Anthony F. Lagalante

Atomic Absorption Spectroscopy: A Tutorial Review*

Atomic absorption spectroscopy is one of the important instrumental techniques for both quantitative and qualitative analysis of metallic and nonmetallic elements in inorganic or organic materials....

Solubility of p-t-butylcalixarenes in supercritical carbon dioxide: a comparison of static and dynamic measurement techniques

Abstract The solubilities of p - t -butylcalix[ n ]arenes ( n =4,6,8) and calix[4]arene have been measured in supercritical carbon dioxide. Solubility measurements were conducted in a high pressure cell with in situ spectrophotometric detection. Measurements were taken over the ranges of 10 to 20 MPa and 40 to 60°C. The p - t -butylcalix[4]arene showed solubility approximately 10 fold higher than both p - t -butylcalix[6]arene and p - t -butylcalix[8]arene with a maximum measured solubility over the studied pressure and temperature ranges of 1.84×10 −5 mol/l. A comparison of these results with measurements made with a commercially available analytical SFE unit for p - t -butylcalix[4]arene showed less than 10% deviation between the two sets of data over a common range of conditions. The SFE unit allows measurements to be made over significantly wider ranges of pressure and temperature than are currently available using the solubility cell.

Kamlet–Taft Solvatochromic Parameters for 25 Glycol Ether Solvents and Glycol Ether Aqueous Solutions

The Kamlet–Taft parameters for 25 glycol ethers and their aqueous solutions were measured. Values for the three Kamlet–Taft parameters: the hydrogen-bond donor ability, hydrogen-bond acceptor ability, and the dipolarity/polarizability, as well as the index of refraction, were determined for each pure glycol ether and each aqueous glycol solution. A correlation matrix between other known solvent parameters and the measured Kamlet–Taft values revealed only one correlation, suggesting that the three measured Kamlet–Taft parameters for the glycol ethers are independent solvent descriptors. Last, trends in the measured Kamlet–Taft values were related to functional group modifications to the basic glycol ether structure.

Evidence of a Host:Guest Complex between p-t-Butylcalix(4)arene and Carbon Dioxide ∗

In this paper we report evidence for an inclusion complex between carbon dioxide and p-t-butylcalix[4]arene. The complex was studied with infrared spectroscopy,single-crystal X-ray diffraction, solid-state NMR, and thermogravimetric analysis.Results indicate that 70% of the p-t-butylcalix[4]arene cavities could be occupiedby a CO2 molecule following exposure at 30 MPa and 40 °C.

High‐pressure equilibrium cell for solubility measurements in supercritical fluids

This paper describes the design, construction, and operation of an ultraviolet‐visible light‐transmission cell for high‐pressure fluids. The cell can be operated at pressures as high as 70 MPa and at temperatures up to 100 °C. This instrument was specifically designed to measure the solubility of solutes in supercritical fluids. The cell has an internal saturator and fluid circulator that are easy to remove and clean. The solubility of ferrocene in supercritical carbon dioxide was measured in the high‐pressure cell described here. At 40 °C, the mole fraction of ferrocene in carbon dioxide increased from 0.00005 to 0.0015 as the solvent density was increased from 5 to 17 mol/L.

Atomic Emission Spectroscopy: A Tutorial Review*

Atomic emission spectroscopy is an important instrumental technique for both quantitative and qualitative analysis of metallic and non-metallic elements in inorganic and organic materials. In this ...