The zinc(II) ion incorporation reaction into 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (H(2)tpfpp) to form the [Zn(tpfpp)] complex has been kinetically investigated using the methanol and water adducts of bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)zinc(II) ([Zn(hfac)(2)L-2]; L = H2O, CH3OH) in supercrifical carbon dioxide (SCCO2) medium at various temperatures and pressures. The metalation reaction is first-order with respect to the porphyrin and Zn(II)-hfac complexes. The kinetic parameters are obtained as follows: k = 3.1 mol dm(-3) s(-1) at 308.2 K and 20.5 MPa, DeltaH(double dagger) = 43.4 +/-1.4 kJ mol(-1), DeltaS(double dagger) = -70 +/- 5 J mol(-1) K-1 for the reaction system {H(2)tpfpp + [Zn(hfac)(2)(CH3H)(2)]} at 20.5 MPa, and k = 7.7 mol(-1) dm(3) s(-1) at 308.2 K and 20.5 MPa, DeltaH(double dagger) = 21 +/- 1 kJ mol(-1), DeltaS(double dagger) = -(1.4 +/- 0.2) x 10(2) J mol(-1) K-1 for the reaction system {H(2)tpfpp + [Zn(hfac)(2)(H2O)(2)]} at 20.5MPa. The activation volumes (DeltaV(double dagger)) at 308.2K are (4.0 +/- 0.4) x 10(2) cm(3) mol(-1) for [Zn(hfac)(2) (CH3OH)(2)] and (3.8 +/- 0.7) x 10(2) cm(3) mol(-1) for [Zn(hfac)(2)(H2O)(2)] in the pressure range from 10 to 35 MPa. In the presence of an excess amount of methanol as a cosolvent, the outer-sphere adducts between methanol and [Zn(hfac)(2)(CH3OH)(2)] are formed by hydrogen bonding with the formation constants of beta(1) = (1.2 +/- 0.3) x 10(2) mol(-1) dm(3) and beta(2) = (1.4 +/- 0.3) x 10(4) mol(-2) dm(6) at 323.3 K and 20.5 MPa, and the outer-sphere adducts, [Zn(hfac)(2)(CH3OH)(2)]-(CH3OH) and [Zn(hfac)(2)(CH3OH)(2)]-(CH3OH)(2), are non-reactive. The mechanistic consideration and specific cosolvent effect will be described on the basis of the rate law and activation parameters. (C) 2003 Elsevier B.V. All rights reserved.