A Highly Luminescent Hexanuclear Molybdenum Cluster – A Promising Candidate toward Photoactive Materials

Abstract

A new Mo 6 cluster complex and its silica and polyurethane composites have been synthesized and characterized. These materials are highly luminescent with emission above 650 nm, produce singlet oxygen with high efficiency, are photostable, and can be excited up to 580 nm. These proper-[a] Institute of Inorganic Chemistry of the AS CR, v.v.i Husinec-Ř ež 1001, 25068 Ř ež,

Superior performance of macroporous over gel type polystyrene as a support for the development of photo-bactericidal materials

“…The hexanuclear molybdenum complex 1 has the valuable property of bright-red room temperature phosphorescence. [24][25][26][27][28][29][30][31][32][33][34][35] In our case solid powder of 1 emitted phosphorescence at λ max = 678 nm, 1@P gel emitted at λ max = 671 nm and 1@P mp displayed emission at λ max = 676 nm. The intensity of both emissions are quenched by oxygen upon exposure of the samples to air.…”

“…For comparison purposes, phosphorescence of 1 in several solvents was recorded at λ max = 671-675 nm (Figure 1d) in accordance with the literature. [24][25][26][27][28][29][30][31][32][33][34][35] The performance of 1@P gel and 1@P mp as bactericidal materials was tested against S.aureus and P.aeruginosa. For both types of microorganisms notable differences were found between the gel-type and macroporous resins, especially in the case of gram positive bacteria.…”

“…22 Recently we have proposed a hexanuclear molybdenum cluster complex (1: [Mo 6 I 8 Ac 6 ] 2-, Ac is acetate; see structure in Figure 1) as photoactive agent for aPDI, 23 owing to its notable photochemical properties. [24][25][26][27][28][29][30][31][32][33][34][35] Regarding the supports for the photoactive agents, a variety of materials have been described in the literature, like polyurethane, cellulose, nylon, chitosan, silica and polystyrene. [13][14][15][16][17][18][19][20] This last polymer is one of the most popular supports employed so far, dating back to the pioneering works of Schaap and Neckers.…”

Triblock copolymer-based luminescent organic–inorganic hybrids triggered by heating and fluoroquinolone antibiotics

“…Previously published papers [6,8] exemplify correlation of the temperature-induced phase transitions in liquid crystals and in aqueous solutions of triblock copolymers with lanthanide-centered luminescence. The development of water soluble supramolecular systems, where luminescence of inorganic luminophor correlates with thermally triggered aggregation of water soluble polymers is of particular importance, since it opens new routes to sense such phase transitions in aqueous solutions through a luminescent response.The reason for choice of hexamolybdenum halide clusters with the {Mo 6 X 8 } 4+ core and six additional terminal ligands as the inorganic luminophor is based on its unique metal-centered luminescence [9][10][11][12][13][14][15][16][17][18][19][20][21].The enhanced response of the clusters luminescence to dioxygen [17,18] makes them promising building blocks for fiber optic probes. It is worth noting that literature data highlight, first of all, the change of inner-and outer-sphere environment as a powerful tool to tune Mo-centered luminescence by an apical ligands substitution [14][15][16] and counter-ions exchange [19,21].…”

Luminescent coordination polymers based on Ca2+ and octahedral cluster anions [{M6Cli8}Cla6]2− (M = Mo, W): synthesis and thermal stability studies

“…Indeed, depending on X and L, some members of this family demonstrate intensive luminescence in the red/near-infrared region with emission lifetimes of hundreds of microseconds and often with significant quantum yields. [11][12][13][14][15][16][17] Due to these properties, materials based on these clusters have been demonstrated to have potential in solar energy harvesting, 18,19 bioimaging, photodynamic therapy, [20][21][22] photo-catalysis, [23][24][25][26][27] oxygen sensing, [28][29][30][31] lighting, [32][33][34] etc.…”