Structural and molecular mechanics studies of bis(dibutyl phosphato)aquastrontium-18-crown-6 and analogous alkaline-earth-metal complexes

Journal Article · Wed May 06 00:00:00 EDT 1987 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00256a007· OSTI ID:6541265

Burns, J H; Kessler, R M

The stability of bis(dibutyl phosphato)aquastrontium-18-crown-6 (1) has been compared with analogous real and hypothetical alkaline-earth-metal complexes by use of molecular mechanics calculations. Trial molecular structures from which energy minimization proceeded were obtained by crystal structure analysis of 1 and from its previously analyzed Ba analogue. Existence of these molecules in solution was also verified by IR and NMR spectra. Crystals of 1 are monoclinic, P2/sub 1//c, with a = 9.23 (1) A, b = 27.24 (3) A, c = 31.55 (3) A, ..beta.. = 94.95 (6)/sup 0/, and Z = 8. In the two independent molecules of the crystal each Sr/sup 2 +/ ion is coordinated by six O atoms of a crown ether, by two monodentate dibutyl phosphato ions, and by one H/sub 2/O molecule. The differences in calculated total energies among these complexes are due primarily to the Coulombic contributions, the strain in the crown molecules being relatively unimportant within wide geometrical limits. An estimate of the selectivity of the crown/dibutyl phosphate combination among the hydrated alkaline-earth-metal ions suggests that they are selected in the order Ba > Sr > Ca > Ra > Mg.

• Research Organization: Oak Ridge National Lab., TN
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6541265
• Journal Information: Inorg. Chem.; (United States), Vol. 26:9
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
POLYETHYLENE GLYCOLS
CRYSTAL STRUCTURE
MOLECULAR STRUCTURE
STRONTIUM COMPLEXES
INFRARED SPECTRA
MOLECULAR MODELS
NMR SPECTRA
SOLUTIONS
THEORETICAL DATA
ALCOHOLS
ALKALINE EARTH METAL COMPLEXES
COMPLEXES
DATA
DISPERSIONS
GLYCOLS
HYDROXY COMPOUNDS
INFORMATION
MATHEMATICAL MODELS
MIXTURES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC POLYMERS
POLYMERS
SPECTRA
400201* - Chemical & Physicochemical Properties