Structural criteria for the rational design of selective ligands. Extension of the MM3 force field to aliphatic ether complexes of the alkali and alkaline earth cations

Journal Article · Wed Jul 13 04:00:00 EDT 1994 · Journal of the American Chemical Society; (United States)

DOI:https://doi.org/10.1021/ja00093a035· OSTI ID:7015378

Hay, B P; Rustad, J R ^[1]

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1. Pacific Northwest Lab., Richland, WA (United States)

Structural requirements for strain-free metal ion complexation by an aliphatic ether group are investigated through the use of both ab initio molecular orbital and molecular mechanics calculations. Hartree-Fock calculations on simple models, M-O(Me)[sub 2] and M-O(Me)(Et), reveal a preference for trigonal planar geometry when aliphatic ether oxygens are coordinated to alkali and alkaline earth cations. This preference is found to be strongest in small, high-valent cations and weakest in large, low-valent cations. Results from the Hartree-Fock calculations are used to extend the MM3 force field for calculation on aliphatic ether complexes with the alkali (Li to Cs) and alkaline earth (Mg to Ba) cations. The resulting molecular model (i) reproduces the experimental crystal structures of 51 different complexes of multidentate ethers with alkali and alkaline earth cations, (ii) explains experimental trends in the structure of five-membered chelate rings of aliphatic ethers, (iii) reveals a fundamental difference between the metal ion size selectivity of five-membered chelate rings of ethers versus that of amines, and (iv) rationalizes trends in the stability of four potassium complexes with the diasteriomers of dicyclohexyl-18-crown-6. 40 refs., 9 figs., 5 tabs.

• DOE Contract Number: AC06-76RL01830
• OSTI ID: 7015378
• Journal Information: Journal of the American Chemical Society; (United States), Journal Name: Journal of the American Chemical Society; (United States) Vol. 116:14; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
ALKALI METAL COMPLEXES
ALKALINE EARTH METAL COMPLEXES
CALCULATION METHODS
COMPLEXES
COMPUTERIZED SIMULATION
CROWN ETHERS
CRYSTAL STRUCTURE
DATA
ETHERS
EXPERIMENTAL DATA
HARTREE-FOCK METHOD
INFORMATION
LIGANDS
MOLECULAR ORBITAL METHOD
MOLECULAR STRUCTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANOMETALLIC COMPOUNDS
SIMULATION
THEORETICAL DATA