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An efficient method is described for the simultaneous introduction of 4-ferrocenylbutyl and n-hexyl side groups into cellulose. For this purpose, cellulose triacetate is treated in dimethyl sulfoxide/NaOH solution with mixtures of 4-bromobutylferrocene and n-hexyl bromide. An almost quantitative conversion of the cellulose hydroxyl groups was reached when less than one ferrocene substituent was attached to the cellulose repeating units on average. At higher degrees of ferrocene substitution, some of the cellulose hydroxyl groups seem to remain unsubstituted. This conclusion has been drawn on the basis of size exclusion chromatography (SEC) with online light-scattering detector where coil contraction was observed with increasing ferrocene content in the cellulose sample. This finding was further supported by IR spectroscopy, viscometry, and conventional SEC investigations. We assume that steric hindrance of the bulky side groups is responsible for incomplete conversion.

An efficient method is described for the simultaneous introduction of 4’-p-benzyl-2,2’:6’,2’’-terpyridine and benzyl side groups into cellulose. For this purpose, cellulose triacetate was treated in dimethyl sulfoxide/NaOH solution with mixtures of 4’-p-bromomethylphenyl-2,2’:6’,2’’-terpyridine and benzyl bromide. An almost quantitative conversion of the cellulose hydroxyl groups was reached when less than one terpyridine substituent was attached to the cellulose repeating units on average. At higher degrees of terpyridine substitution, some of the cellulose hydroxyl groups seem to remain unsubstituted. This conclusion has been drawn on the basis of NMR, IR and solubility measurements. We assume that steric hindrance of the bulky side groups is responsible for incomplete conversion. In a final step, the terpyridine substituents of the cellulose derivatives could be converted quantitatively into ruthenium(II) complexes via treatment with activated [Ru(tpy)Cl3] in N,N-dimethylacetamide/1-butanol (tpy: 2,2’:6’,2’’-terpyridine).

MAK Value Documentation for Glycerol The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the work place (MAK value) of glycerol, considering the endpoints irritation of the respiratory tract and developmental toxicity. Since 2014, the Commission uses an empirical approach to set MAK values for substances with critical effects on the upper respiratory tract or the eyes. However, examination of the study results showed that this approach does not apply for glycerol, because glycerol is not an eye irritant and the minimal to slight metaplasia of the squamous epithelium of the larynx seen in rats at 662 mg/m 3 with glycerol aerosol is not interpreted as adverse. The response does not increase with the exposure duration. Therefore, the MAK value is raised to 200 mg glycerol/m 3 for the inhalable fraction. Peak Limitation Category I for local effects with an excursion factor of 2 is retained, as the effect is hardly concentration‐dependent, a sensory irritation is not known, and glycerol is, if at all, only slightly irritating to the eye. After scaling the oral NOAELs for developmental toxicity of 1310, 1280 and 1180 mg/kg bw and day for rats, mice, and rabbits, respectively, to a concentration at the work place (2293, 1280, and 3442 mg/m 3 ), the differences to the MAK value are considered so large, that damage to the embryo or foetus is unlikely when the MAK value is observed. The classification in Pregnancy Risk Group C is therefore retained.

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