Fotografije prikazuju povijest jednog vremena i namjerno zaustavljeni trenutak života nekoga grada ili pojedinca, stoga ih je potrebno sačuvati. Na našim prostorima općenito nije razvijena svijest ...ljudi o potrebi čuvanja uspomena za buduće naraštaje, pa je stoga velik dio građe otišao unepovrat. Sve to upućuje na nužnost konstantnog educiranja mladih naraštaja i isticanja važnosti čuvanja predmeta u sadašnjosti kako bismo ih sačuvali za budućnost, kao i na nužnost senzibiliziranja javnosti da su muzeji oni koji trajno čuvaju spomen na današnja vremena, koja već za trenutak postaju prošlost.
The bromate–aniline oscillatory reaction was discovered 4 decades ago, but neither the detailed mechanism nor the key products or intermediates of the reaction were described. We report herein a ...detailed study of this reaction, which yielded new insights. We found that oscillatory oxidation of aniline by acidic bromate proceeds, to a significant extent, via a novel reaction pathway with the periodic release of carbon dioxide. Several products were isolated, and their structures, not described so far, were justified on the basis of MS and NMR. One of the main products of the reaction associated with the CO2 release route can be assigned to 2,2-dibromo-5-(phenylimino)cyclopent-3-en-1-one. A number of known compounds produced in the studied reaction, including unexpected brominated 1-phenylpyrroles and 1-phenylmaleimides, were identified by comparison with standards. A mechanism is suggested to explain the appearance of the detected compounds, based on coupling of the anilino radical with the produced 1,4-benzoquinone. We assume that the radical adduct reacts with bromine to form a cyclopropanone intermediate that undergoes a Favorskii-type rearrangement. Further oxidation and bromination steps including decarboxylation lead to the found brominated phenyliminocyclopentenones. The detected derivatives of 1-phenylpyrrole could be produced by a one-electron oxidation of a proposed intermediate 2-phenylamino-5-bromocyclopenta-1,3-dien-1-ol followed by β-scission with the abstraction of carbon monoxide. Such a mechanism is known from the combustion chemistry of cyclopentadiene. The proposed mechanism of this reaction provides a framework for understanding the observed oscillatory kinetics.
Matematičar i član Družbe Isusove Franjo Ksaver Staindl (1746.–1818.) rođen je u Križevcima, a u isusovački novicijat ušao je u Beču. Matematiku je specijalizirao u Grazu. U radu se iznose dosad ...nepoznati biografski podaci te se raspravlja zašto se ne može Franji Ks. Staindlu pripisati samostalno autorstvo udžbenika Institutiones arithmeticae in usum gymnasiorum et scholarum grammaticarum koji je bio u uporabi u hrvatskim zemljama krajem XVIII. i početkom XIX. stoljeća, a Ambroz Matić preveo ga je na hrvatski jezik.
