Regular paper

Sanz, Dionísia; María, Dolores Santa; Claramunt, Rosa M.; Cano, Mercedes; Heras, J.V.; Campo, José A.; Ruiz, F. Aparicio; Pinilla, Elena; Monge, Ángeles

doi:10.1016/s0022-328x(96)06577-1

Cited by 28 publications

(49 citation statements)

References 21 publications

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“…The rhodium centre is not significantly displaced from this plane. Comparison with the structurally characterized complexes Tp 4Bo,3Me Rh(cod),10 Tp i Pr, i Pr Rh(cod),11 Tp Ph Rh(cod),12 and B(pz) 4 Rh(cod)13 shows that the Rh−N and Rh−C bond lengths are equal within experimental errors. Only the bite angles show significant variations.…”

Section: Resultsmentioning

confidence: 84%

“…The structure resembles those of Tp Me Rh(nbd)6 ( 4a ) and Tp i Pr, i Pr Rh(nbd)11 ( 4b ), where the Tp′ ligands are also bonded in a κ 3 ‐fashion, while in Tp Ph Rh(nbd)12 and B(pz) 4 Rh(nbd),13 the polypyrazolylborates coordinate in a κ 2 ‐mode forming planar complexes. The X‐ray analysis shows that all Rh−N separations are significantly shorter in 4 than those in 4a and 4b (Table 6), while the Rh−C separations as well as the C=C distances are the same within experimental errors.…”

Section: Resultsmentioning

confidence: 93%

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Tris(pyrazolyl)methanesulfonate (Tpms) − A Versatile Alternative to Tris(pyrazolyl)borate in Rhodium(I) Chemistry

Kläui

Schramm

Peters

et al. 2001

Eur. J. Inorg. Chem.

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Thallium(I) tris(pyrazol-1-yl)methanesulfonate (TlTpms) has been prepared as a new versatile precursor for Tpms complexes. TlTpms readily reacts with the rhodium(I) complexes [Rh(LL)Cl] 2 [LL = (CO) 2 , cod, nbd] to give the corresponding TpmsRh(LL) complexes [LL = (CO) 2 (2a), cod (3), and nbd (4)]. In solution, 2a reversibly forms the binuclear complex TpmsRh(µ-CO) 3 RhTpms (2b). 3 and 4 react with CO to form 2a. TpmsRh(CO)(PR 3 ) complexes [PR 3 = PPh 3 (5a), PMe 3 (5b), PCy 3 (5d), P(Ph) 2 (PhSO 3 K) (5e)] have been obtained by reaction of 2a with the corresponding phosphanes. The solidstate structures of 2a, 3, 4, and 5a have been determined by X-ray analysis. 2a, 3, and 5a have square-planar geometries

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Section: Resultsmentioning

confidence: 84%

Section: Resultsmentioning

confidence: 93%

Tris(pyrazolyl)methanesulfonate (Tpms) − A Versatile Alternative to Tris(pyrazolyl)borate in Rhodium(I) Chemistry

Kläui

Schramm

Peters

et al. 2001

Eur. J. Inorg. Chem.

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“…The structures of poly(pyrazolyl)borate diene complexes can be rationalised in terms of the steric effects of the coordinated diene and the substituents on the pyrazolyl rings. The space filling diagrams of the complexes [Rh(g-cod)Tp Ph ] 14, 8 [Rh(g-cod)Tp ] 6 and [Rh(g-cod)Tp] 8 show the difference in coordination and geometry with different substituents (Fig. 10).…”

Section: The Molecular Structures Of Complexes 2 4-6 8 and 13mentioning

confidence: 99%

“…The relative abundance of each isomer depends on R and L and, in solution, the solvent. [5][6][7][8] With a j 2 tris(pyrazolyl)borate ligand coordinated and uncoordinated pyrazolyl rings exchange at a rate which depends on the pyrazolyl ring substituents and the co-ligands on the metal. More bulky co-ligands result in slower exchange.…”

Section: Introductionmentioning

confidence: 99%

Solid state and solution structures of rhodium and iridium poly(pyrazolyl)borate diene complexes

et al. 2008

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The structures adopted by a range of poly(pyrazolyl)borate complexes [ML2Tp(x)] [M = Rh, Ir; L2 = diene; Tp(x) = Bp' {dihydrobis(3,5-dimethylpyrazolyl)borate}, Tp' {hydrotris(3,5-dimethylpyrazolyl)borate}, Tp {hydrotris(pyrazolyl)borate}, B(pz)4 {tetrakis(pyrazolyl)borate}] have been investigated. Low steric hindrance between ligands in [Rh(eta-nbd)Tp] (nbd = norbornadiene), [Rh(eta-cod)Tp] (cod = cycloocta-1,5-diene) and [Rh(eta-nbd)Tp'] results in K3 coordination of the pyrazolylborate but [M(eta-cod)Tp'] (M = Rh, Ir) are kappa2 coordinated with the free pyrazolyl ring positioned above and approximately parallel to the square plane about the metal. All but the most sterically hindered Tp(x) complexes undergo fast exchange of the coordinated and uncoordinated pyrazolyl rings on the NMR spectroscopic timescale. For [Rh(eta-cod){B(pz)4}], [Rh(eta-dmbd)Tp'] (dmbd = 2,3-dimethylbuta-1,3-diene) and [Rh(eta-cod)Tp(Ph)] {Tp(Ph) = hydrotris(3-phenylpyrazolyl)borate} the fluxional process is slowed at low temperatures so that inequivalent pyrazolyl rings are observed. The bonding modes of the Tp' ligand (but not of other pyrazolylborate ligands) can be determined by 11B NMR and IR spectroscopy. The 11B chemical shifts (for a series of Tp' complexes) show the general pattern, kappa3 < -7.5 ppm < kappa2 and the nu(BH) stretch kappa3 > 2500 cm(-1) > kappa2. The electrochemical behaviour of the pyrazolylborate complexes is related to the degree of structural change which occurs on electron transfer. One-electron oxidation of complexes with Tp', Tp and B(pz)4 ligands is generally reversible although that of [Ir(etacod)Tp] is only reversible at higher scan rates and that of [Ir(eta-cod){B(pz)4}] is irreversible. Of the complexes with the more sterically hindered Tp(Ph) ligand, only [Rh(eta-nbd)Tp(Ph)] shows any degree of reversible oxidation. The ESR spectra of a range of Rh(II) complexes show coupling to both 14N and 103Rh nuclei in most cases but what appears to be coupling to rhodium and one hydrogen atom, possibly a hydride ligand, for the oxidation product of [Rh(eta-nbd)Tp(Ph)].

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“…The relative abundance of each isomer depends on R and L and, in solution, the solvent. 13,14 The discovery that one-electron oxidation of [Rh(CO)L-{HC(pz¢) 3 }] + (L = phosphines) gave Rh(II) dications 15 led us to investigate the behaviour of similar tris(3,5-dimethylpyrazolyl)methane diene complexes.…”

Section: Introductionmentioning

confidence: 99%

Bonding modes, structures and fluxionality in rhodium and iridium tris(3,5-dimethylpyrazolyl)methane diene complexes

et al. 2009

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The structures adopted by a range of hydrotris(3,5-dimethylpyrazolyl)methane complexes [ML(2){HC(pz')(3)}](+) (M = Rh, Ir; L(2) = diene) have been investigated. There is low steric hindrance between ligands in [Rh(eta-nbd){HC(pz')(3)}](+) (nbd = norbornadiene) and [Rh(eta-dmbd){HC(pz')(3)}](+) (dmbd = 2,3-dimethylbuta-1,3-diene) resulting in kappa(3) co-ordination of the pyrazolylmethane. The complexes [M(eta-cod){HC(pz')(3)}](+) (cod = cycloocta-1,5-diene) (M = Rh, Ir) are kappa(2) co-ordinated with the free pyrazolyl ring positioned above and approximately parallel to the square plane about rhodium or iridium. The HC(pz')(3) complexes undergo fast exchange of the co-ordinated and unco-ordinated pyrazolyl rings on the NMR spectroscopic timescale. However, for [Rh(eta-dmbd){HC(pz')(3)}](+), the fluxional process is slowed at low temperatures, so that inequivalent pyrazolyl rings may be observed. A mechanism for the fluxional process is proposed involving dynamic interconversion between isomeric forms in solution. The bonding mode of the HC(pz')(3) ligand can be determined by (13)C NMR spectroscopy. The (13)C chemical shifts (for the sp(3) hybridised carbon of the ligand) show the general pattern, kappa(3) < 71.5 ppm < kappa(2). The electrochemical behaviour of the pyrazolylmethane complexes is related to the degree of structural change, which occurs on electron transfer and is compared with that of the pyrazolylborate analogues.

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Regular paper

Cited by 28 publications

References 21 publications

Tris(pyrazolyl)methanesulfonate (Tpms) − A Versatile Alternative to Tris(pyrazolyl)borate in Rhodium(I) Chemistry

Tris(pyrazolyl)methanesulfonate (Tpms) − A Versatile Alternative to Tris(pyrazolyl)borate in Rhodium(I) Chemistry

Solid state and solution structures of rhodium and iridium poly(pyrazolyl)borate diene complexes

Bonding modes, structures and fluxionality in rhodium and iridium tris(3,5-dimethylpyrazolyl)methane diene complexes

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