Synthesis, Crystal Structure, and Luminescent Properties of a Helical Complex [(CuL) 2.5 (H 2 O) 0.375 ] (H 2 L = Benzil Bis[(5-bromo oxidobenzylidene)hydrazone]).

A new helical copper (II) complex [(CuL)2.5(H2O)0.375] 1 (H2L = benzil bis[(5-bromo oxidobenzylidene)hydrazone]) was synthesized and characterized by elemental analysis, IR spectra, UV-vis spectra, and single-crystal X-ray diffraction. Complex 1 exhibits a new single-stranded helix with the copper (II) atom having a four-coordination seesaw geometry. The cooperativity of intermolecular C−H···π interactions and C−H···O hydrogen bonds links the helices together to form a three-dimensional network structure. The thermogravimetric and luminescent properties in the solid state of complex 1 have been investigated. [ABSTRACT FROM AUTHOR]