Noncovalently Anchored Organometallic Complexes

Noncovaient Anchoring of Organometallic Complexes via Ionic Interactions 

Chemisorphon of the complexes [Cp MR2], [Cp MR3] or [MR4] (Cp = Cp, Cp M = Zr, Ti, Th R = Me, CH2 Bu, CH2TMS) onto superacidic sulfated zirconia (ZRS , where x refers to activation temperature) [81, 91] and sulfated y-alumina (AIS) [90] afforded active benzene hydrogenation catalysts and ethylene polymer-izahon catalysts. The most active catalyst system for the hydrogenation of benzene (arene Zr = 1.5 1, 25 °C, no solvent, 0.1 MPa H2) was [Cp ZrMe2] -ZRS400, which achieved a TOP of 970 h. The activity of this adsorbate catalyst rivals or exceeds those of the most active heterogeneous arene hydrogenahon catalysts known. The 

To examine the effect on the catalysis of the anion of the metal complex, Brandts [96] immobilized the two different catalyst precursor complexes [Rh(COD)2]BE4 and [Rh(COD)Cl]2 on phosphotungstic acid-modified alumina to form 7-AI2O3/ 

Transition Metal Single Site Catalysts-From Homogeneous to Immobilized Systems 

Ionic immobilization of a Mn(lll)-salen complex in the pores of Al-MCM-41 has been reported by Hutchings and coworkers [98, 99]. The catalytically active species was formed in situ by the reaction of the ligand (R,Rj-3,5-di-tert-butylsalen with Mn -ion-exchanged Al-MCM-41. The efficacy of this material as a catalyst for the epoxidation of (Zj-stilbene using PhlO as the oxygen donor was then examined (stilbene PhlO catalyst = 7 1 0.13, 25°C, CH2CI2). When the [Mn(salen )]-Al- 

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