Electron-deficient heavy chalcogen atoms contain Lewis acidic σ-holes which are able to form attractive supramolecular interactions, known as chalcogen bonding (ChB), with Lewis bases. However, their potential in solution-phase anion binding applications is only just beginning to be realized in simple acyclic systems. Herein, we explore the 5-(methylchalcogeno)-1,2,3-triazole (chalcogen = Se, Te) motif as a novel ChB donor for anion binding. Other than being chemically robust enough to be incorporated into macrocyclic structures, thereby significantly expanding the scope and complexity of ChB host systems, we also demonstrate, by 1H NMR and DFT calculations, that the chalcogen atoms oriented within the macrocycle cavity are able to chelate copper(I) endotopically. Exploiting this property, the first examples of mechanically interlocked [2]rotaxanes containing ChB-donor groups are prepared via an active metal template strategy. Solution-phase 1H NMR and molecular modeling studies provide compelling evidenc...

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Chalcogen Bonding Macrocycles and [2]Rotaxanes for Anion Recognition

New vistas in the chemistry of platinum group metals with tellurium ligands

This perspective begins with the discussion of various basic synthetic approaches applied for the synthesis of several organotellurium ligands, their chemistry derived from platinum group metals, and the reactivity difference among them. It also gives an overview on the development of various bi, tri, and high nuclearity complexes syntheses. Investigations targeting the organotellurium ligand systems revealed a remarkable reactivity due to the dynamic nature of the lone pair available on the tellurium metal, which has led to a serendipitous isolation of the complexes [Cp*Ir(ppy)(η1-Te2Ph2)]+, [Cp*IrOs3(μ-H)2(μ-Tetol)2(CO)7], [Pt{TeC5H3(3-R)N}2Te(PPh3)], [Pt{Ph2PCH(TeC5H3(3-R)NPPh2)}2] (R = H, Me), and various other high nuclearity heterometallic [Cp*Ir(CO)(μ-TeC6H4)2MCp*Cl]Cl (M = Rh, Ir) complexes. Studies of the various complexes investigated the various binding modes of coordination and the facile cleavage of the Te–C and Te–Te bonds of tellurium-based ligand systems. Attempts have been made to present a comprehensive account of the subject matter. Various promising aspects of these complexes, such as their synthesis, reactivity, structures, and applications, are covered in this review.

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Emerging trends in organotellurolate chemistry derived from platinoids

Six copper(i) halide clusters based upon ferrocenyltelluroethers or ferrocenylselenoethers, 1-6, have been synthesized and structurally characterized by an X-ray crystallographic study. These structures include a discrete step-cubane Cu4I4 cluster, a 1D chain with rhomboid Cu2X2 clusters, a 1D chain with cubane Cu4I4 clusters and a 2D network with Cu2I2 clusters. 1-3 are the first structurally characterized example of copper(i) clusters with telluroethers. Their different nuclearities and geometries can be attributed to the different donor atoms and chain flexibility in the ligands. The catalytic activities of six clusters were then investigated in the Ullmann C-N cross-coupling reaction and 2 displayed the best performance with a target product N-(4-phenyl)imidazole in 91.3% yield. From the viewpoint of structure, the specific steric acceptance around Cu(i) in 2 may allow imidazole and iodobenzene to stepwise coordinate with the copper center and give the target product effectively.

Copper(I) halide clusters based upon ferrocenylchalcogenoether ligands: donors, halides and semi-rigidity effects on the geometry and catalytic activity

The reactions of different silver(I) reagents AgX (X- =iodide, trifluoroacetate, triflate) with selenoethers R2Se (R=Me, tBu) in a variety of solvents were investigated in relation with their use as precursors for Ag2Se nanomaterials. Different reaction conditions led to different reactivities and afforded either molecular complexes or metal selenide nanoparticles. The reactions leading to in situ formation of the metal selenide nanoparticles were then extended in the presence of commercial TiO2 (P25) to prepare silver selenide-titania nanocomposites with different Ag/Ti ratios. These nanocomposites, well characterized by elemental analysis (Ag, Se), PXRD, TEM, BET, XPS and UV/Vis studies, were investigated as photocatalysts for the degradation of formic acid (FA) solution. The xAg(2)Se-TiO2 nanocomposites (x=0.01, 0.13 and 0.25 mol%) exhibited a much higher catalytic activity as compared to P25, which is an established benchmark for the photocatalysis under UV light, and retained a good photocatalytic stability after recycling for several times.

A Facile Molecular Precursor-based Synthesis of Ag2 Se Nanoparticles and Its Composites with TiO2 for Enhanced Photocatalytic Activity.

Versatile coordination chemistry of rhodium complexes containing the bis(trimethylsilylmethyl)tellane ligand

The treatment of EPh2 (E = Te, Se) with Ag(O3SCF3) or Cu(O3SCF3)·1/2C6H6 in dichloromethane yields isomorphous complexes [Ag(TePh2)3](O3SCF3) (1), [Cu(TePh2)3](O3SCF3) (2), and [Cu(SePh2)3](O3SCF3) (3). The related reaction of TeTh2 (Th = 2-thienyl, C4H3S) with Cu(O3SCF3)·1/2C6H6 affords [Cu(TeTh2)3](O3SCF3) (4). While not isomorphic with 1–3, its crystal structure bears a close relationship with them. The reaction of TeTh2 or SePh2 with Ag(O3SCF3) yields [Ag(TeTh2)2](O3SCF3) (5) and [Ag(SePh2)2](O3SCF3) (6), respectively. They form dinuclear complexes, the silver centers of which are coordinated to two terminal R2E ligands and linked together by two bridging CF3SO3− ligands. The dinuclear complexes further form supramolecular networks through π–π stacks of the aromatic rings. The treatment of Ag(O3SCF3) with Te(CH2SiMe3)2 results in the formation of a mixture containing polynuclear [Ag{Ag[Te(CH2SiMe3)2]}4]n(O3SCF3)5n (7) and [Ag{Te(CH2SiMe3)2}]n(O3SCF3)n (8). The cyclic repeating units in 7 are connected to polymeric chains by two bridging CF3SO3− ligands. 8 contains a [–Ag–Te(CH2SiMe3)2–]n polymer. There are only weak van der Waals interactions between the polymer chains of 7 and 8.

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Versatile solid-state coordination chemistry of telluroether complexes of silver(I) and copper(I)

TeI2(CH2SiMe3)2(1), TeI2Th(CH2SiMe3 (2), TeI2Ph(CH2SiMe3)(3), and TeI2Th2(4) (Th = 2-thienyl) were synthesized in excellent yields from the corresponding tellanes and I2. The products were characterized by 125Te NMR spectroscopy and single crystal X-ray crystallography. Each TeI2RR′ molecule shows a trigonal bipyramidal coordination around tellurium with the iodine atoms occupying axial positions, and the organic groups and the lone pair occupying equatorial positions. The TeI bonds and the ITeI angles in 1–4 span a range of 2.8407(9)–3.0194(10) A and 171.85(2)–175.71(2)°, respectively. The TeC bonds and CTeC angles show respective ranges of 2.100(6)–2.136(7) A and 95.1(3)–100.9(3)°. In the solid state, the molecules show a varying degree of secondary bonding interactions. With the exception of TeI2(CH2SiMe3)2 (1), the compounds show Te···I or I···I secondary bonding interactions leading to supramolecular assemblies. TeI2Ph(CH2SiMe3) crystallizes as two polymorphs. One (3a) is isomorphic with TeI2Th(CH2SiMe3) (2). The other (3b) shows a lattice of two alternating layers of molecules. In one layer, the molecules are linked into a two-dimensional network by Te···I and I···I interactions whereas the second layer consists of discrete dimers. The strongest Te···I secondary bonding interactions are observed for TeI2Th2. The lattice is composed of tetramers that is reminiscent of those in γ- and δ-TeI4 and also have precedent in TeI2RR′ species. The structures of TeI2Me2 and TeI2Ph2 have been considered for comparison. The trends in 125Te NMR chemical shifts in TeI2RR′ (R, R′ = Me, CH2SiMe3, Th, Ph) are also discussed. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:348–357, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20688

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/hc.20688

Structural trends in TeI2RR′: Crystal structures and NMR spectra of TeI2(CH2SiMe3)2, TeI2Th(CH2SiMe3), TeI2Ph(CH2SiMe3), and TeI2Th2 (Th = 2‐Thienyl, C4H3S)

Preparation and structural characterization of [RuCl2(CO)2{Te(CH2SiMe3)2}2] and [RuCl2(CO){Te(CH2SiMe3)2}3]

The reaction of 1-naphthyl bromide with n-butyl lithium, elemental tellurium, and 1,4-dibromobutane in THF affords both (C10H7)Te(CH2)4Te(C10H7) (1) and [(C10H7)Te(CH2)4]Br (2) in good yields. 1 is preferentially formed at low temperatures and is a rare example of a structurally characterized ditelluroether in which the tellurium atoms are bridged by a hydrocarbon chain. In the solid state, 1 shows secondary bonding TeTe interactions, which connect the molecules into layers which are further linked to 3-dimensional frameworks by TeH hydrogen bonds. [(C10H7)Te(CH2)4]Br (2) is formed concurrently during the synthesis of 1 and is the main product, when the reaction is carried out at room temperature. The revPBE/def2-TZVPP calculations of the reaction profiles indicate that the formation of 2 is somewhat more favourable than that of 1. Furthermore, at room temperature the activation energy for the formation of 2 is lower than that of 1. At low temperatures the activation energy of the reaction leading to 1 is lower than that to 2, which is consistent with the synthetic observations. When 1 was treated with CuBr, [Cu2(μ-Br)2{μ-(C10H7)Te(CH2)4Te(C10H7)}2] (3) was formed. It crystallizes as two polymorphs (3a) and (3b) in which both the packing and the conformation of the ditelluroether ligands are different. The reaction of 1 with HgCl2 produces [(C10H7)Te(CH2)4]2[HgCl4]·CH2Cl2 (4·CH2Cl2) and that of 1 with CuCl2 affords [(C10H7)Te(CH2)4]Cl (5). 2 and 5 are isomorphous.

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Synthesis, characterization, and ligand behaviour of a new ditelluroether (C10H7)Te(CH2)4Te(C10H7) and the concurrently formed ionic [(C10H7)Te(CH2)4]Br.

Merja J. Poropudas

Papers

Versatile coordination chemistry of rhodium complexes containing the bis(trimethylsilylmethyl)tellane ligand

Versatile solid-state coordination chemistry of telluroether complexes of silver(I) and copper(I)

Structural trends in TeI2RR′: Crystal structures and NMR spectra of TeI2(CH2SiMe3)2, TeI2Th(CH2SiMe3), TeI2Ph(CH2SiMe3), and TeI2Th2 (Th = 2‐Thienyl, C4H3S)

Preparation and structural characterization of [RuCl2(CO)2{Te(CH2SiMe3)2}2] and [RuCl2(CO){Te(CH2SiMe3)2}3]

Synthesis, characterization, and ligand behaviour of a new ditelluroether (C10H7)Te(CH2)4Te(C10H7) and the concurrently formed ionic [(C10H7)Te(CH2)4]Br.