Macrocycles Containing Tin. Solid Complexes of Anions Encrypted in Macrobicyclic Lewis Acidic Hosts
Abstract
Crystalline complexes of 1,10-dichloro-1,10-distannabicyclo.8. 8hexacosane and benzyltriphenylphosphonium chloride (complex 3) and of 1,8- dichloro-1,8-distannabicyclo-6.6.6eicosane and tetrabutylammonium fluoride (complex 4) have been studied by X ray crystallography and solid state 119 Sn NMR spectroscopy. The halide ions are encrypted within the cavities of the bicyclic hosts in both complexes. Complex 3 is a stannates stannane species wherein one of the Lewis acidic tins binds the chloride strongly and the other interacts with the chloride only weakly. Complex 4 is a bis-hemistannate species wherein the Lewis acidic tin atoms bind the guest fluoride simultaneously. Low temperature species wherein the Lewis acidic tin the two complexes in halogenated solvents were studied. A chloride jump from one tin to the other was observed in complex 3; the dynamic process has an activation energy of 5.3 kcal/ mol. Line broadening of the tin signals in complex 4 was consistent with a similar fluoride jump with an activation energy of 2.9 kcal/mol. The crystalline complexes were reasonable models for the solution complexes in both cases, and the structural features in the solid state can be used to rationalize the binding in solution.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 27, 1989
- Accession Number
- ADA203765
Entities
People
- John H. Horner
- Martin Newcomb
- Michael T. Blanda
- Philip J. Squatritto
Organizations
- Texas A&M University