34134-63-9Relevant academic research and scientific papers
Synthesis and properties of the 17-electron, tantalum-centered radical Ta(CO)4(Ph2PCH2CH2PPb2)
Koeslag, Mary Ann,Baird, Michael C.,Lovelace, Sherri,Geiger, William E.
, p. 3289 - 3302 (1996)
The novel 17-electron compound Ta(CO)4dppe (dppe = Ph2PCH2CH2PPh2) is formed via hydride hydrogen atom abstraction from TaH(CO)4dppe by the tris(p-fert-butylphenyl)methyl radical. The compound exists in solution as an equilibrium mixture of monomer (the dominant species) and carbonyl-bridged dimer [Ta(CO)4dppe]2 but solely as the latter in the solid state. It is very labile but was characterized electrochemically, IR, Raman, and 1H and 31P{1H} NMR spectroscopically, and chemically. Typical of metal-centered radicals, Ta(CO)4dppe abstracts halogen atoms from organic halides RX to give the halotantalum compounds TaX(CO)4dppe and, in some cases, TaR(CO)4dppe. Cyclic voltammetry experiments show that the oxidation of [Ta(CO)4(dppe)]- in CH2Cl2/0.1 M [Bu4N][PF6] is a one-electron process, irreversible at scan rates below 50 V/s. The formal potential of [Ta(CO)4(dppe)]0/- is estimated as -1.2 V vs ferrocene. The reduced lifetime of the radical is ascribed to reactions with the ionic medium, the main electrochemical oxidation products being TaH(CO)4(dppe) and TaCl(CO)2(dppe)2.
The seven-coordinate hydrido-tantalum complexes 6-n(oligophos)>: preparation and dynamics
Rehder, Dieter,Fornalczy, Michael,Oltmanns, Peter
, p. 207 - 220 (2007/10/02)
The hydrido complexes cis-2> (P2 = Ph2PCH2CH2PPh2), HTa(CO)3Pm (Pm = P3: PhP(CH2CH2PPh2)2, P4: 2, PP3: P(CH2CH2PPh2)3) have been obtained from the photo-chemically produced complexes m> by ion-exchange chromatography on silica gel.The anionic and neutral complexes have been characterized by IR and 31P and 1H NMR spectroscopy.The temperature-dependent 1H(hydride)-31P NMR coupling patterns are interpreted in terms os a hydride-capped octahedral structure with restricted migration of the H(-) ligand between the octahedral faces.
