3,4,5-triselena-tricyclo-[5.2.1.0..sup.2,6 ]decanes and derivatives thereof

Novel 3,4,5-Tri(selena- or tellura-)tricyclo[5.2.1.0..sup.2,6 ]decanes and derivatives are prepared in high yield by contacting a bicyclo[2.2.1]hept-2-ene compound and selenium or tellurium in the presence of a solvent, and a catalyst.

BACKGROUND OF THE INVENTION 
This invention relates to a method for the production of certain novel 
cyclic compounds which contain selenium or tellurium or both. 
The interaction of organic compounds with selenium or tellurium is known 
generally to result in somewhat unusual compounds which often are complex 
and polymeric. Typical preparative methods for said compounds require 
acetylenic compounds, diolefins, difunctional organic compounds, such as 
dihalides, or combinations of these. For example, U.S. Pat. No. 3,149,101 
discloses the reaction between dihalobutadienes and a large class of 
compounds for form the corresponding heterocyclic dienes, e.g., 
tetraphenyltellurophene. The multi-step preparation of 
1,2,3-triselenacyclopentane from 1,2-dibromoethane is disclosed in Volume 
45 of the J. Org. Chem., pp. 2632-6 (1980). The preparation of 
tellurium-containing heterocyclic compounds, such as 
cis-3,5-dibenzylidene-1,2,4-tritellurole from sodium 
phenylethnyltellurolate and ethereal HCl, is described in V. 22 (42) of 
Tetrahedron Letters, pp. 3199-200 (1981). 
U.S. Pat. No. 3,671,467 discloses the reaction of difunctional organic 
molecules having functional moieties selected from the group consisting of 
"halides, epoxy and sulfonate ester groups and diazonium halides" with a 
difunctional reagent containing a diselenide. In particular, Example 1 of 
said patent discloses contacting sodium sulfite (Na.sub.2 So.sub.3), 
selenium, water and 4,6-bis(chloromethyl)-m-xylene at reflex temperature 
to prepare 4,6-bis(methyl)-m-xylene diselenide. Said patent further 
discloses that the products of the reaction generally described in this 
paragraph may be polymerized by reacting the products with additional 
elemental selenium, generally at temperatures of from about 200.degree. C. 
to about 300.degree. C. U.S. Pat. No. 3,971,742 describes a process which 
is similar to the process of U.S. Pat. No. 3,671,467 except that mixtures 
of selenium and tellurium are employed. 
U.S. Pat. No. 4,233,131 discloses the production of compound such as 
ethylene episelenide by irradiating a mixture of elemental selenium and 
olefins of 2-6 carbon atoms with certain electromagnetic radiation. Thus, 
said process does not require the acetylenic compounds, etc., of the 
typical methods described hereinabove for the preparation of selenium- or 
tellurium-containing organic compounds. However, it does require the use 
of electromagnetic radiation. 
Heretofore, novel 3,4,5-tri(selena- or tellura-)polycyclo compounds, as 
described hereinafter, and the corresponding polymers have not been 
prepared. It would be desirable to prepare said polycyclo compounds using 
a single process which would not require electromagnetic radiation or the 
acetylenic compounds, etc., of prior art processes. 
SUMMARY OF THE INVENTION 
The present invention includes novel monomeric 3,4,5-tri(selena- or 
tellura-)polycyclo monomers and their polymers. According to the method of 
the present invention, 3,4,5-tri(selena- or tellura-)polycyclo compounds, 
as hereinafter described, are produced by contacting selenium, tellurium, 
or both and a bicyclo[2.2.1]hept-2-ene, or a derivative thereof, in the 
presence of a solvent and a catalyst under the proper reaction conditions. 
The method of the present invention is advantageous in that it obviates 
the need to use the acetylenic compounds, etc., of the prior art. The 
compounds of the present invention are useful in several applications, 
including uses as cross-linking agents, plasticizers, thermal stabilizer, 
antioxidants, monomers, polymers, and in certain photoconductive 
applications. 
DETAILED DESCRIPTION OF THE INVENTION 
The bicyclo[2.2.1]hept-2-ene compounds that are suitable for use in this 
invention are generally described by the formula 
##STR1## 
wherein each R, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is 
independently a moiety which does not prevent the reaction between the 
bicyclo[2.2.1]hept-2-ene and selenium and/or tellurium under the reaction 
conditions described herein. Examples of typical R, R.sub.1, R.sub.2, 
R.sub.3 and R.sub.4 moieties include hydrogen, halogen, alkyl of from 1 to 
about 15 carbon atoms, aryl of from about 6 to about 15 carbon atoms, or 
cycloalkyl of from about 4 to about 10 carbon atoms; R.sub.1 and R.sub.3 
may further be independently chosen from alkenyl of from 2 to about 10 
carbon atoms, hydroxyl, hydroxyalkyl having from 1 to about 10 carbon 
atoms, dialkylamino having from 1 to about 10 carbon atoms, 
dialkylaminoaklyl wherein the alkyl groups have from 1 to about 4 carbon 
atoms, and alkoxy having from 1 to about 10 carbon atoms; R.sub.1 and 
R.sub.2 when taken together and R.sub.3 and R.sub.4 when taken together 
can be alkylidene of from 1 to about 6 carbon atoms; R.sub.1 and R.sub.3 
when taken together can be --CHYCH.dbd.CY-- wherein Y is hydrogen or 
methyl. Typically, each R.sub.5 independently is hydrogen or alkyl of from 
1 to about 15 carbon atoms. These compounds are also described in U.S. 
Pat. Nos. 3,586,700 and 4,033,982, the teachings of which, with respect to 
these compounds, are incorporated herein by reference. Preferred 
bicyclo[2.2.1]hept-2-ene compounds include, for example, 
dicyclopentadiene, bicyclo[2.2.1]hept-2-ene and 
5-ethenyl-bicyclo[2.2.1]hept-2-ene. 
The source of selenium can be elemental selenium, which is preferred, or 
polyselenides. Similarly, elemental tellurium and polytellurides can be 
employed. 
Theoretically, 3 moles of selenium or tellurium atoms are necessary per 
mole of bicyclo[2.2.1]hept-2-ene compound in order to produce the 
corresponding triselane or tritellurane. Preferably, from about 2.8 to 
about 3 g-atoms of selenium or tellurium are employed per g-mole of 
bicyclo[2.2.1]hept-2-ene compound. Larger or smaller amounts of selenium 
or tellurium can be used, if desired, however, pentacyclic compound 
formation may be observed at selenium or 
tellurium/bicyclo[2.2.1]hept-2-ene compound ratios greater than 3. 
Selenide, telluride or sulfide ions catalyze the reaction of the present 
invention. Examples of suitable catalysts include alkali metal sulfides, 
alkaline earth metal sulfides, alkaline earth metal mercaptides and alkali 
metal mercaptides, and the corresponding selenides and tellurides. 
Preferred catalysts include anhydrous sodium sulfide, sodium sulfide 
nonahydrate (Na.sub.2 S. 9H.sub.2 O) and sodium phenylthiolate. In the 
practice of the present invention, it is preferred that the catalyst be in 
solution. Any amount of selenide, telluride or sulfide ions may be used as 
long as the reaction is catalyzed by those ions. Typically, from about 
1.times.10.sup.-10 to about 1 mole of selenide, telluride or sulfide ions 
are employed per mole of bicyclo[2.2.1]kept-2-ene compound employed; 
preferably from about 1.times.10.sup.-5 to about 0.01 mole of selenide, 
telluride or sulfide ions are employed per mole of 
bicyclo[2.2.1]hept-2-ene compound. Most preferably, the amount of 
selenide, telluride or sulfide ions will range from about 0.001 to about 
0.01 mole of selenide, telluride or sulfide ions per mole of 
bicyclo[2.2.1]hept-2-ene compound. 
Selenide, telluride or sulfide ions are advantageously employed in the form 
of a soluble selenide, telluride or sulfide compound. For the purposes of 
the present invention, the term soluble selenide, telluride or sulfide 
compound refers to selenide telluride or sulfide ion-containing compounds 
which are soluble in one of the possible solvent systems which are 
suitable for use in the method of the present invention. Thus, almost any 
selenide, telluride or sulfide ion-containing compound is a soluble 
selenide, telluride or sulfide compound because there are many solvent 
systems which are capable of solvating the various components of the 
reaction mixture, i.e., catalyst and reactants, to form a homogeneous 
mixture. For example, sodium sulfide is soluble in many polar solvents, 
but is insoluble in most non-polar solvents at the typically employed 
reaction temperatures. 
Ammonia and certain organic amines, such as aniline, can be employed as the 
catalyst. The ammonia catalyst can be introduced into the reaction mixture 
either before the reaction has been started or during the reaction; the 
manner of addition is not critical. A preferred procedure is to bubble the 
ammonia in the form of a gas through a mixture of the reactants; one can 
also bubble the ammonia through a mixture of less than all of the 
reactants and then add the remaining reactants. The concentration thereof 
is not critical and can be varied widely; the sole requirement is that a 
catalytically effective amount be present sufficient to permit the 
production of the 3,4,5-tri(selena- or tellura-)polycyclo compounds. 
A wide number of solvents and combinations of solvents may be employed in 
the practice of the present invention. Polar organic solvents and 
combinations of polar and other inert organic co-solvents are preferred. 
Typical polar organic solvents and combinations of solvents are described 
in U.S. Pat. No. 3,586,700, the teachings of which, with respect to 
solvents, are incorporated herein by reference. An example of a preferred 
combination of solvents is dimethylformamide in combination with pyridine. 
Non-polar or inert organic solvents may be used alone provided that, if 
the catalyst employed is not soluble in said solvent, a phase-transfer 
agent is employed therewith for the purpose of aiding the dissolution of 
the catalyst. Any phase-transfer agent which aids the dissolution of the 
catalyst into the reaction solution may be employed. Several suitable 
phase-transfer agents are well-known, including for example, 
dibenzo-18-crown-6 ether and bis(triphenylphosphine)iminium chloride. 
Typical non-polar solvents include aliphatic and aromatic hydrocarbons 
such as heptane, cyclohexane, 3-methylpentane, isooctane, cumene, toluene 
and the like. toluene is an example of a preferred non-polar solvent. 
Any amount of solvent may be employed as long as it is sufficient to 
dissolve the final product. Typically, from about 100 to about 2000 ml of 
solvent are employed per mole of bicyclo[2.2.1]hept-2-ene compound. 
Preferably, from about 800 to about 1200 ml of solvent are employed per 
mole of bicyclo[2.2.1]hept-2-ene compound. 
In general, any reaction temperature can be employed wherein the thermal 
reaction kinetics are not deleterious to reaction rates, reaction time, 
yield and/or conversion of the bicyclo[2.2.1]hept-2-ene compounds to the 
desired 3,4,5-tri(selena- or tellura-)polycyclo compounds. Typically, the 
reaction temperatures can be varied widely, however, they often fall 
within the range of from about 50.degree. C. to about 150.degree. C. and 
preferably the reaction is conducted within the temperature range of from 
about 90.degree. C. to about 120.degree. C. The reaction is typically 
performed at atmospheric pressure, although sub- or superatmospheric 
pressures may be employed if desired. 
Any reaction period can be employed, however, generally effective reaction 
periods fall within the range of from about 1 hour to about 50 hours. The 
process is preferentially carried out in the presence of an inert 
atmosphere of nitrogen in order to exclude from the reaction medium any 
oxygen or oxidizing agents which are well-known to oxidize organic 
sulfides to sulfoxides or sulfones or other undesirable reaction products. 
When the reactants, catalyst and solvent(s) are properly combined under 
reaction conditions as hereinbefore specified, a 3,4,5-tri(selena- or 
tellura-)polycyclo product will be formed. The novel 3,4,5-tri(selena- and 
or tellura-)polycyclo product compounds of the present invention are 
generally described by the formula: 
##STR2## 
wherein X independently is selenium or tellurium and the other 
substituents are as previously described. 
The crude product of the reaction may be treated by known methods, such as 
those described in Example 1, to recover the desired products. 
The product compounds exist in equilibrium between the monomeric and 
polymeric forms. The general formula for the monomeric form is given 
immediately hereinabove. The polymeric form has a repeating unit of the 
general formula 
##STR3## 
wherein R, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and X are as 
defined hereinabove, wherein n is at least about 2, and wherein the 
quantity ((a+b)/2) has a value of 3. As a general rule, the equilibrium 
shifts to the monomeric form when the product is in solution, and shifts 
to the polymeric form in the absence of solvent. Polymerization can be 
done using the techniques of U.S. Pat. No. 3,586,700, the teachings of 
which are incorporated herein by reference with respect to polymerization 
techniques. 
The following example is given to illustrate the invention and should not 
be construed as limiting its scope.

EXAMPLE 1 
Three-tenths of a g-atom of gray selenium (23.67 g), 1 mole of norbornylene 
(94.16 g), 0.0021 mole of anhydrous sodium sulfide (0.156 g), 1400 ml of 
pyridine and 70 ml of dimethylformamide are added to a 2-liter, 
three-necked, glass flask which is equipped with means for admitting gas 
thereto, a stirring means, and a condensing means. Nitrogen gas is 
admitted to the flask to purge the flask of atmospheric air. The contents 
of the flask are heated up to 110.degree. C. and that temperature is 
maintained for 15 hours. The flask is allowed to cool to about 25.degree. 
C. and unreacted selenium is filtered from the reaction mixture. The 
solvent is then evaporated at 45.degree. C. under a vacuum in a rotary 
vacuum evaporator to obtain a solid product. The solid is washed with 
methanol to separate the pure product from the impurities. The product is 
dried under vacuum at about 25.degree. C. to give 34.86 g of 
exo-3,4,5-triselenatricyclo[2.2.1]hept-2-ene. The selenium content of the 
solid product is 71.39 weight percent. The solid product is a yellow 
powder and has a slight garlic-like odor. 
The monomeric product which forms in Example 1 is analyzed using 60 MHz 
nuclear magnetic resonance.