| Abstract
| - The development of a new, simple synthesis oftri-N-pyrrolylsilane (1) fromtrichlorosilaneand pyrrole provides a convenient starting point for a series ofinteresting transition-metalcomplexes with the tri-N-pyrrolylsilyl ligand.Oxidative addition of 1 toM(CO)2(PPh3)3givesthe six-coordinate compoundsM(SiPyr3)H(CO)2(PPh3)2(Pyr = 1-NC4H4; 2a, M = Ru;2b, M= Os), whereas overall phenyl group-silyl group exchange betweenMPhCl(CO)(PPh3)2 and1 yields the five-coordinate speciesM(SiPyr3)Cl(CO)(PPh3)2(3a, M = Ru; 3b, M = Os).Thenitrosyl complexOs(SiPyr3)HCl(NO)(PPh3)2(4) can be prepared fromOsCl(NO)(PPh3)3 and1. The carbonyl groups in these compounds showrelatively high C−O stretching frequencies,which fall between those found for the trihydroxysilyl andtrichlorosilyl analogues. Bondlengths and angles obtained from the X-ray structure determinations ofHSiPyr3 (1) andOs(SiPyr3)H(CO)2(PPh3)2(2b) indicate that the SiPyr3 moiety undergoessignificant changeson coordination to osmium.
- A simple synthesis oftri-N-pyrrolylsilane (1) has been developed, anda series of interesting five- and six-coordinatetri-N-pyrrolylsilyl transition-metal complexes have beenprepared using 1. X-ray crystal structures of1 andOs(SiPyr3)H(CO)2(PPh3)2(2b) have been determined, showing unusually short Os−Siand particularly long Si−N distances in 2b. It isproposed that the tri-N-pyrrolylsilyl group acts as aπ-acceptor.
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