Koordinativ ungesättigte Dieisenkomplexe: Synthese und Kristallstrukturen von [Fe2(CO)4(μ-H)(μ-PtBu2)(μ-Ph2PCH2PPh2)] und [Fe2(CO)4(μ-CH2)(μ-H)(μ-PtBu2)(μ-Ph2PCH2PPh2)]

✍ Scribed by Hans-Christian Böttcher; Kurt Merzweiler; Christoph Wagner

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: German
• Weight: 180 KB
• Volume: 625
• Category: Article
• ISSN: 0372-7874
• DOI: 10.1002/(sici)1521-3749(199906)625:6<857::aid-zaac857>3.0.co;2-3

✦ Synopsis

Professor Helmut Werner zum 65. Geburtstag gewidmet Inhaltsu È bersicht. [Fe 2 (l-CO)(CO) 6 (l-H)(l-P t Bu 2 )] (1) reagiert spontan mit dppm (dppm = Ph 2 PCH 2 PPh 2 ) unter Bildung von [Fe 2 (l-CO)(CO) 4 (l-H)(l-P t Bu 2 )(l-dppm)] (2 c). 2 c spaltet thermolytisch oder durch Fotobestrahlung sehr leicht einen Carbonylliganden ab und ergibt den korrespondierenden elektronisch und koordinativ ungesa È ttigten Komplex [Fe 2 (CO) 4 (l-H)(l-P t Bu 2 )(l-dppm)] (3). 3 weist eine Fe±Fe-Doppelbindung auf, die durch Addition von Methylen zum entsprechenden Dimetallacyclopropan [Fe 2 (CO) 4 (l-CH 2 )(l-H)(l-P t Bu 2 )(l-dppm)] (4) nachgewiesen werden konnte. Die Reaktion von 1 mit dppe (Ph 2 PC 2 H 4 PPh 2 ) lie-fert [Fe 2 (l-CO)(CO) 4 (l-H)(l-P t Bu 2 )(l-dppe)] ( 5). Im Gegensatz zur Thermolyse von 2 c, die 3 ergibt, verla È uft das Erhitzen von 5 in Toluol rasch unter kompletter Zersetzung. Die Reaktion von 1 mit PPh 3 liefert den Komplex [Fe 2 (CO) 6 (H)(l-P t Bu 2 )(PPh 3 )] (6 a), wa È hrend mit t Bu 2 PH die Verbindung [Fe 2 (l-CO)(CO) 5 (l-H)(l-P t Bu 2 )( t Bu 2 PH)] (6 b) gebildet wird. Die Thermolyse von 6 b ergibt [Fe 2 (CO) 5 (l-P t Bu 2 ) 2 ] sowie die Abbauprodukte [Fe(CO) 3 ( t Bu 2 PH) 2 ] und [Fe(CO) 4 ( t Bu 2 PH)]. Die Moleku È lstrukturen von 3, 4 und 6 b wurden durch Ro È ntgenkristallstrukturanalysen bestimmt.

Coordinatively Unsaturated Diiron Complexes: Synthesis and Crystal Structures of [Fe 2 (CO) 4 (l-H)(l-P t Bu 2 )(l-Ph 2 PCH 2 PPh 2 )] and [Fe 2 (CO) 4 (l-CH 2 )(l-H)(l-P t Bu 2 )(l-Ph 2 PCH 2 PPh 2 )] Abstract. [Fe 2 (l-CO)(CO) 6 (l-H)(l-P t Bu 2 )] (1) reacts spontaneously with dppm (dppm = Ph 2 PCH 2 PPh 2 ) to give [Fe 2 (l-CO)(CO) 4 (l-H)(l-P t Bu 2 )(l-dppm)] (2 c). By thermolysis or photolysis, 2 c loses very easily one carbonyl ligand and yields the corresponding electronically and coordinatively unsaturated complex [Fe 2 (CO) 4 (l-H)(l-P t Bu 2 )(l-dppm)] (3). 3 exhibits a Fe±Fe double bond which could be confirmed by the addition of methylene to the corresponding dimetallacyclopropane [Fe 2 (CO) 4 (l-CH 2 )(l-H)(l-P t Bu 2 )(ldppm)] (4). The reaction of 1 with dppe (Ph 2 PC 2 H 4 PPh 2 ) affords [Fe 2 (l-CO)(CO) 4 (l-H)(l-P t Bu 2 )(l-dppe)] ( 5). In contrast to the thermolysis of 2 c, yielding 3, the heating of 5 in toluene leads rapidly to complete decomposition. The reaction of 1 with PPh 3 yields [Fe 2 (CO) 6 (H)(l-P t Bu 2 )(PPh 3 )] (6 a), while with t Bu 2 PH the compound [Fe 2 (l-CO)(CO) 5 (l-H)(l-P t Bu 2 )( t Bu 2 PH)] (6 b) is formed. The thermolysis of 6 b affords [Fe 2 (CO) 5 (l-P t Bu 2 ) 2 ] and the degradation products [Fe(CO) 3 ( t Bu 2 PH) 2 ] and [Fe(CO) 4 ( t Bu 2 PH)]. The molecular structures of 3, 4 and 6 b were determined by X-ray crystal structure analyses.