Primary Vinyl- and Alkynylstibines: Preparation and Characterization

Abstract

International audiencePrimary unsaturated stibines ethenylstibine (la), E-prop-1-enylstibine (1b), ethynylstibine (2a), and prop-1- ynylstibine (2b) are synthesized by reaction of antimony trichloride with the corresponding vinyltributylstannanes 3a,b and alkynyltributylstannanes 4a,b, respectively, followed by a chemoselective reduction of the formed dichlorostibines Sa,b and 6a,b. Compounds la,b and 2a,b are characterized on the basis of spectral data (NMR, photoelectron spectroscopy and high resolution mass spectrometry). In particular, the PE spectra display very well-resolved bands (1a, 9.3, 10.3, 11.2, 11.9, 13.7, and 15.0 eV; 2a, 9.7, 10.5, and 11.2 eV). The α-unsaturated stibines exhibit a low stability at room temperature even in the presence of a solvent (τ1/2 ca. 1 h) and lead to the formation of oligomeric material or an antimony mirror on the wall of the flask. Attempts to detect C-Sb multiple bond derivatives by a base-catalyzed rearrangement of 1 or 2 were unsuccessful. © 1995, American Chemical Society. All rights reserved

First synthesis and characterization of vinylselenols and vinyltellurols

“…Since 1994, we have been involved in the synthesis of primary low boiling a,b-or b,g-unsaturated phosphines, arsines, stibines, stannanes and mercury hydrides. 3,[9][10][11][12] We have developed an efficient procedure for the preparation of these compounds using vacuum line techniques, via the reduction of the corresponding halo derivatives with excess tributyltin hydride. This approach cannot be used to prepare SH, SeH or TeH derivatives because these products would quickly react with the tin hydride to form the corresponding S-Sn, Se-Sn or Te-Sn derivatives.…”

“…The apparatus already described for the reduction of dichlorostibines was used. 10 The flask containing the precursor [2 mmol of 1a-c or 2a-c diluted in tetraglyme (5 mL)] was fitted on a vacuum line and degassed. Bu n 3 SnH (3 mmol) was then slowly added (30 min) at room temperature with a syringe through the septum.…”

The ground-state rotational spectrum and molecular geometry of ethynylstannane

“…in which N is the number of atoms, m i is the mass of atom i, M is the molecular mass, and c a and d a are constants for each axis a. Use of only the first term in c a to account for the difference e 0 a between the observed zero-point moments of inertia and the unknown equilibrium values leads to a geometry referred to as r (1) m , and correspondingly when both terms in c a and d a are employed to account for e 0 a the result is called a r (2) m geometry. The well-known difficulties produced by isotopic substitution at H were dealt with by introducing a Laurie-type 23 correction d H , which leads to r (1L) m and r (2L) m geometries, respectively.…”

“…Values of c a , d a and d H , as appropriate, are treated as adjustable parameters when the zero-point moments of inertia are fitted to give bond distances and angles. The program STRFIT 21 allows the determination of each of the various r m geometries, but here, because of strong correlations involved when obtaining r (2) m and r (2L) m type quantities, only the r (1) m , and r (1L) m versions are reported. These are included in Table 7, where the quoted errors reflect the good quality of the various fits.…”

“…The synthesis of primary 1-alkynyl heterocompounds is still a great challenge. In the last decade some of the simplest derivatives have been synthesized, such as ethynylarsine, 1 ethynylstibine, 2 or ethynylstannane. 3 Although all of these compounds are kinetically more stable than the corresponding oxygen (ethynol) 4 and nitrogen derivatives (ethynamine), 5 they are quite difficult to prepare and should be kept at low temperature even when diluted in a solvent.…”