Ce/Au(CN)2--Based Coordination Polymers Containing and Lacking Aurophilic Interactions

• Published in: European journal of inorganic chemistry 2016-05, Vol.2016 (13-14), p.2082-2087
• Main Authors: Roberts, Ryan J., Ahern, John C., Patterson, Howard H., Leznoff, Daniel B.
• Format: Article
• Language: English
• Subjects: Aurophilicity; Cerium; Fluorescence spectroscopy; Heterometallic complexes; Polymers
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201600174

New members of the Ln[Au(CN)2]3·3H2O and [nBu4N]2[Ln(NO3)4Au(CN)2] series Ln = Ce (CeAu3 and CeAu respectively) are reported herein where their synthesis, structure and photoluminescence properties are discussed. The first is a 3‐D coordination polymer with aurophilic interactions of 3.35 Å and the latter is a 1‐D coordination polymer that lacks them. At 293 K both CeAu3 and CeAu display characteristic CeIII‐based emission at λmax = 393 nm (5d→2FJ), however in CeAu3 AuI‐based emission (λmax = 410, 1MLCT) dominates the spectrum. At 77 K however, the dominant emission is AuI‐based with characteristic emissions of λmax = 430 nm (1MLCT) and 490 nm (3MLCT). The key difference in the luminescence of these two materials can be rationalized in terms of their respective structures, through either the aurophilic network and lack thereof and/or the rigidity offered in the 3‐D structure of CeAu3. Cerium analogues of [nBu4N]2[Ln(NO3)4Au(CN)2] and Ln[Au(CN)2]3·3H2O systems have been synthesized and characterized with an emphasis on their luminescence properties at 293 and 77 K. These differ in the dominant emissive pathway and can be rationalized based on their respective structure.