A. F. CLIFFORD ganic chemistry from the very origins of chemical science to the present day. Corresponding to its character of long-term balance, the Handbook always has, and will have, definite gaps from the immediate present in its individual volumes. This is a fact which will continue to exist despite all efforts to approach the present moment. A chemist requires another information source in addition to the Handbook for information. Considerations at the Gmelin Institute, as well as those on a broader plane relating to forming a documentation center for chemistry in Germany, have recently resulted in establishing the Arbeitsgemeinschaft Chemie Dokumentation e.V. (Council for Chemical Documentation). Undertaking to create and staff a centralized documentation agency encompassing the entire field of chemistry follows from a realization that a sufficiently powerful means must be devised to cope with all of the tasks confronting individual documentation and information facilities-tasks which threaten to overwhelm such facilities in the relatively near future. However, the idea that an individual paper could be evaluated, arranged, and indexed by a large number of documentation centers made it seem reasonable to collect these centers into a single combined agency. I t has proven to be desirable that the several institutions for chemical documentation agree upon and support common interests within this over-all concept, without losing their own individuality and assigned tasks. I t was thus thought that a paper should be evaluated only by a single collaborator, with the resultant material being worked up in such a way as to satisfy simultaneously the requirements of the several information transmission arrangements being considered-i.e., express information services, handbooks, and computer services. The Handbook has thus acquired an essential position in the information field. A computer can serve as an information source spanning the period of time between the literature closing date
of the Handbook and the present. Keference 2 discusses the position of the Handbook with respect to the computer. Reference is made here to the opinions of E. Pietsch3 and F. Richter4according to whom “the mere arrangement of information promptly in a defined manner, such as is made possible by a computer, will not provide the final form which can serve satisfactorily the progress of science. A large number of bits of information summed up into a mosaic does not really provide a picture of the state of knowledge in a discipline. The Handbook does not merely give citations but rather provides a text, and is in fact a critically reworked text, and gives many kinds of stimuli among the topics near the subject being sought. I n this respect, it far exceeds the performance of a machine.” Consequently, only a systematic Handbook can offer the scientist an opportunity for comparative evaluation and thus encourage creative initiative and effort; a computer is in a position only to provide answers to already formulated definite questions in an equally definite form. Although it is certainly important to have a computer available to aid in data compilation, the Handbook must retain its fundamental importance well into the future most important chemical information tool. LITERATURE CITED Gmelin, Leopold, “Handbuch der theoretischen Chemie,” Jubilee Facsimile Reprint of the First Edition of 1817, in celebration of the 150th anniversary of Gmelin’s Handbook of Inorganic Chemistry, Verlag Chemie, Weinheim, 1967. Buschbeck, K-Chr., W. Lippert, and E. ‘Uehlein, “Das systematische Handbuch in der naturwissenschaftlichen Literatur,” Die Natunuissenschaften 55, 379 (1968). Pietsch, E., “Vorrede zum Nachdruck der 1. Aufl. des GmelinHandbuchs,” “Handbuch der theoretischen Chemie,” Verbatim Reprint of First Edition of 1817, Verlag Chemie, Weinheim, 1967. Richter, F., “Beilstein-Handbuch-75 Jahre arganischchemischer Dokumentation,” Angew. Chern. 70, 279 (1958).
Proposed Rules for Nomenclature for Compounds of Phosphorus, Sulfur, and Related Elements A. F. CLIFFORD Department of Chemistry, Virginia Polytechnic Institute, Blacksburg, Va.
24061
Received April 6, 1970 A subcommittee of the ACS Committee on Inorganic Nomenclature has been meeting for a number of years to develop a rational system of nomenclature for the compounds of phosphorus and related elements. The report of the subcommittee is presented here at the suggestion of the parent committee for general consideration and comment. The membership of the subcommittee has included: A. F. Clifford (Chairman), Roy M. Adams (ex officio), Gail H. Birum, James E. Huheey, A. F. Isbell, Fred Leighton (deceased), Fred McCollough, Patricia M. McDonnell, George W. Parshall, Rudi Raetz (deceased), and Russell J. Rowlett, Jr.
The system of nomenclature for compounds of phosphorus, sulfur, and related elements proposed in the following pages has been developed in answer to objections to systems, proposed and adopted, which have been suggested in the past. As the known chemistry of phosphorus and related elements becomes more complicated and as molecules containing atoms of more different elements including nonsubstituent carbon become known, it is increasingly 180
Journal of Chemical Documentation, Vol. 10, No. 3, 1970
necessary to have an internally consistent system of nomenclature for such compounds. Inasmuch as it seems highly inadvisable to create for these elements yet another new system which is different from that of other elements, every attempt has been made to build upon an existing accepted system-specifically the “a” system-augmenting it as necessary to meet the more complex demands of the chemistry of these elements. The choice of a system
NOMENCLATURE FOR COMPOUNDS OF P, S, AND RELATED ELEMENTS designed for covalent compounds was dictated by the predominantly covalent nature of compounds of most of the elements on the right side of the periodic table. For example, the bonding of phosphorus to adjacent atoms, with the possible exception of certain salt-like phosphides, is almost always covalent. If the nomenclature for these elements were consistent with organic nomenclature, it would be possible to name such compounds as CH3 0
0
COzH 0
C1 CHBr H
F CH3
PHz
0
PF4
class as different and place in different categories substances which chemists intuitively class together. Thus PCls and PC16 would be in different categories, although they are both usually considered to be examples of phosphorus(V). Again, this would place PFj and PF; in the same category although PFs is normally considered to contain phosphorus(V) and is nonoxidizable, whereas PF, is normally considered to contain phosphorus(II1) and is oxidizable.
I
CHzC = P0zPHz 0
without having to change nomenclature systems in the middle of the name. With this in mind, one of the cardinal aims of the Committee may be stated as follows: Since most of the elements on the right of the transition elements in the periodic table are characterized by the covalency of their union with other elements and their proclivity to form catenation compounds, the nomenclature should follow the principles already established for covalent (Le., carbon) compounds. However, it must take account of the greater complexity of the chemistry of the inorganic elements in terms of variation of valence and coordination number.
For this same reason it seemed advisable not to use coordination nomenclature for ions such as P F , since coordination nomenclature for similar anionic centers, for example in such compounds as SFjCHZFSF4CHzPCls
would be inconsistent with the covalent nomenclature used for the rest of the molecule. Another concern of the Committee was that the naming of unicentric and polycentric compounds be mutually consistent, so that it would not be necessary to change systems when the number of central atoms in the compound changes. Since certainly the problems of naming polycentric compounds are the more formidable, it was felt the needs of the nomenclature of polycentric compounds should dictate the choice of systematic names for unicentric compounds. A problem not met in organic nomenclature but which must be dealt with in the case of the nomenclature of these elements is that of variable valence. Various suggestions have been made for dealing with this problemincluding ignoring it. One of the serious suggestions has been to classify compounds according to the coordination number of the central atom (generally with inclusion of nonbonding electron pairs in the enumeration). This approach, although having considerable merit, was rejected by the Committee for several reasons: If coordination number were to be used in the same sense as organic unsaturation to define categories, at least five such categories would he required in the case of phosphorus and up to eight for some other elements. If coordination number were used in the manner of coordination nomenclature, it would be required that every group on every hetero atom be individually enumerated, adding materially to the cumbersomeness of the name. Use of coordination number for categorization would place in the same categories substances which chemists intuitively
Another approach would be to use Stock numbers to indicate oxidation states. There are, however, at least two serious objections to this. The first lies merely in the awkwardness of having to enumerate a list of roman numerals of oxidation state in combination with arabic numerals of position. This would be particularly awkward in oral usage. [See, for example, the application of this system in J. CHEM.DOC.4, 91 (1964), Table IX.] The second lies in the difficulty in defining the Stock oxidation state-for example, the compound H4P206 according to the Stock system contains phosphorus(1V). However, it would be extremely awkward in the name of a complex molecule in order to define oxidation state to have to take into account whether a particular phosphorus atom is attached to another phosphorus or not. I n the Stock system, the P in R 2 P 0 2 H may have any number of different arbitrary oxidation states depending on whether R = H , alkyl, or one or two other phosphorus atoms and also on the nature of the substituents on the phosphorus atoms-this despite the fact that the gross electronic structures do not change. The system which is recommended here is based on the number of unshared pairs of electrons on each atom. This corresponds to the chemist’s intuitive oxidation state regardless of coordination number or nature of attached atoms. The distinguishing factor which differentiates one typical series of compounds of an element from other such series is not the number of ligand or attached groups, but rather, the number of nonbonding electrons in the valence level. This fact is recognized implicitly in the Stock numbering system, in which the formal oxidation state is a function of the number of nonbonding electrons for unicentric compounds (although not, it should be reiterated, of polycentric ones). Thus, all unicentric compounds of phosphorus having no nonbonding electrons are P(V); all having one nonbonding electron pair are P ( I I I ) , and so forth, where nonbonding electrons are taken to be those not involved in sigma bonding. Likewise, all unicentric compounds of manganese having no nonbonding electrons are Mn(VII), all having one are Mn(VI), all having five are Mn(II), and so forth. For catenation compounds, which are most important for the nonmetals and metalloids, however, the Stock designation loses this meaning, as already shown in the case of hypophosphoric acid, which is a compound of P(IV), electronically similar to phosphoric acid containing P(V). A means of recognizing imJournal of Chemical Documentation, Vol. 10, No.
3, 1970
181
A. F. CLIFFORD mediately the electronic structures of such elements in catenation compounds would be desirable. Consequently, a series of suffixes is recommended to be used to designate oxidation states in exactly the same way as the suffixes -ane, -ene, and -yne are used to designate degrees of unsaturation in carbon compounds. This system, being used in the same way as organic designation of unsaturation, has the distinct advantages of being completely compatible with organic-type nomenclature and of not requiring reiteration of a designation of oxidation state or coordination number for each atom in the chain. An extremely important class of covalent inorganic compounds is that having alternating atoms in the chains (Van Wazer’s amoebo compounds). To have to specify the nature and position of each such atom is unnecessary and unduly complicating when the alternative of considering the atoms two at a time is available. Consequently, it is recommended that a slightly modified (or, actually, restricted) siloxane-type nomenclature be allowed as an exception to the strict rules. Another extremely important class of compounds, especially for phosphorus, is that of the polycentric acids. These take on such a variety of forms that to have to give them nonfunctional names-Le., naming and locating each oxo and hydroxy group-would produce excessively cumbersome names. Consequently, it is recommended that the names of phosphorus acids be derived from those of the hydrides in a manner similar to that in which those of the alkanoic acids are derived from those of the alkanes. However, in deference to the inorganic inclination to do away with functional nomenclature, this is the only functional group so considered. Although there is considerable objection to accepting the concept of multiple bonding in naming inorganic compounds, there are cases where it undeniably occurs and can occur within the backbones of long-chain molecules. Examples include many possible phosphorus and sulfur imines and methylenes. In answer to the argument that the multiplicities of these bonds are not integral, it must be pointed out that neither are those in many organic compounds-for example, in the isocyanides and in the imines. The principal advantage to allowing the designation of bond multiplicity, however, is a device to allow
The alternative to this would be to designate and locate each charge center, which under these conditions would be as uncertain a quantity as the bond multiplicity. This would tremendously complicate the naming. Consequently, it is recommended that formal bond multiplicities be recognized and designated in the organic manner. (Isolated charge centers must, of course, be dealt with as such.) A further criterion considered by the Committee was that the system developed be equally applicable to all elements on the right of the copper family in the periodic table, “lest there arise a jungle of nomenclatures,” one for each element, each incompatible with the others. The Committee feels that this aim has been accomplished. An example of the application of this system to halogen nomenclature is reported in J. CHEM.Doc. 4, 91 (1964). I t is recognized, of course, that the systematic names for unicentric compounds which are recommended here will no more replace in common usage the current common names than the name ethanoic acid has replaced acetic acid. However, just as seldom used Geneva names for organic compounds provide the basis for the more complicated names of more complex molecules derived from them, so can the recommended names for monophosphorus compounds be used in systematic fashion as the basis for names of much more complex molecules. PROPOSED SYSTEM FOR THE NOMENCLATURE OF COMPOUNDS OF PHOSPHORUS, SULFUR, AND RELATED ELEMENTS PART I. UNICENTRIC COMPOUNDS
1. Parent Structures 1.1 Parent structures, which need not necessarily have independent existence, are the neutral hydrides having even numbers of unshared electrons. These are named by adding to the name of the central atom (appropriately curtailed) suffixes indicating the number of unshared pairs of electrons assigned to the central atom. The suffixes are Number of unshared pairs
Sufi
0
-ane -ine -uane -uine
1 2 3
Typical parent hydrides are (1)
ZnH? zincane
the atoms involved to be considered neutral as long as there are adjacent compensating formal charges-e.g., HPCIZ-N N \pc12
‘PCh
=N
+
-
- /PClz-N
N
‘’
iC12
‘+PCIz-N 182
cyclotri-P,P-dichlorophosphazanene, not
/
cyclotri-P,P-dichlorophosphazan-Ponia-N-ate.
Journal of Chemical Documentation, Vol. 10, No. 3,
1970
GaH3 gallane :GaH galline
SiHa silane :SiH2 siline
AsHs amne :AsHS arsine :ASH arsuane
SHs sulfane :SH, sulfine :S”z sulfuane
ClHs chlorane :C1H5 chlorinine :%1& chloruane :CIH chloruine
XeHa xenane :XeH6 xenine :XeH4 xenuane :XeH2 xenuine
Exceptions: -Sin heteroatomic chains = thia, and as a bivalent substituent = thio. 1.11 In the event of delocalization of electrons, which might cause doubt in the assignment, for the purposes of nomenclature only, the electrons are considered to be located in such a way as to reduce formal charges to a minimum. E.g.,
NOMENCLATURE FOR COMPOUNDS OF P, S, AND RELATED ELEMENTS (2) ,SiH3
a phosphine, not SiH3,+
P = SiH;
'
:P-SiHs SiH3 (CsH5)&'=CH2
a phosphonium compound;
/
SiH3
+
a phosphane, not (CsHs)3p-CH;
a phosphonium compound.
2. Structures Formed by Substitution 2.1 Oxygen Acids. I n a manner similar to that in which the names of the alkanoic acids are derived from those of the alkanes-e.g., ethanoic acid from ethane-the names of the oxygen acids are derived from those of the parent hydrides by replacement of hydrogen by its equivalent in hydroxy and oxo groups and addition of aquo groups to attain the appropriate standard coordination number for the central atom and adding -oic ,acid, -dioic acid, etc., to the name of the hydride, dropping the final e if necessary. I n establishing the coordination number, each unshared electron pair accounts for one coordination posi(6)
Period
S.C.X
2
3
3.4
5.6
7.8
HOCHO methanoic (HO)&O methanedioic HONO? nitranoic (HO)3i silanetetroic HOPH20X phosphanoic (HOI~PHO # phosphanedioic (H0)3POt phosphanetrioic (HO)2S02 sulfanedioic HOC103 chloranoic ( HO)sSb(OHz) stibanoic (HOhTe telluranehexoic (H0)JO iodanepentoic (HO),Xe02 xenanetetroic (H0)5Eb(OHd, ekabismuthanetrioic
4
6
8
tion. The standard coordination numbers (S.C.N.) used in forming the names of the acids are those usually observed in the most common unicentric oxy acids. They are specifically defined as follows: (3)
Period S.C.N.
2 3
3,4 4
5,6 6
728
8
2.11 Acid Functionality. For acids not having aquo groups attached to the central atom, the number of acid equivalents is designated by enumerating the hydroxyl groups, and affixing the appropriate numerical prefix to the suffix -oic acid, e.g., (4) (H0)zPHO
phosphanedioic acid
For acids having aquo groups attached to the central atom, the number of acid equivalents is designated by enumerating the aquo groups, e.g., (5) (H20)2Sn(OH)4
stannanedioic acid
Further examples include
HONO nitrinoic
HON: nitruanoic
HOPH,
HOP(OH~)
phosphinoic (HOlzPH phosphinedioic (H0)sP: phosphinetrioic (HO)zSO sulfinedioic HOCIOz chlorininoic (HO)3Sb(OHn)z stibinedioic (HO)*Te(OH2) tellurinoic (HO)s1 : iodininepentoic (HO)rXeO xeninetetroic (HO)3Eb(OHi)a ekabismuthinetetroic
phosphuanoic
(HO)?S: sulfuanedioic HOC10 chloruanoic HO$b (OH*)3 stibuanetrioic (H0)2Te(OH%)2
(t)
HOC1: chloruinoic
ioduinedioic ioduanoic (HO)rxe (ah) (HO);X'e(OH2) xenuanetetroic xenuinoic HOEb (OH,)j ekabismuthuane pentoic
I*Hypophosphorous, X Phosphorous, T (Ortho)phosphonc]
The common formulas for the preceding acids are as follows: HCOZH HzCOt HNO2
H4Xe06 HiEbOs- 2H20 or Eb(OHIs 3Hz0
HNO
H2Te02.2H20 HIOz.2H20 or H3103.H 2 0 H4Xe04 EbOH.5Hz0
(ad)
HIO.2HzO
(ah)
H2Xe02. H20
e
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183
A. F. CLIFFORD The naming of such acids as CH3P03H2 is discussed in section 2.111. 2.111 Substituted Acids. I n the case of acids of standard coordination number having groups other than hydroxy, oxo, and aquo substituted for hydrogen in the parent hydride or substituted hydride, as, for example, CH3P03H2, the naming procedure is similar, e.g., ( 7 ) CH3P03Hz
(8) ( C H I ) P P O J ~
(9)
(CH3)zPOH
(10) FS03H (FS0,OH) (11) FSbOsHs [ (HO)SbFOHz]
methylphosphanedioic acid (the standard acid derived from CHsPH4, methylphosphane) dimethylphosphanoic acid (derived from ( C H J Z P H ~dimethyl, phosphane) dimethylphosphinoic acid (from (CH3)zPH, dimethylphosphine) fluorosulfanoic acid (from SHsF, fluorosulfane) fluorostibanoic acid (from SbHaF, fluorostibane)
(Comparisons with Drake report names are given in the Appendix.) When there are more than one kind of substituent groups requiring prefixes, they are named in the alphabetical order. 2.12 Since substitution by S, Se, Te, and Po generally affects the coordination number and acidity in the same way as substitution by oxygen, products of substitution by these elements are named in the same way as their oxygen analogs, e.g., (12) HSPO(OH)? (13) (H0)3P=S
SH I
(14) CHD-P = Se
I SH (15) S=SO(OH)Z
or
thiophosphanetrioic acid or Shydrogen thiophosphanetrioic acid thiophosphanetrioic acid
S,S-dihydrogen selenodithiomethylphosphanedioic acid
(16) S = S O H
phosphuanoic acid phosphuanoate ion
2.14 Anionic centers resulting from only partial loss of acidic hydrogen are named as hydrogen salts of the acids. (26) HzPOL (27) HPHOI
dihydrogen phosphanetrioate hydrogen phosphanedioate
2.15 Esters are named like salts containing the hydrocarbon cation (28) diethyl methylphosphanedioate
CH3PO(OCzHdz
Partial esters are named as though they are acid salts. (29) ethyl hydrogen methylphosphinedioate,
CH3P(OH)OCzHs.
When it can be determined, the location of substituents in esters containing S and its analogs is denoted by the symbols 0-, S-, Se-, Te-, and Po- prefixed to the radical name; these symbols are used in conjunction with the prefixes thio and its analogs, the prefixes hydrothio, thiono, and their analogs being used only where ambiguity would otherwise arise. Examples: (30) (31) (32)
(33) (34) (35)
0,O-diethyl hydrogen dithiophosphanetrioate HSP(S) (0CzHs)z S-ethyl thiophosphanoate HzP(0)SCzHs S-methyl methyl(methy1amino)phosphanoate CHsP(0) (SCH3)NHCHs 0-ethyl S-methyl 0-hydrogen dithiophosphanetrioate HOP(S)(SCH3)(OCzHs) 0-methyl S-ethyl Te-phenyl (propylimino)tellurothiophosphanetrioate C3H5N= P(OCH3) (SCzH5)(TeC6H5) S-methyl 0-phenyl thiosulfanedioate CH3SSOaCsHs
Salts of esters are named similarly except for the lack of a position designation for the cation. For example,
thiosulfanedioic acid
CH3 I
(25) HOP(OH,) P(OH);
methylthiosulfanoic acid
I1
(36) sodium S-ethyl thiophosphinedioate (37) sodium 0-ethyl S-hydrogen dithiophosphanetrioate
Na[OPHSCzH5] Na[HSP(0)S(OC2Hs)]
0
S 11
(17) CHaAsOH
I F
fluoromethylthioarsanoic acid
2.13 The anionic center resulting from the loss of all protons from an -oic acid is designated by the suffix -oate. Salts are named in the usual way. (18)
(19) (20) (21) (22) (23) (24)
PO;^ PHO? CH3PO;' SOAFIOF; Xe02F; O~01F3
phosphanetrioate phosphanedioate methy lphosphanedioate fluorosulfanoate tetrafluoroiodininoate trifluoroxeninoate trifluoroosmanoate
In the case of standard acids having aquo groups in the coordination sphere, the standard anion is that resulting from the loss of only one of the two protons from each aquo group. Thus, 2.131
184
Journal of Chemical Documentation, Vol. 10,
No. 3, 1970
2.16 Anionic centers resulting from addition of a negative ion to a neutral center, the number of unshared electron pairs being the same as for the neutral center, are designated by the suffix -ate, all groups being specified except attached hydrogen. (38) CH3PFj (39) CHSAsH;
methy lpentafluorophosphanate methy laminate
2.17 Anionic centers resulting from loss of protons or other positive ions from the parent hydride-Le., loss of a proton attached to a central atom or an atom in a chain-the number of unshared electron pairs being one more than for the neutral center, are treated as derivatives of the next lower hydride by the rules of section 2.16. Electron pairs will not generally be shown from here on. (40) PH, [Compare (41) PH; (42) PHi(43) PH; (44) HPCO;
phosphinate phosphanate] phosphinate(2-) or phosphinediate phosphuanate phosphaethan-1-uan-1-atoate
NOMENCLATURE FOR COMPOUNDS OF P, S, AND RELATED ELEMENTS 2.2 N e u t r a l derivatives of the p a r e n t hydrides a r e named b y the rules for substitution compounds.
[cf. (CH,),P-Cl HP=O CHsP=O CHsOPH? PF, CH,P CsHiIClz
oxophosphane trimethyloxophosphane methylselenophosphane (methylse1eno)phosphineor [l-phospha-2-selenapropanl-in-2-uaneI trifluorophosphane tetrafluorophosphane tetrachloromethylphosphane dichlorodimethylsulfine dichlorotrimethylarsane (five coordinate phosphorus) chloro tetrameth ylphosphane tetramethylphosphinium chloride] oxophosphine meth yloxophosphine methoxyphosphine trifluorophosphine (phosphorus tritluoride) methylphosphuane dichlorophenylioduane
Cation
Hydride
(88) (89) (90)
phosphane . methylphosphane pentamethylphosphane
(91) (92) phosphine (92a) d i n e (92b) methine (93) (94) phosphuane (94a) sulfuane
PH5 CHsPHI
phosphanium methylphosphanium (CH3)jP pentamethylphosphanium hexamethylphosphanium PHs phosphinium SiH? silinium CH, methinium(carbenium) phosphadiinium PH phosphuanium SH, sulfuanium ~~
PHi
I n multicentered compounds such positive centers a r e designated b y the suffix -onium, if terminal; onio-, if a sidechain; or onia- (placed before -ate a n d -oate) if within a chain. (95)
+
HZAs-PH2-C0;
l-arsa-2-phospha-3-anin-2-onia-l-ate3-oate
See Part I1
List of Prefixes Prefix
Nome
amino-
azidobromochlorocyanatocyanofluoroiminoiodoisocyanatoisothiocyanatonitrilonitrosothiocyanato-thio-seleno-
l,
-polono-
i
mercapto or sulfuanyl selenuany1 telluruanyl polonuanyl thioselenotelluropolono-
Structvre
aminophosphanedioic acid aminoiminophosphanedioic acid aminochlorophosphanoic acid S-hydrogen azidothiophosphanedioic acid bromophosphinoic acid chlorophosphanedioic acid chloropentafluorosulfane dicyanatophosphanoic acid dicyanophosphanoic acid fluorophosphanoic acid iminophosphanetrioic acid iminoiodophosphanedioic acid diiodophosphinoic acid 0-hydrogen isocyanatothiophosphanoic acid iminodiisothiocyanatophosphanoicacid nitrilophosphanoic acid nitrososulfanoic acid chlorothiocyanatophosphinoic acid Used generically or when sulfur, selenium, or tellurium connects another radical to a central atom or chain -SH -SeH -TeH -PoH
(HO)d'(O)NH, (HO)zP(NH)NH? HOP(0)C1(NH2) HOP (O)N,(SH) HP(0H)Br (HO)J'(O)Cl SFsCl HOP(O)(OCN)2 HOP(0) (CN), HP(O)(OH)F (H0)3PNH (HO)2 ("11 HOPI? HP(S)OH(NCO) HOP(") (NCS)? HP(N)OH ONSOZH HOPCl(SCN)
=S = Se = Te =Po
2.3 Positive centers formed b y adding a p r o t o n or its equivalent t o t h e central a t o m of a hydride or s u b s t i t u t e d hydride are denoted b y adding t h e suffix -ium t o the n a m e of t h e compound so t r e a t e d , w i t h elision of t h e final e where required.
3. Radicals 3.1 The fundamental radicals a t t a c h e d t o a n o t h e r group at the central a t o m (Le., derived from the p a r e n t hydride b y removal of a hydrogen a t o m ) are n a m e d b y adding Journal of Chemical Documentation, Vol. 10, No. 3, 1970
185
A. F. CLIFFORD -yl to the name of the hydride, with elision of the final e. For example, (96) (97) (98) (99) (100) (101)
-PHa -PHz
-P -SHE -SH3 -SH
phosphanyl phosphinyl phosphuanyl sulfanyl sulfinyl sulfuanyl (mercapto)
3.11 Other univalent radicals with the free valence a t a central atom are named as compounds of the fundamental radicals. Substituent groups are named according to the Organic Rules. Radicals formed by loss of all hydroxyl groups from inorganic hydroxy acids are named by replacing -ic with -yl. Thus H2POOH phosphanoic acid, H2PO- phosphanoyl (cf. H 0 2 C C 0 2 H ethanedioic acid, -0CCOethanedioyl), OP(OH)3phosphanetrioic acid, OP = phosphanetrioyl. I n the case of radicals derived from acids by loss of hydroxyl groups, which might also be named as radicals derived from substituted hydrides, organic practice is to consider the radical as derived from the acid. For example, -CHO is formyl or methanoyl, not oxomethyl; -0CCH2CO- is malonyl or propanedioyl, not 1,3-dioxotrimethylene. I n like manner, when a similar choice arises for radicals formed by removal of hydroxyl groups from a standard acid of phosphorus and related elements, the name derived from the acid shall be preferred. Thus -PH1O is phosphanoyl, not oxophosphanyl. (102) HzP(0)(103) HzP(S)-
phosphanoyl (not oxophosphanyl) thiophosphanoyl (not thiophosphanyl or thionophosphanyl) (104) HzP(NH)iminophosphan yl (105) HP(N)nitrilophosphanyl (106) N E W difluoronitrilosulfanyl (107) (HO)d’(O)dihydroxyphosphanoyl (108) FSOzfluorosulfanoyl (109) Fsofluorosulfinoy1 (110) CH3PH3methylphosphany 1 (111) CH3PHmethylphosphiny 1 (112) (CH3O)PClchloromethoxyphosphinyl (ch1oromethoxy)phosphinyl (113) (CICHzO)PH(114) CHsOPHzClchloromethoxyphosphanyl (115) ClCHzOPH3(ch1oromethoxy)phosphanyl (116) CH3(HO)P (0)hydroxymethylphosphanoyl (117) CH, (n-CaHs)P (S)- n-butylmethylthiophosphanoyl (118) n-CaHS(CH3S)PH2- n-butyl (methy1mercapto)phosphanyl (119) H(CHaS)P(NH)imino(methy1mercapto)phosphanyl (120) CH3O(HS)P(O)mercaptomethoxyphosphanoyl (121) CHsSOzmethylsulfanoy1 (122) CH3SFatetrafluoromethylsulfanyl (123) IFatetrafluoroiodininyl (124) 1 0 2 dioxoiodininyl (not from standard acid)
3.2 Bivalent and trivalent radicals formed by the loss of H in a hydride radical or equivalent (Le., not an “acid” radical) are named by adding to the final -yl ending the suffix -idene (bivalent) or -idyne (trivalent). (125) (126) (127) (128) (129) (130) 186
HP=
P= PH,= PHzc CHzO(CH3)P(HO)sP=
phosp hinylidene phosphin ylid yne phosphanylidene phosphanylidyne methoxymethylphosphanylidyne trihydroxyphosphanylidene
Journal of Chemical Documentation, Vol. 10, No. 3, 1970
(131) (HO)zP= but (132) CHsOP(0) = and (133) OPH=
dihydroxyphosphanylidyne
methoxyphosphanedioyl phosphanedioyl
3.3 Compound radicals are named in the usual manner. (134) (135) (136) (137) (138) (139) (140) (141)
(CH~O)ZP(S)OHzN(CH3)P(0)SCH3PH(S)NHHaPN= H3P=N(HO)zP(O)O(HO)zP(S)O(HO)(HS)P(O)O(HO)zP(O)S(HO)zP(O)NH(HO)3P=N(HO)zP=C(HO)3P CHSF, = NSFz = NSF, CSiH30CH3SiHzNHCH3SiHZN = ClOsNHFzC102N = (HO)a x e o n(NH) (CF3)aP-
=
dimethoxythiophosphanoyloxy aminomethylphosphanoylthio (methylthiophosphanoy1)amino phosphanylimino phosphany lidenamino dihy droxyphosphanoylox y dihydroxythiophosphanoyloxy hydroxymercaptophosphanoyloxy dihy droxyphosphanoylthio dihydroxyphosphanoylamino trihydroxyphosphan ylidenamino dihydroxyphosphanylidynemethyl trihy droxyphosphanylidenemethyl tetrafluorosulfanylidenamino difluorosulfinylidenamino trifluorosulfanylidynemethyl silyloxy (or siloxy) methylsil ylamino methylsilylimino chloranoylamino difluorodioxochloranylimino (not from standard acid) dihydroxyxenanedioyldiamino tetrakis(trifluoromethy1)phosphanyl
3.4 The same names apply to the free radicals-i.e., the molecules with an odd number of electrons (157) (CF3)aP.
tetrakis(trifluoromethy1)phosphanyl
PART II. POLYCENTRIC COMPOUNDS
The system of nomenclature outlined in the following sections for polycentric compounds builds almost without change on that for unicentric compounds, thus providing a single unifying system. The principal difference is that whereas the names of polycentric compounds are derived from the name of the hydrocarbon of the same chain length, the unicentric compounds are not named as analogs of methane. 1. Compounds containing chains of atoms are named according to thc principles of “a” nomenclature, except that if only elements of one kind occur in the basic chain the numerals denoting the positions of the chain of atoms may be omitted-e.g., (158) PH,PH3PH3PH, (159) PHzPHPHPHz
tetraphosphabutane tetraphosphabutine
For chains containing only phosphorus atoms names such as tetraphosphane or tetraphosphine would be allowed as contractions. When more than one oxidation state is present each must be designated by an appropriate suffix following the root name showing the chain length. The suffixes are given in order of decreasing oxidation state, i.e., taken
NOMENCLATURE FOR COMPOUNDS OF P, S, A N D RELATED ELEMENTS in the order -ane, -ine, -uane, -uine and numbered in such a way as to keep the numbers as low as possible. The positions of the atoms having other than the largest representation are located by numeral, e.g., tetraphosphabutan-2-ine PHaPHPH3PH4 tetraphosphabut-1-anine PHaPHPHPHz tetraphosphabut-1-anin-4-uane PH4PHPHP 1,2,3-triphosphabut-4-anin-l-uane CHSPHPHP diphosphaethanetetroic acid HIOaPP03H2
cyclotriethanene or cyclohexatriene
HC
HCH\
0
Hz03PPP03Hz
triphosphapropanepentoic acid
2. Unsaturation. Multiple bonds are designated by ene and yne, having their usual meaning, and being placed last in the name after ine, ane, etc., but before onium, ate, and oate. The bonds so designated are assumed to be nonpolar or to involve a minimum of charge (cf. section 1.11, Part I). For example, such a bond as occurs in $ 3 P = C H z ,$ 3 P = N H , (CH3)&3=CH2,or N = S F 3 is considered to be double or triple, as the case may be, because this assumes the atoms to be neutral. On the other hand, the ring bonds in B3N3H6 are designated as single bonds because the double bond designation would assume charges on the atoms. ~~H-BH "fjH B ~ /
not
NH-BH
+
NH-BH
B \ +
HZC = CHCHzCH, (OPOZ) 3
disulfaethanedioic acid disulfaethaninedioic acid hexasulfahexa-1,6-dianuane1,6-dioic acid hexasulfahexuane or hexasulfuane
HSSSSSSH
(171) -
%H /
NH=BH
This is done regardless of the known or suspected polarities of the bonds. On the other hand, the P-N bonds in P3N3H6must be considered to be double. Thus
' B H ~:yclotris[borazan-N-onia-B-ate]
+ HJN - 9 - B H 3
1-ammonio-4-boranatocyclohexane
(182)
HsSbPHzCOi
2-phospha-1-stibapropan-2-in2-onia-1-at-3-oate
1,3-dionia-2-ate 3-oxa-1,2,4-triphosphan-2-ine1,4,4-trioate
-O2PHPHOPO;-
(Further discussion of compounds with repeating polyatomic units will be found in Part 11, section 7 . ) Note that where assumption of atomic neutrality gives rise to an absurd or highly unlikely electronic structure, the principle of neutrality must be abandoned, e.g., in the amine oxides. These may be called oxonitranes. I n the case of a single charged site, the multiplicity is taken as the minimum consistent with placing the charge on only one atom. This tends to locate negative charge on the more electronegative atom and positive charge on the less electronegative atom. Thus (190) (R3PCR)-is R3P=CR a carbanion, not Rap= CR a phosphanate a phosphonium ion, (191) (R~PNRz)'is R$-NRp not R3P=NRz, an ammonium ion
This principle also serves to decide the number of unshared pairs on the atoms. For example, each nitrogen atom in both B3N3H6and (RZPN)3is considered to have one unshared pair of electrons. HP =PPHPHz tetraphosphabutin-1-ene HP = PH,PHPH, tetraphosphabut-2-anin-1 -em HP= P(CH3)*PHPHz2,2-dimethyltetraphosphabut2-anin-1-ene
0
I
HzPPPHz
triphosphaprop-2-anin-2-oic acid
OH
S
NH
(H0)zP- P-P
I
'
- P(OHh
Ho Ho
3-imino-1-thiotetraphosphabutane2,4-diinehexoic acid
3. Structures Formed by Substitution on the Chain. The usual radical names for substituents (see Part I ) are prefixed to the name of the parent compound in alphabetical order with position numbers in the usual way (cf. section 2.12). (197)
PH4PPHPH4
c1
- +
butan-1-ene cyclotriphosphoxanoate
~ H ~ E I H ~ H ~2-bora-l,3-diphosphaprop-2-anediine-
cyclotriborazane cyclotriphosphazanene cyclotris [P,P-dichlorophosphazanene] cyclotris[dioxosulfoxane] cyclotetrasulfazinene cyclotetrasulfazinenyl cy clotetrasulfazanenyl perfluorocyclotetrasulfazane
(181)
11
N 'CH'
H03SS03H HOzSSOzH HOLW%SSO3H
H
B
HC I HC
OH
(170)
NCH/"
2-chlorotetraphosphabutane2,3-diine
Structures Formed by Substitution in the Chain. The fundamental chain is defined as the longest chain in the
4.
Journal of Chemical Documentation, Vol. 10, No. 3. 1970
187
A. F. CLIFFORD molecule including nonunicoordinate atoms, except for atoms in acidic groups-i.e., -OH, -SH, -SeH, -TeH, -PoH-and atoms in common polyatom substituent groups such as are given in the List of Prefixes, Part I , section 2.3. Because of the almost invariable bivalency of oxygen, hetero oxygen (designated oxa) and bivalent hetero sulfur (designated thia-distinguished from the higher oxidation states, which are designated sulfa) do not require the use of the suffix -uane. Trivalent nitrogen (aza) similarly requires no ine designated. Pentavalent nitrogen is indicated by the suffix -ane with an appropriate locant. Hetero atoms are designated in alphabetical order according to the principles of “a” nomenclature following the names of the substituents on the chain and preceding the root name designating the chain length. Examples: (198) HzPOPHNHPHz (199) CH3CH2PHOPHNHPHCH3 (200) (H0)zPOPHOPHOCzHs
0 OH I1
(201) (HzN)zPOPOP(OH)z I
NH (202) SF~OSOzOSOzOSFs
(203) FSOzOSFiOS02F
(204) SFsNHSFiNHSFs
(205) SFbNFSFaNFSFs (206) (N=SF3)3 OH (207)
CH30PSPOCHzCHzOCHa OH
(208)
2-aza-4-oxa-triphosphapentine 3-aza-5-oxa-2,4,6-triphosphaoctane-2,4,6-triine 2,4,6-trioxa-1,3,5-triphosphaoctane-1,3,5-triine1-dioic acid (but see also section 7) 1,1-diamino-5-imino-1-oxo2,4-dioxa-1,3,5-triphosphapentan-3-ine-3,5,5trioic acid 1,1,1,1,1,7,7,7,7,7-decafluoro-3,3,5,5-tetraoxotetrasulfoxane (see section 7) 1,3,3,3,3,5-hexafluoro1,1,5,5-tetraoxotrisulfoxane (see section 7) 1,1,1,1,1,3,3,3,3,5,5,5,5,5tetradecafluorotrisulfazane (see section 7) perfluorotrisulfazane (see section 7) perfluorocyclotrisulfazanene (see section 7) 2,6,9-trioxa-3,5-diphospha4-thiadecane-3,5-diine3,5-dioic acid
OH
I 1,1-dithio-4,7-dioxa-l,3,8(HO)ZPOCHZCHZOPSP(SH)~ triphospha-2-thiaoctane1,3,8-triine-1,1,3,8,8pentoic acid (209) SiF3SSiFzSSiF3 perfluorotrisilathiane (209a) SiF3SF4SiF,SF4SiF3 perfluorotrisilasulfane The term “function” is customarily used to mean any atom, group, or arrangement which causes a compound to behave in some characteristic way. Indications of oxidation state are usually made by means of suffixes-e.g., -ene, -yne, -ate, -ite, -(O), -(III), etc. Of other possible functions usually one (the most important, characteristic, convenient, etc.) is selected t o be denoted by a suffix and all others by prefixes. I n this system the only function besides functions of oxidation state (i.e., -ene, -uane, etc.) and charge (-onia, -ate) which is designated by a suffix is the acidic function (and its corresponding anion). All other functions are denoted by prefixes. Substituents and
functions (radicals) on the fundamental chain are named by the commonly accepted prefixes. (Alkoxy and aryloxy derivatives and other analogous chalcogen-containing compounds may be named according to the usual rules for esters.) The parent compound should be chosen to include the maximum number of acidic functions. Examples: diphosphaethanetetroic acid (cf. HOSCOZH ethanedioic acid) triphosphapropane-l,1,3,3tetroic acid (cf. HOZCCH~CO~H propanedioic acid) 1,3-diphosphapropane1,1,3,3-tetroic acid triphosphapropanepentoic acid (no carbon analog) 1,2-diphosphapropan2-oic acid 2,3-diphosphapropane1,2-dioicacid 2,2-ditluoro-2-(pentafluorosulfanylimino) trisulfapropane-1,3-dioic acid
PHa(POzH)CH3 PHa(P0zH)COzH
2-methylsilyl-3-am2-phospha-4-selena1-sulfabutane-1,2,3,4tetroic acid 1,3,5,5-tetramethyl 1-hydrogen 2,4-dioxa1,3,5-triphosphapenta- 1,3,5-triine-1,1,3,5,5pentoate (but see also section 7) CH3
’
(219) c 2 H s o
\
s = -s-
CsH4NOz - p
‘- + ’ N
/
s-
0
CzHs0
OCH~ =
SCH3
0 0 s (220) [(CHa)zN]~POPSP[N(CH3)zlz 1,1,5,5-tetrakis(dimethylamino)-l-oxo-5-thioOH 2-oxa-1,3,5-triphospha4-thiapentan-3-oic acid (221) -0 0 0
+
CH3-P-CHzNH2CH
0
5.
188
Journal of Chemical Documentation, Vol. 10,
No. 3, 1970
l,l-O,O’-diethyl5-0”, 5-S-dimethyl3- (methylp-fitrophenylmino) 3-oxo-1,5-dithio-1,3,5triphospha-2,4-dithiapentane-1,1,5,5-tetroate
=
P-PLCHzBiCH3 6,6,7,7-tetraphenyl-4-aza9-bismutha-2,6,7-triphosphadecan-9-in-5ene-4,7-dionia-9-at2-oate
5.1 If substituent radicals are present which contain only one central atom, the names for unicentric radicals are used. (222)
0
N(CH3)z
(CH30)2POPOPOP(OCzHsh ,
I,
0 0 0 = P(OCHs)2
1,l-diethyl 7,7-dimethyl 3(dimethylamino)5-(dimethoxyphosphanoyloxy) -2,4,6-trioxa1,3,5,7-tetraphosphaheptane-1,5-diine1,1,7,7-tetroate
NOMENCLATURE FOR COMPOUNDS OF P, S, AND RELATED ELEMENTS SFs
For justification of this use of epoxy, see IUPAC
4-chloranoyl-4-pentafluoroOC2Hs
c103
methyl-3-phospha2,4,5-tristanna-6-sulfahexan-3-oic acid
(231)
5.2 If t h e substituent radical contains m o r e than one central a t o m the radical n a m e is composed in the s a m e m a n n e r as for a polycentric compound with t h e p o i n t of a t t a c h m e n t a t t h e n u m b e r one position, except t h a t acidic groups a r e denoted b y prefixes. (224) (CH30)zPOP-
(225) (H0)zPSPS I
OCH3
6. Cyclic compounds which contain at least one c a r b o n a t o m m a y be named b y t h e present m e t h o d s of the R i n g Index except for addition of the suffixes of oxidation s t a t e , charge, and acidity. The prefix cyclo- is inserted before the root n a m e denoting the n u m b e r of atoms in the f u n d a mental ring. However, the names m a y be constructed in the s a m e m a n n e r as for linear compounds. In addition, formal elimination of the rings from the n a m e b y use of such designations as epoxy m a y considerably simplify the problem of naming. 1-(methy1phospha)cyclohexanine (R.I. 204: l-rnethylphosphacyclohexane)
CHz
2,4,6-trioxa-1,3,5triphosphacyclohexan3-inetrioate
0
\P/
O
, OH (232)
1-(1,3,3-trihydroxy2-oxa-1,3-diphospha. propinyl)-l-aza-2,4,6trioxa-3,5-diphosphacyclohexine-3,5-dioic
0.
l-hydroxy-3,3-dimethoxy-3-oxo-2-oxa 1,3-diphosphapropan-l-inyl (or dimethoxyphosphanoyloxy) phosphinoyl 4,4-dihydroxy-2-methoxy-2,4-diphospha-l,3-dithiabutinyl (or 1-methyl 1,3-diphospha-2-thiapropa-l,3-diinoylthio)
0 OH
1-ethyl 3,5-dihydrogen
I
HO’
/ \ (HO),POP - N
’OH I
HO 0
0
acid or 4,8-epoxy-4-aza2,5,7-trioxa-l,3,6,84etraphosphaoctine-1,1,3,6,8pentoic acid
OH (233)
(H0)zPON - P/O\
I
\p/o OH
,o\
0 0 OCHJ IN
(234)
,I
1
(CH30)zPOPOP-S-P 1
/
,
\S/
CHJO 0
C ‘Hz’
CH
1-oxa-2-phosphacyclopentan-2-in-2,4-diene (R.I. 99: 1,2-oxaphosphole)
I1
CH
I1
-CH
6.1 W h e n no carbon a t o m s are in the ring, atoms a r e numbered t o give the lowest alphabetical order. CH3
I
/’
CH2 ,
\SiHz
I \
\
/p-PH HP
(235)
PH
PHz - PH
(236)
3-methyl-1-germana3-phospha-5-plumba2-sila-6-stannacyclohexan-3-ine
I1
HO-P/’-
fi
I
N-PH-N
\p-
Ho\ d0‘P’0C2Hs 0’/?
~p0
S
\JS
OH
(238)
/PHz\C--O,N ’N CH
\
,POCH3 1,1,3,5,9-pentamethy17,9-epoxy-2,4-dioxa1,3,5,7,9-pentaphospha6,8-dithianonane-7,9diine-1,1,3,5,9-pentoate
hexaphosphabicyclo[3.1.O ]hexane-4,5-diine
6-oxa-1,2,3,4,5-pentaphosphabicyclo[3.1.0]hexa4,5-dianine or 1,2epoxypentaphosphacyclopenta-2,3-dianine
0 I
0
/GeHz 2-ethyl 4,6-dihydrogen 4-thio-l-oxa-2,4,6triphospha-3,5-dithiacyclohexan-4-ine2,4,6-trioate
/
/ P--pH \ PH O\ i / PHz - PH3
(237)
PbHz ‘SnHz
1- (1,3,3-trihydroxy-2-oxa1-aza-3-phosphapropinyl) 2,4,6-trioxa-1,3,5-triphosphacyclohexine-3,5-dioic acid or 4,8-epoxy-3-aza2,5,7-tri0~6-2,4,6,8tetraphosphaoctine, 1,1,3,6,8-pentoic acid or (See section 7) 1-(1,3,3trihydroxy-1-aza-2-oxa3-phosphapropinyl) cyclotriphosphoxine3,5-dioic acid
POH
N 0
HO
CHI
(227)
Org. Rules 1965 5212.2, 3rd example.
‘-OH
3,6,8-triaza-1,2,4,5,7,9hexaphosphatricyclo[3.2.1.i3‘Inonanep- OH 1,9-diin-5-ene-2,4,5,711 tetroic acid 0
I
6-aza-7-phospha-1,2,3benzoxadiaza-7-anole
‘SH
/O\ CHSP
‘s/
POP(OCH3)I 0
1,l-dimethyl 3,5-epoxy2-oxa-1,3,5-triphospha4,6-dithiaheptane3,5-diin-l-oate
7 . Chains containing m a n y repeating diatomic u n i t s such as P-0, P-S, P-NH, etc., m a y be named according t o siloxane nomenclature i n which the numerical prefix Journal of Chemical Documentation, Vol. 10, No.
3, 1970 189
A. F. CLIFFORD denotes the number of chain atoms in excess or numbered lower. This must be considered as a contraction of the basic nomenclature. The numbering remains as for the full name, thus accommodating such cases as (251). Examples: 1,s:7,11: 13,17-triepoxynonaphosphoxa-3,5,9,17tetraanine-1,3,9,15,17-pentoic acid (239) (240) (241) (242)
diphosphoxane diphosphoxine diphosphoxuane diphosphoxanine
HaPOPHa HzPOPHz POP HzPOPH4
0
\ N,\
(243)
I1
II
HOP-0- P-0- POH I I1 I HO 0 OH
(244) FSOzOSO~OSOzOSOzF (245)
/N\
/p
/N\
p*o
O+P
o+p
p
OH
0
OH
0
/"\ /N\ Pb
HO-PI triphosphoxanepentoic acid
1,7-difluoro-1,1,3,3,5,5,7,7octaoxotetrasulfoxane
(CH3)3SnNHSn(CH3)zNHSn(CsH5)2NHSnF3
l,l,l-trifluoro-5,5,7,7,7pentamethyl-3,3diphenyltetrastannazane
1,5:7,11:13,17-diepio-(7,ll)-epimethylam~o-8,l2-diethyl2,14,16-trimethylnonaphosphazane-1,3,9,15,17-pentoic acid
0 (252)
\ JN\
/ O
HO-S
S -OH
cyclotris[iosulfanoic acid]
I
OH 0 cyclotriphosphoxan1-inetrioic acid
/P
