En Route to Tunable Catalysts

B3LYP/6-311G(d) (2009) Gaussian09, Revision A.02, Gaussian Inc., Wallingford, CT. 

Fermi-contact shifts and was further verified by comparison of NMR spectra of similar derivatives [25]. A solid-state molecular structure of 14a verified the interaction of the Lewis acid B(CgF5)3 with the distal nitrogen atom. 

Many single-site chromium catalysts exist that are able to polymerize ethylene at a high rate. However, only a few produce long polymer chains at the same time. Chromium(III) complexes with cyclopentadienyl ligands have been identified as catalysts more than 20 years ago, and with the introduction of chelate N-donor-Cp 

(a) Hogan, J.P. and Banks, R.L. (1958) Solid polymers of olefins and production of such polymers. (Phillips Petroleum Co.) US Patent 2825,721, (priority Jan. 27, 1953) (b) Ziegler, K., Breil, H., Holzkamp, E., and Martin, H. (1960) Verfahren zur Herstellung von hochmolekularem Polyathylenen. German Patent 973626, 1960 (priority Nov. 17, 1953). 

283-316 (d) Smith, K.M. (2006) Curr. Org. Chem., 10, 955 -963 (e) McGuiimess, D.S. (2011) in Olefin Upgrading Catalysis by Nitrogen-based Metal Complexes I, Catalysis by Metal Complexes, vol. 35 (eds G. Giambastiani and J. Campora), Springer p. 1-26. 

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