W. Zielenkiewicz et al., VOLUMETRIC PROPERTIES OF TETRAPHENYLPORPHINE, THEIR METALLO-COMPLEXESAND SOME SUBSTITUTED TETRAPHENYLPORPHINES IN BENZENE SOLUTION, Journal of solution chemistry, 25(2), 1996, pp. 135-153
Densities, apparent molar volumes and partial molar volumes of benzene
solutions of tetraphenylporphine, H2TPP, tetraphenylporphine metallo-
complexes, MTPP (where M = Ni,Cu,Zn,Pd,Ag, and Cd) and some substitute
d tetraphenylporphines H2T(i-R)PP (where i = 2-4 and R = -Cl,-CH3, -OC
H3), H2T(i-F)PP (where i = 2,3), H2T(3-Br)PP, and H2T(3-I)PP were dete
rmined at 25 degrees C. It was found that the partial molar volumes of
the studied compounds correlate linearly with the first ionization po
tential of the corresponding metal atom. The calculated values of the
surface and volume accessible to the solvent, and the solvent-excluded
volume for different conformations of H2TPP, were compared with exper
imental data. The volume per molecule for different crystalline forms
of H2TPP and MTPP were compared with the partial molar volumes of the
corresponding compounds in benzene solutions. The correlation between
the partial molar volumes of H2T(3-R)PP and their Van der Waals volume
s are presented for R = -H, -F, -CH3, -Cl, -Br, -OCH3, and -I. The exp
erimental data are rationalized in terms of differences in the conform
ational states of the molecules.