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Synthesis, Characterization, Thermodynamic, and Kinetic Studies of Vapochromic Pt(II) Complexes.

Karimi Abdolmaleki, Mahmood
http://orcid.org/0000-0002-0815-187X
http://rave.ohiolink.edu/etdc/view?acc_num=ucin152233710600004

Abstract Details

2018, PhD, University of Cincinnati, Arts and Sciences: Chemistry.
Vapochromic materials, undergoes a reversible color change upon exposure to certain volatile organic compounds (VOCs). Since color changes are easily detected by eye, these materials are potentially useful in the detection of specific hazardous volatile compounds (e.g., NH3, pyridine, CO, H2S). Therefore, there is considerable interest in understanding the properties of vapochromic materials and their potential practical uses. The most well-known class of vapochromic materials are solids containing molecular platinum(II) complexes, which have been the focus of numerous studies. The tendency of solids containing square-planar d8-electron platinum metal centers to exhibit vapochromic properties is related in part to the propensity of these complexes to form close non-covalent Pt…Pt contacts, which have a strong influence on the solid-state color (e.g., yellow, orange, red, purple) and spectroscopy of these materials. The color changes upon vapor absorption and desorption typically are not a result of chemical reaction. Instead, they are related to vapor absorption/desorption induced changes in crystal packing and intermolecular interactions. The resulting changes in Pt…Pt distances have a dramatic effect on the color and luminescence properties of these materials. However, despite considerable progress, the discovery of vapochromic platinum(II) systems remains largely serendipitous. Moreover, the vapochromic mechanism, energetics, morphological factors, and the relationship between spectroscopic properties, structure, and the sorption/desorption kinetics and thermodynamics are not fully understood. This lack of understanding is preventing researchers from rationally tailoring the response time, selectivity, and sensitivity, as required for sensing applications. Chapter 2 describes the use of a cell phone camera and the CIELAB method (color space specified by the International Commission on Illumination) to characterize the color change in different vapochromic systems. In this study we have developed a semi-automatic color change analysis software that digitally analyzes images (e.g., video frames) collected while a vapochromic material is absorbing or desorbing vapor. Chapter 3 reports a detailed investigation of [Pt(dcmbpy)Cl2].CH2Cl2, which exhibits the unusual behavior of responding to certain vapors without vapor uptake. Specifically, red, solid [Pt(dcmbpy)Cl2].CH2Cl2 changes to green and finally to a yellow material upon exposure to acetone, THF, and methanol vapors. Chapter 4 reports the first example of the determination of the enthalpy of vaporization (?Hvap) and activation energy (Ea) for solvate loss for a homologous series of vapochromic materials. In addition to these parameters, we have evaluated parameters describing sensitivity, speed of color change during vapor desorption, speed of color change during vapor absorption, and the volume attributed to the acetonitrile molecule in the solvate structures of nine salts having very similar compositions.
William Connick, Ph.D. (Committee Chair)
Bruce Ault, Ph.D. (Committee Member)
Michael Baldwin, Ph.D. (Committee Member)
Robert Streicher, Ph.D. (Committee Member)
122 p.
Chemistry
vapochromism; platinum; terpyridine; morphology; Thermodynamic; Kinetic

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Citations

  • Karimi Abdolmaleki, M. (2018). Synthesis, Characterization, Thermodynamic, and Kinetic Studies of Vapochromic Pt(II) Complexes. [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin152233710600004

    APA Style (7th edition)

  • Karimi Abdolmaleki, Mahmood. Synthesis, Characterization, Thermodynamic, and Kinetic Studies of Vapochromic Pt(II) Complexes. 2018. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin152233710600004.

    MLA Style (8th edition)

  • Karimi Abdolmaleki, Mahmood. "Synthesis, Characterization, Thermodynamic, and Kinetic Studies of Vapochromic Pt(II) Complexes." Doctoral dissertation, University of Cincinnati, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin152233710600004

    Chicago Manual of Style (17th edition)

ucin152233710600004
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This open access ETD is published by University of Cincinnati and OhioLINK.