Ferromagnetic Ordering in a Two-Dimensional Copper Complex with Dual End-to-End and End-On Azide Bridges This work was supported by the National Natural Science Foundation of China (NSF 29631040 and 29929001), The Major State Basic Research Development Program (Grant No. G2000077500 and No. G1998061306), and the Malaysian Government research grant R&D No. 305/pfizik/622004.