Exploiting in situ NMR to monitor the formation of a metal–organic framework

The formation processes of metal–organic frameworks are becoming more widely researched using in situ techniques, although there remains a scarcity of NMR studies in this field. In this work, the synthesis of framework MFM-500(Ni) has been investigated using an in situ NMR strategy that provides information on the time-evolution of the reaction and crystallization process. In our in situ NMR study of MFM-500(Ni) formation, liquid-phase ¹H NMR data recorded as a function of time at fixed temperatures (between 60 and 100 °C) afford qualitative information on the solution-phase processes and quantitative information on the kinetics of crystallization, allowing the activation energies for nucleation (61.4 ± 9.7 kJ mol⁻¹) and growth (72.9 ± 8.6 kJ mol⁻¹) to be determined. Ex situ small-angle X-ray scattering studies (at 80 °C) provide complementary nanoscale information on the rapid self-assembly prior to MOF crystallization and in situ powder X-ray diffraction confirms that the only crystalline phase present during the reaction (at 90 °C) is phase-pure MFM-500(Ni). This work demonstrates that in situ NMR experiments can shed new light on MOF synthesis, opening up the technique to provide better understanding of how MOFs are formed.

A new in situ NMR methodology for studying the formation processes of MOFs is reported, supported by SAXS and PXRD experiments. Synthesis of a phosphonate-based MOF is described, from molecular aggregation through to nucleation and crystallisation.     

Purification of a hybrid plasminogen activator protein

Recombinant DNA technology has been employed to produce a hybrid gene in which the kringle and serine protease domains of tissue plasminogen activator are linked to the heavy-chain Fd region of a fibrin-specific antibody. The hybrid gene is co-expressed with antibody light chains. This communication describes a purification procedure for the hybrid protein, involving affinity and ion-exchange chromatography. The purified hybrid protein has been used in vivo and in vitro clot lysis experiments and has been shown to be effective at clot dissolution.     

Coupled cavity modelocking of a Nd:YAG laser using second-harmonic generation

The modelocking of a Nd:YAG laser using second-harmonic generation in an external cavity as the only pulse shortening process is reported. The output of a long pulse Nd:YAG laser was simultaneously modelocked and Q-switched. The average pulse duration was 30–50 ps and the peak power was in the range 60–160 kW.     

Forecasting practice: organisational issues

Although many surveys have been conducted on forecasting practice, the majority of surveys have investigated the utilisation of forecasting methods and relatively few have studied the role of forecasting in changing organisational structures. The aim of this paper is to address this issue by expanding on earlier case studies which suggested the need for a re-location of the forecasting function within the organisation. Current research has shown how the role of forecasting has changed as organisations adapt to meet the business needs of their customers. The evidence reported in this paper was gathered by surveys and structured interviews carried out in the electronics and financial industries in Scotland.     

1H‐Pyrrole‐2‐carbothioamide

The reaction of ethoxy­carbonyl­pyrrole‐2‐thio­carbox­amide with sodium hydro­xide affords the known title compound, C₅H₆N₂S, whose structure shows a three‐dimensional hydrogen‐bonded lattice.     

μ‐Oxo‐bis[(η5‐1,2‐dicarbaundecabor­ato)bis(N,N‐dimethylacetamidinato)tantalum] dichloromethane hemisolvate

The structure of the title compound, [Ta₂O(C₂B₉H₁₁)₂(C₄H₉­N₂)₄]·0.5CH₂Cl₂, contains two (C₂B₉H₁₁)Ta[NC(Me)NMe₂]₂ units bridged by a nearly linear [Ta—O—Ta 163.4 (4)°] μ‐oxo ligand. The dichloromethane molecule lies on a twofold axis.