Function Of Ionization Potential Research Articles

Role of Transition Metals in Metal-Organic Frameworks as Nanoporous Ion Emitters for Thermal Ionization Mass Spectrometry.

Thermal ionization mass spectrometry is a powerful analytical technique that allows for precise determination of isotopic ratios. Analysis of low abundance samples, however, can be limited by the ionization efficiency. Following an investigation into a new type of metal-organic hybrid material, nanoporous ion emitters (nano-PIEs), devised to promote the emission of analyte ions and reduce traditional sample loading challenges, this work evaluates the impact that changing the metal in the material has on the ionization of uranium (U). Being derived from metal-organic frameworks (MOFs), nano-PIEs inherit the tunability of their parent MOFs. The MOF-74 series has been well studied for probing the impact various framework metals (i.e., Mg, Mn, Co, Ni, Cu, Zn, and Cd) have on material properties, and thus, a series of nano-PIEs with different metals were derived from this isoreticular MOF series. Trends in ionization efficiency were studied as a function of ionization potential, volatility, and work function of the framework metals to gain a better understanding of the mechanism of analyte ionization. This study finds a correlation between the analyte ionization efficiency and nano-PIE framework metal volatility that is attributed to its tunable thermal stability and degradation behavior.

Exciton Binding Energies in Conjugated Polyelectrolyte Films

Molecular design: The electronic structure of conjugated polyelectrolytes as a function of ionization potential (IP) and electron affinity (EA) is determined using X-ray absorption and emission spectroscopy (see figure). Different functional groups give rise to dissimilar transport gaps and exciton binding energies.

Study of Host−Guest Interaction of [70]Fullerene with Substituted Calix[6]arenes by Absorption Spectrometric Method

The host−guest interaction of various mono O-substituted calix[6]arenes, namely, (i) 37-benzyl-38,39,40, 41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert-butyl)calix[6]arene (1), (ii) 37-ethylester-38,39,40,41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert-butyl)calix[6]arene (2), and (iii) 37-allyl-38,39,40,41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert-butyl)calix[6]arene (3) with [70]fullerene has been studied in a CCl4 medium by the absorption spectroscopic method. All of the complexes are found to be stable with 1:1 stoichiometry. An absorption band due to a charge transfer (CT) transition is observed in the visible region; with increasing ionization potential of the mono O-substituted calix[6]arenes, the peak energy shifts to the higher energy side and the oscillator strength of CT transition increases. Degrees of CT have been estimated by analyzing the CT transition energy as a function of ionization potential. Thermodynamic parameters for the supramolecular complex formation of [70]fullerene with 1, 2, and 3 receptors are reported. The high formation constant value for the [70]fullerene·2 complex indicates that 2 forms an inclusion complex with [70]fullerene.

Optical transition and ionicity of C60/amine charge-transfer complexes studied by optical spectroscopy

Abstract We have investigated absorption spectra of charge-transfer (CT) complexes of C60 with various aromatic amines with different ionization potentials. An absorption band due to CT transition is observed in the visible region; with increasing ionization potential of amines, the peak energy shifts to the higher energy side and the oscillator strength of CT transition increases. We extract degrees of charge transfer by analyzing the transition energy of the CT band as a function of ionization potential and Raman spectra. The experimental results show that the CT complexes studied here have a neutral character in their ground state.

Line profiles and the kinematics of the narrow-line region in Seyfert galaxies

High signal-to-noise ratio and long-slit CCD spectra at about 100 km/sec resolution have been obtained for six high-ionization Seyfert galaxies. By subtracting the stellar absorption features with the aid of continuum templates, and using deblending techniques, the asymmetry indices of a number of optical emission-line profiles were measured, spanning a wide range in both ionization potential and critical density in each galaxy. The fundamental problem of the cloud-motion direction in the narrow-line region (NLR) has been studied, using these measurements and on the assumption that the preponderance of blueward profile asymmetries requires radial motion as well as a source of extinction. Simple and spherically symmetric NLR simulations are performed to demonstrate that infall and outflow models can be distinguished by comparing asymmetry indices as a function of ionization potential and critical density.