Syntheses, Structures and Magnetic Properties of Trinuclear CuIIMIICuII (M = Cu, Ni, Co and Fe) and Tetranuclear [2×1+1×2] CuIIMnII-2CuII Complexes Derived from a Compartmental Ligand: The Schiff Base 3-Methoxysalicylaldehyde Diamine Can also Stabilize a

The present investigation describes syntheses, characterization and studies of the mononuclear compound [Cu II L⊂ (H 2 O)] (1), the triangular, trinuclear monophenoxido-bridged compounds [{Cu II L} 2 M II (H 2 O) 2 ](CIO 4 ) 2 ·nH 2 O [2 (M = Cu, n = 0), 3 (M = Ni, n = 3), 4 (M = Co, n = 0), 5 (M = Fe, n = 0)] and the tetrametallic self-assembled complex [{Cu II LMn II (H 2 O) 3 }-{Cu II L} 2 ](CIO 4 ) 2 ·H 2 O (6) derived from compartmental Schiff base ligand, H 2 L, which is the [2+1] condensation product of 3-methoxysalicylaldehyde and trans-1,2-diaminocyclohexane. Single-crystal X-ray structures of 2, 5 and 6 were determined. Two pairs of terminal···central metal ions in the trinuclear cores in 2 and 5 are monophenoxido-bridged. Interestingly, the CuO 6 and FeO 6 environments have tetragonally compressed octahedral geometries. On the other hand, the structure of 6 reveals that it is a [2×1+1×2] cocrystal of one diphenoxido-bridged dinuclear [Cu II LMn II (H 2 O) 3 ] 2+ dication and two mononuclear [Cu II L] moieties. Cocrystallization in 6 takes place as a result of water encapsulation. The variable-temperature (2-300 K) magnetic susceptibilities of compounds 2-6 have been measured. The exchange integrals obtained are: the Cu II 3 compound 2, J = -78.9 cm -1 ; the Cu II Ni II -Cu II compound 3, J = -22.8 cm -1 ; the Cu II Cu II Cu II compound 4, J = -7.8 cm -1 ; the Cu II Fe II Cu II compound 5, J = -3.0 cm -1 ; the Cu IT 3 Mn II compound 6, J = -15.1 cm -1 . The monophenoxido-bridging core in 3 and 4 has been proposed after comparison of the structures and magnetic properties of these two compounds with those of 2, 5 and related other compounds. This paper presents rare examples of monophenoxido-bridged Cu II M II Cu II (M = Cu, Ni, Co and Fe) compounds, provides an understanding of the structures from magnetic exchange integrals, and, most importantly, reports on the first example of a cocrystal derived from a 3-methoxysalicylaldehyde diamine compartmental ligand.