Syntheses, structures and properties of two pentacoordinated μ₁,₅ bridged dinuclear metal(II)-dicyanamide (Mdca; M=Cu and Cd) compounds containing a tailored tetradentate bifunctional polyamine

• Published in: Journal of molecular structure Vol. 1004; no. 1-3; pp. 138 - 145
• Main Authors: Khan, Sumitava, Bhar, Kishalay, Adarsh, N.N, Mitra, Partha, Ribas, Joan, Ghosh, Barindra Kumar
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 12.10.2011
• Subjects: cadmium; hydrogen; ions; physicochemical properties; polyamines; spectroscopy; X-ray diffraction
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2011.07.053

Two pentacoordinated dinuclear compounds of the type [M₂(dca)(L)₂](ClO₄)₃·H₂O [M=Cu (1), Cd (2); L=N,N′-bis(3-aminopropyl)-1,2-ethanediamine; dca=dicyanamide] have been prepared and characterized on the basis of microanalytical, spectroscopic and other physicochemical properties. Structures of 1 and 2 are solved by single crystal X-ray diffraction measurements. Structural study reveals that in both compounds each pentacoordinated metal(II) center adopts a distorted square pyramidal geometry with an MN₅ chromophore coordinated by four N atoms of the polyamine (L) in the basal plane and nitrile N atom of single μ₁,₅ bridged dca in the apical position. The dinuclear units in 1 and 2 are engaged in weak intermolecular O–H⋯O, N–H⋯O, N–H⋯N and C–H⋯O hydrogen bondings resulting in 3D network structures in which the crystalline water molecules and counter ions are embedded. Variable-temperature magnetic susceptibility measurement of 1 indicates weak antiferromagnetic interactions among the metal centers.