Supramolecular architectures from the self-assembly of trans-oxamidato-bridged dicopper(II) building blocks and phenyldicarboxylates

Abstract

Compounds [Cu₂(trans-oxen)(tp)]_n·2nH₂O (1·2nH₂O), [{Cu₂(trans-oxpn)(H₂O)₂}{Cu₂(trans-oxpn)}(isophth)₂]_n·7nH₂O (2·7nH₂O) and [Cu₂(trans-oxen)(phth)]_n·2nH₂O (3·2nH₂O) [H₂oxen = N,N′-bis(2-aminoethyl)oxamide, H₂oxpn = N,N′-bis(3-aminopropyl)oxamide, tp = terephthalate, isophth = isophthalate and phth = phthalate] were obtained from the self-organization of trans-oxamidato-bridged dicopper(II) building blocks [Cu₂(trans-L)]²⁺ (L = oxen or oxpn) and phenyldicarboxylate spacers with differently oriented carboxyl groups and their crystal structures determined. All the compounds consist of solvated water molecules and 2-D polymeric coordination networks containing rectangular, H-shaped mosaics and distorted rectangular grids for 1, 2, and 3, respectively. In addition, variegated hydrogen bonds involving solvated water molecules link the 2-D nets into 3-D frameworks. New bridging modes were discovered for the three isomeric phenyldicarboxylates. Magnetic calculations on 2·7nH₂O showed that the planar oxamidato bridge transmits antiferromagnetic interactions between the Cu(II) ions.