Activation of Coordinated Carbon Dioxide in Fe(CO₂)(depe)₂ by Group 14 Electrophiles

Abstract

A CO2 complex of iron(0), Fe(CO2)(depe)2 (1; depe = 1,2-bis(diethylphosphino)ethane) has been prepared by replacement of N2 in Fe(N2)(depe)2 by CO2. The X-ray structure analysis of 1 shows that it has a η2(C,O)-CO2 ligand in a trigonal-bipyramidal Fe geometry with some contribution of an η1(C) mode. Reaction of 1 with R3SnCl in Et2O at −78 °C gives the iron carboxylate complexes FeCl(CO2SnR3)(depe)2 (R = Me, (2a), Ph (2b)). The X-ray structure analysis of 2b shows that the CO2 fragment bridges between the Fe and Sn atoms in a μ-η1(C):η2(O,O‘)-CO2 fashion. Treatment of 1 with Me3SiCl results in the removal of an O atom from the CO2 ligand to give a cationic carbonyliron(II) complex, [FeCl(CO)(depe)2]+Cl- (3a), and (Me3Si)2O. Similarly, 1 reacts with carbon electrophiles such as MeI and MeOTf to give the corresponding cationic iron(II) carbonyl complexes [FeX(CO)(depe)2]+X- (X = I (3b), OTf (3c)) and Me2O.

Iron–dinitrogen coordination chemistry: Dinitrogen activation and reactivity

“…The N 2 ligand can be displaced by a wide variety of ligands including CO, CS 2 , H 2 , CO 2 , and HCl [84,85]. The Fe(DEPE) 2 N 2 complex also cleaves C-S, C-H, and N-H bonds of various heterocycles; however, this resulted in loss of the dinitrogen ligand without functionalization [86].…”

Carbon Dioxide Coordination Chemistry and Reactivity of Coordinated CO2

“…as MeI and MeOTf to give Me 2 O and the corresponding cationic iron(II) carbonyl complexes FeX(CO)(depe) 2 ) + X − , with X = I or OTf [78] . The reaction of Fe(CO 2 ) (depe) 2 with R 3 SnCl in diethyl ether at 195 K gives the iron carboxylate complexes FeCl(CO 2 SnR 3 )(depe) 2 with R = Me or Ph, where the CO 2 moiety bridges the Fe and Sn atoms in a µη 1 (C): η 2 (O,O) -CO 2 fashion.…”

Aspects of carbon dioxide utilization

“…Therefore, it is required to find highly reactive metal catalysts. The investigations of the reaction between carbon dioxide and metal compounds, as transition elements, e.g., Ni [5][6][7][8][9], Pd [10,11], Pt [22], Co [12,55], Rh [13,14,22,34], Ir [15][16][17][18], Fe [19][20][21]34,53], Ru [22][23][24][25][26]34,53], Mn [27][28][29], Re [27,[30][31][32][33][34], Cr [35], Mo [35][36][37][38][39], W [35,[38][39][40][41], V …”