Naphthalimide Trifluoroacetyl Acetonate: A Hydrazine-Selective Chemodosimetric Sensor

The trifluoroacetyl acetonate naphthalimide derivative 1 has been synthesized in good yield. In acetonitrile solution, compound 1 reacts selectively with hydrazine (NH2NH2) to give a five-membered ring. This leads to OFF-ON fluorescence with a maximum intensity at 501 nm as well as easily discernible color changes. Based on a readily discernible and reproducible 3.9% change in overall fluorescence intensity, the limit of detection for 1 is 3.2 ppb (0.1 mu M), which is below the accepted limit for hydrazine set by the U.S. Environmental Protection Agency (EPA). Compound 1 is selective for hydrazine over other amines, including NH4OH, NH2OH, ethylenediamine, methylamine, n-butylamine, piperazine, dimethylamine, triethylamine, pyridine, and is not perturbed by environmentally abundant metal ions. When supported on glass-backed silica gel TLC plates, compound 1 acts as a fluorimetric and colorimetric probe for hydrazine vapor at a partial pressure of 9.0 mm Hg, with selectivity over other potentially interfering volatile analytes, including ammonia, methylamine, n-butylamine, formaldehyde, acetaldehyde, H2O2, HCl, and CO2 being observed. Probe 1 can also be used for the detection of hydrazine in HeLa cells and does so without appreciable interference from other biologically abundant amines and metal ions.U.S. National Science Foundation CHE-1057904Robert A. Welch Foundation F-1018CRI project grant from National Research Foundation of Korea (NRF)Korea government (MSIP) 2009-0081566Chemistr

A Dicationic Calix 4 Pyrrole Derivative and Its Use for the Selective Recognition and Displacement-Based Sensing of Pyrophosphate

A new bis-pyridinium calix[4] pyrrole derivative is reported. This system forms a non-fluorescent complex upon exposure to the chromenolate anion. The resulting supramolecular ensemble binds the pyrophosphate anion with high affinity (K-a (2.55 +/- 0.12) x 10(7) M-1) in acetonitrile. It exhibits sensitive "turn-on" fluorescence when exposed to tetrabutylammonium pyrophosphate, and does so in preference to other anions, including the fluoride and phosphate anions.NRF 2009-0087013BK21 programNational Science Foundation NSF CHE-1057904Chemistr

Method and compositions for treating atheroma, tumors and other neoplastic tissue

The radiation sensitization potential of a candidate compound can be screened by determine its ability to generate one or more reactive oxygen species under appropriate conditions. Compounds determined to have radiation sensitization potential are employed in methods for treating atheroma, tumors and other neoplastic tissue as well as other conditions that typically responsive to radiation sensitization.Board of Regents, University of Texas Syste

Methods and compositions for treating atheroma, tumors and other neoplastic tissue

Injectible formulations comprising motexafin gadolinium are described herein.Board of Regents, University of Texas Syste

A Pyrrole-Based Triazolium-Phane with Nh and Cationic Ch Donor Groups as a Receptor for Tetrahedral Oxyanions that Functions in Polar Media

The pyrrole-based triazolium-phane 1(4+)center dot 4BF(4)(-) has been prepared via the tetraalkylation of a macrocycle originally prepared via click chemistry. It displays a high selectivity for tetrahedral oxyanions relative to various test monoanions and trigonal planar anions in mixed polar organic-aqueous media. This selectivity is solvent dependent and is less pronounced in acetonitrile. Theoretical calculations were carried out in with the chloride anion in an effort to understand the influence of solvent on the intrinsic hydrogen bonding ability of the donor groups (pyrrole N-H, benzene C-H and triazolium C-H). The host-guest interactions between receptor 1(4+)center dot 4BF(4)(-) and representative tetrahedral oxyanions were further analysed by H-1 NMR spectroscopy, and the findings proved consistent with the differences in the intrinsic strength of the various H-bond donor groups inferred from the electronic structure calculations carried out in methanol, namely that (CH)(+)-anion interactions are less important in an energetic sense than neutral CH-anion interactions in polar media. Single crystal X-ray diffraction analyses of the mixed salts 1(4+)center dot HP2O73-center dot BF4- and 31(4+)center dot 4H(2)PO(4)(-)center dot 8BF(4)(-) confirmed that receptor 1(4+) can bind the pyrophosphate and phosphate anions in the solid state.Cai, Jiajia, Benjamin P. Hay, Neil J. Young, Xiaoping Yang, and Jonathan L. Sessler. "A pyrrole-based triazolium-phane with NH and cationic CH donor groups as a receptor for tetrahedral oxyanions that functions in polar media." Chemical Science 4, no. 4 (Jan., 2013): 1560-1567.Chemistr

Water-soluble sapphyrins

Sapphyrins are provided having appended functional groups that render the sapphyrin water-soluble. Such water-soluble sapphyrins are useful for photodynamic therapy, for example.Board of Regents, University of Texas Syste

On The Performance Characteristics Of Electron Ring accelerators

On the basis of our present understanding of the physical phenomena involved in an electron ring accelerator (ERA), a theoretical study is made of the performance which might be expected for an ERA. Rigorous upper bounds are obtained on the rate of energy gain, from which it is shown that, in order to prevent azimuthal instability, parameters must be selected such that (for reasonable fields, injector properties, etc., but with no safety factors) the proton energy gain is less than 80 MeV/m. Numerical examples and approximate formulas are given for the properties of rings satisfying the stability conditions for both azimuthal oscillations and ion-electron oscillations. It is found that for reasonable fields and injector properties, but without safety factors, the useable proton energy gain is less than 45 MeV/m

Supramolecular electron transfer-based switching involving pyrrolic macrocycles. A new approach to sensor development?

This Feature focuses on pyrrolic macrocycles that can serve as switches via energy- or electron transfer (ET) mechanisms. Macrocycles operating by both ground state (thermodynamic) and photoinduced ET pathways are reviewed and their ability to serve as the readout motif for molecular sensors is discussed. The aim of this article is to highlight the potential utility of ET in the design of systems that perform molecular switching or logic functions and their applicability in chemical sensor development. The conceptual benefits of this paradigm are illustrated with examples drawn mostly from the authors' laboratoriesThe work in Austin was supported by the U.S. National Science Foundation (grant CHE-1402004 to J.L.S.) and the Robert A. Welch Foundation (Grant F-1018 to J.L.S.). Financial support from the Spanish MICINN (CTQ2011-24187/BQU) and the Comunidad de Madrid (S2013/MIT-2841 FOTOCARBON) is acknowledge

Sapphyrin multimers

The present invention provides novel sapphyrin dimers, trimers, oligomers and polymers, which multimers may include repeating units of sapphyrin or sapphyrin derivatives alone, or may further incorporate other units such as nucleobases.Board of Regents, University of Texas Syste