Phosphorescent Organogels via “Metallophilic” Interactions for Reversible RGB−Color Switching
摘要:
A trinuclear Au(l) pyrazolate complex bearing long alkyl chains (1) in hexane self-assembles via a Au(l)-Au(I) metallophilic interaction, to form a red-luminescent organogel (lambda(em) = 640 nm, lambda(ext) = 284 nm). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis of an air-dried gel with 1 show the presence of heavily entangled fibers, each consisting of a rectangularly packed columnar assembly of 1. Doping of the organogel with a small amount of Ag+ results in a blue luminescence (lambda(em) = 458 rim, lambda(ext) = 370 nm) without disruption of the gel, while removal of doped Ag+ with cetyltrimethylammonium chloride results in complete recovery of the original red-luminescent gel. Upon heating, these organogels undergo gel-to-sol transition due to the destabilization of the metallophilic interactions, where the red luminescence of the nondoped system becomes hardly visible, while the blue luminescence of the Ag+-doped system turns green (lambda(em) = 501 nm, lambda(ext) = 370 nm). On cooling, these solutions undergo gelation and synchronously recover the original luminescences. The observed RGB (red-green-blue) luminescences are all long-lived (3-6 mus) and assigned to electronic transitions from triplet-excited states.
Phosphorescent Organogels via “Metallophilic” Interactions for Reversible RGB−Color Switching
摘要:
A trinuclear Au(l) pyrazolate complex bearing long alkyl chains (1) in hexane self-assembles via a Au(l)-Au(I) metallophilic interaction, to form a red-luminescent organogel (lambda(em) = 640 nm, lambda(ext) = 284 nm). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis of an air-dried gel with 1 show the presence of heavily entangled fibers, each consisting of a rectangularly packed columnar assembly of 1. Doping of the organogel with a small amount of Ag+ results in a blue luminescence (lambda(em) = 458 rim, lambda(ext) = 370 nm) without disruption of the gel, while removal of doped Ag+ with cetyltrimethylammonium chloride results in complete recovery of the original red-luminescent gel. Upon heating, these organogels undergo gel-to-sol transition due to the destabilization of the metallophilic interactions, where the red luminescence of the nondoped system becomes hardly visible, while the blue luminescence of the Ag+-doped system turns green (lambda(em) = 501 nm, lambda(ext) = 370 nm). On cooling, these solutions undergo gelation and synchronously recover the original luminescences. The observed RGB (red-green-blue) luminescences are all long-lived (3-6 mus) and assigned to electronic transitions from triplet-excited states.
POLYIONIC TRANSITIONAL METAL PHOSPHORESCENT COMPLEX/POLYMER HYBRID SYSTEMS FOR BIOIMAGING AND SENSING APPLICATIONS
申请人:Omary Mohammad A.
公开号:US20120065614A1
公开(公告)日:2012-03-15
A new technique to stabilize transition metal phosphors in a wide variety of stimuli-sensitive polymers and gels is disclosed herein. Other than stabilization in stimuli sensitive/biocompatible matrix some of these transition metal based phosphors are also shown to act as phosphorescent crosslinkers that physically or chemically crosslink polymeric chains to form micro/nanoparticles. The microspheres/nanospheres of the present invention show decreased size and photoluminescence enhancement with particularly high sensitization at physiological pH and temperature. The so formed phosphorescent micro/nanospheres are useful for biological or environmental applications including biological labeling, imaging, and optical sensing. The techniques in the present invention enable usage of imaging agents and sensors at very low concentrations and also minimize or eliminate the usage of toxic chemical crosslinkers typically used to synthesize polymeric micro/nanoparticles.
Phosphorescent Organogels via “Metallophilic” Interactions for Reversible RGB−Color Switching
A trinuclear Au(l) pyrazolate complex bearing long alkyl chains (1) in hexane self-assembles via a Au(l)-Au(I) metallophilic interaction, to form a red-luminescent organogel (lambda(em) = 640 nm, lambda(ext) = 284 nm). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis of an air-dried gel with 1 show the presence of heavily entangled fibers, each consisting of a rectangularly packed columnar assembly of 1. Doping of the organogel with a small amount of Ag+ results in a blue luminescence (lambda(em) = 458 rim, lambda(ext) = 370 nm) without disruption of the gel, while removal of doped Ag+ with cetyltrimethylammonium chloride results in complete recovery of the original red-luminescent gel. Upon heating, these organogels undergo gel-to-sol transition due to the destabilization of the metallophilic interactions, where the red luminescence of the nondoped system becomes hardly visible, while the blue luminescence of the Ag+-doped system turns green (lambda(em) = 501 nm, lambda(ext) = 370 nm). On cooling, these solutions undergo gelation and synchronously recover the original luminescences. The observed RGB (red-green-blue) luminescences are all long-lived (3-6 mus) and assigned to electronic transitions from triplet-excited states.