Chiral and achiral layered divalent metal aromatic ortho-dicarboxylate coordination polymers with bis(4-pyridylmethyl)piperazine ligands: Luminescent behavior and magnetic properties

• Published in: Inorganica Chimica Acta 2010-11, Vol.363 (14), p.3951-3958
• Main Authors: Pochodylo, Amy L., Blake, Karyn M., Braverman, Maxwell A., Farnum, Gregory A., LaDuca, Robert L.
• Format: Article
• Language: English
• Subjects: Cadmium; Cobalt; Coordination polymer; Copper; Ferromagnetism; Luminescence
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2010.07.061

Coordination polymers containing bis(4-pyridylmethyl)piperazine (4-bpmp) and the ortho-dicarboxylate ligands phthalate (pht) or 4-methylphthalate (mpht) have been prepared. {[Cu 2(pht) 2(H4-bpmp) 2(H 2O) 2](NO 3) 2·H 2O} n ( 1) and {[Cu 2(pht) 2(H4-bpmp) 2(H 2O) 2](SO 4)·2H 2O} n ( 2) possess chiral cationic layer motifs. {[Co(pht)(H 2O)(4-bpmp)]·5.5H 2O} n ( 3) displays a (4,4) grid containing ferromagnetically coupled {Co 2(H 2O) 2(pht) 2} dimeric clusters. Four divalent metal coordination polymers containing bis(4-pyridylmethyl)piperazine (4-bpmp) and the ortho-dicarboxylate ligands phthalate (pht) or 4-methylphthalate (mpht) have been prepared by solvent diffusion or hydrothermal methods. {[Cu 2(pht) 2(H4-bpmp) 2(H 2O) 2](NO 3) 2·H 2O} n ( 1) and {[Cu 2(pht) 2(H4-bpmp) 2(H 2O) 2](SO 4)·2H 2O} n ( 2) possess chiral cationic layer motifs formed by the junction of [Cu(H 2O)(pht)] n chains by tethering curled-conformation H4-bpmp + ligands. {[Co(pht)(H 2O)(4-bpmp)]·5.5H 2O} n ( 3) displays a (4,4) grid constructed from anti-syn carboxylate-bridged {Co 2(H 2O) 2(pht) 2} dimeric clusters linked by open-conformation 4-bpmp ligands. {[Cd 2(mpht) 2(H 2O) 2(4-bpmp)(H4-bpmp)]ClO 4·4H 2O} n ( 4) manifests cationic layered motifs based on neutral [Cd 2(H 2O) 2(mpht) 2] dinuclear units with {CdOC 4O} 2 12-membered circuits, linked by open-conformation 4-bpmp and H4-bpmp + ligands. Variable-temperature magnetic data indicate likely concomitant zero-field splitting and ferromagnetic coupling in 3. Violet light emission is observed when 4 is subjected to ultraviolet irradiation.