Unexpected P−Si or P−C Bond Cleavage in the Reaction of Li₂[(C₅Me₄)SiMe₂PR] (R = Cyclohexyl, 2,4,6-Me₃C₆H₂) and Li[(C₅H₄)CMe₂PHR] (R = Ph,^tBu) with ZrCl₄or [TiCl₃(thf)₃]:  Formation and Molecular Structure of theansa-Metallocenes [{(η-C₅Me₄)₂SiMe₂}ZrCl₂] and [{(η-C₅H₄)

Abstract

The (phosphinosilyl)cyclopentadiene 1-SiMe 2 PHMes-2,3,4,5-Me 4 C 5 H, prepared from 1-SiMe 2 -Cl-2,3,4,5-Me 4 C 5 H and LiPHMes (Mes ) 2,4,6-Me 3 C 6 H 2 ), reacts with MeLi to yield Li 2 [(C 5 -Me 4 )SiMe 2 PMes] (2). The (phosphinomethyl)cyclopentadienide Li[(C 5 H 4 )CMe 2 PH t Bu] (4) is obtained by the reaction of LiPH t Bu with 6,6-dimethylfulvene. Li 2 [(C 5 Me 4 )SiMe 2 PR] (R ) cyclohexyl (Cy; 1), Mes (2)) reacts in situ with ZrCl 4 at -30°C to give [{(η-C 5 Me 4 ) 2 SiMe 2 }-ZrCl 2 ] (5). The formation of (PCy) 4 and (PHMes) 2 , respectively, in these reactions was shown by 31 P NMR spectroscopy. In the reaction of Li[(C 5 H 4 )CMe 2 PHR] (R ) Ph (3), t Bu (4)) with ZrCl 4 or [TiCl 3 (thf) 3 ], [{(η-C 5 H 4 )CMe 2 PHR} 2 ZrCl 2 ] (R ) Ph (6), t Bu (7)) and [{(η-C 5 H 4 )CMe 2 -PHR} 2 TiCl] (R ) Ph (9), t Bu (10)) are formed. 6, 7, 9, and 10 slowly decompose on recrystallization from thf, Et 2 O, or toluene with formation of [{(η-C 5 H 4 ) 2 CMe 2 }MCl 2 ] (M ) Zr (8), Ti (11)). The formation of (PR) n (R ) Ph, n ) 4-6; R ) t Bu, n ) 4) and PH 2 R was shown by 31 P NMR spectroscopy. 2, 4, 5-8, and 11 were characterized by NMR spectroscopy ( 1 H, 13 C, 31 P) and the paramagnetic Ti(III) complexes 9 and 10 by EPR spectroscopy and mass spectrometry. 5, 8, and 11 were also characterized by crystal structure determinations.

Novel Ferrocene Derivatives with PH-Functionalized Phosphanylalkylcyclopentadienyl Ligands: Syntheses and Molecular Structures ofrac-[Fe{(η5-C5H4)CMe2PHR}2] (R = Ph, Mes) andrac-[Fe{(η5-C5H4)CMe2PHPh(Cp*TaCl4)}2]

“…However, in the 31 P NMR spectrum, the two Me groups are equivalent, and a doublet of septets is observed. As was observed for Li[(C 5 H 4 )CMe 2 PHR] (R ϭ Ph, [4] Cy [5] ), the signal is shifted to low field by ca. 110 ppm, and the PϪH coupling constant increases by ca.…”

“…[2] While numerous O-and N-functionalized cyclopentadienyl ligands are known, the number of cyclopentadienes with a P-functionalized alkyl or silyl side chain is still small, [1,3] and only recently have we reported the first such compounds in which the P atom has a reactive PϪH bond, namely, 1-SiMe 2 PHCy-2,3,4,5-Me 4 C 5 H, Li 2 [(C 5 Me 4 )SiMe 2 PR] [R ϭ Cy, 2,4,6-Me 3 C 6 H 2 (Mes)], Li[(C 5 H 4 )CMe 2 PHR] (R ϭ Ph, tBu) and Li 2 [(C 5 H 4 )CH 2 CH 2 PPh]. [4,5] The molecular structures of [Li(tmeda)] 2 [(C 5 H 4 )CMe 2 PPh] [6] and [Li(tmeda)]-[(C 5 H 4 )CMe 2 PR 2 ] [7] (R ϭ Ph, Me) were also reported. Such compounds are useful precursors for mono-or dianionic bifunctional ligands in transition metal chemistry.…”

“…[5] Erker et al reported that the complexes [{CyPCMe 2 (η 5 -C 5 H 4 )}M(NR 2 ) 2 ] (M ϭ Ti, R ϭ Me; M ϭ Zr, R ϭ Et) are active catalysts for the polymerization of α-olefins. [8] We now report the synthesis of the novel stable PH-functionalized ferrocene derivatives rac-[Fe{(η 5 Ferrocene derivatives usually show enhanced stability and are generally nontoxic. Thus, their industrial applications range from additives for heating oil to reduce formation of soot, iron-containing fertilizers, UV absorbers and protective coatings for rockets and satellites.…”

Synthesis and reactivity of asymmetrically substituted ansa-bridged zirconocene complexes: X-ray crystal structures of [Zr{R(H)C(η5-C5Me4)(η5-C5H4)}Cl2] (R=Bun, But) and [Zr{Bun(H)C(η5-C5Me4)(η5-C5H4)}(CH2Ph)2]

“…The ansa ligand chelates the zirconium atom and both C 5 rings are bound to the metal in an g 5 mode. The centroids of the cyclopentadienyl rings form an angle with the zirconium atom of 117.5°1b, and 118.3°1c, typical for carbon atom bridged ansa-zirconocene complexes (for example, [Zr{Me 2 C(g 5 -C 5 H 4 ) 2 }Cl 2 ], Ct-Zr-Ct 116.7°) [8]. Selected structural data of 1b and Bond angles (°) Cent(1)-Zr(1)-Cent(2) 117.5 118.3 C(15)-C(1)-Cent (1) 162.23 161.45 C(15)-C(10)-Cent (2) 166.67 163.38 C(1)-C(15)-C (10) 98 (2) 101.0(5) C(1)-C(15)-C (16) 111 (3) 121.3(7) C(10)-C(15)-C (16) 122 (4) 123.3(6) Cl(1)-Zr(1)-Cent (1) 109.01 108.95 Cl(1)-Zr(1)-Cent (2) 109.05 109.77 Cl(2)-Zr(1)-Cent (1) 108.91 108.26 Cl(2)-Zr(1)-Cent (2) 108.93 108.89 Cl(1)-Zr(1)-Cl (2) 102.37 (9) 101.56 (8) Cent (1) and Cent(2) are the centroids of C(1)-C(5) and C(10)-C(14), respectively; * refers to the average bond distance between Zr(1) and the carbon atoms of the C 5 ring of the corresponding cyclopentadienyl moiety.…”

Novel Ferrocene Derivatives with PH-Functionalized Phosphanylalkylcyclopentadienyl Ligands: Syntheses and Molecular Structures ofrac-[Fe{(η5-C5H4)CMe2PHR}2] (R = Ph, Mes) andrac-[Fe{(η5-C5H4)CMe2PHPh(Cp*TaCl4)}2]

“…[2] While numerous O-and N-functionalized cyclopentadienyl ligands are known, the number of cyclopentadienes with a P-functionalized alkyl or silyl side chain is still small, [1,3] and only recently have we reported the first such compounds in which the P atom has a reactive PϪH bond, namely, 1-SiMe 2 PHCy-2,3,4,5-Me 4 C 5 H, Li 2 [(C 5 Me 4 )SiMe 2 PR] [R ϭ Cy, 2,4,6-Me 3 C 6 H 2 (Mes)], Li[(C 5 H 4 )CMe 2 PHR] (R ϭ Ph, tBu) and Li 2 [(C 5 H 4 )CH 2 CH 2 PPh]. [4,5] The molecular structures of [Li(tmeda)] 2 [(C 5 H 4 )CMe 2 PPh] [6] and [Li(tmeda)]-[(C 5 H 4 )CMe 2 PR 2 ] [7] (R ϭ Ph, Me) were also reported. Such compounds are useful precursors for mono-or dianionic bifunctional ligands in transition metal chemistry.…”