A Unique Cobalt(II)-Based Molecular Magnet Constructed of Hydroxyl/Carboxylate Bridges with a 3D Pillared-Layer Motif

Abstract

A new pillared-layer coordination polymer, [Co(3)(pybz)(2)(pico)(2)](n) (1; pybz = 4-(pyridin-4-yl)benzoate, pico = 3-hydroxypicolinate), contains rare 2D [Co(3)(pico)(2)](n)(2n+) layers formed by linear cobalt(II) trimers through the unusual mu(4)-kappaN,O:kappaO'-mu(2):kappaO''-mu(2) bridging mode of pico ligands, which are further cross-pillared by exotridentate bridging pybz ligands to form a three-dimensional structure with an unusual uninodal 8-connected body-centered-cubic topology. The bulk magnetic behavior of 1 exhibits ferrimagnetic long-range ordering below 2.6 K, which mainly arises from the cooperative magnetic effect of the intra- and intertrimer arrangements in the 2D magnetic system based on the nature of the exchange modes of mu(2)-hydroxyl, mu(2)-carboxylate oxygen, and 1,1,3-mu(3)-carboxylate bridges.

Transition metal complexes of a dihydroquinazoline-containing ligand: synthesis, crystal structures and physical properties

“…The magnetic moment of complex 1 is ca. 2.693 cm mol -1 K at 300 K, which is much higher than the expected value of 1.875 cm mol -1 K for a spin-only Co(II) ion with S = 3/2 and g = 2.0, owing to the important orbital contribution to the susceptibility of the Co(II) ion in a high-spin octahedral configuration [33,34].…”

Synthesis, Crystal Structures, and Fluorescent Properties of Two ZnII/CdII Coordination Polymers Constructed from Isomeric Ligands

“…In recent years, several efforts have been made to explore the coordination chemistry of isomeric pyridyl‐carboxylate derivatives such as 3‐pyridin‐3‐yl‐benzoate (3,3‐pybz),4‐pyridin‐4‐yl‐benzoate(4,4‐pybz),3‐pyridin‐4‐yl‐benzoate (3,4‐pybz), and 4‐pyridin‐3‐yl‐benzoate (4,3‐pybz), which can afford a variety of 1D, 2D, and 3D coordination polymers with different metal ions 11–19. Previously, 3,3‐pybz and 4,3‐pybz ligands have been used to construct coordination polymers and to study on various performance, meanwhile achieving good results such as photocatalytic activity and photomagnetism 21,22.…”

“…[6][7][8][9][10] In recent years, several efforts have been made to explore the coordination chemistry of isomeric pyridyl-carboxylate derivatives such as 3-pyridin-3-yl-benzoate (3,3-pybz),4-pyridin-4-yl-benzoate(4,4-pybz),3-pyridin-4-yl-benzoate (3,4-pybz), and 4-pyridin-3-yl-benzoate (4,3-pybz), which can afford a variety of 1D, 2D, and 3D coordination polymers with different metal ions. [11][12][13][14][15][16][17][18][19] Previously, 3,3-pybz and 4,3-pybz ligands have been used to construct coordination polymers and are further linked by the L 1 ligands to give atwo-dimensional layered structure. Classical hydrogen-bonding interactions (O•••H-N) between adjacent layers result in three-dimensional supramolecular structure.…”

Synthesis, Crystal Structure, and Properties of Two 2D Lamella Coordination Polymers Generated from Unsymmetrically Carboxylate Bridging Ligand

“…[1][2][3][4][5] Though the effective and facile approach for the synthesis of such materials is still a great challenge due to the lack of the understanding in formation mechanisms, nevertheless many examples with interesting compositions and structures have been synthesized through judicious combination of a metal "node" and a ligand "spacer," as well as act synergistically to provide access to a vast diversity of structural topologies. [6][7][8] Multicarboxylate ligands are good candidates for the construction of MOFs solids organized by coordination bonds, hydrogen bonds, and π -π stacking interaction, due to their diverse coordination ability. To date, very interesting and promising results have been obtained by the assembly of multicarboxylate ligands and different metal centers.…”