Near‐infrared (NIR) imaging techniques have attracted significant attention for biological and medicinal applications due to the ability of NIR to penetrate deeply into tissues. However, there are very few stable, activatable molecular probes that can utilize NIR light in the wavelength range beyond 800 nm. Herein, we report a new activatable NIR system for photoacoustic imaging based on tautomeric benziphthalocyanines (BPcs). We found that the existence of a free hydroxyl group is crucial for NIR absorption of BPcs. Synthesized water‐soluble hydroxy BPcs exhibited high photostability and no fluorescence, which are desirable features for photoacoustic imaging. We synthesized BPcs in which the free hydroxyl group was masked by an esterase‐labile or an H2O2‐labile group. The photoacoustic signals of these hydroxy‐masked BPcs were increased upon NIR excitation at 880 nm in the presence of esterase or H2O2, respectively. These are rare examples of activatable probes utilizing NIR light at around 900 nm. 相似文献
We designed and synthesized a new type of small helical molecule exhibiting intense circularly polarized luminescence (CPL) ( 12H ) by modifying a 20π-electron hemiporphyrazine with a large transition magnetic dipole moment. The hemiporphyrazine ring was opened and one additional pyridine unit was introduced, resulting in an overlap of two pyridine rings. X-ray structure analysis confirmed that 12H and its zinc complex ( 1Zn ) adopt a helical geometry. A racemic mixture of 1Zn was resolved into two enantiomers ((P)- and (M)- 1Zn ), which exhibited CPL with a high luminescence dissymmetry factor (glum) value of ±2.1×10−2. The origin of the large glum value was rationalized by means of DFT calculations. Helical structures could be formed in a diastereoselective manner by covalently attaching chiral units to the skeleton ( 1’2H and 1’Zn ). 1Zn was found to possess chiral recognition ability for amines. 相似文献
Journal of Radioanalytical and Nuclear Chemistry - This paper discusses the spatiotemporal variation in atmospheric tritiated water (HTO) concentration near the Fukushima Daiichi Nuclear Power... 相似文献
A novel low-symmetry tetrabenzoporphine with D2h symmetry (1) and its zinc complex (2) were prepared via mixed condensation reaction of 5,6-dimethyl phthalimide and 4,5,6,7-tetraphenyl phthalimide with sodium acetate in the presence of zinc acetate. The zinc complex 2 exhibited a split Q band at 640 and 623 nm and a single Soret band at 435 nm. The absorption spectra of 1 and 2 were calculated and analyzed using Hartree-Fock theory based on INDO/S Hamiltonian. 相似文献
A racemic mixture of three-layered [3.3]paracyclophane ([3.3]PCP), 1, has been resolved into two enantiomers, and their absolute configuration was determined from a comparison of experimental chiroptical properties and density functional theory (DFT) calculations. A simple model comprising two p-xylenes and 1,2,4,5-tetramethylbenzene (durene) was used to explain the origin of the chiroptical properties of the three-layered cyclophane system. 相似文献
Neutron diffraction measurements were carried out on H/ D isotopically substituted water in the low-density supercritical condition (T = 673 K, P = 26.3 MPa, and rho = 0.0068 molecules.A-3) in order to obtain direct information on the intermolecular partial structure functions, gHH inter(r), gOH inter(r), and gOO inter(r). In correspondence to the high-density supercritical water previously reported, the intermolecular nearest neighbor peaks in gHH inter(r), gOH inter(r), and gOO inter(r) are diffuse compared with the ambient ones. The nearest neighbor O...O distance (3.3 A) and its coordination number (2.6) were determined from the observed gOO inter(r). These results indicate that the orientational correlation between neighboring water molecules is considerably lost in low-density supercritical water. Small clusters involving a few water molecules are preferentially formed in low-density supercritical water, which is consistent with results obtained by previous IR and NMR studies. 相似文献
This article describes novel optical functionalities such as photomagnetic effects and magnetization-induced second harmonic
generation (MSHG) in several cyano-bridged metal assemblies. Single crystal- and film-types of a cyano-bridged Cu–Mo bimetallic
assembly, , were electrochemically prepared. When this compound was irradiated with light, spontaneous magnetization with a Curie temperature
(TC) of 23 K was observed. Electrochemically prepared FeII[CrIII(CN)6]2/3·5H2O thin film, which was a ferromagnet with TC=21 K, showed photoreduced magnetization. This photomagnetism is due to the change of ferromagnetic coupling between FeII and CrIII. MSHG was observed in CsICoII[CrIII(CN)6]·0.5H2O. This -type Prussian blue analog-based magnet is proven to be a piezoelectric ferromagnet, i.e., condensed matter with both piezoelectric
and ferromagnetism. This MSHG is due to the coupling between a piezoelectric structure of and ferromagnetism with a TC of 46 K.
The copolymerization of ethylene and 5‐hexen‐1‐ol pretreated with trimethylaluminium was performed using [ethylene(1‐indenyl)(9‐fluorenyl)]zirconium dichloride/methylaluminoxane as the catalyst. The 5‐hexen‐1‐ol unit in the copolymer could be increased to about 50 mol‐% with increasing [5‐hexen‐1‐ol/ethylene[ ratio. 13C NMR analysis proved that the poly(ethylene‐co‐(5‐hexen‐1‐ol)) containing 50 mol‐% of 5‐hexen‐1‐ol units is an almost alternating copolymer. 相似文献
Monodisperse poly(D ,L ‐lactide) (PDLLA) microspheres have been prepared by dispersion polymerization of D ,L ‐lactide with a synthetic polymeric stabilizer. The polymerization is carried out in xylene/heptane (1:2, v/v) at 368 K for 3 h with poly[(dodecyl methacrylate)‐co‐(2‐hydroxyethyl methacrylate)] (P(DMA‐co‐HEMA)). P(DMA‐co‐HEMA) has hydroxy groups as an initiation group for pseudoanionic dispersion polymerization. The particle diameter and the coefficient of variation concerning the diameter distribution of the obtained PDLLA microspheres are 3.9 µm and 4.3%, respectively. In addition, from the results of dynamic light scattering measurements, it is found that P(DMA‐co‐HEMA) and the PDLLA‐grafted copolymer form a micellar structure in solution.