The Donor-Acceptor Approach to Molecular Interactions

Solution X-ray Absorption Fine Structure Study of the Eu2+and Sr2+Ions: Unexpected Solvent and Metal Ion Dependencies of the Solvation Numbers

“…c Parameter related to the RDF asymmetry. 37 Actually, the decrease of the structural parameters (metal-to-solvent distance, coordination number, and DW factor) is correlated with increasing DN along the MeCN < H 2 O , DMF < DMSO series for both the Eu 2+ and Sr 2+ cations (Table 6).…”

“…Hence, a decrease in coordination number is observed in the solid state of trivalent lanthanide solvates when increasing the solvation strength of the solvent along the series MeCN < H 2 O , DMF < DMSO. 37 Such an effect is consequently not specific to the Eu 2+ and the Sr 2+ ions in solution but could be observed for other typical hard ions. Note that a steric hindrance effect on coordination number has also been observed among trivalent lanthanides in the very similar DMF and DMA (N,N-dimethyl acetamide) solvents (respective DN values of 26.6 and 27.8).…”

“…Note that a steric hindrance effect on coordination number has also been observed among trivalent lanthanides in the very similar DMF and DMA (N,N-dimethyl acetamide) solvents (respective DN values of 26.6 and 27.8). 37 The decrease in coordination number occurring from DMF to DMA 38 shows that hard ions are subjected to strong solvation steric effects in bulky aprotic oxygen-donor solvents.…”

2,2′,2″-Thiotris(acetic acid) betaine, S(CH2COOH)2(CH2COO), and 2,2′,2″-selenotris(acetic acid) betaine, Se(CH2COOH)2(CH2COO)

“…Salts of the corresponding sulfonium and seIenonium cations, the triacids, [S(CH 2 COOH) 3 ] + and [Se(CH 2 COOH) 3 ] + , however, do not seem to have been isolated. Presumably, these cations are so acidic [2] that their salts may only be obtained from solvents of low donicity [9] and with very weakly basic anions [10]. Schoberi and Lange [11] showed that chlorides and bromides of This suggests that S-and Se-betaines, formally the conjugate bases of sulfonium and selenonium cations bearing two or three acetic acid groups as substituents, have a unique stability causing their Brønsted basicity to be very weak.…”

Interactions of polar hydrogen bond donor solvents with ions: a theoretical study

“…There is also a thermodynamic approach based on the Hildebrand solubility parameter d, applicable for estimating the solubility of nonelectrolytes in organic solvents [7]. Finally, chemical approaches considering solute-solvent interactions in terms of Lewis acidity/basicity [8][9][10][11][12][13], electron pair donors/acceptors [14,15] and H-bonding donors/acceptors [16,17] should be distinguished there. In some cases, solvent effects on chemical and physicochemical properties were described by mixing physical and chemical approaches [6,18].…”