Syntheses, Structures, and Spectro-electrochemistry of {Cp*(PP)Ru}CCCg src="http://pubs.acs.org/images/entities/tbd1.gif" border="
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- 作者：Michael I. Bruce ; Benjamin G. Ellis ; Paul J. Low ; Brian W. Skelton ; and Allan H. White
- 刊名：Organometallics
- 出版年：2003
- 出版时间：August 4, 2003
- 年：2003
- 卷：22
- 期：16
- 页码：3184 - 3198
- 全文大小：450K
- 年卷期：v.22,no.16(August 4, 2003)
- ISSN：1520-6041
文摘
The complexes {Cp*(PP)Ru}2(G SRC="/images/entities/mgr.gif">-C
ges/entities/tbd1.gif">CCges/entities/tbd1.gif">C) (PP = dppm 5a, dppe 5b) have been synthesizedfrom RuCl(PP)Cp* (1a/b) via the corresponding vinylidenes [Ru(=C=CH2)(PP)Cp*]+ (2a/b), deprotonation (KOBut) to the ethynyls Ru(Cges/entities/tbd1.gif">CH)(PP)Cp* (3a/b), oxidative coupling([FeCp2][PF6]) to the bis(vinylidenes) [{Ru(PP)Cp*}2{ges/entities/mgr.gif">-(=C=CHCH=C=)}]2+ (4a/b), anddeprotonation [dbu (4a), KOBut (4b)]. Electrochemistry of 5a/b revealed the expectedsequence of four 1e redox steps, which occurred at significantly lower Eges/entities/deg.gif"> values than foundfor the Ru(PPh3)2Cp analogue. Single-crystal X-ray structure determinations are reportedfor 1a/b, 2a/b, 3a/b, 4a/b, and 5a/b, together with the oxidized products [5b][PF6]n (n = 1,2). In the monocation [5b][PF6] the Ru-C(1) [1.931(2) Å] and C-C distances [1.248-1.338(3) Å] are intermediate between those found in 5b and the dication [5b]2+. The short Ru-C[1.857(5) Å] and experimentally equal C-C distances [1.269-1.280(6) Å] in [5b][PF6]2 confirmthe anticipated dicarbene-cumulene structure for the Ru=C=C=C=C=Ru bridge.