The calculation of sensitometric properties of 1,2,4-triazolo[1,5-a]pyrimidines

Abstract

Quantitative structure–property relationships were proposed by using artificial neural networks and information received from 13C NMR spectra. The suitability of 1,2,4-triazolo[1,5-a]pyrimidines as stabilizers in photographic silver halide materials was determined from their chemical structures. For the numeric coding of the chemical structures of differently substituted 1,2,4-triazolo[1,5-a]pyrimidines 1–44 only information available from their 13C NMR spectra was used. Even an assignment of the 13C NMR chemical shift values to the carbons was not necessary. The best results were achieved by combination of the 13C NMR chemical shifts of carbons of the basic heterocycle and the relative fog Drel using a feed-forward two-layer neural network. For some compounds with a good stabilizing effect the calculated results strongly differ from experimental values giving indication of a mechanism which is not covered by the 13C NMR chemical shifts.