Photoreactors falling film

The first reported synthesis (9,76) (78%) of Cp2V2(CO)5 (7) involved protonation of the dianion [CpV(CO)3]2- made by sodium amalgam reduction of CpV(CO)4. No vanadium hydride is isolated in this reaction. A slightly better yield (89%) results from the photolysis of CpV(CO)4 in THF using a falling-film photoreactor (77). The product 7 is produced via dimerization of an intermediate solvent complex CpV(CO)3(THF) followed by a further carbonyl loss (35). The corresponding Cp complex 7 is also available by an exactly analogous photolysis of Cp V(CO)4 or by protonation of [Cp V(CO)3]2- (JO). 

A falling-film photoreactor is carefully purged with purified nitrogen for 1 h, and charged with 27 g (0.15 mol) of recrystallized benzophenone. The reactor is cooled to -18 °C by a... 

Puma, G. L., and Yue, P. L., 1999b, Comparison of the effectiveness of photon-based oxidation processes in a pilot falling film photoreactor. Environ. Sci. Tech., 33(18) 3210-3216. 

The ligand properties of 1 were investigated utilizing complex formation with W(CO)sTHF generated from the tungsten hexacarbonyl W(CO)6 (Scheme 4) in a falling-film photoreactor. The crude product is a pale yellow and microcrystalline material, soluble in CDCI3. Crystals suitable for X-ray structural studies have not been obtained so far. 

The contact-free photoreactors include the vertical falling film design (Fig. 8-5), the inchned flat bed system (Fig. 8-6) and the batch photoreactor (Figs. 8-7 and 8-8). These reactor configurations do not have a quartz/water interface (as in situations A, B, C, Fig. 8-3), so that the problems related to fouling and film formation are effectively circumvented. Such photoreactor types are even suited for the UV treatment of suspensions and cloudy wastewaters (cf Kim and Thomanetz, 1995). 

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