Pentadienyl-metal-phosphine chemistry: XXI. Synthesis and characterization of electron-rich (pentadienyl)iron[1,2-bis(diethylphosphino)ethane] complexes

• Published in: Journal of organometallic chemistry Vol. 405; no. 1; pp. 121 - 132
• Main Authors: Bleeke, John R., Wittenbrink, Robert J.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05.03.1991; Elsevier Science
• Subjects: Chemistry; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Organic chemistry; Organic compounds; Organometalloidal and organometallic compounds; Physics; Preparations and properties; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Transition metals derivatives; Cationic complex; Iron Organic compounds; Molecular structure; Ditertiary phosphine; Organic ligand; Hapto complex; Transition metal Complexes; Experimental study; X ray diffraction; Crystalline structure
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/0022-328X(91)83162-W

Treatment of (Cl) 2Fe(depe) 2 (depe = Et 2PCH 2CH 2PEt 2) with two equivalents of potassium pentadienide produces (η 3-pentadienyl) 2Fe(depe) ( 1). Compound 1 crystallizes in the orthorhombic space group Pbcn (No. 60) with a = 11.347(1), b = 0.718(2), c = 19.938(3) Å, V = 2198.6(6) Å 3, and Z = 4. In the solid state structure of 1, both η 3-pentadienyl ligands are syn and W-shaped; however, in solution the major “ syn,syn” isomer exists in equilibrium with a minor “syn,anti” isomer. Treatment of compound 1 with one equivalent of protonated depe (Hdepe + BF − 4) leads to loss of trans-1,3-pentadiene and production of (η 3-pentadienyl)Fe(depe) + 2 BF − 4 ( 2). Compound 2 crystallizes in the triclinic space group P1 (No. 1) with a = 10.070(2), b = 10.756(1), c = 8.3622(1) Å, α = 112.04(2), β = 94.93(1), γ = 68.05(1)°, V = 777.1(3) Å 3, and Z = 1. In the solid state structure of 2, the η 3-pentadienyl ligand has a syn geometry and is W-shaped. In solution, the syn-η 3-pentadienyl complex exists in equilibrium with its anti-η 3-pentadienyl isomer.