General Formation of Macro-/Mesoporous Nanoshells from Interfacial Assembly of Irregular Mesostructured Nanounits

Mesoporous core–shell nanostructures with controllable ultra-large open channels in their nanoshells are of great interest. However, soft template-directed cooperative assembly to mesoporous nanoshells with highly accessible pores larger than 30 nm, or even above 50 nm into macroporous range, remains a significant challenge. Herein we report a general approach for precisely tailored coating of hierarchically macro-/mesoporous polymer and carbon shells, possessing highly accessible radial channels with extremely wide pore size distribution from ca. 10 nm to ca. 200 nm, on diverse functional materials. This strategy creates opportunities to tailor the interfacial assembly of irregular mesostructured nanounits on core materials and generate various core–shell nanomaterials with controllable pore architectures. The obtained Fe,N-doped macro-/mesoporous carbon nanoshells show enhanced electrochemical performance for the oxygen reduction reaction in alkaline condition.     

An azo dye for photodynamic therapy that is activated selectively by two-photon excitation

Two-photon photodynamic therapy (TP-PDT) is a promising approach for the treatment of cancer because of its better penetration depth and superior spatial selectivity. Here, we describe an azo group containing cyclized-cyanine derivatives (ACC1 and ACC2) as a two-photon activated, type I based photosensitizer (PS). These small-molecule and heavy atom-free organic dyes showed marked reactive oxygen species (ROS)-generating ability under physiological conditions, as well as fast loading ability into the cells and negligible dark toxicity. Live cell analyses with one- and two-photon microscopy revealed that these dyes showed higher ROS generation ability upon two-photon excitation than upon one-photon excitation via the type I process. The PSs have superior PDT properties compared to conventional Visudyne and 5-ALA under mild conditions. These characteristics allowed for precise PDT at the target region in mimic tumor spheroids, demonstrating that the developed TP PS could be useful in efficient PDT applications and in designing various PSs.

Azo containing dyes as a two-photon selective and type I based photosensitizers (PSs) were developed that exhibit excellent photodynamic therapy properties under mild condition.     

Asymmetric cationic coordination environments in new oxide materials: synthesis and characterization of Pb(4)Te(6)M(10)O(41) (M = Nb(5+) or Ta(5+))

Two new isostructural tellurites, Pb(4)Te(6)M(10)O(41) (M = Nb(5+) or Ta(5+)), have been synthesized by standard solid-state techniques using PbO, Nb(2)O(5) (or Ta(2)O(5)), and TeO(2) as reagents. The structures of Pb(4)Te(6)Nb(10)O(41) and Pb(4)Te(6)Ta(10)O(41) were determined by single-crystal and powder X-ray diffraction. The materials exhibit a three-dimensional framework consisting of layers of corner-shared NbO(6) octahedra connected by TeO(3) and PbO(6) polyhedra. The Nb(5+), Te(4+), and Pb(2+) cations are in asymmetric coordination environments attributable to second-order Jahn-Teller effects. The Nb(5+) cations undergo an intraoctahedral distortion either toward a face or a corner, whereas the Te(4+) and Pb(2+) cations are in distorted environments attributable to their lone pair. In addition, the TeO(3) polyhedra strongly influence the direction of the Nb(5+) intraoctahedral distortion. Infrared and Raman spectroscopy, thermogravimetric analysis, and dielectric measurements are also presented. Crystal data: Pb(4)Te(6)Nb(10)O(41), monoclinic, space group C2/m (No. 12), with a = 23.412(3) A, b = 20.114(3) A, c = 7.5008(10) A, beta = 99.630(4) degrees, V = 3482.4(8) A(3), and Z = 4; Pb(4)Te(6)Ta(10)O(41), monoclinic, space group C2/m (No. 12), with a = 23.340(8) A, b = 20.068(5) A, c = 7.472(2) A, beta = 99.27(3) degrees, V = 3453.8(2) A(3), and Z = 4.     

Metallic macrocycle with a 1,3-alternate calix[4]arene phosphorus ligand

The preparation of an 1,3-alternate calix[4]arene phosphorus ligand, 25,27-bis(2-(diphenylphosphino)ethoxy)-26,28-bis(1-propyloxy)calix[4]arene (3), is presented. Ligand 3 is obtained in three steps in 64% overall yield. Reaction of 3 with [Rh(cot)2]BF4 produced the encapsulated rhodium complex [Rh[(P,P)-diphen-calix[4]arene]]BF4 (4). As revealed by a single-crystal X-ray diffraction study, the rhodium center has a bent coordination environment with a P-Rh-P angle of 135.66(3) degrees. Palladation of 3 employing [Pd(MeCN)4](BF4)2 yielded the chelate palladium complex 7 in which the palladium center has a slightly bent configuration. Treatment of the ligand with Pd(cod)Cl2 and [Pd(eta3-C4H7)(THF)2]BF4 leads to the isolation of the monometallic complex. Full characterization includes X-ray structural studies of compounds 3, 4, and 6.     

An efficient synthesis of novel carbocyclic nucleosides with use of ring-closing metathesis from D-lactose

This paper describes an efficient synthetic route for various types of novel carbocyclic nucleosides. The required stereochemistry of the targeted nucleosides was successfully obtained with use of Grubbs cyclization and Trost allylic alkylation from the carbohydrate chiral template "D-lactose".     

Fluoride-facilitated deuterium exchange from DMSO-d6 to polyamide-based cryptands

Multiple deuterium exchange between DMSO-d6 and amide hydrogens in two hexaamido cryptand fluoride receptors has been verified by 19F and 2H NMR and FAB mass spectral studies. Structural results for one of the complexes indicate a tricapped trigonal prism hydrogen bond coordination geometry around an encapsulated fluoride, with hydrogen bonds from fluoride to six amide and three phenyl hydrogens.     

Anionic templating: synthesis,structure, and characterization of novel three-dimensional mixed-metal oxychlorides Te(4)M(3)O(15).Cl (M = Nb(5+) or Ta(5+))

Two new three-dimensional oxychlorides are reported, Te(4)M(3)O(15).Cl (M = Nb(5+) or Ta(5+)). The isostructural materials were synthesized by chemical transport reactions utilizing TeO(2), M(2)O(5), and MCl(5) (M = Nb(5+) or Ta(5+)) as reagents. The compounds exhibit a three-dimensional cationic tunnel framework, with Cl(-) anions occupying the tunnels. Crystal data: monoclinic, space group C2/c, a = 18.9944(7) A, b = 7.8314(3) A, c = 21.1658(8) A, beta = 116.6400(10) degrees, Z = 8 (T = 295 K).     

Improved expression by cytomegalovirus promoter/enhancer and behavior of vascular endothelial growth factor gene after myocardial injection of naked DNA

Direct injection of the vascular endothelial growth factor (VEGF) gene plasmid DNA into the myocardium was shown to induce development of new blood vessels to increase the circulation in the heart of patients with coronary artery diseases. However, such angiogenic gene therapy (via naked DNA) was limited by low level of gene expression. Furthermore, the temporal and spatial characteristics of VEGF gene transfer in the heart are not known. In this study, we demonstrated that a plasmid vector, containing the human cytomegalovirus immediate early (HCMV IE) promoter and enhancer, induces greater expression of gene in the rat heart monitored by gene fused to the chloramphenicol acetyl transferase (CAT) reporter, than four different viral and cellular promoters. Interestingly, expression of VEGF121 protein showed an earlier peak, a shorter duration, and a wider distribution than that of CAT only. Therefore, a plasmid vector with an HCMV IE promoter/enhancer provides clear advantages over other previously developed plasmids. Furthermore, expression profile of VEGF121 gene may provide useful information in the design of angiogenic gene therapy in the heart.     

Mixed-metal tellurites: synthesis, structure, and characterization of Na1.4Nb3Te4.9O18 and NaNb3Te4O16

Two new mixed-metal tellurites, Na1.4Nb3Te4.9O18 and NaNb3Te4O16, have been synthesized by standard solid-state techniques using Na2CO3, Nb2O5, and TeO2 as reagents. The structures of Na1.4Nb3Te4.9O18 and NaNb3Te4O16 were determined by single-crystal X-ray diffraction. Both of the materials exhibit three-dimensional structures composed of NbO6 octahedra, TeO4, and TeO3 polyhedra. The Nb5+ and Te4+ cations are in asymmetric coordination environments attributable to second-order Jahn-Teller (SOJT) effects. The Nb5+ cations undergo an intraoctahedral distortion toward a corner (local C4 direction), whereas the Te4+ cations are in distorted environments owing to their nonbonded electron pair. Infrared and Raman spectroscopy, UV-vis diffuse reflectance spectroscopy, thermogravimetric analysis, and dielectric measurements were also performed on the reported materials. Crystal data: Na1.4Nb3Te4.9O18, monoclinic, space group C2/m (No. 12), with a = 32.377(5) A, b = 7.4541(11) A, c = 6.5649(9) A, beta = 95.636(5) degrees, V = 1576.7(4) A3, and Z = 4; NaNb3Te4O16, monoclinic, space group P2(1)/m (No. 11), with a = 6.6126(13) A, b = 7.4738(15) A, c = 14.034(3) A, beta = 102.98(3) degrees, V = 675.9(3) A3, and Z = 2.