Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From boron reactant having at least one boron to hydrogen or...
Reexamination Certificate
2000-04-03
2002-04-16
Dawson, Robert (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From boron reactant having at least one boron to hydrogen or...
C528S004000, C528S394000, C528S398000, C252S601000, C423S276000, C423S293000
Reexamination Certificate
active
06372873
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to novel linear, phosphine-borane polymers, particularly high molecular weight phosphinoborane polymers; methods for the preparation thereof and, particularly, thermally-induced dehydrocoupling methods.
BACKGROUND TO THE INVENTION
Carbon comprises less than 0.1% of the Earth's crust, oceans, and atmosphere. Despite this fact, virtually all polymer systems known and commercially available are based on extended catenated structures containing mainly carbon atoms together with a few other elements, such as oxygen and nitrogen. The availability of suitable organic monomers and the extensive synthetic knowledge associated with organic chemistry allows the design and synthesis of new materials and the subsequent fine-tuning of their properties. In contrast, the development of extended structures based on atoms of other elements has been much less successful and still represents a substantial unsolved synthetic challenge. Nonetheless, the relatively few polymer systems based on inorganic elements such as poly(siloxanes), silicones [R
2
Si—O]
n
, polyphosphazenes [R
2
P═N]
n
, polysilanes [R
2
Si]
n
and more recently poly(silynes), poly(stannanes), sulfur-containing polymers, poly(metallocenes), and other metallopolymers illustrate the potential for accessing materials with unexpected properties as well as novel applications.
Thermally-induced dehydrocoupling of phosphine-borane adducts R
2
PH.BH
3
at elevated temperatures of, for example, 150-200° C. has been previously used to prepare cyclic phosphinoborane species, mainly six-membered rings [R
2
P—BH
2
]
3
and, for example, [R
2
P—BH
2
]
3
having considerable thermal and hydrolytic stability.
(1)
In addition in a few cases, low yields of “polymeric” materials have been made, although none has been structurally characterized and, where reported, the molecular weights were relatively very low.
(2)
During the early pioneering work in the 1950's and 1960's on boron-phosphorus compounds, the low yield formation of a range of partially characterized, low molecular weight phosphinoborane polymers were described in patents, technical reports and in the academic literature. For example, pyrolysis of Me
2
P—PMe
2
.BH
3
or RMePH.BH
3
(R=Me or Et) at 175-200° C. in the presence of amines, which were claimed to promote the formation of linear rather than cyclic products, was reported to give polymers [RMeP—BH
2
]
n
with molecular weights of 1,800-6,000 (where determined).
(2,3)
For a general survey of results obtained during this period see G. W. Parshall in “The Chemistry of Boron and its Compounds”: E. L. Muetterties Ed., Wiley, N.Y. (1967) Ch. 9 p 617-646. Dehydrocoupling routes to bonds between inorganic elements have provided important routes to Group 14 polymers.
(4)
Dehydrocoupling has been used to form oligomers and polymers with B—N bonds between borazine rings,
(5)
while coordinate bonds between B and N have recently been used in the preparation of metallopolymers.
(6)
The phosphine-borane adduct Ph
2
PH.BH
3
is known to undergo dehydrocoupling at 180-190° C. and above over a period of 14 h to exclusively and quantitatively yield the cyclic trimer [Ph
2
P—BH
2
]
3
.
(7)
The preparation of very low molecular weight polymers of M
n
1480-2630 from the thermolysis of PhPH
2
.BH
3
at 150-250° C. in the absence of a catalyst has been described.
(8)
PUBLICATIONS
1. C. A. B. Burg and R. I. Wagner,
J. Am. Chem. Soc
. (1953) 75. 3872.
2. R. I Wagner and F. F. Caserio,
J. Inorg. Nucl. Chem
. (1959), 11, 259.
3. A. B. Burg,
J. Inorg. Nucl. Chem
. (1959), 11, 258.
4. See, for example, (a) P. Bianconi, T. W. Weidman
J. Am. Chem. Soc
. (1988), 22, 1697. (b) T. Imori, T. D. Tilley
J. Chem. Soc. Chem. Commun
. (1993), 1607. (c) I. Manners, G. Renner, H. R. Allcock, O. Nuyken
J. Am. Chem. Soc
., (1989), 111, 5478. (d) J. A. Dodge, I. Manners, G. Renner, H. R. Allcock, O. Nuyken,
J. Am. Chem. Soc
(1990), 112, 1268. (e) M. Liang, I. Manners,
J. Am. Chem. Soc.,
(1991), 113, 4044. (f) A. K. Roy
J. Am. Chem. Soc
. (1992), 114, (g) V. Chunechom, T. E. Vidal, H. Adams, M. L. Turner
Angew. Chem. Int. Ed. Engl
. (1998), 37, 1928.
5. P. J. Fuzan et al.
Chem. Mater
. (1990), 2, 96.
6. M. Fontani et al.
Eur. J. Inorg. Chem
. (1998), 2087.
7. W. Gee et al.
J. Chem. Soc
. (1965), 3171.
8. V. V. Korshak et al.
Izv. Akad. Nauk SSR, Ser. Khim
, (1964), 1541.
SUMMARY OF THE INVENTION
The present invention provides novel, polymeric compounds having a linear backbone of alternating phosphorus and boron atoms.
The invention further provides novel, optionally, metal catalysed dehydrocoupling methods to produce linear phosphorus-boron polymers.
Accordingly, in one aspect the invention provides linear backbone phosphorus-boron polymers of the general formula (I)
wherein R
1
-R
4
are the same or different and selected from H, optionally substituted lower alkyl, alkenyl and aryl; and n is at least 2. Preferably, the invention provides a polyphenylphosphinoborane of aforesaid formula (I) wherein R
1
, H and R
4
is phenyl. More preferably, the linear polymers as hereinabove defined included low molecular weight oligomers having weight average molecular weights (M
w
) of about 5,000 and higher molecular weight polymers having M
w
more preferably of at least 10,000, and still more preferably at least 20,000.
In a further aspect, the invention provides a method for producing polymers having a linear backbone of alternating phosphorus and boron atoms, said method comprising dehydrocoupling a phosphine-boron adduct by treating said adduct at a temperature to effect said dehydrocoupling to produce said linear polymer.
Preferably, the aforesaid process is carried out at effective temperatures lower than a temperature which would produce a corresponding phosphorus-boron cyclic trimer compound.
More preferably, the dehydrocoupling methods as hereinabove defined further include the presence of an effective dehydrocoupling catalyst, for example, complexed Rh(I) catalysts or complexes of other metals.
Specific Examples are:
[Rh(1,5-cod)
2
][OTf]
[Rh(PPh
3
)
3
Cl]
[Rh(1,5-cod)(dmpe)][PF
6
]
[Rh(CO)(PPh
3
)
3
H]
anhydrous RhCl
3
RhCl
3
hydrate
[{C
p
*Rh(&mgr;Cl)Cl}
2
]
[{Ir(&mgr;-Cl)Cl}
2
]
[Ir(1,5-cod)
2
][BF
4
]
Cp
2
TiMe
2
Ru
3
(CO)
12
[Pt(1,5-cod)2]
PdCl
2
PtCl
2
; and most preferably
[{Rh(&mgr;-Cl)(1,5-cod)}
2
]
In the foregoing list of compounds, it will be understood that cod represents cyclooctadiene; OTf stands for triflate anion (CF
3
SO
2
O
−
); and Dmpe is dimethylphosphinoethane.
In a further aspect, the invention provides a method of producing the dimer compound of formula I, wherein R
1
and R
2
are Ph, R
3
and R
4
are H and n is 2, i.e.
by treating the phosphine-borane adduct Ph
2
PH—BH
3
at a dehydrocoupling temperature of less than 180° C., preferably in the presence of an effective amount of a dehydrocoupling catalyst.
In alternative methods for producing high molecular weight polymers according to the invention, alkylated derivatives may be made by alkylation of labile hydrogen-bearing phosphorus in the polymers by, for example, reaction with alkylated lithium or Grignard reagents, viz:
Wherein R
2
is an optionally substituted lower alkyl or aryl.
REFERENCES:
patent: 3012076 (1961-12-01), Burg et al.
patent: 3035095 (1962-05-01), English
patent: 3240807 (1966-03-01), Wagner et al.
patent: 3240815 (1966-03-01), Wagner et al.
patent: 3272781 (1966-09-01), Goodrow
patent: 3347800 (1967-10-01), Goodrow et al.
Dorn Hendrik
Manners Ian
Dawson Robert
Robertson Jeffrey B.
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