Structure of catena-μ-bromo-dibromo(phenyl)-tellurium(IV)

Structural isomerism in (p-XC6H4)SeCl3 and (p-XC6H4)SeBr3 (X = F, Cl) compounds. Co-crystallisation of cis- and trans-dimeric forms of (p-ClC6H4)SeCl2(μ-Cl)2(p-ClC6H4)SeCl2. A new structural modification for the “PhSeBr” reagent, Ph2Se2Br2, containing an elongated Se–Se bond

“…19 These findings illustrate that the structure of ArSeX 3 (X = Cl, Br) compounds are dependent on the nature of the aryl group. A similar diversity in structure has been observed for ArTeCl 3 and ArTeBr 3 systems, where both PhTeCl 3 and PhTeBr 3 have chain 80 polymeric structures, [26][27] but substituted aryl derivatives have been shown to exhibit other structural motifs. For example, (p-OPhC 6 H 4 )TeCl 3 is dimeric with trans-(p-OPhC 6 H 4 ) groups, 28 whilst a number of other ArTeCl 3 structures are polymeric but only have a single chloride bridge.…”

Chlorination and Bromination of Dialkyl Tellurides

“…Crystals of 7, 8 and 9 were obtained from slow evaporation of CHCl 3 solutions at ambient temperature. They are in a similar range as found for the aryl derivatives p-C 2 H 5 OC 6 H 4 TeBr 3 (Te1±Br1 2.527(3) A Ê , Te1±Br2 2.509(3) A Ê , Te2±Br5 2.539(2) A Ê , Te2±Br6 2.548 (2) A Ê ) [15] and C 6 H 5 TeBr 3 (Te1±Br12 2.513(2) A Ê , Te1±Br13 2.529(2) A Ê , Te2±Br22 2.525(2) A Ê , Te2±Br23 2.536(2) A Ê ) [16], but slightly shorter than the Te±Br distances found in dialkyltellurium dibromides, e. g. in (CH 3 ) 2 TeBr 2 (Te1±Br1 2.647(5) A Ê , Te1±Br2 2.720(6) A Ê ) [25]. Due to the rather poor quality of the structure determination, the data are not discussed in detail.…”

Synthesis and structural aspects of 1-naphthyltellurium(IV) trichloride (1), bis(mesityl)tellurium(IV) dichloride (2) and bis(chlorobis(2-thiophenyl)tellurium)oxide (3)

“…Here the size of the halogen should be the other determining factor and the preference for dimeric structures increases as size of the halogen increases [8][9][10][11][12]. The isomorphous PhTeCl 3 and PhTeBr 3 exist as polymers made up of infinite chains with bridging halides, but with no TeÁ Á ÁX secondary bonds [8,13]. In contrast to the polymeric chlorides and bromides, PhTeI 3 has been reported to exist as dimers, having either cis or trans oriented phenyl groups [9].…”

“…It has been assumed that among RTeX 3 compounds there is a tendency for the chlorides to be polymeric, the bromides either polymeric or dimeric, the iodides to be dimeric and if R is particularly bulky, monomeric structures would be the rule. Here the size of the halogen should be the other determining factor and the preference for dimeric structures increases as size of the halogen increases [8][9][10][11][12]. The isomorphous PhTeCl 3 and PhTeBr 3 exist as polymers made up of infinite chains with bridging halides, but with no TeÁ Á ÁX secondary bonds [8,13].…”

“…The nearly coplanar four Cl atoms along with the Te atom {deviation from the mean plane is limited to 0.1788 Å (Cl12 atom) and 0.019 Å (Cl23 atom) in molecules I and II respectively} occupy the basal plane. Formation of similar square pyramidal, TeX 4 Y units in the solid state has been observed invariably for the anions [TeX 4 Y] À (Y = X = Cl[64] or Y = aryl group, X = Cl, Br[65]) and among the oligomeric or polymeric supramolecular motifs in the solid state of similar organotellurium trichlorides[3,10,66] as well as organotellurium tribromides[8] including the bromo analog of 1[17]. In the case of neutral organotellurium trichlorides and -tribromides formation of planar TeX 4 units takes place when the central Te atom is approached by a chloro or bromo ligand of an adjacent molecule in a direction trans to the equatorial Cl(Br)-Te bond in preference to that of the C-Te bond resulting in two quasi linear X-Te-X alignments.…”