Issue in Honor of Prof. Domenico Spinelli ARKIVOC 2002 (xi) 54-64 Table 1. Continued Entry CASb Solvent 112 109-87-5 Dimethoxymethane 113 462-95-3 Diethoxymethane 1 -105 -66.5 2 43 88 3 2.64 2.53 Descriptors 4 5 6 1.3541 0.16 0.1 7 8 -0.265 0.797 9 PPs t1 t2 -1.26 -2.58 -1.39 -0.82
(a) Values different from those in ref. 1 are in red, newly inserted data in blue. Descriptors are those reported in ref. 1: 1, melting point (°C); 2, boiling point (°C); 3, dielectric constant; 4, dipole moment ×1030 (C m), 5, refractive index; 6, ET, the normalized Reichardt–Dimroth parameter (kcal/mol); 7, density ×103 (kg/m3); 8, lipophilicity as measured by logP where P is the equilibrium constant of the distribution of the solvent between 1-octanol and water at 25°C; 9, water solubility (log mol/L). (b) Chemical Abstracts Registry Number 21 83 1054 69 55 -4.00 -2.00 0.00 2.00 4.00 6.00 t1 a 83 61 32 54 -3.50 -1.50 0.50 2.50 4.50 t 2 b -4.00 -2.00 0.00 2.00 4.00 6.00
-3.50 -1.50 0.50 2.50 4.50
t1 (ref.1) t2 (ref. 1) Figure 1. Correlation between PPs for solvents 1–103 derived in the present work and those in ref. 1.
Figure 1 shows that, as expected, the PPs for solvents 1–103 derived from the 113 solvents model, with a few exceptions (differences above 0.5 are discussed below), closely resemble those of the 103 solvents model reported in ref. 1. Differences in both t1 and t2 found for triglyme
(54) and tetraethylene glycol (83) can be ascribed to the addition of new values for 54 and correction of logP for 83. Significant differences in t1 for ethanol (10) and in t2 for N,Ndimethylacetamide (32) are due to corrections of descriptor values, while those in t1 for 4methyl- 1,3-dioxol-2-one (21) and diglyme (55) are the result of the insertion of new values. Differences in t2 for chlorobenzene (61) and in t1 for piperidine (69) are probably due to printing errors in Table 15A.1 of ref. 1, as the plot in the same book and PPs in ref. 12 are consistent with our values. Figure 2, the PCA “p1–p2 loadings plot” (see equation 1 in the Experimental Section), elucidates the descriptors information content, and provides guidance for interpreting the physico-chemical meaning of solvents PPs. The first PC, exhibiting high p1 values for
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