relevant articles and documents

Cationic zirconium and hafnium isobutyl complexes as models for intermediates in metallocene-catalyzed propylene polymerizations. Detection of an α-agostic interaction in (C5Me5)2Hf(CH2CHMe 2)(PMe3)+

A series of cationic Zr and Hf isobutyl complexes has been prepared to model the Cp2M{CH2CH(R)(R′)}+ and Cp2M{CH2CH(R)(R′)}(α-olefin)+ intermediates in metallocene-catalyzed α-olefin polymerizations (R′ = growing poly(α-olefin) chain). The cationic hydride [Cp′2Zr(H)(THF)][BPh4] (5, Cp′ = C5H4Me) reversibly inserts isobutylene at 23°C to afford [Cp′2Zr(CH2CHMe2)(THF)][BPh4] (6), in which the isobutyl group adopts a normal structure. The reaction of 6 with PMe3 yields [Cp′2Zr(CH2CHMe2)(PMe 3)][BPh4] (7) which adopts a β-agostic structure and undergoes β-H elimination above -13°C. The reaction of the hafnacyclobutane Cp*2Hf(CH2CHMeCH2-) (10) with [HNBu3][BPh4] in the presence of PMe3 yields [Cp*2Hf(CH2CHMe2)(PMe 3)][BPh4] (12). NMR data, including isotope perturbation of resonance results for deuterium labeled analogues, establish that the isobutyl group of 12 is distorted by an α-agostic interaction. The reaction of 12 with THF, and the reaction of 10 with [HNBu3][BPh4] in THF yield [Cp*2Hf(CH2CHMe2)(THF)][BPh4] (14). Solution NMR data, solid state IR data, and X-ray crystallographic results establish that the isobutyl group of 14 is distorted (Hf-C-C angle 137.5(8)°) but that Hf?Hα agostic interactions are absent. Crystal data for 14: space group P21/c, a = 10.747(3) A?, b = 21.417(3) A?, c = 21.783(8) A?, β = 101.83(4)°, V = 5365(6) A?3, Z = 4, R = 0.053, Rw = 0.086. 14 undergoes predominant β-Me elimination at 58°C. The structures of Cp′2Hf(nBu)(L)+ (17, L = THF, normal butyl group; 19, L = PMe3, β-agostic butyl group) are analogous to those of the corresponding Cp′2Zr(nBu)(L)+ complexes. The structures and reactivity of 6, 7, 12, and 14 are rationalized in terms of the steric and electronic properties of the C5R5- and L ligands.