115227-37-7Relevant academic research and scientific papers
[1,2-Bis(dimethylphosphino)ethane](cyclopentadienyl)methylzirconium(II) [CpZrMe(DMPE)2]: A catalyst precursor for the selective dimerization of ethylene to 1-butene
Wielstra, Ytsen,Gambarotta, Sandro,Chiang, Michael Y.
, p. 1866 - 1867 (1988)
Room-temperature reaction of CpZrCl(dmpe)2 [dmpe = 1,2-bis(dimethylphosphino)ethane] with MeLi led to the formation of the Zr(II) alkyl derivative CpZrMe(dmpe)2 (1), as deep red crystals. Compound 1 is monoclinic, space group C 2/c, with a = 11.675 (5) ?, b = 14.871 (5) ?, c = 28.154 (14) ?, β = 97.08 (4)°, V = 4851 ?3, and Z = 8. Room-temperature reaction of 1 with 3 equiv of ethylene gave 1 equiv of methane and CpZr(dmpe)(η4-butadiene)(CH2CH3) (2), which catalyzes the selective dimerization of ethylene to 1-butene.
Mono(cyclopentadienyl)zirconium(II) and -hafnium(II) chemistry: Synthesis and reactivity of CpM(CO)2(dmpe)Cl [M = Zr, Hf; Cp = cyclopentadienyl; dmpe = 1,2-bis(dimethylphosphino)ethane] via mild-condition carbonylation reaction of CpM(dmpe)2Cl. The crystal structure of CpZr(CO)2(dmpe)Cl
Wielstra, Ytsen,Gambarotta, Sandro,Roedelof, Johannes B.,Chiang, Michael Y.
, p. 2177 - 2182 (2008/10/08)
The Na reduction of CpMCl3(THF)2 (M = Zr, Hf; Cp = cyclopentadienyl; THF = tetrahydrofuran) in the presence of a slight excess of dmpe [dmpe = 1,2-bis(dimethylphosphino)ethane] led to the formation of the two isostructural species CpM(dmpe)2Cl [M = Zr (1), 68%; M = Hf (2), 58%]. Easy replacement of one of the two coordinated dmpe by two molecules of CO was achieved by either a carbonylation reaction under mild conditions or CO abstraction from [CpFe(CO)2]2. The resulting carbonyl derivatives CpM(CO)2(dmpe)Cl [M = Zr (3), 73%; M = Hf (4), 63%] have been isolated and fully characterized. The close similarity in their spectroscopic properties suggested that the two complexes are isostructural. Compound 3 crystallizes in a monoclinic space group of P21/a symmetry with a = 15.664 (10) ?, b = 7.208 (3) ?, c = 16.869 (9) ?, β = 112.89 (4)°, V = 1754 (2) ?3, and Z = 4. The presence of a fast CO exchange in solution has been demonstrated for both 3 and 4 by using 13CO. In agreement with its dynamic behavior in solution, an easy ligand-exchange reaction occurs between 3 and 1 forming the pyrophoric light green carbonyl derivative [CpZr(CO)(dmpe)Cl]2(dmpe) (5). Complex 5 can be more conveniently synthesized by carrying the carbonylation reaction on saturated solutions of 1 in ether. Easy ligand-exchange reactions of both 1 and 3 with butadiene afforded the new butadiene derivative CpZr(η4-butadiene)(dmpe)Cl (6). Vigorous reaction of 3 with 2 equiv of ethylene (1 atm, room temperature) led instead to the evolution of 1 equiv of CO with formation of a yellow solid product, probably CpZr[η2-C(O)CH2CH2CH2CH 2]Cl·1/2(dmpe) (7). Chemical degradation of 7 with 2 equiv of anhydrous HCl gave cyclopentanol in 75% yield.
