Computer-Oriented Chemical Names.

Abstract

A system is described for the transcription of chemical names into capital letters, a rabie numerals, and four symbols, namely, & -* /. To allow such transcribed names to be accommodated in a fixed punched-card field, regular practices are introduced for the contraction of frequently cited functional groups, prefixes, and suffixes. * Based on a paper presented before the Division of Chemical Literature. 150th

Retrieval of Organic Structures from Small-to-Medium Sized Collections.

“…The five measures of the BATCH Number have been selected to relate (1) to the nature (and number) of rings present, if any (B digit); (2) to the nature (and number) of atoms present other than carbon, hydrogen, and oxygen (A digit); (3) to the number of atoms present other than carbon and hydrogen (T digit); (4) to the number of carbon atoms in the empirical formula (C digit); and (5) to the number of hydrogen atoms in the empirical formula (H digit).…”

“…The interpreted cards shown in Figure 2 delineate the assignment of the fields. This layout was standardized only after some experimentation directed to the optimum size of the fields for the notation and chemical name, and certain aspects of that study have been reported (2). The treatment of each field is considered in the following paragraphs.…”

“…In addition, longer names not accommodated by this 32-column field (9 for prefix and 23 for name proper) must be contracted. The systematic approaches adopted in the resolution of these two problems are described in the accompanying paper (2). The use of an offset, variable-length prefix to chemical names has the advantage of facilitating the visual inspection of any printout for a chemical name of interest.…”

“…The shift to a field of 24 columns was undertaken experimentally with the J. T. Baker deck of 5019 compounds. It was found that the names previously assigned to 4236 compounds (84.3%) were directly accommodated in the smaller field, 264 names (5.3%) could be made to fit by simple sorting, inspection, and repunching (for example, dropping of terminal E's unnecessary for comprehension), and 472 (9.5%) could be made to fit by additional systematic contraction following the established practices (2). The remaining 47 names (0.9%) could only be accommodated by the dropping of some "bit" of structural information, such as a position-locant.…”

“…Certain aspects of this approach were suggested by Wiswesser (1). The systematic schemes developed for the statement of chemical names using only capital letters, arabic numerals, and four punctuation marks, and for the contraction of the names to fit within a card field of 32 columns, are described in the accompanying paper (2).…”