NIST Databases

NIST Database 46 Gritically Selected Stability Gonstants of Metal Gomplex-es Database, U.S. Department of Gommerce, Gaithersburg, MD, 1998, ver. 5.0. 

The NIST Chemistry WebBook is probably the most extensive of all chemical compilations. It supersedes many of NIST databases [32, 33, 37, 41, 46, 58] and it is composed by several chapters, some of which [2-12] include thermo-chemical information on a variety of substances. It is regularly updated, with either new values or new chapters. Not all of these chapters have thermochem-ical consistency. For instance, the Neutral Thermochemical Data [3] quotes the... 

This useful and simple-to-use software package relies on Benson s group additivity scheme [47] to estimate thermochemical data for organic compounds in the gas phase. It also contains values from several NIST databases, including NIST Positive Ion Energetics [32] and JANAF Tables [22]. The first version of... 

A limitation of printed databases is that they may become outdated once published, they are unable to incorporate new information on kinetic parameters. The combustion specific databases listed above were published in the period 1973 to 1994 the most recent [23] covers the literature through 1992. This implies that data on combustion related reactions published since 1992 are not considered in these evaluations, and for a number of significant reactions the recommendations may be misleading. This deficiency of printed databases is to some extent overcome by the electronic database [256] offered by National Institute of Standards and Technology (NIST). The NIST database,1 which is regularly updated, also references most of the expert evaluations listed above. The drawback of using these kinds of data compilations is that the user may have to perform some data evaluation, that is, choose between data from various sources. 

SOURCE A. E. Martell and R. J. Motekaitis, NIST Database 46 (Gaithersburg. MD National Institute of Standards and Technology, 2001j. 

NIST Database 17 (NIST Chemical Kinetics, U.S. Department of Commerce, National Institute of Standards and Technology, 1994) and references therein ]... 

NIST Database. Available at www.nist.gov/srd/nistla.htm. Accessed 20 Jan 2009... 

The small number of fundamental mass spectrometric studies on Ge, Sn and Pb derivatives also accounts for our poor knowledge of their thermochemistry. Heats of formation, ionization energies, bond energies and electron affinities of even simple Ge, Sn and Pb species are still scarce and subject to considerable uncertainty, as illustrated in the most recent NIST database. ... 

Figure 3 An example of the use of GC-MS for metabolic profiling. Left A section of the total ion chromatogram from the analysis of TMS-derivatized aqueous tissue extracts from the liver of PPAR- null mouse. Metabolites are identified from exact retention times and comparison of corresponding mass spectra with those in the NIST database. 97 metabolites were quantified. Right Summary of metabolite differences in the tissues of the PPAR-a null mouse. Red- increased relative to control, blue- decreased relative to control. The increased/decreased width of certain arrows reflects relative increased/decreased concentrations across these pathways, respectively.

In 1965, Adams et al. [62] obtained the absolute rate constants for the reaction of OH with a number of solutes, using the competition method the reactions of OH with C03, SCN , and Se03 that give the absorbing radicals C03 ", (SCN)2" and Se03 , respectively, were used as references. Similarly, Thomas [63] determined the rate constant for the reaction of OH with 1 by following the formation of l2 (2max 385 nm, max 940 m moF ) [56], and from that derived the rate constants for other reactions of the OH radical [63]. The NDRL/NIST Database cited above contains 1787, 715, and 171 entries for the reactions of OH, H , and 0 , respectively [7a]. 

Mention has already been made of the publications of Kerr and Moss [23] as a source of bibliography. The same works list information on the kinetics of the reactions surveyed. Although the information is not critically evaluated and is now slightly dated, the coverage is broad, and where no evaluation of data on a particular reaction is available, the Kerr and Moss collection provides a valuable source for the existing data as does the NIST database [22], also discussed in Section 3.3. This too lists the kinetics data and also provides a graphical presentation. 

For example, two comprehensive databases, ICSD and CSD, contain crystallographic data and structural information about inorganic, and organic and metal organic compounds, respectively, while NIST database encompasses all types of compounds but provides only crystal data with references. Other databases are dedicated to specific classes of materials, such as metals and alloys, proteins and macromolecules, minerals or zeolites. Search-match utilities are usually provided with databases or they may be obtained separately. 

A proton contains no electrons and its free energy cannot be calculated quantum mechanically. Calculation of this energy using the standard equations of thermodynamics and the Sackur-Tetrode equation [15] yields the same value as can be deduced experimentally from the NIST database. The translational energy of 1.5RT combined with PV = RT and H= E PV yields a value of H° (H+) equal to 5/2(RT) or 1.48 kcal/mol. Use of the Sackur-Tetrode equation yields the entropy, TS(H+) = 7.76 kcal/mol at 298 K and latm pressure. Finally, since G = H-TS, G°(H+) = -6.28 kcal/mol. 

NIST Databases (see chemistry Web book) http //www.nist.gov/srd/ online.htm... 

For high-temperature liquids, compressed gases, and other systems at intermediate densities, a corresponding-states treatment is preferable. The SUPERTRAPP model for thermal conductivity is similar to that described for viscosity in Section 1.5.2, and is available in the same NIST databases [9, 59],... 

The reactions considered in the TC4 model are shown in Table 2. The model involves 6 adjustment parameters associated with heterogeneous kinetic constants (see reactions 1 to 6 in Table 2). The differential equations associated to the rate laws of the elementary reactions proposed in this study were solved by using a Fortran program developed by Braum and coworkers [3]. The kinetic constants from the homogeneous phase reactions were obtained from the National Institute of Standards and Technology (NIST) database [4] which the following kinetic constant definition holds ... 

The chemistry summarized by these two equations is complex and has been the subject of intensive, ongoing studies [50-62]. For the present we note merely that many early studies utilizing radiation chemistry to quantify reactions of nitrogen oxides [63-69] subsequently became of considerable interest in a biological context two decades later, and that the generation of carbonate radical via equation (15) provides immediate biological interest for the 222 rate constants for this species in the current NDRL-NIST database [27]. 

NIST, United States, publishes a comprehensive database of NMR, IR, and MS spectra. The NIST database is available for sale through 21 commercial distributors, such as Bio-Rad Laboratories. 

Computer matches with the National Institute of Science and Technology (NIST) database initially identified compounds. Many, though not all, were subsequently confirmed using commercial mixtures of analytical standards. The concentrations of all compounds were computed on a relative scale (ion abundance/dm air sampled) but are not reported here. Compounds of interest to regulatory agencies have been rigorously quantified [11-14]. 

A large number of kinetic data are well known and compiled in individual tables, like Landolt BOrnstein [4], and further in the review literature [5]. Also machine-readable databases were arranged, including the NIST database for chemical kinetics [6]. Version 7.0 contains over 38,000 records on over 11,700 reactant pairs. It also includes reactions of excited states of atoms and molecules [7]. Kinetic calculations are substantially more complex in comparison to the field of equilibrium thermodynamics. 

ROM either with or without structures [8]. The current version is the 6th containing some 229,119 reference spectra from 200,500 compounds which can be combined with a version of the NIST database, increasing the total size to 275,821 spectra of 226,334 compounds. The version marketed by the Palisade Corporation is available with a useful data format conversion utility MASSTransit (http //www.wi-leyregistry.com). There is also the PC BenchTop/PBM search system described below which can be purchased for off-spectrometer data processing and analysis of GC/MS runs for example. 

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