Frasi di Friedrich August Kekulé von Stradonitz

Friedrich August Kekulé von Stradonitz foto
1  1

Friedrich August Kekulé von Stradonitz

Data di nascita: 7. Settembre 1829
Data di morte: 13. Luglio 1896

Pubblicità

Friedrich August Kekulé von Stradonitz è stato un chimico tedesco.

Il suo nome è associato alla definizione della struttura del benzene e dei composti aromatici in generale, basata sulla risonanza; struttura che raccontò essergli stata ispirata in sogno e che fino a quel momento era stata un enigma per i chimici dell'epoca.

Kekulé entrò all'università come studente di architettura e ne uscì laureato in chimica. A convincerlo del cambiamento fu il fascino intellettuale di Justus von Liebig insieme alla sua innata curiosità e immaginazione. Nel 1858 coltivò l'idea che l'atomo di carbonio, in tutti i composti organici, si legava agli altri atomi sempre con quattro legami. Prima di quella data i chimici parlavano della composizione percentuale delle sostanze, ma non avevano idee chiare sulla struttura molecolare. Kekulé avanzò l'ipotesi che l'atomo di carbonio poteva legarsi ad altri atomi di carbonio e formare lunghe catene e perfino cicli. In tutte queste strutture il carbonio conservava la sua capacità di combinazione quattro. Con Kekulé nacque la chimica organica strutturale, così come la conosciamo oggi.

Frasi Friedrich August Kekulé von Stradonitz

„One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes.“

— August Kekulé
Context: I was sitting writing on my textbook, but the work did not progress; my thoughts were elsewhere. I turned my chair to the fire and dozed. Again the atoms were gamboling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by the repeated visions of the kind, could now distinguish larger structures of manifold conformation; long rows sometimes more closely fitted together all twining and twisting in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke; and this time also I spent the rest of the night in working out the consequences of the hypothesis. Let us learn to dream, gentlemen, and then perhaps we shall learn the truth... but let us beware of publishing our dreams before they have been put to the proof by the waking understanding. Account of his famous dream of the benzene structure, as quoted in A Life of Magic Chemistry : Autobiographical Reflections of a Nobel Prize Winner (2001) by George A. Olah, p. 54<!-- also partially quoted in Serendipity, Accidental Discoveries in Science (1989) by Royston M. Roberts , pp. 75-81 -->

Pubblicità

„I fell into a reverie, and lo, the atoms were gamboling before my eyes.“

— August Kekulé
Context: I fell into a reverie, and lo, the atoms were gamboling before my eyes. Whenever, hitherto, these diminutive beings had appeared to me, they had always been in motion. Now, however, I saw how, frequently, two smaller atoms united to form a pair: how a larger one embraced the two smaller ones; how still larger ones kept hold of three or even four of the smaller: whilst the whole kept whirling in a giddy dance. I saw how the larger ones formed a chain, dragging the smaller ones after them but only at the ends of the chains. Statements about a reverie in 1854 (1890), as quoted in "The Experimental Basis of Kekulé's Valence Theory" by Erwin N. Hiebert, in Journal of Chemical Education (1959)<!-- , 36, pp. 321-328 -->

„Let us learn to dream, gentlemen, and then perhaps we shall learn the truth . . . but let us beware of publishing our dreams before they have been put to the proof by the waking understanding.“

— August Kekulé
Context: I was sitting writing on my textbook, but the work did not progress; my thoughts were elsewhere. I turned my chair to the fire and dozed. Again the atoms were gamboling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by the repeated visions of the kind, could now distinguish larger structures of manifold conformation; long rows sometimes more closely fitted together all twining and twisting in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke; and this time also I spent the rest of the night in working out the consequences of the hypothesis. Let us learn to dream, gentlemen, and then perhaps we shall learn the truth... but let us beware of publishing our dreams before they have been put to the proof by the waking understanding. Account of his famous dream of the benzene structure, as quoted in A Life of Magic Chemistry : Autobiographical Reflections of a Nobel Prize Winner (2001) by George A. Olah, p. 54<!-- also partially quoted in Serendipity, Accidental Discoveries in Science (1989) by Royston M. Roberts , pp. 75-81 -->

Anniversari di oggi
Osho Rajneesh foto
Osho Rajneesh156
filosofo indiano 1931 - 1990
Alexandr Isajevič Solženicyn foto
Alexandr Isajevič Solženicyn17
scrittore, drammaturgo e storico russo 1918 - 2008
ʿUmar Khayyām foto
ʿUmar Khayyām19
matematico, astronomo e poeta persiano 1048 - 1131
Mario Tobino foto
Mario Tobino17
scrittore, poeta e psichiatra italiano 1910 - 1991
Altri 36 anniversari oggi
Autori simili
Chaim Weizmann foto
Chaim Weizmann2
politico e chimico israeliano
Ernest Rutherford foto
Ernest Rutherford3
chimico e fisico neozelandese
Robert Boyle foto
Robert Boyle2
chimico, fisico e inventore irlandese
Antoine-Laurent de Lavoisier foto
Antoine-Laurent de Lavoisier2
nobile, biologo e filosofo francese
Primo Levi foto
Primo Levi176
scrittore, partigiano e chimico italiano
Johann Gottlieb Fichte foto
Johann Gottlieb Fichte44
filosofo tedesco
Heinrich Von Kleist foto
Heinrich Von Kleist12
drammaturgo e poeta tedesco
Erich Fried foto
Erich Fried6
poeta austriaco
Marie Curie foto
Marie Curie8
chimica e fisica polacca naturalizzata russa e in seguit...
Teodorico di Nieheim4
storico tedesco