Synthesis of Tellurabenziporphyrin and Its Pd(II) Complex

Abstract

An unprecedented tellurabenziporphyrin containing C, N, and Te donor atoms was synthesized by condensing benzitripyrrane and tellurophene diol under acid catalyzed conditions. The tellurabenziporphyrin readily forms a Pd(II) complex when treated with PdCl in CHCl/CHCN. The crystal structures of tellurabenziporphyrin and its Pd(II) complex revealed that the benzene ring hinders the π-electron delocalization. An unusual five-membered ring formed inside the macrocycle due to the strong interaction between "Te" and "N" in the Pd(II) complex.

Chemistry inside a Porphyrin Skeleton: Platinacyclopentadiene from Tellurophene

“…Thus, the tellurium to platinum substitution reaction begins from a side‐on platinum(II)‐η 1 ‐tellurophene coordination, detected in 4‐PtCl 2 complex. Similar binding mode has been observed for palladium(II) complexes with tellurophene‐containing porphyrinoids [17, 29, 38] . Reaction of 4‐PtCl 2 with silver(I) acetate (monitored by 1 H NMR at 300 K: Figure S3) presumably leads to a more reactive bisacetate analog, [ 4‐Pt(OAc) 2 ], easily transformed into 5 .…”

“…Similarb inding mode has been observedf or palladium(II)c omplexesw ith tellurophene-containing porphyrinoids. [17,29,38] Reaction of 4-PtCl 2 with silver(I) acetate (monitored by 1 HNMR at 300 K: Figure S3) presumably leads to am ore reactive bisacetate analog, [4-Pt(OAc) 2 ], easily transformed into 5.T he proposed transmetalationm echanism Similar insertions into thiophene, selenophene and tellurophene rings are known for several transitionm etal complexes including platinum [13,[39][40][41] to give products with six-membered rings. The subsequentt ellurium-carbon bond cleavage leads to tellurium extrusion to yield the platinum(II) complex 5.T he scope of such ar eplacement by other transition metal ions remains to be tested.…”

“…Similarb inding mode has been observedf or palladium(II)c omplexesw ith tellurophene-containing porphyrinoids. [17,29,38] Reaction of 4-PtCl 2 with silver(I) acetate (monitored by 1 HNMR at 300 K: Figure S3 includes platinum(II) insertion into at elluropheneC ÀTe bond via oxidative addition to generate the transient 7°(Scheme 5). Similar insertions into thiophene, selenophene and tellurophene rings are known for several transitionm etal complexes including platinum [13,[39][40][41] to give products with six-membered rings.…”

28-Hetero-2,7-Naphthiporphyrins: Horizontal Expansion of the m-Benziporphyrin Macrocycle

“…In this respect, carbaporphyrinoids incorporating phenylene rings, , namely, m -benziporphyrins 1-X , − oxy- m -benziporphyrins, , and p -benziporphyrins 2-X , , were found particularly alluring, giving an access to complexes with metal···arene π, and σ bonds (Figure ). Benziporphyrins demonstrated formation of coordination compounds with variety of metals, metalloids, and nonmetals. − Moreover, in cases of palladium­(II), rhodium­(III), and gold­(III) , complexes of 1-NH and 2-NH the metal···π interactions were envisaged to be stimuli of unusual reactivity resulting in the contraction of benzene unit to cyclopentadiene, leading eventually to complexes of 21-carbaporphyrins.…”

Synthesis and self-assembly of thiol-modified tellurophenes

“…Therefore, the ongoing exploration of these unique metalloid-containing heterocycles, including their synthesis and polymerization, is important. [37][38][39][40][41][42][43][44][45][46][47] Additionally, thiophene and polythiophene derivatives have been directly conjugated to metal surfaces through thiosulfate and thiol linkers, 48 demonstrating the interest in chalcogenophenes for these materials. Given the unique chemistry and potential applications of both small molecule and polymeric tellurophenes, and considering that tellurophene derivatives have been shown to function as sensors of oxygen and multidentate anionic species, 49,50 developing a route to a solid-state detection system expands the environments in which a tellurophene-based sensor can be used.…”