An Improved Protocol for the Synthesis and Nanofiltration of Kim and Park’s Aminocyclopentadienyl Ruthenium Chloride Racemisation Catalyst

Abstract

An improved synthesis of aminocyclopentadienyl ­ruthenium chloride catalyst 1 is reported. A combination of catalyst 1 and phosphazene base 3 is shown to effect racemisation of 1-­phenylethanol. Removal of 1 and 3 by nanofiltration is a practical and effective purification method.

Key words

racemisation - ruthenium - phosphazene - nanofiltration

References

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9

Starmem is a trademark of W. R. Grace and Co, USA. Starmem 120 and 122 have nominal MWCO of 200 and 220 g mol^-1. MWCO is determined from a plot of rejection vs. molecular weight for n-alkanes in toluene.

11

Recovery of species i (Rec_i) is defined as the molar percentage permeated through the membrane and is calculated using Equation [1] :
Retention of species i (Ret_i) is defined as the molar percentage retained by the membrane and is calculated using Equation [2] , where C_i,r and C_i,p and V_r and V_p are the molar concentrations of i and volumes, respectively, in the retentate and permeate:

14

Starmem^TM membranes and the nanofiltration cell were obtained from Membrane Extraction Technology Ltd, UK (www.membrane-extraction-technology.com).