Synergistic effects of phosphine oxides on the extraction of nickel(n) with 2-hydroxy-N-phenylbenzamide into n-butanol

Department of Chemistry, The University of Burdwan, Burdwan-713 104, West Bengal, India E-mail : basu_sukalyan@yahoo.co.in Manuscript received 18 November 2010, revised 12 April 2011, accepted 20 April 2011 The extraction behavior of nickel(II) from dilute hydrochloric acid medium using 2-hydroxy-N-phenylbenzamide (HA) and its mixture with several neutral donors e.g. tri-octylphosphine oxide (TOPO), tri-butyl phosphine oxide (TBPO) and tri-phenyl phosphine oxide (TPPO) were investigated. The extraction constants for the binary species [Ni(A)2] and ternary species [Ni(A)2(B)] were determined, where HA = undissociated chelating agent and B = neutral donors. The result was very much in accordance with the trend in basic characters of the donors. Thermodynamic parameters were also evaluated, following the extractions under varying temperature