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.

Reactions of diphenyltellurium oxide with organostibonic acid and polymeric triphenylantimony oxide have been investigated independently. Single crystal X-ray diffraction studies have revealed the formation of novel and rare mixed valent Sb(v)/(iii) containing polyoxostibonates {(C6H5)3Te}2{Na2(H2O)2(p-Br-C6H4Sb(V))10(Sb(III))4[(C6H5)2Te]4(O)30(OH)4} and {(C6H5)3Te}4{[(C6H5)2Sb(V)]4(Sb(III))4(O)12(OH)4} . Solution (125)Te NMR supports the solid state structures presented. Interestingly, during the assembly of these POMs several processes happen simultaneously. Rarely observed reduction from Sb(v) to Sb(iii), complete dearylation of organoantimony precursors and complexation ability of a tetraorganoditelluroxane moiety stabilizing large and novel POM structures (as in ) along with the formation of triphenyltellurium cations which not only provide charge balance but also stabilize the POM framework (as in ) by weak interactions are reported.

The reaction of polymeric triphenylantimony oxide with various protic ligands like phenylphosphinic acid, diphenylphosphinic acid, tert‐butylphosphonic acid, and phenylseleninic acid has been investigated. Single‐crystal X‐ray structural elucidation revealed the formation of [Ph3Sb(HPhPO2)2]2 (1), [Ph3Sb(Ph2PO2)2] (2), [Ph3Sb(tert‐BuPO3H)2] (3), [Ph3Sb(PhSeO2)2]2 (4), and [(Ph3Sb)2(μ‐O)(μ‐PhSeO2)2] (5), respectively. Hydrolysis and dearylation of 3 yielded [(Ph2Sb)2(PhSb)(μ3‐O)(μ2‐O)2(OH)2(μ‐tBuPO3)2{(C2H5)4N}2] (6) possessing in situ generated Ph2Sb(O)(OH) and PhSbO3H2 moieties. The 31P NMR spectrum of 1 shows P–H three‐bond coupling seen for the first time in organophosphorus‐based compounds. Further 31P NMR spectroscopy at lower temperatures revealed 1 to be a fluxional molecule. 77Se NMR spectroscopy indicates the formation of different molecular clusters from crystallization processes carried out under varying solvent conditions.

The anion exchange reactions of Cl-macrocycle 1a [(p-MeO-C6H4)2Te)2(μ-O)(μ-PhSeO2)(μ4-Cl)]2 with AgNO3, AgClO4 and AgBF4 yielded colourless solids whose single crystal X-ray diffraction studies revealed the formation of 12-membered macrocycles [(p-MeO-C6H4)2Te)2(μ-O)(μ-PhSeO2)(μ-X)]2 [X = NO3 (2), ClO4 (3), BF4 (4)]. ESI-MS studies revealed that macrocycles 2–4 retain their integrity in solution. The solution (125)Te NMR spectrum of 4 shows the appearance of a triplet ((1)JTe···F = 568 Hz) that can be assigned to coupling between (125)Te nuclei and two fluorine atoms in BF4(−) ions.

The coordination chemistry of cationic divalent pnictogen ligands, such as nitrenium and phosphenium, has been well-explored in recent years. However, corresponding studies of a heavier congener, stibenium ion, are rare. To better facilitate a Sb+–metal interaction, a tridentate P-Sb+-P ligand with two phosphine buttresses was designed and synthesized, and its coordination chemistry toward late transition metals was investigated. The stibenium ligand was delivered as an activated P­(SbCl)­P-AgOTf complex (2) that releases AgCl and the P-Sb+-P ligand upon the treatment with transition metals. Reacting 2 with Rh­(I) and Ir­(I) metals yielded the anticipated stibenium–transition-metal complexes [(Rh­(COD)­Cl)2(μ-PSb+P)] OTf ([3]­[OTf]) and [(Ir­(COD)­Cl)2(μ-PSb+P)] OTf ([4]­[OTf]). The M–Sb+–M bridging structure was confirmed by single-crystal X-ray crystallography, and the bonding situation was examined computationally. Theoretical studies revealed the presence of three-center delocalized M–Sb+–M bonding interactions in [3]­[OTf] and [4]­[OTf].