Chem. Commun.: synthesis of new fluoroalkanes by coordination chemistry

Catenanes are important classes of mechanically interlocked molecules (MIMS) Catenane comes from the Latin catena (chain), which means a molecule consisting of a linked ring The alkanes contain many tiny and interlocking atomic rings, but each ring is not connected by any valence bond force The simplest example is [2] catenane, where the number in brackets represents the number of links Some specific components can be controlled by photochemistry or electrochemistry The ring in the alkane can rotate freely If there is motion, there will be one or more thermodynamic stable points If it can be controlled by the outside world, it can form a molecular switch In 1983, Sauvage and his colleagues first disclosed the first synthesis guidance template of [2] alkanes, which is based on a specially designed o-phenanthroline ligand surrounding copper (I) ions Since then, there have been a large number of highly efficient synthetic methods for soxhydrocarbons Ring closing synthesis (RCM) is a reliable and efficient reaction because of its mild reaction conditions and wide adaptability of catalyst Therefore, RCM has been frequently used as a shear method in many synthesis of ligands Although several well-known heteroaromatic ligands have been used in transition metal directed synthesis of MIMS, new ligands need to be found if we want to build alkanes and rotaxanes with unprecedented photophysical, photochemical and electrochemical properties Dipy-mc and M-CAT (source: chem Commun.) were synthesized by a team from Turkey First, the dual RCM reaction was carried out with ml 2 type complex to obtain bis (cyano) copper (II) and bis (cyano) zinc (II) [2] soxane Then KCN / N 2H 4 · H 2O was used to separate copper (II), and the corresponding boron difluoride complex was obtained, which is the first fluorescent f-bodipy [2] alkane Synthesis of CN cat and BOD cat (source: chem Commun.) in order to find new available ligands, the research team focused on the metal complexes of pyrimidine (Dipyrrole) and bis (dipyridine) for the synthesis of transition metal template alkanes For dipyrimidine, it has long been used to obtain ml 2 and ml 3 transition metal complexes with charge neutrality, stability and abundant ligands, which can coordinate with metal ions such as Zn (II), Cu (II), CO (Ⅲ), Fe (Ⅱ), Fe (Ⅲ), Cr (Ⅱ), Cr (Ⅲ), Ni (II) and Pd (II) Recently, several fluorescent bis (dipyridine) complexes have been synthesized The research team hopes to develop a new type of [2] alkanes with fluorescence characteristics First, the main module DIPY needs to be synthesized, and then the corresponding large ring dipy-mc is formed by RCM method at room temperature Then, the enantiomeric Znl2 and cul2 complexes were synthesized The methanol solution of M (OAC) 2 (M: Zn (II) or Cu (II)) was added to the 2-fold equivalent DIPY dichloromethane solution, and the reaction took place in nitrogen protection at room temperature for one day After purification, the stable metal complexes Znl2 and cul2 were obtained, the yield was 90% and 85%, respectively Finally, the fluorescent f-bodipy [2] alkanes were obtained by a series of demetallization and functional group modification The team then used X-ray, 1H-NMR and UV to study the geometry, chemical shift and fluorescence characteristics of the compounds The 1H-NMR spectra of DIPY, Znl2, Zn cat, DIPY cat and BOD cat (source: chem Commun.) in short, the research team proved that bis (dipyridine) metal complexes can be used for MIMS metal ion template synthesis This study can be regarded as a starting point for the construction of MIMS with unprecedented fluorescence properties, such as alkanes and cycloalkanes, using bipyrimidine chemistry Considering the diversity of pyrimidine derivatives, it is obvious that the future of fluorescent MIMS is bright The work of the research team is continuing Paper link: http://pubs.rsc.org/en/content/article landing/2017/cc/c7cc07021g ා! Divabstract