Isomer Dependence in the Assembly and Lability of Silver(I) Trifluoromethanesulfonate Complexes of the Heteroditopic Ligands, 2‑, 3‑, and 4‑[Di(1<i>H</i>‑pyrazolyl)methyl]phenyl(di‑<i>p</i>‑tolyl)phosphine

Three isomers of a new heteroditopic ligand that contains a di­(1<i>H</i>-pyrazolyl)­methyl (−CHpz₂) moiety connected to a di­(<i>p</i>-tolyl)­phosphine group via a <i>para</i>-, <i>meta</i>-, or <i>ortho</i>-phenylene spacer (<i><b>pL</b></i>, <i><b>mL</b></i>, and <i><b>oL</b></i>, respectively) have been synthesized by using a palladium(0)-catalyzed coupling reaction between HP­(<i>p</i>-tolyl)₂ and the appropriate isomer of (IC₆H₄)­CHpz₂. The 1:1 complexes of silver­(I) trifluoromethanesulfonate, Ag­(OTf), were prepared to examine the nature of ligand coordination and the type of supramolecular isomer (monomeric, cyclic oligomeric, or polymeric) that would be obtained. The single crystal X-ray diffraction studies showed that [Ag­(<i><b>pL</b></i>)]­(OTf), <b>1</b>, and [Ag­(<i><b>mL</b></i>)]­(OTf), <b>2</b>, possessed cyclic dimeric dications, whereas [Ag­(<i><b>oL</b></i>)]­(OTf), <b>3</b>, was a coordination polymer. The polymeric chain in <b>3</b> could be disrupted by reaction with triphenylphosphine, and the resulting complex, [Ag­(<i><b>oL</b></i>)­(PPh₃)]­(OTf), <b>4</b>, possessed a monometallic cation where the ligand was bound to silver in a chelating κ²<i>P,N</i>- coordination mode. The solution structures of <b>1</b>–<b>4</b> were probed via a combination of IR, variable-temperature multinuclear (¹H, ¹³C, ³¹P) NMR spectroscopy, as well as by electron spray ionization (ESI)­(+) mass spectrometry. A related complex [Ag­(<i>m</i>-IC₆H₄CHpz₂)₂]­(OTf), <b>5</b>, was also prepared, and its solid-state and solution spectroscopic properties were studied for comparison purposes. These studies suggest that the cyclic structures of <b>1</b> and <b>2</b> are likely preserved but are dynamic in solution at room temperature. Moreover, both <b>3</b> and <b>4</b> have dynamic solution structures where <b>3</b> is likely extensively dissociated in CH₃CN or acetone rather than being polymeric as in the solid state