Tetramethoxy‐λ⁴‐tellane and Tetrakis(2,2,2‐trifluoroethoxy)‐λ⁴‐tellane

Abstract

Two tetraalkoxy‐λ4‐telluranes were prepared from tellurium tetrachloride and the sodium salts of methanol and 2,2,2‐trifluoroethanol, respectively. Their molecular structures which were determined by single‐crystal X‐ray diffraction show dipolar intermolecular contacts. NBO analyses for the title compounds were conducted to assess the role of the stereochemically active lone pair on the tellurium atoms.

Bis(ethyleneglycolato-κ2O,O′)tellurium(IV)

“…Crystal structures of seven similar four coordinate Te 4+ complexes with oxo ligands have previously been reported by Day & Holmes (1981), Yosef et al (2007), Annan et al (1992), Fleischer & Schollmeyer (2001), Betz et al (2008) and Lindqvist (1967), all of which have a distorted seesaw geometry of the Te centre. The geometries or the Te-O bond lengths in these structures do not differ remarkably from those in the title compound.…”

“…For the use of Te 4+ ethylene glycol solutions in electrodeposition of Te and Te compounds, see: Nguyen et al (2012); Wu et al (2013). For crystal structures of related four-coordinate Te 4+ complexes with oxo ligands, see: Day & Holmes (1981); Yosef et al (2007); Annan et al (1992); Fleischer & Schollmeyer (2001); Betz et al (2008); Lindqvist (1967). Table 1 Selected bond lengths (Å ).…”

“…The O-Te-O bond angles that define the seesaw are 105.59° and 153.53° compared to 94.83 (14)° and 159.65 (13)° in the title compound. In tetrakis(methoxy)tellurium(IV) (Betz et al, 2008), the O-Te-O bond angles are 89.99° and 171.42°.…”

Carbon Dioxide Fixation with Dialkyltellurium(IV) Dihydroxides

“…The coordination sphere of the tellurium atoms is completed by one (Te1 of 1 ) and two (Te2 of 1 and Te1, Te2, Te3 of 2 ) secondary Te···O contacts [2.88(1)–2.904(6) Å for 1 and 3.007(5)–3.488(5) Å for 2 ] that are up to 17 % shorter than the sum of the van‐der‐Waals radii (3.5 Å) 35. It is to note that such secondary Te···O contacts are commonly observed for Te IV compounds, as exemplified in the recently reported crystal structures of Te(OCH 3 ) 4 and Te(OCH 2 CF 3 ) 4 36. The two water molecules (O7 and O8) and the two hydroxy groups (O1 and O6) of 2 are involved in hydrogen bonds.…”

2. Selenium– and tellurium–halogen reagents

“…TeCl4 system achieved isolated yields of 58 % (R = Me) or 64 % (R = CF3CH2)[79]. An unexpected transformation is observed in the reaction of TeCl4 with ethane-1,2-diol in a 1:1 molar ratio in acetonitrile at reflux.…”