RESUMO
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].
RESUMO
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 24 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.
RESUMO
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.
