Structural and Electronic Characterization of a Photoresponsive Lanthanum(III) Complex Incorporated into Electrospun Fibers for Phosphate Ester Catalysis

Abstract

Herein, we present the light-induced synthesis and characterization of a La 3+ /spiropyran derivative complex (LaMC) and its application as a catalyst when incorporated into electrospun polycaprolactone (PCL) fibers. In addition to experimental methods, computational calculations were also essential to better understand the structure and electronic characteristics of LaMC. The LaMC complex was identified as a 10-coordinated structure with the La 3+ ion coordinated by four oxygens from the phenolate and the carbonyl of the carboxyl acid group from both MC ligands and by six oxygens from three nitrate ligands. In addition, LaMC was capable of getting reversibly isomerized by UV or visible light cycling. All PCL fibers were successively obtained, and their morphologies, surface properties, and catalytic behavior were studied. Results showed that PCL/LaMC fibers were capable of catalyzing bis(2,4-dinitrophenyl)phosphate degradation efficiently. Complete hydrolysis was accomplished in only 1.5 days relative to the half-life time of 35 days for the uncatalyzed hydrolysis at pH 8.1 and 25 °C.

Spiropyran-incorporated honeycomb porous films with reversible multistimuli-responsive properties

“…[1][2][3][4][5] Incorporating stimuli-responsive compounds into the system is one of the effective ways to endow materials with switchable characteristics. [6][7][8] Accordingly, various types of stimulusresponsive molecules including azobenzene, phenoxyquinone, bisthienylethene and spiropyran (SP) derivatives have been explored so far. [9][10][11] Isomerization processes such as cis/trans isomerization, ring opening/closure, and phenyl group migration of these molecules upon external stimuli were able to induce changes in the material properties.…”

Editorial: Photochromic Materials: Design and Applications

“…In this context, the chromic materials have been considerably focused for designing devices for multiple applications. Photochromism can be described as a reversible conversion of a chemical species between two isomeric forms caused by electromagnetic radiation absorption, resulting in a color change (Reis et al, 2020). Figure 1A shows the evolution of publications over the years considering the keyword photochromism on the Scopus website.…”

Electrospun Materials for Biomedical Applications

“…Electrospun fibers ranging from nanometers to micrometers in diameter have been applied in many research areas including chemistry, materials science, engineering, and chemical engineering, as well as medicine, pharmacology, and pharmaceutics. Based on a large variety of polymers (natural or synthetic ones), types of collectors, and nozzle configurations, a vast and complex number of electrospun materials can be obtained, allowing those electrospun fibers to be applied for catalysis [ 1 ], separation and purification [ 2 , 3 ], chemical sensing [ 4 , 5 ], food packaging [ 6 ], tissue engineering [ 7 ], wound dressing [ 8 ], and drug delivery [ 9 ], among others. The ability to produce nanofibers with different biocompatible and biodegradable polymers, with low cost, unique physicochemical properties, small diameter, high volume to surface area ratio, has raised interest in the technique for the production of materials applied in drug biomedical applications.…”