Anion-Controlled Assembly of Silver(I)/Aminobenzonitrile Compounds: Syntheses, Crystal Structures, and Photoluminescence Properties

Five coordination compounds (CCs) of the formulas {[Ag­(m-abn)2]·NO3}n (1), {[Ag2(m-abn)6]·(ClO4)2} (2), {[Ag­(o-abn)2]·NO3}n (3), [Ag­(o-abn)2(NO2)]n (4), and {[Ag­(o-abn)2]·PF6}n (5) (m-abn = 3-aminobenzonitrile,
and o-abn = 2-aminobenzonitrile) were synthesized
and structurally characterized by element analysis, IR, powder X-ray
diffraction, and X-ray single-crystal diffraction. Structural analysis
reveals that aminobenzonitrile acts as bidentate μ2-N,N′ or monodentate μ1-N ligands in 1–5. Complex 1 is a 1D chain
comprised of C2-symmetric [Ag­(m-abn)]2 14-membered rings. The uncoordinated
NO3– anions interact with the 1D chain
to form a resulting 2D supramolecular sheet through N–O···N
hydrogen bond. Complex 2 is a discrete binuclear Ag­(I)
CC incorporating concurrent bidentate μ2-N,N′
and monodentate μ1-N m-abn ligands.
The variation of anions from NO3– to
ClO4– results in the dimensionalities
of 1 and 2 decreasing from 1D to 0D. When
using o-abn, complexes 3–5 are obtained as 1D chain with C2-symmetric [Ag­(o-abn)]2 12-membered rings,
2D sheet with coordinated μ2-η1:η2 NO2– anions, and 1D chain with
centrosymmetric [Ag­(o-abn)]2 12-membered
rings, respectively. Supramolecular interactions such as hydrogen
bonding and π···π stacking are also proven
effective in shaping the dimensionalities of the solid state structures
of 1–5. Our results demonstrate that
the anions are driving forces for the selection of different structures.
Moreover, results about emissive behaviors and thermal stabilities
of them are discussed.