Crystal Retro-Engineering: Structural Impact on Silver(I) Complexes with Changing Complexity of Tris(pyrazolyl)methane Ligands

The preparation and structures of seven new silver(I) complexes involving the parent tris(pyrazolyl)methane unit,
[C(pz)3], as the donor set, {[C6H5CH2OCH2C(pz)3]Ag}(BF4), {[C6H5CH2OCH2C(pz)3]2Ag3}(CF3SO3)3, {[HOCH2C(pz)3]Ag}(BF4), {[HOCH2C(pz)3]Ag}(CF3SO3), {[HC(pz)3]2Ag2(CH3CN)}(BF4)2, {[HC(pz)3]Ag}(PF6), and
{[HC(pz)3]Ag}(CF3SO3), are reported. This project is based on a retro-design of our multitopic C6H6-n[CH2OCH2C(pz)3]n
(pz = pyrazolyl ring, n = 2, 3, 4, and 6) family of ligands in such a way that each new ligand has one fewer
organizational feature. The κ2−κ1 bonding mode of the [C(pz)3] units to two silvers, also observed with the multitopic
ligands, is the dominant structural feature in all cases. Changing the counterion has important effects on the local
structures and on crystal packing. When these structures are compared to similar ones based on the multitopic
C6H6-n[CH2OCH2C(pz)3]n ligands, it has been shown that the presence of the rigid parts (central arene core and
the [C(pz)3] units) are important in order to observe highly organized supramolecular structures. The presence of
the flexible ether linkage is also crucial, allowing all noncovalent forces to manifest themselves in a cumulative and
complementary manner.