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†
Abstract
Aminoallenylidene complexes trans-[Cl(dppm)2RuC3(NRR′)(CH3)]+ are obtained from the regioselective addition of C
C
C
CH2]+. Unsymmetrically substituted
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, the