Hydrocarbon soluble polymetalated 1-alkene compositions are described, and these compositions may be characterized by the formula ##STR1## wherein R is hydrogen, a hydrocarbyl group or R.sup.1 M, M is an alkali metal, R.sup.1 is a divalent oligomeric hydrocarbyl group comprising moieties derived from a conjugated diene, and wherein the total number moieties derived from a conjugated diene in all of the R.sup.1 groups in Formula I is from about 2 to about 30. Preferably, the alkali metal is lithium. Hydrocarbon soluble polymetalated 1-alkene catalysts for anionic polymerizations are also described which comprise the reaction product of a 1-alkyne, an organometallic compount R.degree.M, and a 1,3-conjugated diene wherein R.degree. is a hydrocarbyl group, M is an alkali metal, the mole ratio of conjugated diene to 1-alkyne is at least about 2:1, and the reaction is conducted at a temperature of at least about 70.degree. C.

TECHNICAL FIELD OF THE INVENTION 
This invention relates to novel polymetalated 1-alkyne compositions. More 
particularly, this invention relates to such compositions containing two, 
three or four alkali metal substituents per molecule. The compositions are 
useful as catalysts in anionic polymerizations. 
BACKGROUND OF THE INVENTION 
Various alkali metal acetylides have been described in the literature, and 
various procedures for preparing such acetylides have been suggested. U.S. 
Pat. No. 3,303,225 describes a procedure for preparing alkali metal 
acetylides containing more than one alkali metal atom per molecule. In 
particular, the polymetalated acetylenes are prepared by reacting an 
organoalkali metal compound with an acetylene under conditions to effect 
step-wise replacement of, first, the acetylenic hydrogen atom and, second, 
the hydrogen atoms attached to the carbon atom which is alpha to the 
acetylenic linkage. The patentees indicate that the metalated 1-acetylenes 
are active as polymerization initiators for vinylidene-containing 
monomers. 
The metalation of 1-butyne with excess n-butyllithium is discussed by 
Eberly and Adams in J. Organometal. Chem., 3(1965) 165-167. The authors 
report that two moles of n-butyllithium react with one mole of 1-butyne to 
yield a hexane-insoluble 3-methylpropynylene-1,3-dilithium. Three moles of 
n-butyllithium are reported to react with one mole of 1-butyne to yield a 
hexane-insoluble 3-methylpropynylenedilithium n-butyllithium adduct. 
The stereopolymerization of butadiene and styrene in the presence of 
acetylenes and ketones is described by H. E. Adams et al, in Kautschuk und 
Gummi. Kunststoffe 18. Jahrgang, pp. 709-716, Nr, 11/1965. The authors 
studied the reaction of 1-butyne with 1, 2 and 3 moles of n-butyllithium 
in hexane, and the use of the materials obtained from such reactions as 
catalysts. The reaction of 1-butyne with one mole of n-butyllithium 
resulted in the formation of a white precipitate where the acetylenic 
hydrogen was replaced by lithium. When a second mole of n-butyllithium was 
added slowly to the reaction mixture, the white precipitate dissolves and 
the product is a clear lemon-yellow solution. Upon standing at room 
temperature, the solution becomes cloudy, and after about 210 hours, the 
precipitation of a yellow solid is complete. The product was identified as 
1,3-dilithio-1-butyne. When an excess of n-butyllithium is added to the 
precipitate of 1,3-dilithio-1-butyne, the precipitate dissolves to form a 
golden-yellow solution. There were signs of precipitation after two weeks, 
and after two months, a copius precipitate had formed. The precipitate is 
identified as a complex of 1,3-dilithio-1-butyne and n-butyllithium. 
The use of dilithium salts in the polymerization of butadiene is reported 
by Makowski et al, J. Macromol. Sci.--Chem., E2(4) pp. 683-700, July, 
1968. Among the lithium compounds studied were the 1,3-dilithioacetylides 
such as the compounds obtained by reacting 1-hexyne with n-butyllithium in 
ratios of 0.5 and 0.67. At a ratio of 0.5, homogeneous catalyst solutions 
in hydrocarbons were obtained. Above this ratio, some precipitate was 
present. In all cases, however, polymerization with butadiene resulted in 
low molecular weight polymer solutions. That is, where the catalyst 
solution included precipitated solids, the solids dissolved during the 
course of the polymerization. At the ratio of 0.5, the polymer solution 
was very viscous, and at the ratio of 0.67 a gelled solution resulted. 
However, when Attapulgus clay was added to the viscous solution or to the 
gelled solution, fluid solutions were obtained. This result was attributed 
to the presence of water in the clay. 
Masuda et al, Macromolecules, Vol. 20, No. 7, (1987) pp 1467-1487 describe 
the preparation of poly[3-(trimethylsily)-1-alkynes]. The monomeric 
3-(trimethylsilyl)-1-alkynes are prepared by reacting a 1-alkyne with 
n-butyllithium to prepare the 1,3-dilithiated intermediate which is then 
reacted with chlorotrimethylsilane to form the desired monomer. 
Polylithium polymerization initiators also are described in U.S. Pat. No. 
3,377,404. The initiators are prepared by first contacting an excess of 
lithium with an organic halide containing two to four halogen atoms in a 
polar solvent such as ether. The intermediate formed in the this step can 
be represented by the formula 
EQU RLi.sub.x 
wherein x is an integer of two to four and R is a hydrocarbon group. In a 
second step, the intermediate is contacted with a small amount of a 
conjugated diene such as 1,3-butadiene. The amount of diene is generally 
from about one to about ten moles per mole of lithium compound. After the 
intermediate has been treated in this manner, a substantial portion or all 
of the polar solvent is removed and replaced by a hydrocarbon diluent. The 
polylithiated hydrocarbon soluble compounds prepared in this manner are 
reported to be useful as initiators of the polymerization of conjugated 
dienes. 
U.S. Pat. No. 3,784,637 describes multi-functional polymerization 
initiators prepared from polyvinylsilane compounds or polyvinylphosphine 
compounds. More particularly, the multi-functional polymerization 
initiators are prepared by reacting an organomonolithium compound such as 
n-butyllithium with a polyvinyl phosphine compound or polyvinylsilane 
compound. Preferably, the reaction is conducted in the presence of a 
solublizing monomer such as a polymerizeable conjugated diene, 
monovinyl-substituted aromatic compound, or mixtures thereof. Examples of 
solublizing monomers include conjugated dienes such as 1,3-butadiene and 
aromatic vinyl compounds such as styrene. 
SUMMARY OF THE INVENTION 
Hydrocarbon soluble polymetalated 1-alkyne compositions are described, and 
in one embodiment, these compositions may be characterized by the formula 
##STR2## 
wherein R is hydrogen, a hydrocarbyl group or R.sup.1 M, M is an alkali 
metal, R.sup.1 is a divalent oligomeric hydrocarbyl group comprising 
moieties derived from a conjugated diene, and wherein the total number 
moieties derived from a conjugated diene in all of the R.sup.1 groups in 
Formula I is from about 2 to about 30. Preferably, the alkali metal is 
lithium. 
In another embodiment, the invention relates to hydrocarbon soluble 
polymetalated 1-alkyne catalyst for anionic polymerizations comprising the 
reaction product of a 1-alkyne, an organometallic compount R.degree.M, and 
a 1,3-conjugated diene wherein R.degree. is a hydrocarbyl group, M is an 
alkali metal, the mole ratio of conjugated diene to 1-alkyne is at least 
about 2:1, and the reaction is conducted at a temperature of at least 
about 70.degree. C. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Polymetalated 1-alkyne compositions of one embodiment of the present 
invention are characterized by the formula 
##STR3## 
wherein R is hydrogen, a hydrocarbyl group or R.sup.1 M, M is an alkali 
metal, R.sup.1 is a divalent oligomeric hydrocarbyl group comprising 
moieties derived from a conjugated diene, and wherein the total number 
moieties derived from a 1,3-conjugated diene in all of the R.sup.1 groups 
in Formula I is from about 2 to about 30. 
As noted, R may be hydrogen or a hydrocarbyl group which may be a saturated 
aliphatic, saturated cycloaliphatic or an aromatic group generally 
containing up to about 20 carbon atoms. In one embodiment, R is an alkyl 
group containing from 1 to 15 carbon atoms. In another embodiment, R is an 
alkyl group containing 1 to 6 carbon atoms. In a further embodiment R is 
an alkyl group containing from 3 to about 9 carbon atoms. M is an alkali 
metal including lithium, sodium, potassium, rubidium, cesium and francium. 
Lithium, sodium and potassium are preferred alkali metals, and lithium is 
the most preferred alkali metal, particularly when the polymetalated 
compositions of the present invention are to be used as polymerization 
catalysts. 
The substituent R.sup.1 is a divalent oligomeric hydrocarbyl group 
comprising moieties derived from a 1,3-conjugated diene. The conjugated 
dienes may be any of a variety of 1,3-conjugated dienes including those 
containing from four to 12 carbon atoms, and preferably from four to eight 
carbon atoms per molecule. Specific examples of the conjugated dienes 
include: 1,3-butadiene; isoprene; 2,3-dimethyl-1,3-butadiene; 
1,3-pentadiene(piperylene); 2-methyl-3-ethyl-1,3-butadiene; 
3-methyl-1,3-pentadiene; 1,3-hexadiene; 2-methyl-1,3-hexadiene; 
1,3-heptadiene; 1,3-octadiene; etc. In one preferred embodiment, the 
moeties of the oligomeric group R.sup.1 are derived from 1,3-butadiene, 
isoprene or piperylene. 
The number of moieties derived from a conjugated diene in the R.sup.1 
groups of the composition of Formula I may be varied over a range of from 
two to about 30. Generally, the total number of moieties derived from a 
conjugated diene in all of the R.sup.1 groups in the composition of 
Formula I is from about three to about 30. In one preferred embodiment, 
the total number of conjugated diene derived moieties in all of the 
R.sup.1 groups in the composition of Formula I is from about eight to 
about 20. The number of moieties derived from a conjugated diene in the 
oligomeric groups R.sup.1 can be varied to provide compositions of Formula 
I having a weight average molecular weight of from about 200 to about 
3000. In one preferred embodiment, the weight average molecular weight of 
the compositions of Formula I is within a range of from about 800 to about 
2000. 
The hydrocarbon soluble tri- and tetrametalated 1-alkyne compositions 
characterized by Formula I and additional hydrocarbon soluble 
polymetalated 1-alkyne compositions of other embodiments of the present 
invention can be obtained by reacting a 1-alkyne, an organometallic 
compound R.degree.M, and a conjugated diene at a temperature above about 
70.degree. C. The 1-alkyne may be represented by the formula 
EQU R(R.sup.3)C(H)--C.tbd.CH (II) 
wherein R and R.sup.3 are each independently hydrogen or a hydrocarbyl 
group. Representative examples of such 1-alkyne compounds include 
1-propyne; 1-butyne; 1-pentyne; 1-hexyne; 1-octyne; 1-decyne, 1-dodecyne; 
1-hexadecyne; 1-octadecyne; 3-methyl-1-butyne; 3-methyl-1-pentyne; 
3-ethyl-1-pentyne; 3-propyl-6-methyl-1-heptyne; 3-cyclopentyl-1-propyne; 
etc. 
The organometallic compound may be represented by the formula R.degree.M 
wherein R.degree. is a hydrocarbyl group which may be a saturated 
aliphatic group, a saturated cycloaliphatic group, or an aromatic group. 
Generally, R.degree. will contain up to about 20 carbon atoms. M is an 
alkali metal including lithium, sodium, potassium, rubidium, cesium and 
francium. Representative examples of the organometallic compound 
R.degree.M include: methylsodium, ethyllithium; propyllithium; 
isopropylpotassium, n-butyllithium, s-butyllithium; t-butylpotassium; 
t-butyllithium; pentyllithium; n-amylrubidium; tert-octylcesium; 
phenyllithium; naphthyllithium; etc. The conjugated dienes which are 
reacted with the intermediate to form the desired compositions are 
preferrably 1,3-conjugated dienes of the type which have been described 
above. 
In a preferred embodiment, the polymetalated 1-alkyne compositions of the 
present invention are prepared by the method which comprises the steps of 
(a) reacting a 1-alkyne with an organometallic compound R.degree.M to form 
an intermediate, and 
(b) reacting said intermediate with a conjugated diene at a temperature of 
at least about 70.degree. C. The mole ratio of R.degree.M to 1-alkyne is 
between about 2:1 and about 4:1. The mole ratio of conjugated diene to 
1-alkyne in the reaction is at least about 2:1 and may be as high as about 
30:1. More generally, the ratio will be in the range of from about 8:1 to 
20:1. 
The reaction of the 1-alkyne with the organometallic compound followed by 
reaction with the conjugated diene can be carried out in the presence of 
an inert diluent, and particularly, in the presence of a hydrocarbon such 
as an aliphatic, cycloaliphatic or aromatic hydrocarbon. Representative 
examples of suitable hydrocarbon diluents include n-butane, n-hexane, 
isooctane, decane, dodecane, cyclohexane, methylcyclohexane, benzene, 
toluene, xylene, etc. Preferred hydrocarbons are aliphatic hydrocarbons 
containing from four to about 10 carbon atoms per molecule. Mixtures of 
hydrocarbons can also be utilized. 
The number of metal substituents introduced into the compositions of the 
present invention will depend primarily upon the type of 1-alkyne, and the 
relative amounts of the 1-alkyne and the organometallic compounds present 
in the initial reaction to form the intermediate. In order to obtain at 
least one metal substituent on the carbon atom which is alpha to the 
alkyne group, more than one mole of the organometallic compound must be 
reacted with one mole of the 1-alkyne since the first hydrogen to be 
displaced by the metal is the hydrogen attached to the acetylenic group. 
Accordingly, the compositions of the present invention generally will be 
obtained by reacting at least about two moles of an organometallic 
compound with each mole of the 1-alkyne. When the 1-alkyne contains two 
hydrogens attached to the carbon atom adjacent to the triple bond (a 
methylene carbon), a molar ratio of organometallic compound to 1-alkyne of 
2:1 results in the formation of a dimetal compound, and the use of a molar 
ratio of 3:1 results in a trimetalated compound. For example, the reaction 
of one mole of propyne with one mole of n-butyllithium will form 
1-lithiopropyne; two moles of n-butyllithium will form 
1,3-dilithiopropyne; three moles of n-butyllithium will form 
1,3,3-trilithiopropyne; and four moles of n-butyllithium will form 
1,3,3,3-tetralithiopropyne. The reaction between one mole of 1-butyne and 
one mole of n-butyllithium results in the formation of 1-lithio-1-butyne; 
the reaction of one mole of 1-butyne with two moles of n-butyllithium 
results in the formation of 1,3-dilithio-1-butyne; and the reaction of one 
mole of 1-butyne with three moles of n-butyllithium at a temperature in 
excess of about 70.degree. C. results in the formation of 
1,3,3-trilithio-1-butyne. Larger amounts of the organometallic compound 
can be utilized, but such larger amounts are usually unnecessary. The 
reaction between the 1-alkyne and the organometallic compound to form the 
intermediate can be effected in temperatures of 20.degree. -30.degree. C., 
and the reaction is generally conducted in an inert atmosphere such as 
under nitrogen. The reaction generally is conducted at atmospheric 
pressure. The intermediate obtained from the first step is a polymetalated 
alkyne which is either insoluble or only slightly soluble in hydrocarbons. 
The reaction between the intermediate and the conjugated diene to form a 
hydrocarbon soluble product is conducted at a temperature above 70.degree. 
C. and more generally at a temperature of from about 70.degree. C. to 
about 150.degree. C. The reaction generally is completed in less than 
about 5 hours, and the reaction results in a change in the color of the 
solution from a yellow to red or reddish brown. At about 80.degree. C. the 
reaction is completed in about 3 hours. At higher temperatures, the 
reaction is completed in less than 3 hours. If the reaction mixture is 
heated for too long a period, the catalytic activity of the resulting 
product may be reduced. The product of this reaction is a polymetalated 
alkyne containing one or more divalent oligomeric hydrocarbyl groups 
comprising moieties derived from the conjugated diene. Relatively small 
amounts of the conjugated diene are reacted with the intermediate in the 
second step. The mole ratio of conjugated diene to 1-alkyne in the 
intermediate is at least about 2:1 and may be as high as 30:1. In one 
preferred embodiment, the mole ratio of conjugated diene to 1-alkyne is in 
a range of from about 8:1 to about 20:1. 
The polymetalated compounds of this invention contain active as well as 
inactive metal. The presence of at least two different types of carbon 
metal linkages in the compositions of this invention can be shown by both 
chemical and physical evidence. Gilman titration with allyl bromide 
distinguishes between metal acetylide (--C.tbd.C--M) which is inactive and 
other carbon lithium linkages (--C--C--M) which are active, J. Organometal 
Chem., 1 (1963) 8. Titration of the compositions of this invention show 
50%, 67% and 75% of the total carbon-metal linkages are "active" 
corresponding to di-, tri-, and tetra-metalated alkynes. Ultraviolet and 
visible spectral studies show peak absorbances at 300-340 NM and 400-450 
NM for the compositions of this invention corresponding to inactive and 
active metal linkages, respectively. 
An important property of these compositions is that they are soluble in 
hydrocarbon solvents, and the solutions are stable at room temperature for 
an extended period of time. The terms "soluble in hydrocarbon solvent" or 
"hydrocarbon soluble" as used in the specifications and claims indicate 
that the materials are soluble in hydrocarbons to the extent of at least 
about 5 per 100 g of solvent, particularly an aliphatic solvent such as 
hexane, at temperatures of about 25.degree. C. The compositions are useful 
as catalysts in the anionic polymerization and copolymerization of various 
hydrocarbon monomers. 
The following examples illustrate the preparation of the intermediates and 
the hydrocarbon soluble polymetalated 1-alkyne compositions of the present 
invention. Unless otherwise indicated, all parts and percentages are by 
weight, temperatures are in degrees centigrade and pressure is at or near 
atmospheric pressure.

PREATION OF INTERMEDIATES 
EXAMPLE A 
To a solution of 2 ml. (13.56 mM) of 1-octyne in 30 ml. of hexane in a 
7-ounce beverage bottle equipped with rubber liner, 3-hole crown cap and 
magnetic stirrer is charged 9 ml. (13.56 mM, 1.5M solution) of 
n-butyllithium in hexane through a disposable syringe at room temperature 
under nitrogen. The monolithium salt was precipitated immediately as a 
white solid. Additional n-butyllithium solution in hexane (9 ml., 13.56 
mM, 1.5M solution) is added to the bottle and the mixture is stirred 
magnetically at room temperature to form a pale yellow solution and a 
yellow solid precipitate. Titration of the yellow solid utilizing the 
procedure described by H. Gilman indicates 50.6% active carbon-lithium 
linkage. The calculated active carbon-lithium linkage for this product is 
50%. 
EXAMPLE B 
To a solution of 1-octyne (0.55 ml., 3.73 mM) in 20 ml. of hexane, 
n-butyllithium (7 ml., 11.2 mM, 1.6M solution) is added slowly through a 
disposable syringe at room temperature under nitrogen. After the addition 
is complete, the resulting pale lemon solution containing a small amount 
of precipitate is vigorously shaken, and then the mixture is allowed to 
stand at room temperature for five hours. Titration of the solid product 
by the Gilman technique indicates that 96-98% of the theoretical 
carbon-lithium linkages are obtained. 
PREATION OF DIENE-MODIFIED POLYMETALATED 1-ALKYNES 
EXAMPLE 1 
To a solution of 1-octyne (0.8 ml., 5.42 mM, 98% purity) in 20 ml. of dry 
hexane in a 7-ounce beverage bottle equipped with rubber liner and 
three-hole crown cap are charged 7 ml. of n-butyllithium (10.85 mM, 1.55M 
solution) through a disposable syringe at room temperature under nitrogen. 
The resulting slurry is shaken vigorously to complete the reaction. The 
resulting pale yellow solution is allowed to stand at room temperature for 
about one hour. To the solution is charged 25 gms. of 1,3-butadiene in 
hexane (24.2% butadiene, 112 mM butadiene). The mixture is tumbled in a 
bath maintained at about 80.degree. C. for three hours. The resulting 
reddish brown solution is cooled at room temperature. Analysis of the 
solution by Gilman's titration technique indicates 48.9% active 
carbon-lithium linkages. The calculated active carbon-lithium linkage for 
1,3-dilithio-1-octyne is 50.0%. 
EXAMPLE 2 
To a solution of 0.55 ml. of 1-octyne (3.73 mM) in dry hexane contained in 
a 7-ounce bottle equipped with rubber liner and three-hole crown cap are 
charged 7 ml. of n-butyllithium (11.2 mM, 1.6M solution) through a 
disposable syringe at room temperature under nitrogen. The resulting 
slurry is shaken vigorously to complete the reaction, and the resulting 
pale yellow solution is allowed to stand at room temperature for one hour. 
To this solution is charged 25 gms. of 1,3-butadiene in hexane (24.2% 
butadiene, 112 mM butadiene). The mixture is tumbled in a bath heated to 
about 80.degree. C. for three hours, and the resulting reddish brown 
solution is cooled and stored. Analysis of the solution obtained in this 
manner indicates active carbon-lithium linkage of 63.6%. The calculated 
active carbon lithium linkage for 1,3,3-trilitho-octyne is 66.7%. 
EXAMPLE 3 
To a 1500 ml. glass reactor equipped with thermometer, stirrer, heating 
means, pressure means, inlet and outlet ports are charged 150 gms. of dry 
hexane, 217 gms. (498 mM) of n-butyllithium (1.54M) in hexane, and a 
solution of 18 gms. (166.3 mM) of 1-octyne in 30 gms. of dry hexane. The 
reaction mixture is maintained under a nitrogen atmosphere as the 
n-butyllithium and 1-octyne are added to the reactor. After the above 
ingredients are added to the reactor, the mixture is stirred at room 
temperature for 30 minutes under nitrogen, and 360 gms. of a 
1,3-butadiene/hexane blend containing 87.5 gms. of 1,3-butadiene are added 
to the reactor. This mixture is stirred at 80.degree. C. for 150 minutes 
whereupon a homogeneous red solution is obtained. This solution is allowed 
to cool to room temperature and transferred to storage bottles under a 
nitrogen atmosphere. Gilman's titration indicates the presence of 62.18% 
active carbon-lithium linkages at 0.2708 molarity. The calculated 
carbon-lithium linkage is 66.7%. 
Two-hundred grams of the catalyst solution is coagulated with excess 
methanol in the presence of an antioxidant (e.g., 1% 
di-tertiary-butyl-para cresol). The resulting oily product is dried at 
50.degree. C. under vacuum. Gel permeation chromatography analysis of the 
product indicates a 1123 Mw. 
EXAMPLES 4-6 
The general procedure of Example 2 is repeated utilizing different 
1-alkynes as summarized in Table I. The reaction conditions and the 
analysis of the resulting products also are summarized in Table I. 
TABLE I 
______________________________________ 
Example 4 5 6 
______________________________________ 
1-alkyne 1-hexyne 1-nonyne 1-dodecyne 
Hexane (ml.) 20 20 20 
1-alkyne (mM) 3.73 3.73 3.73 
n-BuLi (nM) 11.20 11.20 11.20 
Bd-Hexane* (g) 
25 25 25 
Temp. (.degree.C.) 
80 80 80 
Time (hrs.) 3 3 3 
Product Color reddish brown 
% Active C--Li bond** 
59.5 60.0 59.3 
______________________________________ 
*blend contains 24.2% Bd. 
**determined by Gilman titration. 
The polymetalated 1-alkynes of the present invention are stable for an 
extended period of time at room temperature. For example, the 
polymetalated compositions can be stored at room temperature under a 
nitrogen atmosphere for up to six months or more without significant loss 
of their activity as catalysts for anionic polymerization reactions. 
The polymetalated 1-alkyne compositions of the present invention are useful 
as catalyts for the anionic polymerization of a variety of hydrocarbon 
monomers including olefins such as ethylene, styrene, 
.alpha.-methylstyrene, divinylbenzene and vinyl toluene; and dienes such 
as butadiene, isoprene, piperylene and 2,3-dimethylbutadiene. The 
catalysts also may be utilized for preparing copolymers or mixtures 
containing two or more of the above olefins, dienes, or mixtures thereof. 
The polymers and copolymers obtained in this manner contain alkali metal, 
and polymers of these types have been referred to as "living polymers". 
The "live ends" of the polymers (i.e., the carbon-alkali metal bonds) can 
be used to couple the polymers or to introduce terminal, functional groups 
such as silane, hydroxyl, carboxyl, mercapto, amino, etc. by procedures 
well known to those skilled in the art. 
While the present invention has been described in connection with certain 
specific embodiments, it will be appreciated that modifications of the 
disclosed invention will be suggested to those skilled in the art upon 
reading this disclosure. Therefore, it is to be understood that the 
invention disclosed herein is intended to cover such modifications as fall 
within the scope of the appended claims.