How solvents affect the stability of cationic Rh(i) diphosphine complexes: a case study of MeCN coordination

Abstract

Cationic rhodium(I) diphosphine complexes, referred to as Schrock-Osborn catalysts, are privileged homogeneous catalysts with a wide range of catalytic applications. The coordination of solvent molecules can have a significant influence...

Major–minor concept revisited: causes for the reversal of thermodynamically determined intermediate ratios under reaction conditions

“…37 Thus, it is more elegant to extract the rate constants from the raw data by applying eqn (4) instead (see ESI†). 33,38,39 This relation allows the direct utilisation of the measured extinctions without knowledge of the extinction coefficients.with ζ = k 1 [ 1b ] 0 Q λ ; ζ 1 = k 1 and ζ 2 = k −1 Q λ −1 .…”

“…34 This result is surprising, since it is known from the literature, that NBD complexes are generally more stable than their COD analogues (Table 1). 32,33 The present work deals with the reasons for the observed reversal of the intermediate ratio under catalytic hydrogenations conditions for the model reaction (Scheme 2) by determination of all rate constants involved. The experimentally demonstrated effect is of great importance for explaining the direction of e.g.…”

“…31 Since k 2NBD > k 2COD (ref. 32) and > , 32,33 just as k 2maj > k 2min and > , 3,7 the hydrogenation of a NBD/COD mixture (Scheme 2) with [Rh(PP)(MeOH) 2 ] + is an ideal way to represent or to “experimentally simulate” the internal processes of an asymmetric hydrogenation of prochiral olefins. One diolefin is hydrogenated faster than the other, and one diolefin complex is thermodynamically more stable than the other.…”

“…34 This result is surprising, since it is known from the literature, that NBD complexes are generally more stable than their COD analogues (Table 1). 32,33…”

P,N-type phosphaalkene-based Ir(i) complexes: synthesis, coordination chemistry, and catalytic applications

“…Although strongly coordinating to group 9 metals, 50 acetonitrile is known to undergo replacement by stronger donors such as pyridine, 51 and complex 8a slowly converted into the complex showing the two doublets at 285.5 and 6.8 ppm. The reaction can be accelerated by heating over a period of 12 h at 60 °C.…”