Dimeric, Two‐Dimensional and Metal‐Centered Rectangular Heterometallic Cu II –Ag I /Cd II /Ba II Systems Derived from a Single Compartmental Ligand

The present study deals with one dimer‐of‐dinuclear type compound, [{Cu II LAg I (NO 3 )} 2 ] ( 1 ), one pentametallic and metal‐centered rectangle type compound, [Ba II (Cu II L) 4 ](ClO 4 ) 2 ( 2 ), and one dinuclear based two‐dimensional coordination polymer, [Cu II LCd II (μ 1,5 ‐dicyanamide) 2 ] n ( 3 ), where H 2 L=N,N′‐bis(salicylidene)‐1,4‐butanediamine. The syntheses and crystal structures of 1–3 , electrospray ionization mass spectra in positive mode of 1 and 2 and variable‐temperature magnetic properties of 2 , are described. Two symmetry related diphenoxo‐bridged dinuclear Cu II Ag I moieties are interlinked in 1 by Ag–π (η 2 ‐) bonds to form dimer‐of‐dinuclear type structure. One diphenoxo‐bridged dinuclear Cu II Cd II moiety is interlinked with four symmetry related dinuclear moieties by four μ 1,5 ‐dicyanamide ligands, which link Cd II centers, to generate two‐dimensional polymeric structure in 3 . In the [Ba II (Cu II L) 4 ] 2+ cation in 2 , the Ba II ion is coordinated to two μ‐phenoxo oxygen atoms of each of the four [Cu II L] fragments; the four copper(II) ions are positioned to form an approximate rectangle, i. e., the pentametallic [Ba II (Cu II L) 4 ] 2+ cation in 2 is a metal‐centered rectangle. ESI‐MS positive of 1 and 2 have been recorded and the ions in the spectra have been reasonably assigned. Variable‐temperature magnetic studies of 2 reveal very weak antiferromagnetic interaction ( J =–0.14 cm –1 ) between the copper(II) ions. The structure of 2 represents a new type among compounds from related ligands.