A Caged Neutral 17-Valence-Electron Iron(I) Radical [Fe(CO)(Cl)(P((CH))P)]: Synthetic, Structural, Spectroscopic, Redox, and Computational Studies.

UV irradiation of yellow CHCl solutions of -Fe(CO)(P((CH))P) () and PMe (10 equiv) gives, in addition to the previously reported dibridgehead diphosphine P((CH))P (46%), a green paramagnetic complex that crystallography shows to be the trigonal-bipyramidal iron(I) radical -[Fe(CO)(Cl)(P((CH))P)] (; 31% after workup). This is a rare example of an isolable species of the formula [Fe(CO)(L)(X)] ( = 0-3, L = two-electron-donor ligand; X = one-electron-donor ligand). Analogous precursors with longer P(CH)P segments ( = 12, 14, 16, 18) give only the demetalated diphosphines, and a rationale is proposed.

A Co(III)-peroxo-arylboronate complex formed by nucleophilic reaction of a Co(III)-peroxo species.

In this work, we report the generation and characterization of two new Co(III)-peroxo complexes 2 and 3. 2 is best described as a mononuclear Co-(O) complex that exhibits an O-isotope sensitive OO bond stretching vibration at 845(-49) cm, indicating a relatively weak peroxo moiety compared to those of other Co-(O) complexes reported previously. Complex 3 is a Co-peroxo-arylboronate species having a rare {CoOOBO} five-membered metallocycle, which is structurally characterized using X-ray crystallography.

Direct Activation of the C(sp)-NH Bond of Primary Aliphatic Alkylamines by a High-Valent Co(μ-O) Diamond Core Complex.

Aliphatic alkylamines are abundant feedstock and versatile building blocks for many organic transformations. While remarkable progress has been made to construct C-N bonds on aliphatic and aromatic carbon centers, the activation and functionalization of C(sp)-NH bonds in primary alkylamines remain a challenging process. In the present work, we discovered an unprecedented method to directly activate the C(sp)-NH bond of primary alkylamines by a high-valent dinuclear Co(μ-O) diamond core complex.

Opening the Co(μ-O) Diamond Core by Lewis Bases Leads to Enhanced C-H Bond Cleaving Reactivity.

The high-valent diiron(IV) intermediate is the key oxidant that cleaves strong C-H bonds of methane in the catalytic cycle of soluble methane monooxygenase (sMMO). sMMO- was previously reported as a bis-μ-oxo Fe(μ-O) diamond core but was recently described to have an open core with a long Fe···Fe distance. We recently reported a high-valent Co(μ-O) diamond core complex () that is highly reactive with sp C-H bonds.

Highly Reactive Co(μ-O) Diamond Core Complex That Cleaves C-H Bonds.

The selective activation of strong sp C-H bonds at mild conditions is a key step in many biological and synthetic transformations and an unsolved challenge for synthetic chemists. In nature, soluble methane monooxygenase (sMMO) is one representative example of nonheme dinuclear iron-dependent enzymes that activate strong sp C-H bonds by a high-valent diiron(IV) intermediate . To date, synthetic model complexes of sMMO- have shown limited abilities to oxidize strong C-H bonds.