Photochemistry with laser radiation in condensed phase using miniaturized photoreactors

Abstract

SummaryMiniaturized microreactors enable photochemistry with laser irradiation in flow mode to convert azidobiphenyl into carbazole with high efficiency.

Photochemical Transformations Accelerated in Continuous‐Flow Reactors: Basic Concepts and Applications

“…Brase et al. have used laser irradiation for the photolysis of biphenyl azides to form carbazoles (Scheme ) 63. A peek microreactor was used in which four reaction chambers with different depth were housed.…”

“…Brase et al have used laser irradiation for the photolysis of biphenyl azides to form carbazoles (Scheme 8 A). [63] A peek microreactor was used in which four reaction chambers with different depth were housed. Irradiation of the reaction medium was achieved with frequency-tripled Nd:YAG laser (l = 355 nm, 8 kHz pulse frequency, pulse duration 26 ns), which matches the absorption area of azides.…”

Laser‐Mediated Photo‐High‐p,T Intensification of Vitamin D3 Synthesis in Continuous Flow

“…Photochemistry in miniaturized continuous photoreactors offers interesting features relating to the high surface/volume ratio, such as having uniform illumination conditions even at high concentration and safe processing of hazardous photo intermediates or end products without overheating. [20] Due to this unique features, the whole field of photo flow chemistry is largely emerging, yet only a few reports used a laser such as Matsushita et al [21] , Bremus-Koebberling et al [22] , and Fuse et al [23] In all these approaches, the laser is placed perpendicular to the capillary and not in line with it, simply because it needs a special alignment for the latter to avoid losses due to reflections. The small diameter of the laser beam and the respective small exposed area limits the residence time, which compromises the efficiency of the reaction.…”

A compact photomicroreactor design for kinetic studies of gas‐liquid photocatalytic transformations

“…This makes the scale‐up of batch reactors via a dimension enlarging approach very challenging. In addition, safety risks are associated with some photochemical processes carried out in batch reactors, such as aerobic oxidations, and reactions involving the use of toxic and hazardous materials, for example, diazonium salts and azides …”