Synthesis and investigation of the metal–metal interactions in heterobimetallic Cr/Rh and Cr/Ir complexes

Abstract

A new chromium tris(phosphinoamide) precursor is used to synthesize open shell (S = 3/2) heterobimetallic Cr/Rh and Cr/Ir complexes featuring metal-metal bonds.

Mechanism of Isomerization and Methyl Migration in Heterobimetallic Rhenium–Iridium Complexes: Experimental and DFT Study

“…Heterobimetallic complexes featuring two metals with vastly different properties and reactivity are of notable interest because of their connection to heterogeneous catalysts that use an early transition metal oxide support and a late noble metal catalyst. − In the case of homogeneous systems, heterobimetallic complexes of early and late metals are important because they can carry out chemistry that neither metal by itself can do and in enabling multielectron redox processes. Thomas and Lu have independently reported on a number of heterobimetallic complexes and demonstrated their utility in organic transformations and small-molecule activation. − …”

Paramagnetic Metal–Metal Bonded Heterometallic Complexes

“…This led to the conclusion that there is a partial bond with a predicted bond order of 0.5 and a calculated Mayer bond order of 0.41. 83…”

“…To support the two metals, research groups have focused on providing either a 3-fold symmetric or a 4-fold symmetric coordination environment. The groups of Lu and Thomas have both utilized 3-fold symmetric ligand scaffolds to support a variety of unique heterobimetallic species. − Some of these species have found success in catalytic transformations and small molecule activation, ,,,,, cross-coupling reactions, ,,, and C–H activation. , Detailed description of their reactivity is described elsewhere. ,, In addition to these 3-fold symmetric species, the groups of Vargaftik, Doerrer, Zamora, and Berry have synthesized heterobimetallic compounds supported by four ligands in a paddlewheel arrangement, affording structures with C 4 symmetry. − Remarkably, the compounds comprising this section display a wide range of magnetic behavior, sometimes counterintuitive and surprising.…”

Nature of the Short Rh–Li Contact between Lithium and the Rhodium ω-Alkenyl Complex [Rh(CH2CMe2CH2CH═CH2)2]−

“…12,44 Despite this variety in the description of the M−M interaction, modern computational studies generally suggest that the interactions between Li or Mg and late transition metals are predominantly ionic and that covalent (dative) interactions play a minor role at best. 37,43,52,53,58 Rhodium forms a variety of heterobimetallic complexes with main-group metals, 59−61 transition metals, 62 and f-block elements. 63 Of these, one complex is known, [Li(TMEDA)]-[(COD)Rh(CH 2 SiMe 3 ) 2 ], 31 in which the Li−Rh distance is shorter than the 2.70 Å sum of the covalent radii of lithium (1.28 Å) and rhodium (1.42 Å).…”

“…Rhodium forms a variety of heterobimetallic complexes with main-group metals, − transition metals, and f-block elements . Of these, one complex is known, [Li­(TMEDA)]­[(COD)­Rh­(CH 2 SiMe 3 ) 2 ], in which the Li–Rh distance is shorter than the 2.70 Å sum of the covalent radii of lithium (1.28 Å) and rhodium (1.42 Å) .…”