Solid State and Solution Structures of Lanthanide Nitrate Complexes of Tris-(1-napthylphosphine oxide).

Coordination complexes of lanthanide metals with tris-1-naphthylphosphine oxide (NapPO, L) have not been previously reported in the literature. We describe here the formation of lanthanide(III) nitrate complexes Ln(NO)L (Ln = Eu to Lu) and the structures of [Ln(NO)L]·2L (Ln = Eu, Dy, Ho, Er) and L. The core structure of the complexes is an eight-coordinate [Ln(NO)L] with the third and fourth ligands H-bonded via their oxygen atoms to one of the naphthyl rings.

Stellated cuboctahedron of Fe.

The solvothermal reaction of FeCl ⋅ 4HO and HTBC[4] in a basic dmf/EtOH solution affords an [Fe ] Keplerate conforming to a stellated cuboctahedron. Magnetic and heat capacity measurements reveal spin frustration effects arising from the high symmetry. A crossover between inverse and direct magnetocaloric effects is observed at ~10 K for applied-field changes lower than 3 T.

Halogen bonding with carbon: directional assembly of non-derivatised aromatic carbon systems into robust supramolecular ladder architectures.

Carbon, although the central element in organic chemistry, has been traditionally neglected as a target for directional supramolecular interactions. The design of supramolecular structures involving carbon-rich molecules, such as arene hydrocarbons, has been limited almost exclusively to non-directional π-stacking, or derivatisation with heteroatoms to introduce molecular assembly recognition sites. As a result, the predictable assembly of non-derivatised, carbon-only π-systems using directional non-covalent interactions remains an unsolved fundamental challenge of solid-state supramolecular chemistry.

Influence of Fluorinated Substituents on the Near-Infrared Phosphorescence of 5d Metallocorroles.

The influence of fluorinated substituents on the luminescent properties of rhenium-oxo, osmium-nitrido, and gold triarylcorroles was studied via a comparison of four ligands: triphenylcorrole (TPC), tris(-trifluoromethylphenyl)corrole (TCFPC), tris{3,5-bis(trifluoromethyl)phenyl}corrole (T3,5-CFPC), and tris(pentafluorophenyl)corrole (TPFPC). For each metal series examined, fluorinated substituents were found to enhance the luminescent properties, with the phosphorescence quantum yields and triplet decay times increasing in the order TPC < TCFPC < T3,5-CFPC < TPFPC. Among the 11 complexes examined, the highest phosphorescence quantum yield, 2.

Facile synthetic routes to bridge-functionalised calix[4]arenes.

Ring-opening of furans at the equatorial methylene bridge positions of a calix[4]arene gives access to a range of new molecules (in good yield) that have widespread potential impact in supramolecular chemistry amongst other areas.

Rhenium Corrole Dimers: Electrochemical Insights into the Nature of the Metal-Metal Quadruple Bond.

The interaction of free-base triarylcorroles with Re(CO) in 1,2-dichlorobenzene in the presence of 2,6-lutidine at 180 °C under strict anerobic conditions afforded approximately 10% yields of rhenium corrole dimers. The compounds exhibited diamagnetic H NMR spectra consistent with a metal-metal quadruple bond with a σπδ orbital occupancy. One of the compounds proved amenable to single-crystal X-ray structure determination, yielding a metal-metal distance of ∼2.

Purification of Propylene and Ethylene by a Robust Metal-Organic Framework Mediated by Host-Guest Interactions.

Industrial purification of propylene and ethylene requires cryogenic distillation and selective hydrogenation over palladium catalysts to remove propane, ethane and/or trace amounts of acetylene. Here, we report the excellent separation of equimolar mixtures of propylene/propane and ethylene/ethane, and of a 1/100 mixture of acetylene/ethylene by a highly robust microporous material, MFM-520, under dynamic conditions. In situ synchrotron single crystal X-ray diffraction, inelastic neutron scattering and analysis of adsorption thermodynamic parameters reveal that a series of synergistic host-guest interactions involving hydrogen bonding and π⋅⋅⋅π stacking interactions underpin the cooperative binding of alkenes within the pore.

High Ammonia Adsorption in MFM-300 Materials: Dynamics and Charge Transfer in Host-Guest Binding.

Ammonia (NH) is a promising energy resource owing to its high hydrogen density. However, its widespread application is restricted by the lack of efficient and corrosion-resistant storage materials. Here, we report high NH adsorption in a series of robust metal-organic framework (MOF) materials, MFM-300(M) (M = Fe, V, Cr, In).

Synthesis and molecular structure of perhalogenated rhenium-oxo corroles.

As part of our efforts to develop rhenium-oxo corroles as photosensitizers for oxygen sensing and photodynamic therapy, we investigated the potential β-perhalogenation of five ReO meso-tris(para-X-phenyl)corroles, Re[TpXPC](O) (X = CF, H, F, CH, and OCH), with elemental chlorine and bromine. With Cl, β-octachlorinated products Re[ClTpXPC](O) were rapidly obtained for X = CF, H, and CH, but X = OCH resulted in overchlorination on the meso-aryl groups. Full β-octabromination proved slower relative to Cu and Ir corroles, but the desired Re[BrTpXPC](O) products were finally obtained for X = H and F after a week at room temperature.

Guest-Controlled Incommensurate Modulation in a Meta-Rigid Metal-Organic Framework Material.

Structural transitions of host systems in response to guest binding dominate many chemical processes. We report an unprecedented type of structural flexibility within a meta-rigid material, MFM-520, which exhibits a reversible periodic-to-aperiodic structural transition resulting from a drastic distortion of a [ZnON] node controlled by the specific host-guest interactions. The aperiodic crystal structure of MFM-520 has no three-dimensional (3D) lattice periodicity but shows translational symmetry in higher-dimensional (3 + 2)D space.

Iridium Corroles Exhibit Weak Near-Infrared Phosphorescence but Efficiently Sensitize Singlet Oxygen Formation.

Six-coordinate iridium(III) triarylcorrole derivatives, Ir[TpXPC)]L, where TpXPC = tris(para-X-phenyl)corrole (X = CF, H, Me, and OCH) and L = pyridine (py), trimethylamine (tma), isoquinoline (isoq), 4-dimethylaminopyridine (dmap), and 4-picolinic acid (4pa), have been examined, with a view to identifying axial ligands most conducive to near-infrared phosphorescence. Disappointingly, the phosphorescence quantum yield invariably turned out to be very low, about 0.02 - 0.

Capture of nitrogen dioxide and conversion to nitric acid in a porous metal-organic framework.

Air pollution by nitrogen oxides, NO, is a major problem, and new capture and abatement technologies are urgently required. Here, we report a metal-organic framework (Manchester Framework Material 520 (MFM-520)) that can efficiently confine dimers of NO, which results in a high adsorption capacity of 4.2 mmol g (298 K, 0.

Reversible coordinative binding and separation of sulfur dioxide in a robust metal-organic framework with open copper sites.

Emissions of SO from flue gas and marine transport have detrimental impacts on the environment and human health, but SO is also an important industrial feedstock if it can be recovered, stored and transported efficiently. Here we report the exceptional adsorption and separation of SO in a porous material, [Cu(L)] (HL = 4',4‴-(pyridine-3,5-diyl)bis([1,1'-biphenyl]-3,5-dicarboxylic acid)), MFM-170. MFM-170 exhibits fully reversible SO uptake of 17.

C pNMR of "crumple zone" Cu(II) isophthalate metal-organic frameworks.

NMR spectroscopy of paramagnetic materials (pNMR) has the potential to provide great structural insight, but many challenges remain in interpreting the spectra in detail. This work presents a study of a series of structurally analogous metal-organic frameworks (MOFs) based on 5-substituted isophthalate linkers and Cu(II) paddlewheel dimers, of interest owing to their "crumple zone" structural rearrangement on dehydration/rehydration. C MAS NMR spectra reveal a wide variation in the observed resonance position for chemically similar C species in the different MOFs but, despite this, resonances are overlapped in several cases.