Rhodium complexes dinitrogen

The bulky ruthenium TMP complex Ru(TMP) is very electron deficient in the absence of any coordinating ligand, and a tt-complex with benzene has been proposed. In fact, it readily coordinates dinitrogen, forming the mono- and bis-N adducts Ru(TMP)(N2)(THF) and Ru(TMP)(N2)2, - As a result, the use of the TMP ligand for careful stereochemical control of the chemistry at the metal center, which has been very successful for the isolation of elusive rhodium porphyrin complexes, is less useful for ruthenium (and osmium) because of the requirement to exclude all potential ligands, including even N2,... 

Citra, A., Andrews, L., 1999, Reactions of Laser Ablated Rhodium Atoms With Nitrogen Atoms and Molecules. Infrared Spectra and Density Functional Calculations on Rhodium Nitrides and Dinitrogen Complexes , J. Phys. Chem. A, 103, 3410. 

The product of reaction (30) is thought to coordinate a further molecule of ethyldiazoacetate trans to the iodoalkyl group which looses dinitrogen, yielding a hexacoordinate rhodium carbene complex according to Eq. (31) which transfers its carbene moiety to an attacking alkene molecule. 

Rhodium(O).—Low-temperature (10 K) matrix isolation techniques have produced the novel dinitrogen complexes [Rh(N2)J (x = 1—4).114 The [Rh(N2)4] species was shown from i.r. studies to have a distorted tetrahedral geometry in solid nitrogen, but an approximately regular tetrahedral symmetry in solid argon. 

Miessner, H., Surface-chemistry in a zeolite matrix—Well-defined dinitrogen complexes of rhodium supported on dealuminated Y-zeolite. J. Am. Chem. Soc. 116,11522 (1994). 

Rhodium(-I) complexes, 904,905 Rhodium(O) complexes, 905, 906 triphenylphosphinc, 905 Rhodium I) complexes, 906-929 anionic, 906 bidentatc anions N-methylsalicylaldiminato, 908 pentanc-2,4-dionato, 908 trifluoroacetato, 908 bridged, 908-911 dinitrogen, 919 bi nuclear, 920 four-coordinate anions, 925 hydrido, 921 hydride dinitrogen, 920 penlacoordinate anions, 929... 

A series of carbene rhodium complexes of the general composition [Rh(L)( = CRR )(ri -C5H5)] (R = R = aryl L = SbPp3 or PR3) has been prepared from the square-planar precursors [Rh(Cl)( = CRR )(L)2] and NaCsHs and their reactivity towards nucleophiles studied. The complex [BpMe2Rh(co)(pyridine)] [Bp = dihydridobis(3,5-dimethylpyrazolyl)borate] reacts with Mel to yield the novel carbene complex [HB(Me2Pz)2Rh(H)(I)(py-ridine) C(0)Me ], resulting from formal addition of Mel across the Rh-C bond concomitant with hydride transfer from B to Rh. " A series of thermally stable PCP-type rhodium carbene complexes have been prepared from dinitrogen... 

Increasing the number of electrons reduces the activation of N2, because the electrons occupy the orbitals which are bonding with respect to the NN bond, and actually stabilize it. In agreement with this prediction dinitrogen is sufficiently activated to be reduced by protonation by dinuclear complexes of titanium(II), zirco-nium(Il), niobium(III), tantalum(III), molybdenum(IV), and tungsten(IV), whereas it is not reduced by protonation by certain d -d complexes, such as those of molybdenum(O), ruthenium(II), or rhodium(I). Apparently dinuclear complexes M-N=N-M in which M has the d electronic configuration can be intermediates in dinitrogen reduction in protic media, particularly if they represent part of polynuclear complexes (vide infra). 

The olefin complexes of iron, nickel, rhodium, and iridium described in this chapter have found broad application in the synthesis of phosphine, phosphite, and carbonyl derivatives of these metals. In Chapter Two, the synthesis of another labile olefin complex, (ethylene)bis(tricyclohexylphosphine)nickel, is described as an initial step in synthesis of a complex of dinitrogen. 

Praetorius JM, Wang R, Crudden CM. Structure and reactivity of dinitrogen rhodium complexes containing N-heterocyclic carbene Hgands. Eur I Inorg Chem. 

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