Correlation table

A series of monographs and correlation tables exist for the interpretation of vibrational spectra [52-55]. However, the relationship of frequency characteristics and structural features is rather complicated and the number of known correlations between IR spectra and structures is very large. In many cases, it is almost impossible to analyze a molecular structure without the aid of computational techniques. Existing approaches are mainly based on the interpretation of vibrational spectra by mathematical models, rule sets, and decision trees or fuzzy logic approaches. 

The initial measurement of electrical resistance must be made after considerable time. Phenomenological information has been determined based on the corrosion rate expected at what period of time to initiate readings of the electrical resistance. Since these values are based on experiential fac tors rather than on fundamental (so-called first) principles, correlation tables and lists of suggested thicknesses, compositions, and response times for usage of ER-type probes have developed over time, and these have been incorporated into the values read out of monitoring systems using the ER method. 

Knowing the substitution pattern of both benzene rings A and B, one can deduce the molecular structure from the CH connectivities of the CH COSY and CH COLOC plots. The interpretation of both experiments leads firstly to the correlation Table 41.1. 

K. Nakamoto. Infrared Spectra of Inornanie and Ciiordiruitum Compounda, 2ful edn., Wiley, New York. 1970,. 338 pp (Sec also / Am. Chem. Soc. 79, 4904-8 (1957) for detailed correlation table.)... 

Some of these group frequencies are listed in Table 19.1, and amore complete correlation table is provided in Appendix 11. 

A full revision has been made to the appendices and some of those used in the Fourth Edition have now been incorporated into the main text where appropriate. At the same time other tables have been extended to include more organic compounds and additional appendices include correlation tables for infrared, absorption characteristics for ultraviolet/visible, and additional statistical tables, along with the essential up-dated atomic weights. 

Comprehensive correlation tables of various ion series, characteristic fragment ion and neutral fragments from different classes of compounds are available in various sources (Refs 10, 11 63). A number of general rules in understanding fragmentation mechanisms and for prediction of prominent peaks in a spectrum are summarized in Refs 10 63... 

MINITAB readily produces many useful manipulations of data such as were obtained in this experiment. Figure 2 shows histograms of the responses, indicating that, for the limited number of data points, the experimental values for each response approach a normal distribution. Thus, the statistical analysis was considered valid. Table III shows a copy of the computer printout of a correlation table with all the responses. Clearly, Property A and Property B are negatively correlated, as predicted, but Property B and Property E are not well correlated. 

In spite of higher capacity of tin electrode on tungsten current collector in comparison with tin electrode on copper current collector, specific capacities for unit of electrode mass have the reverse correlation (Table 3). 

Fairly good agreement exists between the calculated value of 1682 cm-1 and the experimental value of 1650 cm-1. Based upon the Hooke s law approximation, numerous correlation tables have been generated that allow one to estimate the characteristic absorption frequency of a specific functionality [3], It becomes readily apparent how IR spectroscopy can be used to identify a molecular entity, and subsequently to physically characterize a sample or to perform quantitative analysis. 

What about all the other peaks You can ascribe some sort of meaning to each of them, but it can be very difficult. That s why frequency correlation diagrams, or IR tables, exist (Fig. 120). They identify regions of the IR spectrum where peaks for various functional groups show up. They can get very complicated. Check to see if you can find the C—H stretch and the C—O stretch that are in all four spectra, using the correlation table. It can be fun. 

IR interpretation can be as simple or as complicated as you d like to make it. You ve already seen how to distinguish alcohols from ketones by correlation of the positions and intensities of various peaks in your spectrum with positions listed in IR tables or correlation tables. This is a fairly standard procedure and is probably covered very well in your textbook. The things that are not in your text are... 

Just like refractive index, the °Brix scale is quite dependent on the temperature. Manual Abbe refractometers do not compensate for this temperature effect. Special correlation tables are used to adjust the readings to a standard temperature, 20°C. Digital refractometers, on the other hand, can operate over a fairly wide range of sample temperatures (+15 to +40°C) and automatically apply these temperature corrections. See Workplace Scene 15.2. 

A record of the correlations between the representations is constructed with association lists while taking the product, and these can be used to display character correlation tables in both... 

Table IV. Terminal Display of Character Correlation Tables...

The examples used above to illustrate the features of the software were kept deliberately simple. The utility of the symbolic software becomes appreciated when larger problems are attacked. For example, the direct product of S3 (order 6) and S4 (isomorphic to the tetrahedral point group) is of order 144, and has 15 classes and representations. The list of classes and the character table each require nearly a full page of lineprinter printout. When asked for, the correlation tables and decomposition of products of representations are evaluated and displayed on the screen within one or two seconds. Table VII shows the results of decomposing the products of two pairs of representations in this product group. 

Note The correlation table for HD /HD is obtained from that for by interchange of and i i. ... 

Table 3. Correlation table for the interchange of peaks upon sterilization. For example heating converts peak 1 into peaks 10 and 16...

The correlation tables on the following pages show how the main types of compounds are reduced to various products by different reducing agents. The tables list only the reactions contained in this book (with exceptional cases omitted). If a reagent for a certain conversion is not listed, that does not necessarily mean that it cannot accomplish a particular reduction. Reagents listed in parentheses apply only under special conditions or are used exceptionally. 

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