4. The first structurally characterized 3,4′-bipyridine copper(I) coordination polymer with an approximately rectangular molecular box Hoong-Kun Fun,S. Shanmuga Sundara Raj,Ren-Gen Xiong,Jing-Lin Zuo,Zhi Yu,Xiao-Lei Zhu,Xiao-Zeng You J. Chem. Soc. Dalton Trans. 1999 1711