0181641 - UFCH-W 20030062 RIV GB eng J - Journal Article
Winter, R. F. - Hartmann, S. - Záliš, Stanislav - Klinkhammer, K. W.
Aminoallenylidene Complexes of Ruthenium(II) from the Regioselective Addition of Secondary Amines to Butatrienylidene Intermediates: A Combined Experimental and Theoretical Study of the Hindered Rotation around the CN-Bond.
Journal of the Chemical Society. Dalton Transactions. - (2003), s. 2342-2352. ISSN 1472-7773
R&D Projects: GA MŠMT OC D15.10
Institutional research plan: CEZ:AV0Z4040901
Keywords : aminoallenylidene complexes * ruthenium * experimental study
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.023, year: 2002

Aminoallenylidene complexes trans-[Cl(dppm)2RuC3(NRR'')(CH3)]+ are obtained from the regioselective addition of secondary amines to trans-[Cl(dppm)2Ru=C=C=C=CH2]+. Unsymmetrically substituted amines give rise to Z/E isomeric mixtures. Dynamic 31P-NMR spectroscopy gave an energy barrier of about 85 kJ/mol T for rotation around the CN-bond pointing to a large contribution of the iminium alkynyl resonance form trans-[Cl(dppm)2RuůCC-C(=NRR'''')(CH3)]+. This is also indicated by the pronounced bond length alternation within the RuC3N-chain as is revealed by X-ray structure analysis of the Z isomer of the (benzylmethyl)methylamine derivative 2d. The issue of NR2 rotation was also addressed by DFT calculations on the trans-[Cl(dhpm)2RuC3{N(CH3)2}(CH3)]+ model complex (dhpm = H2PCH2PH2). Upon rotation around the iminium type CN bond nitrogen lone pair and the -system of the allenylidene ligand are decoupled resulting in a significantly longer CN bond.
Permanent Link: http://hdl.handle.net/11104/0078176