New 17 electron complexes of iron

Formation of organometallic hydroxo and oxo complexes by oxidation of transition metal hydrides in the presence of water. X-Ray structures of [CpMo(OH)(PMe3)3][BF4] and [CpMo(O)(PMe3)2][BF4]

“…These comprise (averaged Mo-O distances in parentheses) [Mo2(µ-OH)2(µ-O2CMe)(edta)] -(H4edta = ethylenediaminetetraacetic acid) [2.04(1) Å], 52 [Mo2L2Cl2(M-OH)2] 2+ [2.13(1) Å], 53 [Mo2L2(µ-O2CMe)(µ-OH)2] 3+ [2.08(1) Å], 53 and [Mo2L2Br2(µ-OH)(µ-Br)] 2+ (L = 1,4,7-triazacyclononane) [1.84(2) Å]. 5 The distance in 2 compares relatively well with some of those reported above. A compensation of different effects might be responsible for this similarity: compound 2 is electronically more saturated than the above edge-bridged bioctahedral examples (less oxygen π bonding is allowed), and the OH ligand in 2 experiences a stronger trans influence from the PMe3 ligand.…”

“…The first one involves the oxidation reaction itself. Reaction (5), a model of the oxidation process of 1, is strongly exothermic. Equalizing the calculated energy difference with the free energy change (both PV and entropy contributions are probably negligible), we arrive at a calculated reduction potential of 21.15 V for complex CpMoH(PH3)3 relative to the ferrocene standard.…”

“…The first one involves the oxidation reaction itself. Reaction (5), a model of the oxidation process of 1, is…”

Synthesis, Structure, and Protonation Studies of Cp*MH3(dppe) (M = Mo, W). Pseudo-Trigonal-Prismatic vs Pseudo-Octahedral Structures for Half-Sandwich Group 6 M(IV) Derivatives

“…The dichotomy between classical and nonclassical hydrides − and possible mechanisms of hydride fluxionality have been studied extensively. A few mononuclear transient 17-electron polyhydride species have been produced by either chemical or electrochemical oxidation of the saturated polyhydride precursors, − whereas a greater body of work has been carried out on monohydride systems. − The transient 17-electron species, [M−H] +• , usually decomposes by deprotonation, the outcome being determined by the basic properties of the solvent vs M−H as well as by the reactivity of the depronotated product M • . In particular, when the starting compound M−H captures the proton, the resulting [MH 2 ] + species may either remain as a stable (classical or nonclassical) hydride product or lead to the replacement of one or more H 2 molecules with as many molecules of a monodentate ligand (usually a coordinative solvent).…”

Paramagnetic organometallic ionic liquids exhibiting thermochromism based on monomer–dimer equilibrium of cationic half-sandwich complexes

“…The T values of 1-3 at 300 K were 0.35, 0.36, and 0.47 emu K mol −1 , respectively, and they decreased slightly with decreasing temperature. The magnetic moment of the paramagnetic monomer of iron-thiolate complexes is considered to be ~0.65 emu K mol −1 [9,12]. The value is similar to that of the ferrocenium cation and larger than the spin-only value (0.375 emu K mol −1 ) due to orbital contribution [13].…”