The first urea azine molecule and its coordination to uranium in the first actinide guanidinate complexes

The urea azine molecule (CyNH)(2)C=N-N=C(HNCy)(2) (1) was easily prepared by reaction of the carbodiimide CyN=C=NCy and H(2)NNH(2) and this novel type of bis-guanidine proved useful in affording chelating and bridging ligands for the building of polynuclear compounds, as illustrated by the synthesis of the first uranium guanidinate complexes (THF)(2)Li(mu-Cl)(2)UCl(mu-L)](2) (2) and UCl(mu-L)(2)UCl(2)(micro-Cl)(2)UCl(mu-L)](2) (3) (L = - 2H); the X-ray crystal structures of compounds - were determined.