Reaction databases general synthetic reactions

This is a combined archival database with 171629 reactions originating predominantly from about 300 Journals and some patents. It comprises the Theilheimer databa.se (46785 reactions 1946-1980), the core database from the former ORAC system (about 65 000 reactions, mainly 1980-1991), and several databases produced by MDL (CLF Current Literature File 36600 general synthetic reactions 1983-1991. CHIRAS 13 200 asymmetric reactions 1975-1991. Metalysis 12000 metal-mediated reactions 1974-1991). Although the time coverage of RefLib does really start at 1946, the onset of Theilheimer, there are almost 4000 reactions with pre-1946 references (2600 with literature only before that year). 

Obviously, use of such databases often fails in case of interaction between additives. As an example we mention additive/antistat interaction in PP, as observed by Dieckmann et al. [166], In this case analysis and performance data demonstrate chemical interaction between glycerol esters and acid neutralisers. This phenomenon is pronounced when the additive is a strong base, like synthetic hydrotalcite, or a metal carboxylate. Similar problems may arise after ageing of a polymer. A common request in a technical support analytical laboratory is to analyse the additives in a sample that has prematurely failed in an exposure test, when at best an unexposed control sample is available. Under some circumstances, heat or light exposure may have transformed the additive into other products. Reaction product identification then usually requires a general library of their spectroscopic or mass spectrometric profiles. For example, Bell et al. [167] have focused attention on the degradation of light stabilisers and antioxidants... 

Multidimensional Database. A relational database in which multiple general types of data are stored, indexed, and cross-referenced, for use by several different groups. In chemistry, an example would be a database containing reactions, 2D structures, perhaps generic structures or libraries, and 3D models. Such a database would be used by synthetic, chemical informatic, and molecular modeling scientists. A data warehouse is often a multidimensional database, whereas a data mart is usually single-dimensional. 

The program does not use a database library of known reactions but simply generates all possible construction reactions in a generalized form, using a simple but rigorous and numerical description of molecules and reactions -. The form derives from a synthetically fundamental definition of four kinds of attachment on any skeletal carbon H for hydrogen (or electropositive element) ... 

For an existing database containing few and/or short schemes, such as Theilheimer or The Journal of Synthetic Methods (JSM), this would represent an increase in the total number of reactions of about 20% over that for single-step reactions alone, and a negUgible increase over manual registration of summary reactions (the increase is due to the inclusion of some summary reactions that were not registered manually). The time required to execute a search will increase at the same rate, since REACCS RSS search time is generally hnear with the number of reactions. 

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