Hydrogen-bonding in ethanol adducts to bis(3-R-penta-2,4-dionato)nickel(II) species

Ethanol adducts of bis(3-R-penta-2,4-dionato) nickel(II) have been prepared by recrystallization of the corresponding nickel bisacetylacetonate specie s from ethanol, and their crystal structures have been determined by X-ray diffraction: R = methyl, C16H30NiO6, a = 5.177(1), b = 9.326(1), c = 9.649( 1), a = 95.39(1), beta = 100.04(1), gamma = 97.16(1), space group P (1) ove r bar, Z = 1; R = phenyl, C26H34NiO6, a = 5.176(1), b = 9.677(1), c = 14.45 8(1), a = 92.333(3), beta = 93.945(4), gamma = 96.011(6), space group P (1) over bar Z = 1; R = phenyl, C26H34NiO6, a = 27.399(1), b = 5.349K(1), c = 19.827(2), beta = 117.410(7), space group C2/c, Z = 4. The compounds show r emarkable differences in their ability to form hydrogen bonds in the solid phase and in solution, depending upon the nature of the substituent in the 3-position of the acetylacetone fragment. Analysis of the strength of hydro gen bonds within the limits of supermolecular approximation based on the re sults of calculations by DFT method has been carried out and were found to correlate with experimental observations.