2 research outputs found
Synthesis, structure, and properties of a new Co(II) diphosphonate based on auxiliary ligand 2,2'-bipyridine
<p>The example of Co(II)-<i>N</i>-heterocyclic complex based on 1-hydroxyethylidenediphosphonic acid (H<sub>5</sub>L = CH<sub>3</sub>C(OH)(PO<sub>3</sub>H<sub>2</sub>)<sub>2</sub>), namely [Co<sub>2</sub>(H<sub>3</sub>L)<sub>2</sub>(2,2′-bipy)<sub>2</sub>] <b>1</b>, has been solvothermally isolated using the second ligand 2,2'-bipyridine (2,2'-bipy) and characterized by powder X-ray diffraction (PXRD), elemental analysis, IR, and thermal gravimetric analyses. The single-crystal X-ray diffractions show that complex <b>1</b> possesses a 0-D structure built from binuclear unit [Co<sub>2</sub>(O–P–O)<sub>2</sub>] by μ<sub>2</sub>-(O–P–O) bridge. Then, H-bonding and π–π stacking interactions further expand this 0-D structure into a 3-D supramolecular framework. Fluorescent measurements reveal that the maximum emission peak is centered at 421.5 nm, mainly deriving from intraligand π*–π transition state of the second ligand 2,2'-bipy (λ<sub>em</sub> = 419.5 nm, λ<sub>ex</sub> = 235 nm). Magnetism data indicate that <b>1</b> exhibits ferromagnetic behavior within binuclear Co(II) unit via μ<sub>2</sub>-(O–P–O) bridge in <i>syn</i>-<i>anti</i> mode.</p