NIST–JANAF Thermochemical Tables for the Iodine Oxides Cite as: Journal of Physical and Chemical Reference Data 25, 1297 (1996); https:// doi.org/10.1063/1.555994 Submitted: 25 July 1995 . Published Online: 15 October 2009 M. W. Chase ARTICLES YOU MAY BE INTERESTED IN NIST-JANAF Thermochemical Tables for Oxygen Fluorides Journal of Physical and Chemical Reference Data 25, 551 (1996); https:// doi.org/10.1063/1.555992 NIST–JANAF Thermochemical Tables for the Bromine Oxides Journal of Physical and Chemical Reference Data 25, 1069 (1996); https:// doi.org/10.1063/1.555993 JANAF Thermochemical Tables, 1982 Supplement Journal of Physical and Chemical Reference Data 11, 695 (1982); https:// doi.org/10.1063/1.555666 Journal of Physical and Chemical Reference Data 25, 1297 (1996); https://doi.org/10.1063/1.555994 25, 1297 © 1996 American Institute of Physics for the National Institute of Standards and Technology. NIST -JANAF Thermochemical Tables for the Iodine Oxides Malcolm W. Chase Standard Reference Data Program, National Institute of Standards and Technology, Gaithersburg, Maryland 20879 Received July 25, 1995; revised manuscript received May 1, 1996 The thermodynamic and spectroscopic properties of the iodine oxide species have been reviewed. Recommended Nl.sT-JANAF Thermochemical Tables are given for six gaseous iodine oxides: 10, 010, 100, 101, lIO, and 1°3 , Sufficient information is not available to generate thermochemical tables for any condensed phase species. Annotated bibliographies (over 400 references) are provided for all neutral iodine oxides which have been reported in the literature. There is a lack of experimental thermodynamic and spec­ troscopic information for all iodine oxide species, except IO(g) and OIO(g). The recom­ mended thermochemical tables are based on estimates for the structure, vibrational fre­ quencies, and enthalpy of formation based in part on the spectroscopic and thermodynamic data for the other halogen oxides [1. Phys. Chern. Ref. Data 25, 551 (1996); ·25, 1061 (1996)]. Although there is a definite lack of information in comparison with the other halides, this information is provided for the iodine oxides for the following reasons: (1) to complete the study of the halogen oxide family and (2) to stress the need for additional experimental measurements. Of all the species mentioned in the literature, many have not been isolated or characterized. In fact, some do not exist. Throughout this paper, uncertainties attached to recommended values correspond to the uncertainty interval, equal to twice the standard deviation of the mean. © 1996 American Institute of Physics and American Chemical Society. Key words: evaluated/recommended data; iodine oxides; literature survey; spectroscopic properties; thermodynamic properties. Contents 1. Introduction................................ 1298 6. NIST -JANAF Thermochemical Tables. .. 1320 1.1 References for Introduction. .. 1299 6.1 IO(g)................................. 1321 2. Chemical Species Coverage. .. 1300 6.2 OIO(g) ................................ 1322 3. Historical Perspective of Iodine Oxide Studies. .. 1300 6.3 100(g)................................ 1323 4. Summary of the Data for the Iodine Oxide 6.4 I03(g)................................. 1324 Species ................................. " 1301 6.5 IOI(g)................................. 1325 4.1 Spectroscopic Information. .. 1301 6.6 lIO(g)................................. 1326 4.2. Thermodynamic Information............ " 1301 7. Conclusions ... ·.......... :................... 1327 5. Discussion of the Literature Data. .. 1302 8. Acknowledgments.......................... 1327 5.1 10.................................. 1302 9. References-Annotated Bibliography. .. 1327 5.2 102' . .. 1304 5.3 Iodyl-I02' . .. 1304 5.4 100. .. 1305 List of Tables 5.5 1°2.24 , . • • . • • . • • • . • • . • • . • • . • .• 1305 5.6 103' . .. 1305 1a. Solid iodine oxide species: Preparation and '::Y./ 1U4. .. 1305 related reactions . .. 1310 5.8 120. .. 1306 1b. Solid iodine oxide species: Decomposition and 5.9 12°2' .............................. " 1306 related reactions . .. 1311 5.10 120:; ................................. 1306 2. Iodine oxide species: Neutrals, radicals, and ions 5.11 12°4 ................................. 1306 in solution . .. 1314 5.12 12°5 ......•.......................... 1307 3. Iodine oxide species: Electronic energy levels... 1315 5.13 12°6' ................. , .............. 1308 4. Iodine oxide species (10): Dissociation energy 5.14 12°7...• . • • • • . • • • . • • • • . • • • . • • • . •. 1308 (D~) ..................................... 1317 5.15 1:;08................................. 1309 5. Iodine oxide species: Structures and vibrational 5.16 14°9 ................................. 1309 frequencies. .. 1318 5.17 16°13 .... , . • . .. 1309 6. Thermodynamic properties of the iodine 5.18 1'0019 ............................... 1309 oxides. .. 1327 0047-2689/96/25(5)/1297/44/$14.00 1297 J. Phys. Chern. Ref. Data. Vol. 25. No.5. 1996 1298 MALCOLM W. CHASE 1. Introduction the reading of the individual articles yielded many additional references, most of which are included in the attached bibli­ ography. Not included are those articles or books (textbooks As a continuation of previous studies which dealt with the and handbooks) which are simply presenting a summary of thermodynamic properties of the chlorine oxides, I oxygen properties, with no critical evaluation. Note that the earliest fluorides,2 and bromine oxides,3 this study deals with the reference for any iodine oxide species was in the 1800s. iodine oxides. We will not discuss the astatine oxides, as However, these bibliographies are not complete in their cov­ there appears to be only an estimated D~ value reported in erage for the 1800s. Even though many of these citations are the literature for AtO(g). Specifically, this study examines not relevant to this study, future investigators will not have the the~odynamic properties of the neutral oxides, not the to search the past literature, but simply concentrate on the gaseous ionic and aqueous ionic species. The main purpose publications since 1994. of this article is to generate thermochemical tables for iodine The current edition (i.e., 1985) of the JANAF Thermo­ oxide species. In general, there are scant data available for 4 c~emical Tables does not include any iodine oxygen spe­ the description of the spectroscopic and thermodynamic data CIes, whereas the Thermodynamic Properties of Individual for any of the iodine oxides, except for 10(g) and OIO(g). Substancess only includes IO(g). This latter critical review Although the prime emphasis was on the diatomic and tri­ referred to data from four spectroscopic studies, three ESR a~omic species, a thorough search of all iodine oxygen spe­ stud~es, one microwave study, and four dissociation energy CICS was conductcd to dccidc which species had sufficient studieS, the !atest of all these citations being dated 1975. The data. Of the iodine oxides mentioned in the literature, only NBS tables gave information for IO(g) at 298.15 K, for five have been isolated and (at least, partially) characterized: C P , S, H, and the formation properties, but only an enthalpy IO(g), OIO(g), I 0 (cr), I 0 (cr), I 0 (cr). 2 4 2 s 4 9 of formation for ILOj(cr). (Information for four iodine oxide For the time period 1907-1994, there are only 354 cita­ aqueous ions is also included.) Similar information was tions in Chemical Abstract Services (CAS) dealing with the given in Thermal Constants of Substances,7 although these iodine oxides; of these, 196 are for 1 0 (with the majority of 2 s authors additionally include an enthalpy of formation of a these dealing with commercial· applications, as opposed to pentoxide hydrate. (Information for one iodine oxide aque­ providing property data) and 73 references deal with 10. Of ous ion is included.) These latter two evaluations were per­ the approximately 20 oxides mentioned in the literature formed in 1964 and 1965, respectively, and were based on however, some do not exist. ' the same references. Iodine oxides are also of interest due to their involvement There are many NASA-JPL publications on chemical ki­ in the transport of iodine in a post-accident nuclear environ­ netics in which enthalpy of formation tables are given. Of all ment, while 10 is of interest both because of its similarity to the iodine oxides, only 10(g) is listed by NASA-JPL. 8 These CIO (ozone depletion) and as a tropospheric ozone sink. data are presented without citation or reference to the origi­ Spectroscopic studies have shown that the ground and first nal source. Most of the recommendations are based upon excited electronic states of the halogen monoxides play an data in the IUP AC Evaluation (Atkinson et al. 1989 9 intermediate role in the photochemistry of upper atmosphere 10 ' , 1992 ). Some of the values are different from the current (e.g., CIO in stratosphere and 10 in ionosphere limit the at­ IUP AC recommendations, reflecting recent studies that have mospheric abundance of ozone). 120 s is discussed in many not yet been ,!ccepted and incorporated into that publication. articles dealing with the compound's preparation or reaction. IUPAC cites the origin of their values. All citations given by Specifically, 120 5 has key applIcations in detecting CO(g). IUPAC are included in this article. Despite this relevance of the halogen oxides, basic physical Iodine and its oxides were reviewed by Roman II for the properties, in particular