Synthesis and Characterization of Ph4Te4I4, Containing a Te4 Square, and Ph3PTe(Ph)I

Abstract

Four tellurium atoms are weakly linked into a Te4 square in Ph4Te4I4 (1), which is formed from the reaction of Ph2Te2 with diiodine. This novel structural modification was not previously observed for organoelement–halogen compounds of Group 16. Subsequent reaction of 1 with four equivalents of PPh3 produces the charge‐transfer complex Ph3PTe(Ph)I (2).

Synthesis and crystal structures of new complex salts containing both cationic and anionic tellurium(IV) species: the role of secondary bonds in the arrangement of tellurium based tectons

“…The low frequency peak, around δ 580, is attributed to the cationic [Te(C 6 H 5 )(CH 3 ) 2 ] + species, which corresponds well to the value found for [Te(C 6 H 5 ) (CH 3 ) 2 ]I (δ 550 in DMSO). 17 The lower field peak, attributed to the anionic [TeX 4 Ph] -species, show chemical shifts at δ 1234.81, 1203.87 and 951.08 for 1, 2 and 3 respectively. The chlorine atom, being the most electronegative of the halides, deshields best the tellurium atom.…”

“…The solid state structures of the tellurium(IV) compounds are themselves very interesting owing to the occurrence of secondary tellurium-halogen bonds (Te···X), 1 which create exceptional supramolecular structures, leading to the formation of polymeric chains, dimeric structures, or monomers with fairly strong intermolecular interactions. [2][3][4][5][6] We have been interested for some time in the synthesis and crystal structures of TeX 3 R compounds and their derivatives, such as the [TeX 4 R] -anions. These halogenated tellurates may be considered tectons (any species whose interactions are dominated by particular associative forces that induce the self-assembly of an organized network with specific architectural or functional features 7 ) where the different packing arrangements in the crystal lattice of [TeX 4 R] -salts are determined by the secondary bonds which complete the octahedral coordination at tellurium.…”

“…[2][3][4][5][6] We have been interested for some time in the synthesis and crystal structures of TeX 3 R compounds and their derivatives, such as the [TeX 4 R] -anions. These halogenated tellurates may be considered tectons (any species whose interactions are dominated by particular associative forces that induce the self-assembly of an organized network with specific architectural or functional features 7 ) where the different packing arrangements in the crystal lattice of [TeX 4 R] -salts are determined by the secondary bonds which complete the octahedral coordination at tellurium. We have already observed this tendency in a great number of examples with cations of alkali metals or pyridonium and ammonium derivatives.…”

Telluranes: potential synthons for charge-transfer complexes (involving hypervalent Te–I bonds) and serendipitous synthesis of the first triphenyl methyl phosphonium salts containing [C4H8TeI4]2− and [TeI6]2−anions

“…In view of the interesting CT complexes obtained by the reactions of Ph 2 Se 2 I 2 and Ph 4 Te 4 I 4 with PPh 3 [15,16], C 4 H 8 TeI 2 was reacted with PPh 3 at ambient temperature in 1:4 stoichiometric ratio and instead of ) could be obtained but dark brown crystals of 5 did not appear. When benzene was used as a solvent the reaction did not yield even 4.…”

Synthesis of new T-shaped hypervalent complexes of tellurium showing Te–π-aryl interactions: X-ray characterization of [(mes)XTe(μ-X)Te(mes)(etu)] (X=Br, I) and [Ph(etu)Te(μ-I)Te(etu)Ph][PhTeI4] (mes=mesityl; etu=ethylenethiourea)

“…Recently, we have described [11] the one-pot synthesis and the structures of the compounds PhE II (L)PhE 0IV X 4 (E = Te, Se; E 0 = Te; X = Br, I; L = thiourea, N,N 0 -tetramethylhiourea): in the two salts of the four complexes [(tmtu) PhTe(l-Br)TeBr 3 Ph] 2 , [(tu)PhTe(l-I)TeI 3 -complex) counter ions, since both cation and anion are complexes themselves, with different oxidation states of the atomic centers, +2 and +4 for the cation and the anion, respectively. We report now the synthesis of the novel compounds of tellurium(II) [(mes)BrTe(l-Br)Te(mes)(etu)] (1) and [(mes) ITe(l-I)Te(mes)(etu)] (2), also the mixed valence complex [Ph(etu)Te(l-I)Te(etu)Ph][PhTeI 4 ] (3) {mes = mesityl(2,4, 6-trimethylphenyl); etu = ethylenethiourea(2-imidazolidinethione); Ph = phenyl}. Such molecular assemblies (in the case of 1 and 2) are yet unknown and the T-shaped [12,13] X-Te-X bonds are quite equal and linear. In the cation complex of 3, the iodine bridge between two tellurium atoms suggest that the delocalization of the positive charge is limited to the two bicentric molecular orbitals localized at the three atoms Te-I-Te [14,15].…”