The metal directed assembly of a trinuclear macrocyclic copper(II) complex

Encapsulation of Cyanometalates by a Tris‐macrocyclic Ligand Tricopper(II) Complex: Syntheses, Structural Variation, and Magnetic Exchange Coupling Pathways

“…A comparison of the structures of Cu 6 Cr 4 , Cu 6 W 2 , Cu 6 Mo , and Cu 6 Fe 2 35 may help to design new architectures of similar assemblies. Due to the triazine spacer, the tris‐macrocyclic ligand copper( II ) host [Cu 3 (L)] 6+ may adopt one of two energetically stable conformations: either syn , anti , in which the macrocyclic ligand copper( II ) subunits are oriented on different sides of the plane of the aromatic spacer groups,35, 44, 45 or syn , syn , in which all three macrocyclic ligand tricopper( II ) subunits are on the same side 35. The energy barrier between these two conformers seems to be small enough to be overcome in the free [Cu 3 (L)] 6+ host in solution at ambient temperature 35.…”

“…The energy barrier between these two conformers seems to be small enough to be overcome in the free [Cu 3 (L)] 6+ host in solution at ambient temperature 35. 44, 45 Therefore, the structure of the host in the solid depends on the balance of various forces due to the crystal lattice. Our observations so far indicate that, upon interaction of the tricopper( II ) host complex with cyanometalates, [Cu 3 (L)] 6+ generally adopts the syn , syn conformation.…”

Interactions between Copper(II) Complexes of Mono-, Bis-, and Tris(macrocyclic) Ligands and Inorganic or Organic Guests

“…They include the mono(macrocyclic) ligand complexes [Cu(L 1 )(OClO 3 [17] [Cu(L 1 )(CA-H)-(OClO 3 )]·H 2 O (9) (CA-H ϭ cyanurate), [17] [Cu(HL 1 )-(OClO 3 )](ClO 4 ) 2 ·2H 2 O (10), [16] [Cu(HL 1 )(OClO 3 ) 2 ]-(BA-H)·3H 2 O (11) (BA-H ϭ barbiturate), [17] and [Cu 3 (L 3 )(OH 2 ) 2 (OClO 3 ) 4 ](ClO 4 ) 2 ·3H 2 O (12). [18] The copper(II) ions in all structures reported here are coordinated to four nitrogen donors in the macrocycles, resulting in nearly planar CuN 4 chromophores (rms ϭ 0.01Ϫ0.04 Å ), with the copper(II) centers deviating from these planes only slightly (0.01Ϫ0.07 Å ). The pentaaza macrocycles all have the expected trans-III (RRSS) configuration.…”

“…In three of the structures (1, 8, and 9), copper(II) is coordinated to the parent ligand L 1 , while in the other four (2, 3, 10, and 11) the melamine fragment is protonated at the central nitrogen atom ([N (8) and N (18) in Figure 2b,c), and so copper(II) is coordinated to HL 1 . In the published structures (9 and 11), specific supramolecular interactions of the melamine fragments with substrates (carboxylates) were discussed.…”

“…The previous observation of the syn,anti isomer of [Cu 3 (L 3 )] 6ϩ [18] and the species resulting from the reaction between 5 and benzene-1,3,5-tricarboxylate (see below) indicate that the syn,syn and syn,anti conformations of [Cu 3 (L 3 )] 6ϩ have similar energies and a low activation barrier for interconversion. Therefore, we do not assume that [Fe 2 (CN) 11 ] 7Ϫ is assembled inside the cavity of the host; the formation of 6, rather, is assumed to be a stepwise process.…”