Controlled Expansion of a Strong-Field Iron Nitride Cluster: Multi-Site Ligand Substitution as a Strategy for Activating Interstitial Nitride Nucleophilicity.

Multimetallic clusters have long been investigated as molecular surrogates for reactive sites on metal surfaces. In the case of the μ -nitrido cluster [Fe (μ -N)(CO) ] , this analogy is limited owing to the electron-withdrawing effect of carbonyl ligands on the iron nitride core. Described here is the synthesis and reactivity of [Fe (μ -N)(CO) (CNAr ) ] , an electron-rich analogue of [Fe (μ -N)(CO) ] , where the interstitial nitride displays significant nucleophilicity.

A Metal-Organic Framework with Exceptional Activity for C-H Bond Amination.

The development of catalysts capable of fast, robust C-H bond amination under mild conditions is an unrealized goal despite substantial progress in the field of C-H activation in recent years. A Mn-based metal-organic framework (CPF-5) is described that promotes the direct amination of C-H bonds with exceptional activity. CPF-5 is capable of functionalizing C-H bonds in an intermolecular fashion with unrivaled catalytic stability producing >10 turnovers.

Crystalline Coordination Networks of Zero-Valent Metal Centers: Formation of a 3-Dimensional Ni(0) Framework with m-Terphenyl Diisocyanides.

A permanently porous, three-dimensional metal-organic material formed from zero-valent metal nodes is presented. Combination of ditopic m-terphenyl diisocyanide, [CNAr], and the d Ni(0) precursor Ni(COD), produces a porous metal-organic material featuring tetrahedral [Ni(CNAr)] structural sites. X-ray absorption spectroscopy provides firm evidence for the presence of Ni(0) centers, whereas gas-sorption and thermogravimetric analysis reveal the characteristics of a robust network with a microdomain N-adsorption profile.

Comparison of nucleophilic- and radical-based routes to the formation of manganese-main group element single bonds.

Using the stable metalloradical Mn(CO)(CNAr), we report the formation of manganese-main group complexes via the single-electron functionalization of main group halides. The reactions occur in a simple 1 : 1 stoichiometry, and demonstrate the utility of using stable open-shelled organometallics as precursors for metal-main group compounds. This has enabled the preparation of manganese complexes bearing terminal -EX substituents, as shown through the isolation of Mn(SnCl)(CO)(CNAr) and Mn(BiCl)(CO)(CNAr) from SnCl and BiCl, respectively.

Electrochemical Properties and CO-Reduction Ability of m-Terphenyl Isocyanide Supported Manganese Tricarbonyl Complexes.

To circumvent complications with redox-active ligands commonly encountered in the study of manganese electrocatalysts for CO reduction, we have studied the electrochemistry of the manganese mixed carbonyl/isocyanide complexes XMn(CO)(CNAr) (X = counteranion), to evaluate the pairing effects of the counteranion and their influence over the potential necessary for metal-based reduction. The complexes described herein have been shown to act as functional analogues to the known homoleptic carbonyl manganese complexes [Mn(CO)] (n = 1-, 0, 1+). The m-terphenyl isocyanide ligand CNAr improves the kinetic stability of the resulting mixed carbonyl/isocyanide systems, such that conversion among all three oxidation states is easily effected by chemical reagents.

Robust, Transformable, and Crystalline Single-Node Organometallic Networks Constructed from Ditopic m-Terphenyl Isocyanides.

The preparation of 3D and 2D Cu(I) coordination networks using ditopic m-terphenyl isocyanides is described. The incorporation of sterically encumbering substituents enables the controlled, solid-state preparation of Cu(I) tris-isocyanide nodes with a labile solvent ligand in a manner mirroring solution-phase chemistry of monomeric complexes. The protection afforded by the m-terphenyl groups is also shown to engender significant stability towards heat as well as acidic or basic conditions, resulting in robust single-metal-node networks that can transition from 3D to 2D extended structures.

Kinetic Destabilization of Metal-Metal Single Bonds: Isolation of a Pentacoordinate Manganese(0) Monoradical.

The 17e(-) monoradical [Mn(CO)5 ] is widely recognized as an unstable organometallic transient and is known to dimerize rapidly with the formation of a MnMn single bond. As a result of this instability, isolable analogues of [Mn(CO)5 ] have remained elusive. Herein, we show that two sterically encumbering isocyanide ligands can destabilize the MnMn bond leading to the formation of the isolable, manganese(0) monoradical [Mn(CO)3 (CNAr(Dipp2) )2 ] (Ar(Dipp2) =2,6-(2,6-(iPr)2 C6 H3 )2 C6 H3 ).