Preparation of RHgCl via transmetalation of (8-quinolyl)SnMe₃and redistribution to R₂Hg (R = 8-quinolyl): a highly distorted diorganomercury(ii) with 84 degree C–Hg–C angle

Abstract

Transmetalation occurs upon addition of HgCl2 to (8-quinolyl)SnMe3 to yield (8-quinolyl)HgCl. The molecule features a frustrated Hg-N Lewis pair; however the mercury(II) center showed low affinity for sulfur Lewis bases, S8 or thiophene. In the presence of NH4SCN, ligand redistribution led to R2Hg. The molecule was found as linear or bent polymorphs, depending on the solvent of recrystallization. The geometry about Hg(II) in the bent polymorph is distorted trigonal prismatic that features a C-Hg-C angle of 84°, weak intramolecular Hg-N contacts, and two intermolecular η(2)-quinoline contacts in which the neighboring R2Hg molecule participates as a bis-η(2)-bidentate ligand.

Synthesis and characterization of some new organotellurium compounds based on quinoline

“…The IR spectra of all new prepared compounds 1-10 show strong absorption band around the region 1614-1691 cm -1 range is characteristic, originating from the stretching mode of the C=N bonds. These values are in good agreement with previous works [2,[9][10][11]. The IR spectra of compounds 2-7 are quite similar to those of 8-(quinolyl)mercuric chloride (1).…”

“…The IR spectra of compounds 1-10 display weak bands in the region between 3051 and 3076 cm -1 , however at higher frequency, are assigned to C-H stretching vibrations of aromatic rings of quinolone [12,13]. Also, the IR spectra of compounds 1-10 show two bands in the range 1527-1583 and 1521-1436 cm -1 can be attributed to asymmetrical and symmetrical stretching of aromatic C=C, respectively [2,[11][12][13]. Furthermore, several variable bands between 611 and 806 cm -1 range can be assigned to aromatic bending of C-H. A weak band was appeared in IR spectra of compounds 2-7 at range 457-466 cm -1 may be attributed to Te-C stretching [14].…”

“…Quinoline is a hetero aromatic compound, so the n → π* and the π → π* transitions are expected to be shown, however the band due to the n → π* transition is generally weak, while the bands associated with the π → π* transitions do not present fine structure and are observed in two regions, which cover up the band owed to the n → π* transition and showed two maximum absorption peaks at 330 and 263 nm. The absorption at the long wavelength is characterized to present vibrational fine structure dependent on the physical state and solvent polarity [2,21]. In comparison with the compounds 1-7 , it is possible to verify that the maximum peak at 261 nm for the free quinoline is red-shifted (about 5-13 nm), as 268 nm for compounds 1 and 2; 274 nm for compounds 3 and 7; 270 nm for compound 4; 276 nm for compound 5; and 272 nm for compound 6.…”

“…Furthermore, bis [2-(8-hydroxyquinolineazo)-1-naphthalenyl]ditelluride and bis [2-(8-hydroxyquino lineazo)naphthyl] telluride were prepared by action of hydrazine hydrate with the corresponding tribromide and dichloride, respectively. Kumar et al [5] reported the preparation of bis [2,2,4-tri methyl-6-(ethyltelluro)-1,2-dihydroquinoline] ditelluride from the reaction of 6-bromo-2,2,4-trimethyl-1,2-dihydroquinoline with tert-butyllithium at -78 °C in dry diethyl ether, followed by insertion of tellurium into carbon-lithium bond and finally air oxidation of the resulting product.…”

“…On the other hand, transmetallation is a wellknown synthetic tool for the synthesis of main group organometallic compounds, especially with tellurium element [2]. Tris (8-quinolinyl)telluronium chloride was prepared by transmetallation of 8-lithio-quinoline with tellurium tetrachloride with low yield of bis (8-quinolinyl) telluride [3].…”