ISSN:
0009-2940
Keywords:
Diselenolates
;
Thallium complexes
;
Lead complexes
;
Selenium complexes
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Preparation, Structures, and Thermal Decomposition Reactions of Complexes Consisting of TlI, PbII, and SeII and 2,2-Dicyanoethylene-1,1-diselenolateThe 2,2-dicyanoethylene-1,1-diselenolate-containing compounds (AsPh4)2[Tl2(Se2C=C(CN)2)2], (AsPh4)2[Pb(Se2C=C-(CN)2)2], and (NBu4)2[Se(Se2C=C(CN)2)2] have been prepared and characterized by single-crystal structure analysis. The molecular structures of the complex anions 1-3 are significantly influenced by the presence of stereochemically active lone pairs. 1 is dimeric with an Se4Tl2 octahedral centre with a Tl-Tl distance of 3.547(4) Å and an average Tl-Se bond length of 3.143(4) Å. In 2 Pb constitutes the centre of a distorted pseudo-trigonal bipyramid PbSe4E [Pb-Seave = 2.948(3) Å] with one equatorial position obviously occupied by the lonepair E. In 3 the ligands are coordinated to the central Se, which is situated in a centre of symmetry, in an undistorted way giving rise to a Ψ-octahedral SeSe4E2 geometry [Se-Seave = 2.617(2) Å]. The compounds (AsPh4)2 · 1, (AsPh4)2 · 2 and (NBu4)2 · 3 have been decomposed thermally to yield TlSe, PbSe as well as Se. The observed contamination of TlSe and PbSe with As is avoided by using (NBu4)2 · 1 and (NBu4)2 · 2 as precursor materials.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250709
