Über die Bildungsweise von Eisen‐nonacarbonyl aus Eisen‐pentacarbonyl

Abstract

Eber die Eildung von Eisen-nonacarbonyl aus Eisen-pentacarbonyl liegen bereits zahlreiche L,iteratur-Angaben1-4) vor. Es finden sich jedoch nirgends genaue Versuchsbedingungen angegeben, die gestatten, das Eisennonacarbonyl in nennenswerter Ausbeute und in absoluter Reinheit bequem zu erhalten. Gelegentlich einer Untersuchung iiber E i s e n-pe n t acar bo n y 1 fanden wir, daB eine Lijsung desselben in Eisessig in einer W a s s e r s t o f f -A t m o s p h a r e den1 direkten S o n n e n l i c h t ausgesetzt, sich in kiirzester Zeit in das E i s e n -n o n a c a r b o n y l umwandelt, das sich in schonen, groflblattrigen, orangeroten Krystallen abscheidet. Auch in einer Losung von E s s i g s s u r ea n h y d r i d tritt in gleicher Keinheit und in gleicher Ausbeute die Urnwandlung zu Nonacarbonyl ein. In beiden Fallen kann auch die Wasserstoff-Atmosphare durch Vakuum ersetzt werden.Verwendet man sndere 1,osungsmittel fur das r:isexi-pentacarbonyl, wie z. B. Chloroform, Aceton, Wther usw., so tritt wohl zuerst die Bildung ron Sotiacarbonyl ein: cs entstehen jedoeh bei der Sonnen-Belichtung braunrote, schmierige Kehruprodukte, nelche die Reinheit u n d die Aiisbeute des I'rlparates wesentlich heeintr5chtigen.

The Binuclear Cyclopentadienylvanadium Carbonyls (η5‐C5H5)2V2(CO)7 and (η5‐C5H5)2V2(CO)6: Comparison with Homoleptic Chromium Carbonyls

“…[31] The BP86 calculated frequencies for CpV(CO) 4 and CpV(CO) agree very well with the experimental frequencies. However, there are significant differences between the ν(CO) frequencies calculated by the usually more reliable BP86 method and those found in matrices for CpV(CO) 3 and CpV(CO) 2 . In particular, although the positions of the calculated ν(CO) frequencies are reasonably close to those found experimentally, the calculated frequency separations are significantly different from those found experimentally.…”

“…Photolysis of Fe(CO) 5 has been known [2] since 1927 to give Fe 2 (CO) 9 ( Figure 1), with the formal Fe-Fe single bond required to give each iron atom the favored 18-electron configuration. [3] However, no evidence has been found for any binuclear Cr 2 (CO) n derivatives from the photolysis or thermolysis of Cr(CO) 6 including Cr 2 (CO) 11 with a Cr-Cr single bond required to give each chromium atom the favored 18-electron configuration.…”

Organometallic photochemistry at the end of its first century

“…In studies conducted in the gas phase, where there is no opportunity to transfer this energy to a solvent, multiple CO-loss is often observed. Not surprisingly the extent of CO-loss is often a function of the energy of the incident photons as in the case of CpMn(CO) 3 which yields a mixture of CpMn(CO) 2 and CpMn(CO) at 355 nm, but mostly CpMn(CO) at 266 nm [98].…”

“…9. First 10 ls of the photolysis of (BuCp) 2 Mo 2 (CO) 6 following the recombination of radicals to form the gauche and trans rotamers [107].…”

“…The first recorded instance appears to have been the recognition by Dewar and Jones in 1905 that sunlight resulted in the conversion of the very newly discovered Fe(CO) 5 into a new substance [1], the correct formula of which was later reported by Speyer and Wolf to be Fe 2 (CO) 9 [2]. Photolysis remains the preferred method for the preparation of Fe 2 (CO) 9 and its synthesis is described in Organometallic Synthesis, perhaps the single most influential synthesis reference in the field [3].…”