Application of Crystalline Matrices for the Structural Determination of Organic Molecules.

While single-crystal X-ray diffraction (SC-XRD) is one of the most powerful structural determination techniques for organic molecules, the requirement of obtaining a suitable crystal for analysis limits its applicability, particularly for liquids and amorphous solids. The emergent use of porous crystalline matrices that can absorb organic compounds and stabilize them via host-guest interactions for observation via SC-XRD offers a way to overcome this hindrance. A topical and current discussion of SC-XRD in organic chemistry and the use of preformed matrices for the analysis of organic compounds, with a particular focus on the absolute structure determination of chiral molecules, is presented.

Toward Frameworks with Multiple Aligned and Interactive Fe(CO) Rotators: Syntheses and Structures of Diiron Complexes Linked by Two -Diaxial α,ω-Diphosphine Ligands ArP(CH)PAr.

Reactions of (η-benzylideneacetone)Fe(CO) and the α,ω-diphosphines ArP(CH)PAr afford the trigonal bipyramidal diiron tetraphosphorus complexes ,-(CO)Fe[ArP(CH)PAr]Fe(CO) (/Ar = 3/Ph , 4/Ph , 4/-tol ; 56-19%). Crystal structures establish essentially parallel P-Fe-P axes, iron-iron distances of 5.894(9)-5.

Iodosylbenzene Coordination Chemistry Relevant to Metal-Organic Framework Catalysis.

Hypervalent iodine compounds formally feature expanded valence shells at iodine. These reagents are broadly used in synthetic chemistry due to the ability to participate in well-defined oxidation-reduction processes and because the ligand-exchange chemistry intrinsic to the hypervalent center allows hypervalent iodine compounds to be applied to a broad array of oxidative substrate functionalization reactions. We recently developed methods to generate these compounds from O that are predicated on diverting reactive intermediates of aldehyde autoxidation toward the oxidation of aryl iodides.

In Operando Analysis of Diffusion in Porous Metal-Organic Framework Catalysts.

The potential to exert atomistic control over the structure of site-isolated catalyst sites, as well as the topology and chemical environment of interstitial pore spaces, has inspired efforts to apply porous metal-organic frameworks (MOFs) as catalysts for fine chemical synthesis. In analogy to enzyme-catalyzed reactions, MOF catalysts have been proposed as platforms in which substrate confinement could be used to achieve chemo- and stereoselectivities that are orthogonal to solution-phase catalysts. In order to leverage the tunable pore topology of MOFs to impact catalyst selectivity, catalysis must proceed at interstitial catalyst sites, rather than at solvent-exposed interfacial sites.

cis-Decalin oxidation as a stereochemical probe of in-MOF versus on-MOF catalysis.

Development of catalyst-controlled C-H hydroxylation could provide direct access to valuable synthetic targets, such as primary metabolites. Here, we report a new family of porous materials, comprised of 2-dimensional metalloporphyrin layers and flexible aliphatic linkers, and demonstrate C-H hydroxylation activity. We demonstrate that the stereochemistry of cis-decalin oxidation provides a useful tool for differentiating catalysis in from catalysis on porous materials, which is critical to leveraging the potential of porous materials for catalyst-controlled oxidation chemistry.