Three novel organosilver(I) coordination networks constructed from diallylmelamine and polycarboxylates incorporating silver-vinyl bonding

Abstract

Diallylmelamine combines with Ag₂O and auxiliary polycarboxylates to give three stable crystalline network structures, namely, [Ag₂(dama)₂(nipt)·H₂O·C₂H₅OH]_n (1), [Ag₂(dama)(glu)]_n (2), and [Ag₄(dama)₂(pma)·2H₂O]_n (3), (dama = diallylmelamine, H₂nipt = 5-nitroisophthalic acid, H₂glu = glutaric acid, H₄pma = pyromellitic acid), which have been successfully synthesized and characterized by elemental analysis, FT-IR Spectra, powder X-ray diffraction and thermogravimetric analyses, and single-crystal X-ray diffraction. Complex 1 is a 1D double-chain extended by μ₂-N,N′-(η²-vinyl)-dama and μ₃-nipt along the b axis. Notably, dama ligands in 1 display two coordination modes (bidentate μ₂-N,N′-(η²-vinyl) and monodentate μ₁-N) and two different conformations (cis^anti-gauche and trans^anti-anti). In 2, a pair of centrosymmetric glu ligands clamp two Ag(I) ions to form a half paddle-wheel [Ag₂(COO)₂] secondary building unit (SBU) which is further extended by μ₂-N,N′-(η²-vinyl)-dama to form a 1D tape. Complex 3 is a 2D sheet built from μ₃-N,N′,N′′-(η²-vinyl)-dama and μ₈-pma. Interestingly, apparent silver–vinyl interactions with a η² mode were commonly observed in the solid-state structures of 1–3 (Ag–C = 2.311(4)–2.467(5) Å). The structural dissimilarity between 1 and 2 is caused by the different auxiliary polycarboxylates and different coordination modes of dama. In addition, the thermal stabilities and emissive behaviors of them were also investigated.