End groups of linear polymers are specified by prefixes cited in front of the name of the polymer. This is illustrated by a systematic name for a methyl phenyl ether of polyethylene glycol:

a-methyl-w-phenoxypoly(oxyethylene)


The system of nomenclature for regular single-strand and quasi-single-strand inorganic and coordination polymers is explained in an IUPAC document,(4) and summarized in the IUPAC Red Book(5) and in an ACS book on inorganic chemical nomenclature.(6) It is based on selection and naming of a preferred constitutional repeating unit (CRU). Once a CRU is identified, it has to be oriented in such a way that the subunit of the highest seniority is selected as the left terminal and other subunits are placed sequentially according to specified criteria.

Examples

1. Polyphosphazenes

preferred CRU IUPAC inorganic name: catena-poly[(diethoxophosphorus)-m-nitrido] common name: poly(diethoxyphosphazene)

According to the rules for linear organic polymers,(3) this polymer would be reoriented and named: poly[nitrilo(diethoxyphosphoranylidyne)]

2. Polysiloxanes

IUPAC inorganic name: catena-poly[(methylphenylsilicon)-m-oxo] common name: poly(methylphenylsiloxane)

According to the organic polymer rules:(3) poly[oxy(methylphenylsilylene)


b. An aminophenyl-terminated poly(dimethylsiloxane)(7) is named:

a-[(4-aminophenyl)dimethylsilyl)-w-(4-aminophenyl)poly(oxy(dimethylsilylene)]


3. Polysilanes

IUPAC inorganic name: catena-poly[(diethylsilicon)(dimethylsilicon)]

According to the organic polymer rules:(3) poly(1,1-diethyl-2,2-dimethyldisilanylene)

The structure and the name represent an ideal alternating copolymer, assuming that the alternating units, diethylsilylene and dimethylsilylene, came from two different monomers.

One might be tempted to indicate that in a structure-based name, e.g.,

poly(diethylsilylene-alt-dimethylsilylene),

but this would be contrary to the current nomenclature rules. The connective "alt" (alternating) is meant to be used with the source-based names only. Secondly, for a regular single-strand polymer, the largest regularly repeating constitutional unit is selected in constructing a structure-based name. Thus for a copolymer such as

-A-B-A-B-A-B-A-B-

the structure-based name is "poly(A-B)", rather than "poly(A-alt-B)". In our case, "disilanylene" is the proper "parent" bivalent group, rather than two consecutive "silylene" bivalent groups.

b. The source-based nomenclature for copolymers(8) would indicate the starting monomers and what is known about the polymer, e.g., an alternating sequence:

poly(dichlorodiethylsilane-alt-dichlorodimethylsilane)

If other monomers or starting reactants were used to arrive at the same polymer, the source-based names would reflect that, e.g.,

poly(diethylsilane-alt-dimethylsilane)
poly(1,2-dichloro-1,1-diethyl-2,2-dimethyldisilane)
poly(1,1-diethyl-2,2-dimethyldisilane)

The source-based names do not indicate the type of reaction which would have to take place such as reductive coupling with sodium, dehydrogenative coupling with a catalyst, or anionic polymerization.

Some of the above monomers are hypothetical, yet are useful to illustrate the naming process for polymers. Incidentally, the potential polymerization of disilenes to form linear polysilylenes has been discussed, and the anionic polymerization of masked disilenes to form highly ordered alternating polysilylene copolymers has been successful.(9)

c. The structure-based nomenclature for irregular copolymers(10) would indicate individual constitutional units not joined together:

poly(diethylsilylene/dimethylsilylene)

d. The corresponding source-based name for a copolymer of unspecified sequence would be:

poly(dichlorodiethylsilane-co-dichlorodimethylsilane)

e. If the copolymer has regular blocks with unspecified sequential arrangement of the blocks, the structure and the name would be:

poly[poly(diethylsilylene)/poly(dimethylsilylene)]

REFERENCES

1. Polym. Prepr.1991, 32(1), 655-656; 32(3),7-9, 1992, 33(2), 6-7.
2. Polym. Prepr. 1992, 33(1), 6-11.
3. IUPAC. "Nomenclature of Regular Single-Strand Organic Polymers". Pure Appl. Chem. 1976, 48, 373-385. Reprinted as Chapter 5 in "Compendium of Macromolecular Nomenclature" (The Purple Book). Blackwell Scientific Publications, Oxford, 1991; available in the U.S. from CRC Press, Boca Raton, Florida.
4. IUPAC. "Nomenclature for Regular Single-Strand and Quasi-single-Strand inorganic and Coordination Polymers". Pure Appl. Chem. 1995, 57, 149-168. Reprinted as Chapter 6 in "Compendium".
5. IUPAC. "Nomenclature of Inorganic Chemistry" (The Red Book) Scientific Publications, Oxford, 1991; pp. 197-198.
6. Block, B.P.; Powell, W.H.; Fernelius, W.C. "Inorganic Chemical Nomenclature". American Chemical Society, Washington, DC, 1990; pp. 57-66.
7. Babu, J.R.; Sinai-Zingde, G.; Riffle, J.S. "Synthesis of a,w-arylamine functionalized poly(dimethylsiloxanes)". Polym. Prepr. 1991, 32(1), 152-153.
8. IUPAC. "Source-Based Nomenclature for Copolymers". Pure Appl.Chem. 1985, 57, 1427-1440. Peprinted as Chapter 7 in "Compendium".
9. Sakamoto, K.; Yoshida, M.; Sakurai, H. "Highly Ordered High Molecular Weight Alternating Polysilylene Copolymer Prepared by Anionic Polymerization of Masked Disilene". Macromolecules 1990, 23, 4494-4496.
10. IUPAC. "Structure-Based Nomenclature for Irregular Single-Strand Organic Polymers". In preparation.


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* Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213.

** Chemical Abstracts Service, P.O. Box 3012, Columbus, OH 43210.