Cationic complexes of rhodium(I) and their reactivity toward air

New Ligands for Rh‐Catalysed Hydroformylation of 1‐Octene in Supercritical Carbon Dioxide – X‐ray Structure of [Rh{PPh2(OC9H19)}4]PF6

“…In this case, a relatively airstable, yellow, oily solid was obtained in 76 % yield. The mass spectrum of the isolated product has a signal m/z = 1679.7 corresponding to the cationic fragment [Rh (2) [13] with similar 31 P NMR spectroscopic data (δ = 148 ppm, J P,Rh = 170 Hz). [14] In the reaction of [Rh(cod) 2 + (R = Me: δ = 132.2 ppm, J P,Rh = 159 Hz; R = Et: δ = 130.5 ppm, J P,Rh = 156 Hz), [15] along with a septuplet signal for PF 6 -at δ = -143.1 ppm (J F,P = 712.…”

The crystal structure of dioxygentetra(dimethylphenylarsine)rhodium(I) perchlorate

“…The observed O-O length of 1.46 A approached the range anticipated for irreversible dioxygen uptake. We thus decided to determine the structure of the known (Haines & Singleton, 1971;Haines, 1971) (2), b= 17.42 (2), c= 10"30 (2) A; c~=89.9 (1), fl=87"9 (1), y=128"6 (1)°; Dm=1"74, Dc=1"72 g cm -3. V=1855 ,~3 Z=2, ¢t= 42"73 cm-A reddish-brown plate-like crystal, with c along the longest axis, dimensions 0.052 x 0.18 x 0.32 ram, was used for data collection.…”

Zwitterionic Relatives of Cationic Platinum Group Metal Complexes: Applications in Stoichiometric and Catalytic σ‐Bond Activation

“…Notwithstanding the utility of 3 and related phenylborate zwitterions as pre-catalysts, several observations bring into question the identity of key reactive intermediates in transformations that employ cationic or zwitterionic pre-catalysts of this type, especially when co-ligands such as dppb are added. These observations include the loss of BPh 4 À from such zwitterions upon treatment with CO, [70] CO 2 , [28] and acetone, [76] and the clean conversion of cationic [Rh(cod)-(dppb)] + BPh 4 À (10) into zwitterionic 13 upon exposure to an atmosphere of H 2 (Scheme 6). [52] Indeed, a solution NMRspectroscopic investigation of 3 in the presence of dppb revealed that zwitterionic [(h 6 -C 6 H 5 BPh 3 )Rh(diene) n -(dppb) 1Àn ] and cationic [Rh(diene) n (dppb) 2Àn ] + BPh 4 À species (n = 0, 1) coexist and interconvert in solution.…”