In the infrared spectra of mono- and di-nitrate esters of the l,4;3,6-dianhydrides of d-mannitol, d-glucitol, and l-iditol in benzene solution (0.04 M in nitrato groups), the frequencies of the va(NO2) and v(ON) bands (singlets) were 1 645 ± 3 and 843 ± 3 cm−1, respectively, whereas the vs(NO2) band occurred at frequencies characteristic of either an endo (1 282 ± 1 cm−1) or an exo (1 274 ± 1 cm−1) configuration of the nitrato group; the ratios of the band areas were 1.5:1.0:1.0, respectively.The stereospecific frequency of the vs(NO2) band was attributed to non-bonded intramolecular interaction between the nitrato group and vicinal oxy groups on the basis of the spectra run in a series of solvents and the molecular conformations determined by X-ray crystallography. This new stereochemical probe permitted the assignment of the structure, configuration, and conformation in a series of nitrate esters.

No abstract

The photolysis of nitrate esters dissolved in benzene or ethanol or absorbed on hlter paper occurred readily under illumination in the 265 mp t o 334 mp spectral region. Equimolar amounts of 1,4;3,6-dianhydro-D-glucitol-2,5-dinitrate and diphenylamine dissolved in absolute ethanol or benzene did not react in the dark a t 25'. Irradiation of the nitrogen-purged solutions for 2 hours a t 15' with a mercury arc followed by chromatographic separation yielded 2-nitro-, 4-nitro-, N-nitroso-, and 4-nitroso-diphenylamine together with about 4% unreacted diphenylamine and an unidentified mixture of more polar compounds. In a partial fractionation of the aromatic photoproducts approximately 80% of the original diphenylamine was recovered in the form of the monosubstituted derivatives which contained about 37% of the original ester nitrogen as C-nitro groups and 2 to 3% as C-and iV-nitroso groups.

A microbiological surveillance programme was initiated in Durban, South Africa, to provide an objective assessment of changes in the local seawater quality before and after the commissioning of two submarine outfalls in 1969 and has been ongoing until the present day. A classification system including Escherichia coli I, helminthic parasite ova, pathogenic staphylococci, salmonellae, shigellae, and salinity was used. This system, functioning as an audit, has proved useful in detecting problem areas which may have passed unnoticed in the routine E coli I assessments performed by the Durban Municipality. The salient features that have manifested themselves are (a) alterations in the seawater quality have been shown to be invariably a consequence of changes effected upon the shore or meteorological events and (b) that measuring more than one indicator of water quality, plus the use of salinity as a physical parameter for assessing the dilution or impairment of pristine seawater, has proved valuable.

The 2‐methoxybenzoic acids (VI) and (XI), prepared as outlined in the reaction scheme, are coupled with the diaminopyridine (VII) to form the corresponding imidazopyridines (VIII) and (XIII).