Half-Sandwich Rh Coordination Complexes:Preparation And Structure Transformation

Supramolecular coordination complexes are discrete compounds with structures similar to classical metal-organic frameworks?MOFs?.In the past few decades,various two-dimensional?2D?and three-dimensional?3D?supramolecular coordination complexes with different shapes and sizes have been reported successively.The half-sandwich organometallic complexes Cp*M?Cp*=pentamethylcyclopentrene,M=iridium/rhodium?and?p-cymene?Ru are ideal discrete supramolecular building units with advantages of easy preparation,easy crystallization,good solubility and good coordination stability,which can be used to construct rings,cages and complex supramolecular compounds.On the basis of previous research work,this paper designed and synthesized metal precursors containing half-sandwich Cp*Rh units,and coordinated with different types of organic ligands to construct cyclic metalla[3]catenane and irregular polynuclear metallic cyclic compounds,and their topological structure and the transformation between structures were studied.The details are as follows:1.Cyclic metalla[3]catenane complexes were selectively prepared by one-pot self-assembly of organic ligands containing pyridine groups?4,4?-azopyridine or 1,2-bis?4-pyridyl?ethylene?and the dinuclear rhodium precursor composed of a 1,6,7,12-tetrachloro-3,4,9,10-perylene diimide group.In addition,by using the special arrangement of oxygen atoms on the perylene diimide groups in the molecule to achieve the capture and release of sodium ions.2.Taking[Cp*Rh Cl₂]₂ as the basic building block,dodeca-nuclear and nona-nuclear rhodium?III?cyclic compounds were synthesized by two-step reactions with a polydentate rigid ligand containing both carboxyl groups and a tetrazolyl group under different conditions.Interestingly,X-ray single crystal diffraction study shows that there are many coordination modes between ligands and metal centers in cyclic complex,and there are also?????interactions between different molecules.