Coordination polymers and discrete complexes of Ag(I)-<i>N</i>-(pyridylmethylene)anilines: synthesis, crystal structures and photophysical properties

<p>Reactions of AgO<sub>2</sub>C<sub>2</sub>F<sub>3</sub> with (<i>E</i>)-<i>N</i>-(pyridylmethylene)aniline in which the pyridyl N is in the <i>p</i>- or <i>m-</i>position yielded two 1-D coordination polymers, [(AgO<sub>2</sub>C<sub>2</sub>F<sub>3</sub>)<sub>2</sub>(L<sub>a</sub>)<sub>2</sub>]<sub>n</sub> (L<sub>a</sub> = (<i>E</i>)-2,6-diisopropyl-<i>N</i>-(pyrid-3-ylmethylene)aniline) (<b>1</b>) and [(AgOC<sub>2</sub>F<sub>3</sub>)<sub>2</sub>(L<sub>d</sub>)<sub>2</sub>]<sub>n</sub> (L<sub>d</sub> = (<i>E</i>)-2,6-diisopropyl-<i>N</i>-(pyrid-4-ylmethylene)aniline) (<b>5</b>), and three discrete complexes, [(AgO<sub>2</sub>C<sub>2</sub>F<sub>3</sub>)<sub>2</sub>(L<sub>a</sub>)<sub>4</sub>] (<b>2</b>), [AgO<sub>2</sub>C<sub>2</sub>F<sub>3</sub>(L<sub>b</sub>)<sub>2</sub>] (L<sub>b</sub> = (<i>E</i>)-<i>N</i>-(pyrid-4-ylmethylene)aniline) (<b>3</b>) and [(AgOC<sub>2</sub>F<sub>3</sub>)<sub>2</sub>(L<sub>c</sub>)<sub>4</sub>] (L<sub>c</sub> = (<i>E</i>)-2,6-dimethyl-<i>N</i>-(pyrid-4-ylmethylene)aniline) (<b>4</b>). The structures were determined by MS, FT-IR and NMR spectroscopies, elemental analysis and single crystal XRD. <b>1</b> is an organometallic coordination polymer with silver in η<sup>1</sup>-arene coordination, but is a discrete dimeric complex <b>2</b> when crystallized from warm diethylether. The geometries around silver(I) in <b>1</b> and <b>4</b> are tetrahedral, ‘inverted seesaw’ in <b>2</b> and T-shaped in <b>3</b> and in all the anion seems to play a role. Ag(I) centers in <b>5</b> have distorted trigonal bipyramid and inverted seesaw geometries. The trifluoroacetate anions in these complexes display variable monodentate and short bridging coordination patterns. All complexes absorb and strongly emit UV-Vis radiation at room temperature.</p>