Preparation and crystal structure of [(Me3Si)(2)N](2)TeCl2

[(Me3Si)(2)N](2)TeCl2 can be prepared in good yields by treating [(Me3Si)(2 )N](2)Te with an equimolar amount of SO,CI,. The almost colourless crystals are monoclinic with space group P2(1)/c having the unit cell parameters a= 8.517(2), b=11.667(2), c=24.376(5) Angstrom, beta=91.05(3)degrees V=2421.13 (9) Angstrom(3), Z=4. The molecule is monomeric, containing four-coordinate d tellurium of trigonal bipyramidal geometry with the two chlorine atoms oc cupying axial positions and the two (Me3Si)(2)N substituents two equatorial positions. The third equatorial position holds the tellurium lone-pair. Th e short Te-N and Si-N bonds and the long Te-Cl bonds can be understood in t erms of a delocalized pi-electron distribution in the equatorial plane and its interaction with the axial chlorine atoms. A comparison of structural a nd spectroscopic trends in analogous molecular species supports this bondin g scheme. Close intermolecular Te ... Cl contacts expand the coordination s phere of tellurium to six.