Microporous porphyrin solids

Three-dimensional porous metal-metalloporphyrin framework consisting of nanoscopic polyhedral cages

An unprecedented nanoscopic polyhedral cage-containing metal-metalloporphyrin framework, MMPF-1, has been constructed from a custom-designed porphyrin ligand, 5,15-bis(3,5-dicarboxyphenyl)porphine, that links Cu(2)(carboxylate)(4) moieties. A high density of 16 open copper sites confined within a nanoscopic polyhedral cage has been achieved, and the packing of the porphyrin cages via an "ABAB" pattern affords MMPF-1 ultramicropores which render it selective toward adsorption of H(2) and O(2) over N(2), and CO(2) over CH(4).

Functional mixed metal-organic frameworks with metalloligands

Immobilization of functional sites within metal-organic frameworks (MOFs) is very important for their ability to recognize small molecules and thus for their functional properties. The metalloligand approach has enabled us to rationally immobilize a variety of different functional sites such as open metal sites, catalytic active metal sites, photoactive metal sites, chiral pore environments, and pores of tunable sizes and curvatures into mixed metal-organic frameworks (M'MOFs). In this Minireview, we highlight some important functional M'MOFs with metalloligands for gas storage and separation, enantioselective separation, heterogeneous asymmetric catalysis, sensing, and as photoactive and nanoscale drug delivery and biomedical imaging materials.

Post-synthesis modification of a metal-organic framework to form metallosalen-containing MOF materials

A series of metallosalen-based metal-organic frameworks (MOFs) have been prepared by the post-synthesis modification of Mn(III)SO-MOF, a Mn(3+)(salen)-based MOF. Treatment of Mn(III)SO-MOF with H(2)O(2) effects the removal of the Mn(3+) ions from the salen struts, which can then be remetalated with a variety of metal precursors to form isostructural MSO-MOF materials. The presence of the new metallosalen struts in MSO-MOF was fully confirmed by ICP-OES, MALDI-TOF MS, PXRD, and TGA. Furthermore, the remetalated Mn(II)SO-MOF material displays similar catalytic activity and porosity to the parent MOF.

Multireference and multiconfiguration ab initio methods in heme-related systems: what have we learned so far?

This work reviews the recent applications of ab initio multireference/multiconfiguration (MR/MC) electronic structure methods to heme-related systems, involving tetra-, penta-, and hexa-coordinate species, as well as the high-valent iron-oxo species. The current accuracy of these methods in the various systems is discussed, with special attention to potential sources of systematic errors. Thus, the review summarizes and tries to rationalize the key elements of MR/MC calculations, namely, the choice of the employed active space, especially the so-called double-shell effect that has already been recognized to be important in transition-metal-containing systems, and the impact of these elements on the spin-state energetics of heme species, as well as on the bonding mechanism of small molecules to the heme. It is shown that expansion of the MC wave function into one based on localized orbitals provides a compact and insightful view on some otherwise complex electronic structures. The effects of protein environment on the MR/MC results are summarized for the few available quantum mechanical/molecular mechanical (QM/MM) studies. Comparisons with corresponding DFT results are also made wherever available. Potential future directions are proposed.

A vanadium porphyrin with temperature-dependent phase transformation: synthesis, crystal structures, supramolecular motifs and properties

A vanadium porphyrin, V(O)TMeOPP (1; TMeOPP=5, 10, 15, 20-tetrakis(4-methoxyphenyl)-21 H, 23H-porphyrin), has been synthesized by solvothermal reactions and characterized by single-crystal X-ray diffractions at room temperature and low temperature to reveal two different structures 1R and 1L, respectively. Both 1R and 1L crystallized in the orthorhombic system, but their space groups were different: Pbca and Pca2(1) for 1R and 1L, respectively. The cell parameters of a, b, and c were different and the cell volume of 1R was larger than that of 1L by circa 200 Å(3). 1R and 1L were characteristic of an isolated motif with a five-coordinate vanadium(IV) ion and a saddle-distorted nonplanar porphyrin macrocycle. Molecules of 1R were interconnected through hydrogen-bonding interactions to yield a 3D framework; whilst for the low-temperature phase 1L, there were more hydrogen-bonding interactions that link the molecules to construct a more-complex 3D supramolecular network. In a solution of acetone, the title compound exhibited purple and green colors at room temperature and low temperature, respectively, which is unprecedented for vanadium porphyrins. The spectral data of UV/Vis, FT-IR, and MALDI-TOF-MS of 1R and 1L are reported together with the electrochemical data.

A metalloporphyrin functionalized metal–organic framework for selective oxidization of styrene

A functional metal–organic framework assembled from palladium-porphyrin struts and cadmium(ii) nodes presents interesting topological network structure, high stability and significant catalytic activity.

[meso-Tetra-kis(4-heptyl-oxyphen-yl)porphyrinato]nickel(II)

In the title compound, [Ni(C(72)H(84)N(4)O(4))], the four-coordinate Ni(II) ion in the middle of the planar 24-membered porphyrin ring is located on a crystallograpic inversion center, with Ni-N distances of 1.946 (2)-1.951 (2) Å. The 4-heptyl-oxyphenyl groups are twisted with respect to the porphyrin mean plane, the dihedral angles being 88.5 (3) and 79.1 (2)°.