Variability in the Structures of Luminescent [2‐(Aminomethyl)pyridine]silver(I) Complexes: Effect of Ligand Ratio, Anion, Hydrogen Bonding, and π‐Stacking

Abstract

The reaction of 2‐(aminomethyl)pyridine (2‐amp) with silver(I) salts of triflate (OTf–), trifluoroacetate (tfa–), and tetrafluoroborate (BF4–) produce monomeric, dimeric, bridged, and polymeric structural motifs. The structural characteristics are dependent upon the ratio of ligand/metal in the structure as well as the ability of the anion to coordinate to the metal centers and form hydrogen bonds to the bound ligands. The silver coordination environment takes on several geometries including near linear (6), trigonal (4), tetrahedral (1), and both trigonal‐bipyramidal and square‐based pyramidal in a single structure (2). Structures 2, 3, and 5 also display short Ag–Ag contacts ranging from 2.8958(3) to 3.0305(4) Å. The species with metal–metal interactions, which are connectively very similar to their metal‐isolated counterparts of 1, 4, and 6, are held together only by weak π‐stacking interactions or hydrogen bonds to their respective anions. Low‐temperature luminescence spectra were collected for all compounds and are compared. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Silver coordination complexes of 2-(diphenylphosphinomethyl)aminopyridine with weakly interacting counterions

“…In our BPMP coordination studies with the tfa -ion, it was observed that the coordination of tfa -influences the formation of a structure unique from the structures isolated with the BF 4 -and 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 13 OTf -ions; this is also observed here [24,25]. Even though 2-pyridyl ligands are typically not capable of polymer formation due to the limited flexibility of the N pyridyl moiety, polymer structures are isolable when a counterion or solvent molecule coordinates to the metal center(s) preventing chelation [2,27,41]. The unique portion of the polymer features two distinct Ag(I) centers: a four-coordinate Ag1 and three-coordinate Ag2.…”

“…While the sterically less hindered DPAP-2 is important to formation of the large ring, the tfa -ion aids in the formation of the polymer. Although it is not uncommon to isolate structures with coordinating tfa -ions, the formation of the 1-dimensional polymer 3 is attributed to the bridging tfa -ions [24,25,[41][42][43][44][45][46][47].…”

“…The Ag1···N2 distance is 2.804(3) Å, which is 15 ~ 0.5 Å longer than the Ag-N pyridyl distance seen with DPAP-2 and BPMP ligands. The C6 carbon of the pyridyl ring is 3.280(5) Å from the plane of the N3 ring of the 5,5'-dmbpy ligand, which is a typical distance for π-stacking seen in similar structures [24,25,41,45,46].…”

Synthesis, structure and luminescent property of a new hybrid solid based on Keggin anions and silver-organonitrogen fragments

“…The possible reason is that the energy received by ligand is partially lost. It is noteworthy that this low energy luminescence is unusual, in comparison with the large numbers of blue emission Ag(I) coordination polymers [38,39] and representing a singular example with orange fluorescent property for potential uses as photoluminescence materials.…”

Self-assembly of discrete metallosupramolecular luminophores

“…In the case of Ag(I), much work has been devoted to coordination of phosphine-and sulfur-based ligands [65], which are complementary to such a soft metal centre, while relatively little work has been directed toward luminescent assemblies based on N-heterocyclic ligands and Ag(I) [66]. Tetranuclear grid-like structures can be assembled with bis-bidentate Schiff-base ligands, which are readily obtained by condensation of diamines with 2-formyl pyridine (Fig.…”