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Homogenous iridium complexes with asymmetric ligands and different tether lengths have been solid‐supported and prepared in multi‐gram quantities. Packed in a fixed‐bed, they have been used in continuous flow for up to 120 hours in the asymmetric transfer hydrogenation of APs in 2‐propanol to make 1‐phenethyl alcohols in > 95 % conversion and ee. The CsDPEN ligand and C5 tether showed higher performance than TsDPEN and the C14 tether, whilst the ketone feed concentration and reaction temperature were optimized to enable the catalyst to be used at 5 mol‐% loading with a residence time of 39 minutes. The total amount iridium leaching of from the support during sustained operation was 58–147 ppm. The flow system gives higher catalyst turnover numbers than the related batch reactions, but the nature and concentration of the base were found to influence strongly the catalyst's performance, with the finding that triethylamine maintains high enantioselectivity but slowly deactivates the catalyst, whilst potassium tert‐butoxide does the opposite. The utility of the system is shown in the high ee's and good conversions achieved for a range of aryl alcohols.

Characterisation of anodic aluminium oxide coatings and measurement of their thickness using microscopic techniques is valuable for analysing the effectiveness of the prior anodising process. Three different methods for preparing samples to view the coating cross-section (mechanical fracturing, cryogenic fracturing and metallography) were trialled and assessed for speed of implementation, simplicity and achievable measurement accuracy. Cryogenic fracturing was found to be destructive to samples. Mechanical fracturing yielded relatively accurate coating thickness measurements and coating structural information. Metallography provided the most accurate coating thickness measurement at the expense of coating structural information.

Crystallization in solutions under steady cooling is considered in the case of progressive nucleation, in which new crystallites are continuously nucleated among the already growing ones. Expressions are obtained for the total volume and number of crystallites as functions of the steadily increasing undercooling. These expressions are employed for determining the dependence of the relative critical undercooling u c for crystallization on the cooling rate q . The resulting u c ( q ) formula reveals that in the case of crystallization by progressive nucleation, the often used semi-empirical Nyvlt equation is an approximation which contains only the linear terms in the relationship between ln u c and ln q . The results obtained are also directly applicable to overall crystallization of melts at sufficiently small undercoolings.

A new insight for quantitative determination of the complex interaction of kinetics of reactive crystallization is gained by a study of the acidification of monosodium glutamate with hydrochloric acid in a semi-batch reactor. The dynamic equilibrium of the l-glutamic acid ions, their simultaneous presence in the solution, and the effect on the crystal size and size distribution are simulated using a mathematical model based on integration of the population balance equation with the crystallization kinetics and thermodynamics of the process. The model includes equations of chemical reactions, pH, nucleation, size-independent growth, and population balance. This allows a precise determination of the driving force for the reactive crystallization and the parameters of the nucleation and crystal growth rate expressions. The model considers the effect of the controlling parameters such as the rate of addition of the acid and the initial concentrations of ionic species and can be used to predict the concentrati...

In-process ATR FTIR spectroscopy is used to measure concentration and supersaturation in drowning-out of benzophenone from methanol/water solution and to study the effect of the rate of the aqueous antisolvent addition. A selected peak ratio in terms of IR transmittance or absorbance is monitored on-line and used to develop calibration equations for the concentration of the solute in the mixed solvent as a function of the ratio and the quantity of the antisolvent added. The benzophenone solubility in the mixed methanol/water solvent is found to be a nonlinear function of the respective solubilities of the solvents accounting not only for the dilution effect, but also for the binding of solvent molecules by the antisolvent molecules.

Closed-loop computer control of solution supersaturation based on in-process measurements of the concentration using ATR-FTIR spectroscopy and adaptive determination of the corresponding temperature profile has been applied to control the crystallization of monosodium glutamate from an aqueous solution. The crystal size and its distribution are varied and optimized by applying different control strategies such as rapid desupersaturation, constant supersaturation, and step-changing supersaturation profiles.