Reactivity of 1,4-Bis[2-(5-phenyloxazoly)]benzene toward Cu Salts under Different Reaction Conditions

Four novel copper−POPOP coordination complexes:  [Cu(NO3)(POPOP)]n (1), [CuCl(POPOP)0.5]n (2),
Cu2(POPOP)2(CH3COO)4 (3), and [Cu3(POPOP)(CH3COO)6]n (4) (commercial name:  POPOP = 1,4-bis[2-(5-phenyloxazoly)]benzene), are obtained from the assembly reactions of Cu(I or II) ions and POPOP in the presence
of different anions. Single-crystal X-ray diffraction studies reveal that 1 consists of a zigzag chain formed by Cu(I)
atoms bridged by POPOP; 2 consists of two-dimensional (2D) infinite neutral coordination layers of [CuCl]n units
bridged also by POPOP; 3 consists of discrete [Cu2(CH3COO)4] units with POPOP monodentately coordinated to Cu
atoms; and the structure of 4 features a unique 2D (4,4) topological network and can be regarded as the combination
of a chain of [Cu(POPOP)]n2+ and the building blocks [Cu2(CH3COO)6]2-.