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Homo- and heterodinuclear complexes of the tetrakis(pyrazolyl)borate ligand.
Dalton Trans. 2010 Jul 07; 39(25):5899-907.DT

Abstract

Monometallic complexes of the tetrakis(pyrazolyl)borate ligand [ML(2){B(pz)(4)}] {M = Rh, Ir; L(2) = eta-cod, eta-nbd, (CO)(2), (CO)(PPh(3))} have two free pyrazolyl rings which can be coordinated to a second ML(2) unit to give the dimeric compounds [L(2)M{mu-B(pz)(4)}ML(2)](+), and to a metal halide to give heterobimetallic species [L(2)M{mu-B(pz)(4)}M'Cl(2)]. (1)H NMR spectroscopy shows that [(eta-cod)Rh{mu-B(pz)(4)}Rh(eta-cod)](+) 1(+), [(eta-nbd)Rh{mu-B(pz)(4)}Rh(eta-nbd)](+) 2(+), [(eta-cod)Ir{mu-B(pz)(4)}Ir(eta-cod)](+) 3(+) and [(CO)(2)Rh{mu-B(pz)(4)}Rh(CO)(2)](+) 4(+) are fluxional at room temperature. Cooling a solution of [(eta-cod)Rh{mu-B(pz)(4)}Rh(eta-cod)](+) 1(+) to -90 degrees C slows the fluxional process, which involves inversion of the two B-(N-N)(2)-M six-membered rings. Attempts to synthesise the asymmetric complexes [(eta-cod)Rh{mu-B(pz)(4)}Rh(eta-nbd)](+) 7(+), [(eta-cod)Rh{mu-B(pz)(4)}Ir(eta-cod)](+) 8(+) and [(eta-cod)Rh{mu-B(pz)(4)}Rh(CO)(2)](+) 9(+) produced a mixture of [L(2)M{mu-B(pz)(4)}ML(2)](+), [L'(2)M'{mu-B(pz)(4)}M'L'(2)](+) and the desired species. The heterobimetallic complexes [L(2)Rh{mu-B(pz)(4)}M'Cl(2)] (M' = Co, L(2) = eta-cod 10; M' = Co, L(2) = eta-nbd 11; M' = Co, L = CO 12; M' = Co, L(2) = (CO)(PPh(3)) 13; M' = Zn, L(2) = eta-cod 14; M' = Zn, L(2) = eta-nbd 15; M' = Pd, L(2) = eta-cod 16) possess square planar Rh(I) linked to square planar Pd(II) or tetrahedral Zn(II) and Co(II) centres. The paramagnetic Co(II) complexes give (1)H NMR spectra with signals shifted over a range of 75 ppm. The UV-Vis spectra of 10-13 show four bands, one MLCT at Rh and three d-d transitions arising from the splitting of the (4)T(1)(P) excited state due to approximate C(2v) symmetry at Co.

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Authors+Show Affiliations

Hallett AJ
School of Chemistry, University of Bristol, Bristol, UK BS8 1TS. hallettaj@cardiff.ac.uk
Adams CJ
No affiliation info available
Anderson KM
No affiliation info available
Baber RA
No affiliation info available
Connelly NG
No affiliation info available
Prime CJ
No affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

20508889

Citation

Hallett, Andrew J., et al. "Homo- and Heterodinuclear Complexes of the Tetrakis(pyrazolyl)borate Ligand." Dalton Transactions (Cambridge, England : 2003), vol. 39, no. 25, 2010, pp. 5899-907.
Hallett AJ, Adams CJ, Anderson KM, et al. Homo- and heterodinuclear complexes of the tetrakis(pyrazolyl)borate ligand. Dalton Trans. 2010;39(25):5899-907.
Hallett, A. J., Adams, C. J., Anderson, K. M., Baber, R. A., Connelly, N. G., & Prime, C. J. (2010). Homo- and heterodinuclear complexes of the tetrakis(pyrazolyl)borate ligand. Dalton Transactions (Cambridge, England : 2003), 39(25), 5899-907. https://doi.org/10.1039/c0dt00044b
Hallett AJ, et al. Homo- and Heterodinuclear Complexes of the Tetrakis(pyrazolyl)borate Ligand. Dalton Trans. 2010 Jul 7;39(25):5899-907. PubMed PMID: 20508889.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Homo- and heterodinuclear complexes of the tetrakis(pyrazolyl)borate ligand. AU - Hallett,Andrew J, AU - Adams,Christopher J, AU - Anderson,Kirsty M, AU - Baber,R Angharad, AU - Connelly,Neil G, AU - Prime,Christopher J, Y1 - 2010/05/28/ PY - 2010/5/29/entrez PY - 2010/5/29/pubmed PY - 2010/5/29/medline SP - 5899 EP - 907 JF - Dalton transactions (Cambridge, England : 2003) JO - Dalton Trans VL - 39 IS - 25 N2 - Monometallic complexes of the tetrakis(pyrazolyl)borate ligand [ML(2){B(pz)(4)}] {M = Rh, Ir; L(2) = eta-cod, eta-nbd, (CO)(2), (CO)(PPh(3))} have two free pyrazolyl rings which can be coordinated to a second ML(2) unit to give the dimeric compounds [L(2)M{mu-B(pz)(4)}ML(2)](+), and to a metal halide to give heterobimetallic species [L(2)M{mu-B(pz)(4)}M'Cl(2)]. (1)H NMR spectroscopy shows that [(eta-cod)Rh{mu-B(pz)(4)}Rh(eta-cod)](+) 1(+), [(eta-nbd)Rh{mu-B(pz)(4)}Rh(eta-nbd)](+) 2(+), [(eta-cod)Ir{mu-B(pz)(4)}Ir(eta-cod)](+) 3(+) and [(CO)(2)Rh{mu-B(pz)(4)}Rh(CO)(2)](+) 4(+) are fluxional at room temperature. Cooling a solution of [(eta-cod)Rh{mu-B(pz)(4)}Rh(eta-cod)](+) 1(+) to -90 degrees C slows the fluxional process, which involves inversion of the two B-(N-N)(2)-M six-membered rings. Attempts to synthesise the asymmetric complexes [(eta-cod)Rh{mu-B(pz)(4)}Rh(eta-nbd)](+) 7(+), [(eta-cod)Rh{mu-B(pz)(4)}Ir(eta-cod)](+) 8(+) and [(eta-cod)Rh{mu-B(pz)(4)}Rh(CO)(2)](+) 9(+) produced a mixture of [L(2)M{mu-B(pz)(4)}ML(2)](+), [L'(2)M'{mu-B(pz)(4)}M'L'(2)](+) and the desired species. The heterobimetallic complexes [L(2)Rh{mu-B(pz)(4)}M'Cl(2)] (M' = Co, L(2) = eta-cod 10; M' = Co, L(2) = eta-nbd 11; M' = Co, L = CO 12; M' = Co, L(2) = (CO)(PPh(3)) 13; M' = Zn, L(2) = eta-cod 14; M' = Zn, L(2) = eta-nbd 15; M' = Pd, L(2) = eta-cod 16) possess square planar Rh(I) linked to square planar Pd(II) or tetrahedral Zn(II) and Co(II) centres. The paramagnetic Co(II) complexes give (1)H NMR spectra with signals shifted over a range of 75 ppm. The UV-Vis spectra of 10-13 show four bands, one MLCT at Rh and three d-d transitions arising from the splitting of the (4)T(1)(P) excited state due to approximate C(2v) symmetry at Co. SN - 1477-9234 UR - https://www.unboundmedicine.com/medline/citation/20508889/Homo__and_heterodinuclear_complexes_of_the_tetrakis_pyrazolyl_borate_ligand_ L2 - https://doi.org/10.1039/c0dt00044b DB - PRIME DP - Unbound Medicine ER -