12‐Membered Macrocycles Containing Ditelluroxane and Selenotelluroxane Units

Abstract

The reaction of benzeneseleninic acid with bis(p‐methoxyphenyl)tellurium dihalide [halide = Cl (1), Br (2)] afforded colorless crystals in moderate yield. Single‐crystal X‐ray diffraction revealed the formation of 12‐membered macrocycles [(p‐MeO‐C6H4)2Te(μ‐O)(μ‐PhSeO2)(μ4‐X)]2 [X = Cl (1), Br (2)] where the halogen atoms, which are stabilized by Te–X interactions, cap the macrocycle on both sides. The reaction of NaI with 1 afforded the iodo‐capped macrocycle [(p‐MeO‐C6H4)2Te(μ‐O)(μ‐PhSeO2)(μ4‐I)]2 (3) in good yield. In the solid‐state structures of 1–3, the alignment of the phenyl group on Se changes with respect to the macrocycle. Macrocycle 3 shows rare Se–π interactions, which lead to the formation of a supramolecular polymeric network. Further reaction of methaneseleninic acid with bis(p‐methoxyphenyl)tellurium dichloride in methanol in the presence of triethylamine afforded a 12‐membered macrocycle [(p‐MeO‐C6H4)2Te(μ‐O)(μ‐MeSeO2)(μ4‐Cl)]2 (4), which is structurally similar to 1–3.

Te4Se2O6 macrocycle stabilizing triangular planar and tetrahedral anions

“…9 The 12-membered ring Te The average Te-O bond length of the ditelluroxane unit in 2 is 2.0028(14), which is slightly higher than the previously reported average Te-O bond lengths of 12-membered macrocyles. 5,6 The average O-Te-O angle 169.2( 6)°is similar to that reported previously and the Te-O-Te angle is 114.39(7)°, which is considerably less when compared to previously reported 12-membered macrocycles (123.10°-126.90°). The average Se-O bond length in 2 is 1.6975(15) Å, which is similar to that reported earlier, whereas the O-Se-O angle is 103.91(8)°, which is slightly less when compared to previous reports (105.70°-107.77°).…”

“…† The average Te-O bond lengths of ditelluroxane units in 3 and 4 are 1.9975(15) and 1.9974(12), respectively, which are slightly high when compared to that of previous reports. 5,6 The average O-Te-O angles are 170.66( 6)°a nd 170.45( 6)°for 3 and 4, respectively, which are also higher when compared to the previous results. The average Se-O bond length and O-Se-O angles in 3 and 4 are 1.6976( 17) Å and 105.29(9)°and 1.7017(13) Å and 105.16(7)°, respectively.…”

“…The average Se-O bond length in 2 is 1.6975(15) Å, which is similar to that reported earlier, whereas the O-Se-O angle is 103.91(8)°, which is slightly less when compared to previous reports (105.70°-107.77°). 6 Macrocycles 3 and 4 resulted from the replacement of spherical chloride ions in 1a by perchlorate and tetrafluoroborate ions, respectively. The Te-O interactions in 3 fall in the range of 3.0078(18)-3.581(3) Å with an average of 3.208(2) Å, which is less when compared to the sum of the Van Der Waals radii (3.58 Å) and slightly high in comparison to the previously reported Te-O interactions.…”

“…These bond angles are almost similar to those reported earlier; whereas, the bond lengths are on a slightly higher side. 5,6 Weak intermolecular C-H⋯O interactions 13 in 2, 3 and C-H⋯F interactions 14 in 4 have been observed upon analysing the solid state packing of the crystal structures of 2-4 (ESI †).…”

“…5 Using a similar synthetic methodology, the reactivity of diorganotellurium dihalides with phenyl/methyl seleninic acid has been investigated, which resulted in the assembly of 12-membered inorganic macrocycles (1a-c) comprising two tetraorganoditelluroxane motifs assembled together with two phenyl/methyl seleninates to form a dicationic Te 4 Se 2 O 6 macrocyclic core, which is further stabilized by two halide ions (chloride/ bromide) that are present above and below the macrocycle. 6 Interesting conformational changes in the solid state structures of the 12-membered macrocycles have been observed starting from 1a-c, where different sized spherical ions namely chloride, bromide and iodide, respectively, stabilized the dicationic macrocyclic core. After observing such interesting flexible behaviour of the 12-membered macrocyclic core, anion exchange reactions with different anions displaying varying geometry around a central element were performed to check the stability and flexibility of this 12-membered macrocyclic host.…”