3590-59-8Relevant articles and documents
FIVE-COORDINATE COMPLEXES OF 2,2-DIBUTYL-1,3,2-DIOXASTANNOLANS
Davies, Alwyn G.,Price, Allan J.
, p. 7 - 14 (1983)
2,2-Dibutyl-1,3,2-dioxastannolans, Bu2Sn(OCR2)2, unlike the dioxastannanans, Bu2Sn(OCR2)2CR2, or the acyclic dialkoxides, Bu2Sn(OR)2, react with ligands L, such as pyridine, dimethyl formamide, dimethyl sulphoxide, sulpholane, and tetrahydrofuran to form a series of solid complexes, Bu2Sn(OCR2)2L.Under reduced pressure, the ligands, L, are lost, and the dioxastannolans are regenerated.Measurements of IR, 1H and 119Sn NMR, and Moessbauer spectra, and of molecular weights in solution, imply that the complexes have a trigonal bipyramidal configuration, with equatorial butyl groups, apical ligand L, and the dioxastannolan ring bridging apical and equatorial positions.It is suggested that the relative stability of these complexes results from minimisation of angle strain in the 5-membered ring.
Oligomerization equilibria and dynamics of 2,2-di-n-butyl-1,3,2-dioxastannolanes
Grindley, T. Bruce,Thangarasa, Rasiah
, p. 1364 - 1373 (1990)
The 119Sn and 13C NMR spectra of solutions of 2,2-di-n-butyl-1,3,2-dioxastannolane (1) and a number of its symmetrical derivatives in nonpolar solvents have been studied as functions of temperature and concentration. The compounds studied included (1S,6S)-8,8-di-n-butyl-7,9,8-dioxastannabicyclo[4.3.0]nonane (2), obtained from di-n-butyltin oxide and (S,S)-1,2-cyclohexanediol. A new method of resolution of trans-1,2-cyclohexanediol has been developed. Solutions of 1, 2, and related derivatives of disecondary diols were found to contain mixtures of oligomers that have been identified as dimers, trimers, tetramers, and pentamers. In contrast to earlier work, no evidence for the presence of monomers was obtained. The compositions of the mixtures are extremely temperature dependent; trimers and tetramers are the major constituents below -20 °C, but dimers increasingly dominate as the temperature is raised. Thermodynamic parameters for the equilibria of 1 and 2 have been measured. A derivative of a ditertiary diol, 2,2-di-n-butyl-4,4,5,5-tetramethyl-1,3.2-dioxastannolane, exists in nonpolar solvents predominantly as a dimer over the temperature range studied, from -60 to +80 °C. Activation parameters for a process in this dimer that causes the 13C NMR signals of the pairs of nonequivalent methyl carbons to coalesce have been determined by total line shape analysis. A series of related reversible associative processes involving dimers, trimers, tetramers, pentamers, and possibly monomers and hexamers accounts for the changes observed in the NMR spectra with temperature.
Une methode simple et efficace de preparation des dihydrures organostanniques
Deleuze, H.,Maillard, B.
, p. C14 - C17 (2007/10/02)
A new and efficient method of preparation of R2SnH2 is proposed.Organodioxastannolanes were used as starting materials, these compounds being easily obtained by azeotropic distillation of water from a solution of diorganotin oxides and 1,2 diols in cyclohexane.Their reduction by commercial BH3/THF complex gave raw dialkyltin dihydrides with excellent yields and high purity degrees. Keywords: Borane; Reduction; Dialkylstannanes; 1,3-dioxa-2-stannolanes; Synthesis