Emissive Azobenzenes Delivered on a Silver Coordination Polymer

Abstract

Azobenzene has become a ubiquitous component of functional molecules and polymeric materials because of the light-induced trans→cis isomerization of the diazene group. In contrast, there are very few applications utilizing azobenzene luminescence since excitation energy typically dissipates via non-radiative pathways. Inspired by our earlier studies with 2,2′-bis[N,N′-(2pyridyl)methyl]diaminoazobenzene (AzoAMoP) and related compounds, we investigated a series of five aminoazobenzene derivatives and their corresponding silver complexes. Four of the aminoazobenzene ligands, which exhibit no emission under ambient conditions, form silver coordination polymers that are luminescent at room temperature. AzoAEpP (2,2′-bis[N,N′-(4pyridyl)ethyl]diaminoazobenzene) assembles into a three-dimensional coordination polymer 2 (AgAAEpP) that undergoes a reversible loss of emission upon the addition of metal coordinating analytes like pyridine. The switching behavior is consistent with the disassembly-reassembly of the coordination polymer driven by displacement of the aminoazobenzene ligands by coordinating analytes.

Modulation of Electronic Mobility of a One‐Dimensional Coordination Polymeric Molecular Wire with Light

“…Recent reports have suggested that gold nanoparticles can enhance the isomerization process in acyclic azobenzenes through gold‐mediated electron transfer, increasing the rate of the photoswitching (Figure ) . Azobenzene can also be functionalized and used as a ligand for coordination polymers (CP), including conducting the CPs . Recent reports have shown that silver‐based CPs exhibit electrical conductance, which begets the question of whether it is possible for such a polymer to exhibit differential electronic mobility upon switching with light (Figure ).…”

“…[42][43][44] Azobenzene can also be functionalized and used as al igand for coordination polymers (CP), including conductingt he CPs. [45] Recent reportsh ave shown that silver-based CPs exhibit electrical conductance,w hich begetst he question of whether it is possible for such ap olymer to exhibit differential electronic mobility upon switching with light ( Figure 1). In this work we reportt he synthesis of ao ne-dimensional (1D) CP based on a cyclic-azobenzene coordinated to aA g + -ion.…”

MOF Decomposition and Introduction of Repairable Defects Using a Photodegradable Strut

“…Incorporating azobenzene ligands onto the side chains of struts can create photoresponsive MOFs. Azobenzene cis ← trans photoisomerization provides a technique to block MOF channels; however, azobenzene isomerization is nearly, or completely, restricted when the ligand is utilized as a structural support. Moreover, photochromic diarylethene derivatives have been incorporated as MOF struts, and local framework movement can be achieved by diarylethene ring opening and closing, but the framework change is minimal and the MOF skeleton is retained.…”

MOF Decomposition and Introduction of Repairable Defects Using a Photodegradable Strut

“…Azobenzene cis ! trans photoisomerization provides at echnique to block MOF channels; [5] however,a zobenzene isomerization is nearly, [6,7] or completely, [8,9] restrictedw hen the ligandi su tilized as as tructurals up-port. Moreover,p hotochromicd iarylethened erivatives have been incorporated as MOF struts,a nd local frameworkm ovement can be achieved by diarylethene ringo peninga nd closing, [10][11][12] but the framework change is minimal andt he MOF skeleton is retained.…”