A Dirhoda‐Heterocyclic Carbene

Abstract

The linear μ‐carbido complex [Rh2(μ‐C)Cl2(dppm)2] (dppm=bis(diphenylphosphino)methane) reacts with dimethylacetylene dicarboxylate (DMAD) to afford [Rh2(μ‐C)(μ‐DMAD)Cl2(dppm)2], which features a bent RhCRh linkage (124.7°) that might be described as a dirhoda‐heterocyclic carbene, as demonstrated by coordination to further metal centers.

Phosphorus-ylides: powerful substituents for the stabilization of reactive main group compounds

“…boryl 6 d ,18 and even metallo substituents. 19 For stabilizing low-valent and electron-deficient compounds strong σ- and π-donors are particularly well suited such as aryl or amido groups, but also other σ- and π-donor substituents have emerged in recent years. Prominent examples are N-heterocyclic imines 20 and their carbon 21,22 and phosphorus 23 derivatives.…”

Cp2Ti(κ2-tBuNCNtBu): A Complex with an Unusual κ2 Coordination Mode of a Heterocumulene Featuring a Free Carbene

“…On the basis of the above spectroscopic and computational analysis, the best descriptor of 3 is that of an unusual free Ti IV -diamidocarbene, in which the σ­(N–C) bonds interact further with the metal via a bond of π-symmetry. This is the first example of an unsupported κ 2 -bound heterocumulene, as well as the first example of a 4-membered metal-containing free N-heterocyclic carbene, although several metal-containing carbene − and metal-containing N-heterocyclic carbene coordination complexes have been reported. − …”

Chromium carbides and cyclopropenylidenes

“…[32][33][34][35][36][37][38] Recently, Hill and co-workers have reported a bent dimetallacumulene, which has rather a dimetallocarbene character, called dirhoda-heterocyclic carbene. 39 The dimetallocarbene species 39,40 can bind various Lewis acids to form trinuclear  3 -carbides, which have been investigated by Takemoto and Matsuzaka. 41,42 Carbido complexes have been generally prepared by deprotonation of methylidynes, 26,40,42 metallation of halocarbynes, 28,43 or multiple C-X bond cleavages of various carbide sources, such as CO, 10,[44][45][46]…”

“… 32–38 Recently, Hill and co-workers have reported a bent dimetallacumulene, which has a rather dimetallocarbene character, called dirhoda-heterocyclic carbene. 39 The dimetallocarbene species 39,40 can bind various Lewis acids to form trinuclear μ 3 -carbides, which have been investigated by Takemoto and Matsuzaka. 41,42 …”