‘Tellurium acetylacetonates’: crystal structures of 1,1-dichloro-1-telluracyclohexane-3,5-dione and 1-telluracyclohexane-3,5-dione

Abstract

The crystal structures of the title compounds Cl₂TeC₅H₆O₂, (I) and TeC₅H₆O₂, (II) have been determined by the heavy-atom method and refined by least squares to R 0.060 (I)(1 642 reflections) and 0.058 (II)(1 182 reflections). Crystals of (I) are monoclinic, a= 10.565(7), b= 22.03(1)·c= 7.185(3)Å, β= 130.74(6)°,Z= 6, space group Cm; crystals of (II) are orthorhombic, a= 5.2765(9), b= 10.744(2), c= 22.296(6)Å, Z= 8, space group I2cb. The structures comprise monomeric units. In (I) the tellurium environment is pseudo-trigonal-bi-pyramidal with axial chlorines [means : Te–Cl 2.49 Å: Cl–Te–Cl 171.8°(opposite to the ‘lone pair’)]; C–Te–C is 95.5°. In (II) C–Te–C is reduced to 89.5°. Te–C in both compounds is 2.16 Å.