Related Experiment Video
Updated: Jun 2, 2026

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Loops, chains, sheets, and networks from variable coordination of Cu(hfac)2 with a flexibly hinged aminoxyl radical
Martha Baskett1, Armando Paduan-Filho, Nei Fernandes Oliveira
1Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Abstract:
One pair of reactants, Cu(hfac)(2) = M and the hinge-flexible radical ligand 5-(3-N-tert-butyl-N-aminoxylphenyl)pyrimidine (3PPN = L), yields a diverse set of five coordination complexes: a cyclic loop M(2)L(2) dimer; a 1:1 cocrystal between an M(2)L(2) loop and an ML(2) fragment; a 1D chain of M(2)L(2) loops linked by M; two 2D M(3)L(2) networks of (M-L)(n) chains cross-linked by M with different repeat length pitches; a 3D M(3)L(2) network of M(2)L(2) loops cross-linking (M-L)(n)-type chains with connectivity different from those in the 2D networks. Most of the higher dimensional complexes exhibit reversible, temperature-dependent spin-state conversion of high-temperature paramagnetic states to lower magnetic moment states having antiferromagnetic exchange within Cu-ON bonds upon cooling, with accompanying bond contraction. The 3D complex also exhibited antiferromagnetic exchange between Cu(II) ions linked in chains through pyrimidine rings.
Related Concept Videos
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Coordination Compounds and Nomenclature
Coordination Number and Geometry
Radical Formation: Homolysis
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Valence Bond Theory
