X-ray crystal structure of the trifluoroacetylcobalt complex CF3COCo(CO)3(PPh3) – Implications for the relationship between structure and reactivity toward migratory insertion of carbon monoxide in cobalt alkyl complexes

Comparison of the Thermal and Reductive Decarbonylation of a Rhodium Trifluoroacetyl Diphosphine Complex

“…The major difference, as expected, is in the Rh−C bond length, with the acyl complex having the shorter bond (1.946 vs 2.014 Å). This trend is in agreement with two previously reported pairs of perfluoroacyl and perfluoroalkyl complexes of rhodium and platinum − but is in contrast to our results with cobalt, where the Co−C bond length of the trifluoromethyl complex was shorter than that of the trifluoroacetyl complex . On the other hand, the Rh−C bond length for the acetyl complex reported by Moloy and Petersen (1.981 Å) is, as expected, significantly longer than the trifluoroacetyl bond length of 1 .…”

“…This trend is in agreement with two previously reported pairs of perfluoroacyl and perfluoroalkyl complexes of rhodium and platinum [37][38][39] but is in contrast to our results with cobalt, where the Co-C bond length of the trifluoromethyl complex was shorter than that of the trifluoroacetyl complex. 40 On the other hand, the Rh-C bond length for the acetyl complex reported by Moloy and Petersen (1.981 A ˚)21 is, as expected, significantly longer than the trifluoroacetyl bond length of 1. However, the carbon-oxygen (1.182 A ˚) and carbon-carbon (1.513 A ˚) bond lengths of the acyl ligand are shorter in the acetyl complex than in the trifluoroacetyl complex (1.207 and 1.579 A ˚, respectively).…”

Phosphine induced migratory CO insertion into the Fe–CH2 bond of the organometallic polymer -[(η5-C5H4)Fe(CO)2CH2SiMe2]n- and characterization of model iron complexes

“…IR (THF, cm -1 ): 1913 (n C≡O), 1600 (nC=O); 1 H NMR (THF-d 8 ): 0.28 (s, 12H, SiMe 2 ), 2.18 (s, 4H, P(CH 2 ) 2 P), 2.26 (s, 4H, (C=O)CH 2 ), 3.95-4.74 (8H, C 5 H 4 ), 7.09-7.56 (20H, Ph); 13 C NMR (THF-d 8 ): d 2.15 (SiMe 2 ), 26.2 (PCH 2 CH 2 P), 52.1 (C=O)CH 2 ), 85.6, 90.5, 96.2 (C 5 H 4 ), 130.2,131.9,135.3,139.4 (Ph),222.4 (d,FeC≡O,2 [Starting reagents: THF, 5.0 mL; 1, 1.0 g (4.03 mmol); Ph 2 P(CH 2 ) 3 PPh 2 , 0.83 g (2.02 mmol)] (Yield: 1.30 g, 1.43 mmol, 70.8%). IR (THF, cm 9,129.5,131.1,132.9 (Ph),221.3 (d,FeC≡O,2 [Starting reagents: THF, 5.0 mL; 1, 1.0 g (4.03 mmol); Ph 2 P(CH 2 ) 4 PPh 2 , 0.85 g (2.02 mmol)] (Yield: 1.18 g, 1.28 mmol, 63.4%). IR (THF, cm -1 ): 1913 (n C≡O), 1598 (nC=O); 1 H NMR (THF-d 8 ): 0.02 (s, 12H, SiMe 2 ), 0.23 (s, 4H, P(CH 2 ) 2 ), 1.20 (s, 4H, (CH 2 ) 2 ), 2.18 (s, 4H, (C=O)CH 2 ), 4.20-4.62 (8H, C 5 H 4 ), 6.96-7.55 (20H, Ph); 13 C NMR (THF-d 8 ): d 1.93 (SiMe 2 ), 15.0 (CH 2 CH 2 ), 31.0 (d, PCH 2 , 1 J P-C = 30.0 Hz), 52.2 (C=O)CH 2 ), 87.7, 91.6, 95.2 (C 5 H 4 ), 129.7,132.8,135.5,139.1 (Ph),221.3 (d,FeC≡O,2 (10).…”

[1,3-Bis(diphenylphosphino)propane-κ2P,P′]diiodido(perfluoropropyl)rhodium(III) dichloromethane solvate

“…Unfortunately, there are no reported structures for hydrocarbon Rh(III)-alkyl complexes with which to compare the title compound. The shortening of the metal-carbon bonds in perfluoroalkyl transition metal complexes, and the concomitant strengthening of this bond, has previously been explained in terms of electrostatic effects caused by the relatively large positive charge on the α-carbon of the perfluoroalkyl group (Gunawardhana et al, 2008).…”