The reversibility of supramolecular systems is a key feature for applications such as sensing, drug delivery and catalysis. The rate constants for the association and dissociation of host-guest complexes are determined in real-time kinetic studies. The residence time of a guest in a complex has direct implications on the development of functional supramolecular systems. Studies with simple macrocycles and a capsule will be described which show that the residence time of a guest can be varied by a factor of 20 million. Cyclodextrin have very fast guest binding dynamics on the nanosecond to microsecond time domain. The guest residence time in cucurbit[n]urils is lengthened because of ion-dipole interactions between the guest and this host and it can be shortened for some type of guests with the addition of metals cations. Finally, in the case of an octa-acid cavitand which forms dimeric capsules the access of small molecules to a guest in the capsule was shown to be 100,000 times faster than the release of the guest from the capsule.

超分子錯体形成の可逆性がセンサー、医薬送達、触媒反応に用いる際の鍵となる。シクロデキストリンからキャビタンド、キューカービチュリルに至る幅広いホスト系における錯形成・解離のダイナミックスに関する最新の成果について講演していただく予定です。

In 1912 Giacomo Ciamician, a pioneer in synthetic photochemistry, presented his spectacular vision of the 'Photochemistry of the Future' (Science 1912, 36, 385). 100 years have passed and organic photochemistry is still widely neglected by the chemical industry. Recently, microflow chemistry has emerged as a new synthesis tool. The combination of microspace and flow mode is especially advantageous for photochemical transformations. The thin reaction channels guarantee extensive transmission of light throughout the reaction mixture even at high chromophore concentrations. In addition, the continuous flow mode allows for an accurate control of the irradiation time and furthermore minimizes secondary photoreactions. Over the last years we have studied a series of homogeneous and heterogeneous photoreactions to evaluate the potential of microflow photochemistry. In all cases examined, the reactions performed under microflow conditions gave higher conversions or yields thus proving the superiority of the microphotochemistry concept. We have also designed and tested new microreactor setups, among them a novel 10-microcapillary twin-tower for parallel microflow photochemistry.

工業的利用も視野に入れたマイクロフロー・リアクターを用いる光化学反応の最新の成果について講演していただく予定です。

大阪大学・ｱｰﾍﾝ工科大学　日独共同大学院プログラムのアーヘン側のコーディネーターのOkuda 教授（数理情報自然科学研究科）はオレフィン重合やメタンなど小分子の活性化で活躍されておられる研究者です。今回の来日を機会に講演をお願いしました。

本講演の前（13:30～15:00）には同じくｱｰﾍﾝ工科大学のAlbrecht Salzer 教授による講演（The Agostic Bond in Synthesis and Catalysis）もありますので、併せてご聴講ください。 皆様のご来聴を歓迎いたします。