Dissertations / Theses: 'Tetracyanoethylen'

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Pisliakov, Andrei. "Theory of time- and frequency-gated spontaneous emission from systems with nonadiabatic coupling and dissipation." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=970018401.

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De, Fusco Giulia Carlotta. "Density Functional Study of Tetracyanoethylene-based Organic Magnets." Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522860.

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DaSilva, Jack Guy. "Pressure dependent magnetic investigation of tetracyanoethylene-based molecule-based magnets and their analogues." Thesis, The University of Utah, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3593070.

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Several metal-tetracyanoethylene (TCNE) compounds, including the [bis(pentamethylcyclopentadienyl)iron(III)][tetracyanoethylene], [FeCp*2][TCNE], family of molecule-based magnets and two cyanide based MBMs were investigated by pressure dependent DC magnetic measurements. The 0-D electron transfer salts: [FeCp*2][TCNE], ferromagnetic [FeCp*2][TCNQ] (TCNQ = 7,7,8,8-tetracyanoquinodimethane), metamagnetic [FeCp*2][TCNQ], [FeCp*2][HCBD] (HCBD = hexacyanobutadiene), and [FeCp*2][DDQ] (DDQ = 2,3-dichloro-5,6-dicyano-p-benzoquinone) exhibited an array of magnetic behavior both at ambient and applied pressure. [FeCp*2][TCNE] and [FeCp*2][HCBD] exhibited weak ferromagnetism above 4.2 and 3.1 kbar, respectively. The ferromagnetic polymorph of [FeCp*2][TCNQ] displayed linear increase to the critical temperature, Tc, and the bifurcation temperature, Tb, reaching 5.01 and 5.46 K, respectively at 10.3 kbar. The coercive field, Hcr, displayed exponential-like increase, reaching 550 Oe at 10.3 kbar. The metamagnetic polymorph of [FeCp*2][TCNQ] displayed linear increase of the Tc at low applied pressure, reaching 2.90 at 2.9 kbar, then transitioned to a paramagnetic state at further applied pressure. [FeCp*2][HCBD] transitioned from a paramagnetic state at ambient pressure to a weak ferromagnetic state at 3.1 kbar with a Tc, H cr, and Hc of 2.46 K, 25 Oe, and 2,200 Oe, respectively. The Tc and H c then increased linearly with further applied pressure to 4.80 K and 10,000 Oe, while the Hcr increased exponentially to 795 Oe, at 11.4 kbar. [FeCp*2][DDQ] exhibited paramagnetic behavior at ambient and applied pressures up to 9.2 kbar. The structurally related 2-D MnII(TCNE)I(H2O) and 3-D MnII(TCNE) 3/2(I3)1/2, showed significant increases to the Tc, Tb, and Hcr with applied pressure. A high- and low-pressure regions were observed for MnII(TCNE)I(H2O). 2-D [Ru2(O2CBu t)4][M(CN)6] · H2O (M = Fe, Cr) displayed suppression of hysteretic properties at high applied pressure and irreversibility of the suppression. A Mean Field (MF) analysis of three structurally related non-cubic Prussian blue analogues (PBA) was performed to assess the intensity of their coupling modes. These values were framed by the reinvestigation of several known cubic PBAs and comparing the coupling intensities, as well as evaluating the MF theory in the context of these structures as several had been evaluated by other means.

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Banerjee, Siddthartha. "Photo retro Diels-Alder reaction of the adducts of tetracyanoethylene and polyaromatic compounds." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4842.

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Thermally induced retro-Diels Alder (rDA) reaction has been extensively used for the preparation of many reactive intermediates in organic synthesis. But the uses of photo-retro Diels-Alder (PrDA) reaction in organic synthesis were sparingly reported in literature. Due to its spatial and temporal control, PrDA can be used in making of photosensitive materials, in drug delivery and also for mechanistic studies. Diels-Alder adducts of tetracyanoethylene (TCNE) and polyaromatic compounds (anthracene, napthacene, pentacene and phencyclone) were synthesized and were subjected to PrDA reaction through 254-nm irradiation. The quantum yield and the consequent photoreactivity of these DA adducts follow the following order. TCNE/naphthacene greater than] TCNE/anthracene greater than or equal to] TCNE/pentacene This trend was explained by a mechanism of charge-separated intermediates. The stability of the charge-separated intermediate is the governing factor of this trend of photoractivity of DA adducts. Based on these results it is possible to design a proper DA adduct and consequently predict the feasibility of the PrDA reaction. ID: 030423433; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2011.; Includes bibliographical references (p. 28-29). M.S. Masters Chemistry Sciences Industrial Chemistry

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Lincoln, Derek M. "The electronic structure and field effects of an organic-based room temperature magnetic semiconductor." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1193833038.

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Chilcote, Michael A. "Controlling Anisotropy in Organic-Based Magnets for Coherent Magnonics." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1546565729485741.

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Richter, Sebastian. "Neue binäre CN-Verbindungen sowie Vorläufersubstanzen von monomerem C3N4." Doctoral thesis, Universitätsbibliothek Chemnitz, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-155547.

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Gegenstand dieser Arbeit sind Versuche zur Synthese neuer binärer Kohlenstoffnitride im Allgemeinen und von C3N4-Vorläuferverbindungen im Speziellen. Hierbei werden v. a. die Herstellung und die Eigenschaften organischer Polyazide beschrieben, die aufgrund ihrer Gefährlichkeit durch zahlreiche Folgereaktionen in weniger brisante Moleküle überführt werden mussten. Als Derivatisierungsreaktionen kamen hierbei beispielsweise die 1,3-dipolare Cycloaddition mit Norbornen und Cyclooctin, die STAUDINGER-Reaktion mit verschiedenen Phosphinen sowie die Aza-WITTIG-Reaktion zum Einsatz. Es konnten dabei u. a. zehn Röntgeneinkristallstrukturen erhalten und als Strukturbeweis aufgeführt werden. Zahlreiche hochaufgelöste Massenspektren sowie Elementaranalysen und NMR-Daten bestätigten außerdem alle neu erhaltenen Strukturen. Einen weiteren Schwerpunkt dieser Arbeit stellen Versuche zur Synthese von monomerem C3N4 dar, dessen Herstellung zwar nicht gelang, für dessen Bildung allerdings neue Möglichkeiten ausgehend von verschiedenen Edukten beschrieben werden. Darüber hinaus wurden bereits bekannte Moleküle auf ihre Eignung als C3N4-Vorläufer untersucht, wobei z. B. durch Azid-Addition an Nitrilgruppen unerwartete neue Produkte erhalten werden konnten.

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Franson, Andrew J. "Patterning and Characterization of Ferrimagnets for Coherent Magnonics." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595333967161284.

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Yeh, Yu Fang, and 葉友芳. "Ultrafast Time-Resolved Fluorescence Studies of Intermolecular Charge Transfer in Toluene-Tetracyanoethylene and Benzene-Tetracyanoethylene Complexes." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/43049831802034357455.

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Cheng, Ting-Pu, and 鄭亭菩. "Ultrafast Time-Resolved Fluorescence Studies of Intermolecular Charge Transfer Dynamics in Olefin-Tetracyanoethylene Complexes." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/48juvh.

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碩士 國立清華大學 化學系所 106 We studied the charge-transfer (CT) state relaxation dynamics of a series of electron donor-acceptor (EDA) complexes with broadband ultrafast time-resolved fluorescence spectroscopy implemented by optical Kerr gating and transient absorption spectroscopy. The EDA complexes studied here are those containing various olefins (1-hexene, 2-hexene, 1-methylcyclohexene, 2,3-dimethyl-2-butene) as the donor and tetracyanoethylene (TCNE) as the acceptor. In our experiments, the CT state of the EDA complexes are directly reached by femtosecond laser excitation in either CH2Cl2 or CCl4 solutions, and the subsequent temporal evolution of the fluorescence spectra were measured to explore the charge recombination (CR) dynamics. EDA complexes with various arenes, including methyl substituted and non-methyl substituted benzenes, as the donor have been studied previously in our laboratory. We used the total fluorescence intensity function P(t) to analyze CT state relaxation and CR dynamics of EDA complexes. We found two different decay behaviors in these olefin-TCNE complexes. The faster component (<1 ps) was assigned to vibrational relaxation and solvation , the slower component was attributed to CR. We concluded that the most important difference between the olefin-TCNE and arene-TCNE complexes was the electronic coupling strength. The greater electronic coupling strength in the olefin-TCNE complexes extremely accelerates CR reactions and result in a weak dependence of ET rate on the driving-force.

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Yu, Chin Ann, and 于慶安. "Ultrafast Time-Resolved Fluorescence Studies of Intermolecular Charge Transfer Dynamics in Tetracyanoethylene-Methylbenzene Complexes." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/39670260453970693098.

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碩士 國立清華大學 化學系 103 This dissertation employed an ultrafast time-resolved fluorescence (TRFL) spectrometer implemented by optical Kerr gating (OKG) and density functional theory calculations implemented in the Gaussian 09 program to study electron transfer dynamics in tetracyanoethylene-methylbenzene (TCNE-MBZ) complexes (MBZ = Benzene, Toluene, p-Xylene) in two solvents (CH2Cl2, CCl4) of different polarities. We used femtosecond laser to excite the TCNE-MBZ complexes to the CT-states, and the resulting TRFL spectra were measured. Analyses of the total fluorescence intensity function P(t), which describes the temporal evolution of excited state population and transition dipole moment, revealed complex relaxations associated with charge recombination (CR). We found different decay behaviors in two solvents. The fastest component which are in the similar time scale (< 0.2 ps) for the three complexes is assigned to CT2→CT1 transition, and the slowest component is ascribed to CR. The CR time constants in CH2Cl2 for TCNE-p-Xylene, TCNE-Toluene, TCNE- Benzene are 0.5, 7 and 29 ps, respectively, The CR time constants in CCl4 for TCNE-p-Xylene, TCNE-Toluene, TCNE- Benzene are 290, 820 and 150 ps, respectively. We concluded that CR time constants are consisted with the behavior in the Marcus inverted region. However the CR rates in CCl4 is reverted when the driving force(-∆G0) increase in the case of TCNE-Benzene. We use the intersecting state model (ISM) to explain this unexpected behavior. ISM accounts for structural relaxation of complex which the Marcus theory does not consider. Finally, we found that the CR rates of complexes in polar solvent is faster than in nonpolar solvent, which is mostly due to solvation effet.

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Yen, Wei-Cheng, and 顏煒城. "Ultrafast Time-Resolved Optical Kerr Gating Fluorescence Studies of Intermolecular Charge Transfer in Olefin-Tetracyanoethylene Complexes." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/sx3w6a.

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碩士 國立清華大學 化學系所 106 The charge-transfer (CT) state relaxation dynamics of a series of electron donor-acceptor (EDA) complexes was studied with broadband ultrafast time-resolved fluorescence spectroscopy implemented by optical Kerr gating. The EDA complexes studied here are those containing various arenes or olefins as the donor and tetracyanoethylene (TCNE) as the acceptor. In our experiments, the CT state of the EDA complexes are directly reached by femtosecond laser excitation in either CH2Cl2 or CCl4 solutions, and the subsequent temporal evolution of the fluorescence spectra were measured to explore the charge recombination (CR) dynamics. EDA complexes with various arenes, including methyl substituted and non-methyl substituted benzenes, as the donor have been studied previously in our laboratory. Here, we present our data on CT state relaxation and CR dynamics of EDA complexes containing a series of olefins (1-hexene, 2-hexene, 1-methylcyclohexene, 2,3-dimethyl-2-butene) as the donor and TCNE as the acceptor. The analysis of the total fluorescence intensity function P(t), which described the temporal evolution of the population of the excited states and the transition dipole moments, revealed the relaxations of the complexes. We found two CT-state decay behaviors of the complexes in these two solvents. The faster components of the complexes are in the similar time scale (<0.3 ps in CH2Cl2；<1 ps in CCl4), which are assigned to the structural relaxation of the CT state, and the slower ones (1-3 ps in CH2Cl2；10-20 ps in CCl4) are identified as the CR. We found that the CR rates of olefin-TCNE complexes are faster than arene-TCNE complexes with similar driving force (-∆G0) for electron transfer. Surprisingly, the CR rate constants are strikingly nonvariant among the different olefin-TCNE complexes despite large differences in the driving force (-∆G0) for electron transfer.

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Chen, Guan-Shao, and 陳冠劭. "Ultrafast Time-Resolved Fluorescence Studies of Intermolecular Charge Transfer Dynamics in non-Methyl Substituted Benzene-Tetracyanoethylene Complexes." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/bx3j2j.

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碩士 國立清華大學 化學系所 106 Ultrafast dynamics of substituted benzene-TCNE complexes in two solvents (CH2Cl2, CCl4) was investigated in ultrafast time-resolved fluorescene (TRFL) spectrometer implemented by optical Kerr gating (OKG). We used femtosecond laser to excite the non-methyl substituted benzene-TCNE complexes to CT states, and the resulting TRFL spectra were measured. We used the total fluorescene (P(t)) to analyze the result which reveal complexes relaxations associated with charge recombination(CR). We found different decay behaviors in different solvents. The fastest component in the similar time scale (<0.2 ps) for three complexes (chlorobenzene(PhCl)-TCNE、fluorobenzene(PhF)-TCNE、benzonitrile(PhCN)-TCNE) is assigned to CT2→CT1 transition and the slowest component is ascribed to CR. The CR time constant in CH2Cl2 for PhCl-TCNE、PhF-TCNE、PhCN-TCNE are 45, 21 and29 ps, respectively. The CR time constant in CCl4 for PhCl-TCNE、PhF-TCNE、Tolunitrile-TCNE、PhCN-TCNE、4-chlorobenzonitrile-TCNE are 580, 470, 210, 140 and 280 ps, respectively. We concluded that no matter which solvents we used, CR time constants of methylbenzene-TCNE complexes are consisted with the behavior in the Marcus inverted region. However, the others violate the behavior. We use the intersecting state model (ISM) which accounts for structural relaxation of complex that the Marcus theory doesn’t consider to explain this unexpected behavior.

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Yang, Wan Ru, and 楊宛儒. "Ultrafast Time-Resolved Optical Kerr Gating Fluorescence Studies of Intermolecular Charge Transfer in Substituted-Benzene-Tetracyanoethylene Complexes." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/86092917914042574049.

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碩士 國立清華大學 化學系 103 We employed a broadband ultrafast time-resolved fluorescence (TRFL) spectrometer implemented by the optical Kerr gating (OKG) to study the charge transfer (CT) state dynamics of methyl-substituted benzene-tetracyanoethylene (MBZ-TCNE, MBZ = benzene, toluene and p-xylene) in two solvents (CH2Cl2, CCl4) of diffrernt polarities. The CT-state of the MBZ-TCNE complexes are reached via femtosecond laser excitation, and the observed TRFL spectra reveal CT-state relaxation dynamics from the initial CT-state to charge recombination (CR). We used a total fluorescence intensity function P(t) to describe the excited-state population and transition dipole moment evolution with time during CT-state relaxation. The three complexes studied in two solvents exhibit a very fast initial decay component of similar time scale (< 0.2 ps), which can be assigned to CT2→CT1 internal conversion. The CR time constants for p-XY-TCNE (λex = 383 nm), TOL-TCNE ( nm) and BZ-TCNE ( nm) are 0.6, 7 and 29 ps in CH2Cl2. The equilibrium CR time constants for p-XY-TCNE (λex = 383 nm), TOL-TCNE ( nm) and BZ-TCNE ( nm) are 280, 850 and 150 ps in CCl4. The CR rate constants of MBZ-TCNE in CH2Cl2 are in line with the expectation for the Marcus inverted region, but CR rates in CCl4 do not agree with Marcus inverted region. The unexpected reversed -G0 dependence of the equibrium CR rates in CCl4 can be explained by the intersecting state model (ISM), which takes structural relaxation of complexes into account. Finally, CR rates of the CT-state of these MBZ-TCNE complexes are much faster in polar solvents due to the strong polar solvation.

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Chen, Chieh-Lin, and 陳捷琳. "Ultrafast Time-resolved Fluorescence Study of the Solvent Effect on Electron Transfer Dynamics in Complexes of Tetracyanoethylene with Benzene." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/45830434815527934522.

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Wen, Yi-Fan, and 温逸凡. "Ultrafast Time-Resolved Optical Kerr Gating Fluorescence Studies of Intermolecular Charge Transfer in non-Methyl Substituted Benzene- Tetracyanoethylene Complexes." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/kh66vv.

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碩士 國立清華大學 化學系所 106 In this thesis, we used an ultrafast time-resolved fluorescence (TRFL) spectrometer implemented by optical Kerr gating (OKG) and density functional theory calculations to study the electron transfer dynamics in some substituted benzene-tetracyanoethylene (SBZ-TCNE) complexes (SBZ = Chlorobenzene, Fluorobenzene, Benzonitrile, p-Tolunitrile, p-Chlorobenzonitrile) in two solvents (CH2Cl2, CCl4) with different polarities. We used a femtosecond laser to excite the SBZ-TCNE complexes to the charge-transfer (CT) states, and obtained the information from their absorption, fluorescence and TRFL spectra. The analysis of the total fluorescence intensity function P(t), which described the temporal evolution of the population of the excited states and the transition dipole moments, revealed the relaxations of the complexes such as the charge recombination (CR). We found different decay behaviors of the complexes excited states in two solvents. The fastest components of the complexes are in the similar time scale (< 0.2 ps), which is assigned to CT2→CT1 transition, and the slowest one is identified as the CR. The CR time constants of PhCl-TCNE, PhF-TCNE, PhCN-TCNE in the CH2Cl2 are 45, 21, and 28 ps. The CR time constants of PhCl-TCNE, PhF-TCNE, PhCN-TCNE, p-MePhCN-TCNE and p-ClPhCN-TCNE are 580, 470, 140, 210 and 280 ps, respectively. We found that the CR rates of complexes in the polar solvent are faster than in the nonpolar solvent which is mostly due to solvation effects. Surprisingly, the relationship between CR time constants and -∆G0 does not completely obey the Marcus theory and exhibits a double-inversion behavior. We used the intersecting state model (ISM) to explain this unexpected behavior. This model proposed that ultraexothermic reactions accompany large changes in structures which can affect the reorganization energy, and reaction barrier, resulting in the observed double-inversion behavior.

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Hung, Chih-Chang, and 洪志昌. "Electron-Transfer Dynamics of Tetracyanoethylene-Methylbenzene Electron Donor-Acceptor Complexes Studied by Ultrafast Time-resolved Optical Kerr Gating Fluorescence Spectroscopy." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/07195938509400445029.

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Dissertations / Theses on the topic 'Tetracyanoethylen'

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