Crystallographic and theoretical analyses of the structures of rhenium formyl and acyl complexes of the formula (.eta.5-C5H5)Re(NO)(PR3)(COR')

Synthesis of Oxorhenium Acetyl and Benzoyl Complexes Incorporating Diamidopyridine Ligands: Implications for the Mechanism of CO Insertion

“…The oxorhenium vinyl ( 6 ) and aryl complexes ( 7 ) were also synthesized by this method. The 1 H NMR spectrum of 6 displays a resonance at 6.67 ppm for Re–C–H α , which is similar to the case for the rhenium vinyl complex, CpRe(NO)(PPh 3 )(CHC(CH 3 ) 2 ), isolated by Gladysz and co-workers, in which H α resonates at 7.14 ppm . Complex 6 is not very stable in solution.…”

Unusual Degradation of the Rhenium Silyl Ester Cp(NO)(PPh3)ReCO2SiMe2Ph to the Bimetallic μ-η1(C(Re)):η1(O,O‘(Re)) Carbon Dioxide Complex Cp(NO)(PPh3)ReCO2Re(NO)(CO)(PPh3)OSiMe2Ph

“…Remaining ligands on Re(2) include PPh 3 and CO trans to the metallocarboxylate O's and NO trans to the silanolate. The μ-η 1 (C(Re 1 )):η 2 (O,O‘(Re 2 )) carboxylate ligand on 3 has Re−C = 2.063(5) Å, which, although relatively short for a μ 2 -η 3 -CO 2 bimetallocarboxylate, , is reasonable for an acyl complex Cp(PPh 3 )(NO)ReCOR 11b. The symmetrical chelation of the carboxylate oxygens to Re(2) resembles that observed in Gibson's Cp*(CO)(NO)Re(CO 2 )Re(PPh 3 )(CO) 3 , although unsymmetrical chelation was noted for Gladysz's Cp(PPh 3 )(NO)ReCO 2 SnPh 3 .…”

Deprotonation of the Transition Metal Hydride (η5-C5Me5)(PMe3)IrH2. Synthesis and Chemistry of the Strongly Basic Lithium Iridate (η5-C5Me5)(PMe3)Ir(H)(Li)

“…The Ir-C 14 and C 14 -O bond distances were found to be 2.036 and 1.235 Å, respectively, in the range expected from comparison with other late metal acyl complexes. [57][58][59][60][61] is roughly in the C-CdO plane of the acyl group. The sum of angles around the carbonyl carbon atom was found to be 360°, indicating symmetric bonding of the acyl carbon to Ir.…”

“…Consequently, the study of such complexes has drawn considerable attention. [57][58][59][60][61][63][64][65][66][67][68][69][70][71][72] We anticipated that complexes 7a-c would undergo thermal reductive elimination to produce the transient unsaturated 16e Cp*(PMe 3 )Ir fragment and aldehyde products. While acyl hydride complexes 7a-c were found to exhibit varying degrees of thermal stability, they gave complex mixtures of products, which by 1 H NMR analysis in each case included at least some of the carbonyl derivative Cp*Ir(PMe 3 )(CO) (8).…”

“…Acyl and alkoxycarbonyl hydrides are believed to be intermediates in a large number of industrially important processes including the Fischer−Tropsch reaction, the water-gas shift reaction, and olefin hydroformylation. Consequently, the study of such complexes has drawn considerable attention. − ,− We anticipated that complexes 7a − c would undergo thermal reductive elimination to produce the transient unsaturated 16e Cp*(PMe 3 )Ir fragment and aldehyde products. While acyl hydride complexes 7a − c were found to exhibit varying degrees of thermal stability, they gave complex mixtures of products, which by 1 H NMR analysis in each case included at least some of the carbonyl derivative Cp*Ir(PMe 3 )(CO) ( 8 ).…”