Some investigations of organotellurium chemistry

Abstract

Diaryl ditellurides, Rote, (R = Ph, p-CH3,C6H4,
p-CH30C6H4) , P-C2H5OC6H4, p-PhOC6H4 and 1-Naphthyl were
prepared. The IR and Raman spectra of these compounds
between 400-40 on™ | are presented. Detailed assignments of
the spectra of PhoTe, are attempted. The tellurium-telluriun
stretching frequency in all cases is identified between
167-187 cm’. The evidence from these spectroscopic data
suggested that the structure of diaryl ditellurides have Cy
skeletal symmetry. There is no evidence to support previous
claims that. diphenyl ditelluride readily dissociates into
radicals in solution, Attempts to prepare unsymmetrical
diaryl ditellurides were unsuccessful.

The infrared and where possible the Raman spectra
between 400-40 cm-1 of five classes of aryltelluriumn
trihalides, RTeX, (R = Ph, p-CHzC¢Hy» p-CHz0C GH,
p-C 5H, OC 6H, aand p-PhOC 6H, (X = Cl, Br and I) are presented.
The tellurium-halogen vibrational modes are indicated and
. detailed assignments for spectra of Phiexs are offered.
The low frequency data and other physical evidence suggested
the compounds are associated to some degree with dimeric
structures the most probable for chlorides and iodides in
which the tellurium atom has coordination number five.
There is evidence that some bromides, notably PhTebr,,
(p-CH3C ¢H, )TeBr., and (p-PhOC ¢H, )TeBrz are more associated.
The structures are best described as involving donor-acceptor interaction between X” and RTeX+2.

The infrared and Raman spectra of aryltelluriumn
oxyhalides, RTeOX (R = Ph, P-CoH,OC EH, x = Cl, ary) ete
presented. The tellurium oxygen vibrational modes of the
compounds are assigned. p-Phenetyltellurium trichloride Was:
hydrolysed with 40% sodium ekiouats solution, the products
obtained are RTeOOH, and (RTeO) 0 when the previous one was
acidified with dilute acetic acid. The assignment of
tellurium oxygen vibrational modes of these products are
also given. PhTeCl, and (p~C 5H, OC EH, )TeC1, both reacted
with pyridine in benzene gave RTeCly PyH*. The mechanism of
hydrolysis of aryltellurium trihalides with water is
suggested.

The micro-analysis method of tellurium in
organotellurium compounds by atomic absorption spectroscopy
is developed. The compounds were decomposed with concentrated
nitric acid and perchloric acid, and the absorption
of aqueous solutions was recorded. Telluric acid AR grade
is used as a standard,

Date of Award	1972
Original language	English