Bis-π-cyclopentadienyl-zirkon(IV)-aroxide

Abstract

Aus Bis-π-cyclopentadienyl-zirkondibromid und Phenol bzw. substituierten Phenolen bilden sich bei Gegenwart von Aminen die Bis-π-cyclopentadienyl-zirkondiphenoxide als farblose, verhältnismäßig stabile Substanzen. Werden 1.2-Dihydroxybenzol und 2.2'-Dihydroxybiphenyl verwendet, so gelingt die Darstellung cyclischer Verbindungen mit Fünf- bzw. Siebenringstruktur, während 1.8-Dihydroxynaphthalin nicht unter Bildung des analogen Sechsringes reagiert. Die IR-Spektren dieser Verbindungen werden diskutiert.

Replacing Chloride by Alkoxide: Cp2Zr(H)OR, Searching for Alternatives to Schwartz's Reagent

“…In our case, room-temperature addition of 1 equiv of ROH (R: Ph, C 6 F 5 , t Bu) to a stirred suspension of Cp 2 ZrH 2 only resulted in the formation of the toluene-soluble zirconocene dialkoxide complexes Cp 2 Zr(OR) 2 , 1a − c , and a white residue (Scheme ). Compounds 1a − c were identified by their NMR spectra in comparison to literature data. ,− The remaining insoluble material isolated in these reactions was identified as Cp 2 ZrH 2 by treatment with excess acetone, which revealed only 1 H NMR signals associated with the formation of the 1,2-insertion product of acetone: Cp 2 Zr(O i Pr) 2 ( 1 H NMR: δ 6.03 (s, 10H), 4.10 (q, 2H, J = 6 Hz), 1.07 (d, 12H, J = 6 Hz)) . Treatment with acetone proved to be a convenient and reliable technique to test for zirconium hydride bonds in insoluble zirconocene complexes.…”

“…All reactions were carried out under an inert atmosphere using Schlenk and glovebox techniques. Cp 2 Zr(OPh) 2 , Cp 2 Zr(BH 4 ) 2 , Cp 2 Zr(H)(BH 4 ), Cp 2 ZrMe 2 , Cp 2 Zr(OPh) 2 , Cp 2 Zr(OC 6 F 5 ) 2 PhOSiMe 3 , C 6 F 5 OSiMe 3 , and t BuOSiMe 3 were prepared according to literature procedures. Cp 2 ZrH 2 , Cp 2 ZrCl 2 , and other chemicals were purchased from common commercial suppliers.…”