... A self-assembled macrocyclic tetranuclear molecular square [Co(HL)]4 4+ [H2L = tetra(2-pyridyl)thiocarbazone] Chun-ying Duan,*a Ze-hua Liu,a Xiao-zeng You,a Feng Xueb and Thomas CW Mak*b a Coordination Chemistry Institute and The State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, PR China b Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong ...