Characterization of a Rhodium(I) σ-Methane Complex in Solution

  title={Characterization of a Rhodium(I) $\sigma$-Methane Complex in Solution},
  author={Wesley H. Bernskoetter and Cynthia K. Schauer and Karen I. Goldberg and Maurice Brookhart},
  pages={553 - 556}
Methane Loosely Bound For the most part, molecular bonds involve sharing of electrons between two discrete atoms. In certain cases, however, a third atom can also attract a portion of the electron density without fully cleaving the bond. Such loose complexes between C-H bonds and transition metals are often invoked as short-lived intermediates in metal-catalyzed reactions of hydrocarbons, though they are rarely observed directly. Bernskoetter et al. (p. 553) glimpse this coordination motif for… 
Synthesis and Characterization of a Rhodium(I) σ-Alkane Complex in the Solid State
This strategy enables the structural determination, by x-ray diffraction, of an alkane (norbornane) σ-bound to a d8–rhodium(I) metal center, in which the chelating alkane ligand is coordinated to the pseudosquare planar metal center through two ρ-C–H bonds.
Binding methane to a metal centre
The σ-alkane complexes of transition metals, which contain an essentially intact alkane molecule weakly bound to the metal, have been well established as crucial intermediates in the activation of
Pressure‐Enhanced C–H Bond Activation in Chloromethane Platinum(II) Complexes
The nature of the interaction between chloromethanes CH4–nCln and Pt(II) complexes has been studied by highpressure X-ray diffraction and infrared spectroscopy in combination with DFT calculations.
Unsupported boron-carbon σ-coordination to platinum as an isolable snapshot of σ-bond activation.
It is shown that coordination of the borirene ligand is based on electron donation from the B-C σ bond to the metal, aided by a strong Pt-to-B dative interaction, and has broad implications as a model for the metal-mediated activation of strong p-block-p-block σ-bonds.
The quest for stable σ-methane complexes: computational and experimental studies
A series of cationic late transition metal pincer complexes with tridentate, neutral pincer ligands and their corresponding metal methyl complexes have been investigated by density functional theory
Mechanism of hydrogenolysis of an iridium-methyl bond: evidence for a methane complex intermediate.
Evidence for key σ-complex intermediates in the hydrogenolysis of the iridium-methyl bond of (PONOP)Ir(H)(Me)(+) (1) has been obtained and significant shortening of the Ir-H bond for the hydrogen being transferred is shown.
Facile C-H bond cleavage via a proton-coupled electron transfer involving a C-H...Cu(II) interaction.
The present study provides mechanistic details of a mild aromatic C-H activation effected by a copper(II) center ligated in a triazamacrocylic ligand, affording equimolar amounts of a Cu(III)-aryl
Mechanistic Aspects of Aryl-Halide Oxidative Addition, Coordination Chemistry, and Ring-Walking by Palladium.
This contribution describes the reactivity of a zero-valent palladium phosphine complex with substrates that contain both an aryl halide moiety and an unsaturated carbon-carbon bond. Although η(2)
C-H bond activation reactions of ethers that generate iridium carbenes.
The findings described in this Account are of fundamental importance for various facets of C-H bond activation chemistry, and with suitable modifications of the ancillary ligands, they could be even broader in scope.


Investigations of iridium-mediated reversible C-H bond cleavage: characterization of a 16-electron iridium(III) methyl hydride complex.
New iridium complexes of a tridentate pincer ligand, 2,6-bis(di-tert-butylphosphinito)pyridine (PONOP), have been prepared and used in the study of hydrocarbon C-H bond activation, resulting in a cationic five-coordinate iridium(III) phenyl hydride product.
The Effect of Alkane Structure on Rates of Photoinduced C−H Bond Activation by Cp*Rh(CO)2 in Liquid Rare Gas Media: An Infrared Flash Kinetics Study
C−H bond activation via photoinduced reaction of Cp*Rh(CO)2 (1) with alkanes (RH) in liquid Kr and liquid Xe solution has been studied by time-resolved infrared spectroscopy. Irradiation leads to the
.alpha. Agostic assistance in Ziegler-Natta polymerization of olefins. Deuterium isotopic perturbation of stereochemistry indicating coordination of an .alpha. carbon-hydrogen bond in chain propagation
The well-defined, homogeneous Ziegler-Natta olefin polymerization systems that have been reported recently provide an unprecedented opportunity to investigate the mechanism of this important process.
Heterolytic Activation of c-h bond in methane with (HN=CHCH=NH)M(CH3) (M = Pd+, Pt+, Rh+, Ir+, Rh, Ir): Comparative density functional study of Activation mechanisms
Activation of methane by oxidative addition and σ-bond metathesis has been investigated for (N-N)M(CH3) (M = Pd+, Pt+, Rh+, Ir+, Rh, Ir; N-N = (HNCHCHNH) using different density functional
The coordination chemistry of saturated molecules
The key feature, of course, is the availability of a low-energy filled "lone pair" orbital available for donation to a vacant orbital on the electron-accepting metal ion.
Comparison of the C−H Activation of Methane by M(C5H5)(CO) for M = Cobalt, Rhodium, and Iridium
The C−H activation reactions of methane by MCp(CO) (Cp = C5H5) for the metals cobalt, rhodium, and iridium have been studied using a variety of methods including a recently developed scaling scheme,
Understanding and exploiting C–H bond activation
The recent development of promising catalytic systems highlights the potential of organometallic chemistry for useful C–H bond activation strategies that will ultimately allow us to exploit Earth's alkane resources more efficiently and cleanly.
Evidence for alkane coordination to an electron-rich uranium center.
A series of five uranium-alkane complexes of the general formula [(ArO)3tacn)U(alkane)].(cy-alkanes) has been synthesized and crystallographically characterized and revealed a pseudo-six-coordinate trivalent uranium core structure with a coordinated alkane ligand at the axial position.
Ab Initio Calculations of the Geometries and Bonding Energies of Alkane and Fluoroalkane Complexes with Tungsten Pentacarbonyl
Ab initio calculations of the bonding energies of alkanes and fluoromethanes to W(CO)5 have been performed in several basis sets and at a variety of different levels of electron correlation. The
Time-resolved infrared (TRIR) study on the formation and reactivity of organometallic methane and ethane complexes in room temperature solution
Activation parameters for the reactions of the organometallic methane and ethane complexes with CO have been measured, and the ΔH‡ values represent lower limits for the CH4 binding enthalpies to the metal center of WCH4 and MnCH4.