Trägerfixierte Organometallkomplexe, III. Polysiloxan‐gebundene (Ether‐phosphan)ruthenium(II)‐Komplexe und ihre CP‐MAS‐NMR‐spektroskopische Charakterisierung

Abstract

The reaction of the functionalized ether-phosphane ligand CH,0(CH,),P(Ph)(CH,)3Si(OMe)3 (lc) with C~, R U ( P P~~)~ (2) and HRuC~(CO)(PP~~)~ (3) results in the formation of the monochelated (ether-phosphane)ruthenium(II) complex Cl,Ru(P-O),(PnO) (4c) and the hydride HRuCl(CO)(P-O), (5c) (P-O: ql-P-coordinated; P"0: $-O"P-coordinated). Compounds 4c and 5c are polycondensated to the corresponding polysiloxane-bound complexes 4c' and 5c'. 31P-chemical shifts of the immobilized species 4c' and 5c' in the solid-state CP-MAS NMR spectra are compared with those of the 31P{1H)-NMR spectra of monomeric complexes 4b, c and 5b, c with the ligands CH30(CH2)2P(Ph)(CH2)3SiMe3 (1 b) and 1 c in solution. No change in the structure between the monomeric and polymeric species could be observed. According to "Si CP-MAS NMR-spectroscopic investigations the polysiloxane chains are connected by ruthenium complexes to a network with favourable properties. The chelated polysiloxane-bound red complex 4c' adds CO in the solid state to give quantitatively yellow Qll-trQnS-ClzRU(Co),(P -O), (6 c'). In the presence of carbon monoxide there is an equilibrium between 5c' and HRuCl(CO),(P-O), (7c') which was also found in solution for 5b, c and 7b, c. The reactions indicate that the chemistry of polysiloxane-bound ether-phosphane complexes can well be compared with the chemistry in solution. 31P CP-MAS NMR spectra of the complexes 4c' and 5c' are strongly dominated by a chemical shift anisotropy which shows a fingerprint pattern both for monomeric crystalline complexes 4a, 5a [containing ligand Ph2P (CH&0CH3 (1 a)] and polysiloxane-bound phosphane complexes 4c' and 5c'.

Chemistry in Interphases—A New Approach to Organometallic Syntheses and Catalysis

“…If the gel of 7(T n ) 3 is swollen in ethanol and treated with methanal at 60 8C, a smooth reaction in the interphase takes place with formation of the carbonyl(hydrido)ruthenium complex(ii) 8(T n ) 3 (Scheme 10). [140] To obtain further evidence for the chemical exchange process in 7(T n ) 3 (see Scheme 7) the gel swollen with ethanol or methanol was treated with acetic acid and carbon monoxide, respectively (Scheme 10). The reaction of acetic acid with the fluxional ruthenium complex 7(T n ) 3 results in liberation of hydrogen to give the acetato complex 9(T n ) 3 in the interphase (Scheme 10), as was shown by IR spectroscopy.…”

“…[86] In a carbon monoxide atmosphere the Ru À O bond in 7(T n ) 3 is cleaved, forming the corresponding carbonyl complex 10(T n ) 3 . [140] This reaction has been monitored by 31 P CP/ MAS NMR spectroscopy. In Figure 11 spectrum A displays the exchange signal of the highly swollen gel of 7(T n ) 3 .…”

Chemie in Interphasen – ein neuer Weg für die metallorganische Synthese und Katalyse

“…Wird das Gel von 7(T n ) 3 mit Ethanol gequollen und bei 60 8C mit Formaldehyd versetzt, so findet in der Interphase eine glatte Reaktion unter Bildung des Carbonyl(hydrido)ruthenium(ii)-Komplexes 8(T n ) 3 statt (Schema 10). [140] Um einen weiteren Beweis für den chemischen Austausch in 7(T n ) 3 (siehe Schema 7) zu erhalten, wurde das mit Ethanol oder Methanol gequollene Polymer mit Essigsäure bzw. Kohlenmonoxid behandelt (Schema 10).…”

“…[86] Durch Kohlenmonoxid wurde die Ru-O-Bindung in 7(T n ) 3 gespalten, wobei der Carbonylkomplex 10(T n ) 3 entstand. [140] Diese Reaktion wurde 31 P-CP/MAS-Schema 10. Beispiele für Reaktionen eines Ruthenium(ii)-Komplexes in der Interphase.…”

Immobilization of Carbonylnickel Complexes: A Solid-State NMR Study

“…The sol−gel process for instance provides the option of a tailored silica support material with a high loading of catalyst. It has been successfully applied for example by Lindner , and Schubert. , However, this procedure is only feasible for very stable transition metal complexes, and not all of the catalyst is later easily accessible for the substrate. The steric and chemical environment of the metal nuclei is not very well defined.…”