Structure and magnetic properties of a copper malonate/dipyridylamine layered coordination polymer with both syn–anti and anti–anti copper carboxylate chains

Coordination polymers using (2-pyridyl)alkylamine-appended carboxylates: magnetic properties

“…Examination of the magneto-structural data of the carboxylato-bridged coordination polymers 16,34,36,37,43,48,50 reported in the literature have allowed the following generalizations to emerge. The exchange coupling is strongly antiferromagnetic with a syn-syn conformation (small metal-metal distance and hence good overlap of magnetic orbitals), very weakly so (eventually ferromagnetic) with a syn-anti conformation and weak to moderately antiferromagnetic with an anti-anti conformation.…”

“…For syn-anti conformations, both weak ferromagnetic and antiferromagnetic coupling is observed. 16b, 34,36,37,43,50 The observed coupling depends on the structural features of the Cu-O-C-O-Cu 0 bridge unit, which controls the overlap of the magnetic orbitals. The non-planarity of this unit is expected to reduce the overlap, which in turn is to favor ferromagnetic exchange coupling.…”

“…The non-planarity of this unit is expected to reduce the overlap, which in turn is to favor ferromagnetic exchange coupling. 16b, 34,36,37,43,50 The nature and extent of coupling also depends on the coordination geometry of the Cu II centers. For a square planar/square pyramidal geometry, the ground state of the Cu II ion is described by the d x 2 Ày 2 orbital and for a trigonal bipyramidal geometry the relevant metal orbital is d z 2.…”

Divergent layer topologies in divalent metal aliphatic dicarboxylate coordination polymers containing 3-pyridylmethylnicotinamide

“…The inclusion of a hydrogen-bonding capable dipyridyl ligand can alter topology in these systems. For example, {[Cu 2 (mal) 2 (dpa)(H 2 O) 2 ]$H 2 O} n (dpa ¼ 4,4 0 -dipyridylamine) possesses both antieanti and anti-syn carboxylate bridging modes within different [Cu(mal)] n chain motifs, pillared by dpa ligands into a (6,3) herringbone layer instead of a more common (4,4) grid [10]. Few cadmium malonate phases have been reported [11,12].…”

CdIIand CoIIcoordination polymers constructed from benzene-1,4-dicarboxylic acid and 2-(pyridin-3-yl)-1H-benzimidazole ligands

“…So far, several rational synthetic strategies have been proposed to achieve the metalorganic supramolecular arrays, and one of the most effective approaches is to employ appropriate bridging building blocks capable of binding metal centres through direct dative bonds (Montney & LaDuca, 2007;Senkovska & Kaskel, 2006;Shen, 2014;Sun & Jin, 2005). In this regard, aromatic multicarboxylate ligands, such as benzene-1,4-dicarboxylic acid (1,4-H 2 bdc), have been widely used to construct MOFs with diverse topologies and interesting properties.…”