10026-03-6Relevant articles and documents
Heavy atom analogues of 1,2,3-dithiazolylium salts: Preparation, structures and redox chemistry
Risto, Maarit,Assoud, Abdeljalil,Winter, Stephen M.,Oilunkaniemi, Raija,Laitinen, Risto S.,Oakley, Richard T.
, p. 10100 - 10109 (2008)
Synthetic routes to salts of the benzo[1,2,3]thiatellurazolylium cation [2c]+ and its selenium analogue [2b]+ are described. Access to the cation frameworks involves the intermediacy of N,N,S-trisilylated 2-aminobenzenethiol. The latter reacts smoothly with selenium and tellurium halides ECl4 (E = Se, Te) to afford the desired heterocyclic benzo cations [2b]+ and [2c]+ as their chloride salts. Anion exchange provides the corresponding GaCl4-, OTf - and TeCl5- salts of [2c]+, all of which have been characterized by X-ray crystallography. While the gallate salts of the sulfur and selenium cations [2a]+ and [2b]+ crystallize as ion-paired cations and anions, salts of [2c]+ adopt solid-state structures that display strong association of the cations via short intermolecular Te-N′ bonds. However, crystallization of [2c]+ salts in dichloroethane in the presence of GaCl3 leads to cleavage of the dimers and the formation of a Lewis acid adduct at nitrogen. Reduction of the benzo cations [2a,b]+ affords the respective radicals 2a,b, both of which have been characterized by electron paramagnetic resonance (EPR) spectroscopy. Attempts to generate the corresponding radical 2c have been unsuccessful, although a material of nominally correct elemental composition can be generated by chemical reduction. The energetics of association of [2a,b,c]+ in solution has been probed by means of density functional theory calculations using the polarized continuum model. The results suggest that the dimeric nature of the Te-centered cation is retained in solution. The strength of the interaction is, however, less than in N-alkylated tellurodiazolylium salts.
Gutbier, A.,Engeroff, F.
, p. 193 - 193 (1915)
Meyer, J.
, p. 145 - 145 (1914)
Thermal transformations of gold(III) complexes with chalcogen tetrachlorides
Volkov,Fokina,Pekhn'o,Yanko
, p. 121 - 124 (2008/10/08)
Thermal transformations of chalcogen chloride complexes of gold(III) of the AuCl3L type (L = SCl4, SeCl4, TeCl 4) have been investigated in the temperature range of 20-500°C. The melting points are found to be 108°C for AuCl3SCl 4, 153°C for AuCl3TeCl4, and 201°C for AuCl3SeCl4. For decomposition according to the scheme AuCl3L → AuCl3 + L, the thermal stability sequence of the complexes is AuCl3SCl4 3SeCl 4 3TeCl4 (133, 260, and 340°C, respectively). The role of gold trichloride → gold monochloride thermolysis and its dependence on the presence of chlorine vapor are demonstrated. The presence of chlorine vapor widens the temperature region of existence of AuCl3 and raises the gold monochloride → metallic gold thermolysis end temperature. The general scheme of thermal transformations of chalcogen chloride complexes of gold(III) is given: AuCl3L (s) →T1 AuCl3L(l) →-LT2 AuCl3(s) →-Cl2 T3 AuCl(s) →-Cl2T4 Au (s). Therefore, the thermal decomposition of AuCl3L complexes proceeds with the sequential reduction of gold: Au(III) → Au(I) → Au(0).
Syntheses of THF solutions of SeX2 (X = Cl, Br) and a new route to selenium sulfides SenS8-n (n = 1-5): X-ray Crystal Structures of SeCl2(tht)2 and SeCl2·tmtu
Maaninen, Arto,Chivers, Tristram,Parvez, Masood,Pietikaeinen, Jarkko,Laitinen, Risto S.
, p. 4093 - 4097 (2008/10/08)
A simple and efficient synthesis of solutions of pure SeCl2 in THF or dioxane (ca. 0.4 M) at 23 °C was achieved by treatment of elemental selenium with an equimolar amount of SO2Cl2. SeCl2 was characterized by 77Se NMR and Raman spectra. SeCl2 forms 1:1 or 1:2 adducts with tetramethylthiourea (tmtu) or tetrahydrothiophene (tht), respectively. The crystal structure of SeCl2·tmtu (1) reveals a T-shaped geometry [d(Se-Cl) = 2.443(4) A] with weak intramolecular Se-Cl interactions [d(Se-Cl) = 3.276(4) A]. Crystals of 1 are triclinic, space group P1, with a = 8.473(3) A, b = 9.236(3) A, c = 7.709(4) A, α = 109.90(3)°, β= 92.26(4)°, γ = 107.89(3)°, V = 532.9(4) A 3, and Z =2. The complex SeCl2(tht)2 (2) adopts a square planar geometry with d(Se-Cl) = 2.4149-(8) A. Crystals of 2 are monoclinic, space group C2/c, with a - 15.6784(8) A, b = 9.1678(4) A, c = 9.1246(4) A, β= 110.892(2)°, V = 1225.3(1) A,3 and Z = 4. The reaction of Ph3PS with SeCl2 gives Ph3PCl2 and a complex mixture of selenium Sulfides SenS8-n (n = 1-5), which were identified by 77Se NMR. Halogen exchange between SeCl2 and Me3SiBr in THF yields thermally unstable SeBr2 (ca. 0.4 M) characterized by 77Se NMR and Raman spectra.
