Assembly of zinc metallacrowns with an a-amino hydroxamic acid ligand

In the assembly of metallacrowns for molecular recognition,luminescence,and molecular magnetism[1;D$IF]applications,substituting the ring ion can have profound effects on the structure,stability,and physical properties of the inorganic macrocycle.The assembly of Zn（II） metallacrowns with an a-amino hydroxamic acid ligand（phe HA） was investigated to compare the assembly behavior with the well studied metallacrowns containing Cu（II） and Ni（II）.Electrospray ionization mass spectrometry reveals that the benchmark species Zn5（phe HA）42+and Ln Zn5（phe HA）53+assemble in pyridine,which is consistent with the behavior of Cu（II） and Ni（II）.A Ln Zn4（phe HA）43+species is also observed in a 1:1DMF-pyridine mixture.An unprecedented La（III）[16-MCZn（II）,phe HA,Hphe HA-6]5+complex was crystallographically characterized that possesses unusual C2 symmetry.These results provide insights into the design of functional metallacrowns through ring ion substitution.