Isolation and molecular structures of novel organotellurium(iv) halides, oxyhalide and mixed halide

Abstract

The formation of chiral (R)-[2-(4-ethyl-2-oxazolinyl)phenyl]tellurium(IV) trihalides (trichloride (5), tribromide (6) and triiodide (7)) and (R)-[2-(4-ethyl-2-oxazolinyl)phenyl]tellurium(II) bromide (8) is described. The molecular structure of the first chiral organotellurium(IV) triiodide (7) is discussed. The most interesting feature of the structure of 5 is the observation of the shortest intramolecular TeN distance for any organotellurium(IV) trichloride. Compounds 5 and 6 do not undergo electrophilic addition reaction with olefins. Attempted addition reaction of 6 with olefin in methanol leads to the isolation of the rare partially hydrolysed tellurium(IV) halide, methyl-2-(dibromooxotellurium)benzoate (9). Novel stable mixed halide 12 was isolated from the bromination of 11. DFT calculations indicate that both the isomers 12a and 12b have similar stability.

Amidofluorene-appended lower rim 1,3-diconjugate of calix[4]arene: synthesis, characterization and highly selective sensor for Cu2+

“…Moreover, upon addition of Cu 2+ , at higher concentrations of L a broad signal appeared at the area of 600–800 nm which can be related to a d→d transition (see Supporting Information File 1, Figure S13). This result is in accordance with those reported in literature [10] and indicates that the L binds copper as Cu 2+ .…”

“…[5–9]. However, excess amounts of Cu 2+ are hazardous, due to generate reactive oxygen species (ROS) that disturbs cellular metabolism [10–11]. On the other hand, its deficiency may cause haematological and neurological diseases [12].…”

“…Calix[4]arene derivatives having different binding centers such as nitrogen, oxygen and sulfur sites for recognition of metal ions can be readily synthesized [14,16–17]. A number of calix[4]arene-based fluorescence sensors for copper ions have been reported in the literature [18–27], including calix[4]arene bearing anthraceneisoxazolymethyl [3], quinolone [28], 5-nitrosalicylaldehyde [29], 3-alkoxy-2-naphthoic acid [30], coumarine [31] and benzothiazole [10,15] groups.…”

Crystal structure ofrac-(3aR*,9aS*)-4,4,4-trichloro-1,2,3,3a,4,9a-hexahydro-4λ5,9λ4-cyclopenta[4,5][1,3]tellurazolo[3,2-a]pyridine

“…For general background and synthesis, see: Petragnani & Stefani (2007); Borisov et al (2013). For related compounds, see: Singh et al (1990); Sundberg et al (1994); Zukerman-Schpector et al (2000); Kandasamy et al (2003); Raghavendra et al (2006);Dutton et al (2009); Lee et al (2010); Rakesh et al (2012). Symmetry codes: (i) Àx; Ày þ 2; Àz þ 1; (ii) x; Ày þ 3 2 ; z À 1 2 ; (iii) x; Ày þ 1 2 ; z À 1 2 ; (iv) Àx þ 1; y À 1 2 ; Àz þ 1 2 .…”

Synthesis and structural aspects of 1-naphthyltellurium(IV) trichloride (1), bis(mesityl)tellurium(IV) dichloride (2) and bis(chlorobis(2-thiophenyl)tellurium)oxide (3)

“…Recently, in the coordination chemistry of organotellurium compounds [14,15], the synthesis and the molecular structure of (a-naphthyl)TeI 3 and (a-naphthyl)TeBr 3 has been reported [16,17]. Though a large number of organotellurium trichlorides have been explored so far, only a few have been studied crystallographically [3,5,10,13,18,19] including the sterically encumbered supermesityltellurium(IV) trichloride [20]. The reason for less exploration of crystallographic studies of such compounds may be partially attributed to the difficulty encountered in recrystallization of these compounds, which are highly insoluble due to their polymeric structures.…”