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24, Lost, and Six Feet Under: Post-traumatic television in the post-9/11 era. (open access)

24, Lost, and Six Feet Under: Post-traumatic television in the post-9/11 era.

This study sought to determine if and how television texts produced since September 11, 2001, reflect and address cultural concerns by analyzing patterns in their theme and narrative style. Three American television serials were examined as case studies. Each text addressed a common cluster of contemporary issues such as trauma, death, and loss.
Date: May 2008
Creator: Anderson, Tonya
System: The UNT Digital Library
The Actions and Operational Thinking of Generals Stratemeyer and Partridge during the Korean War:  Adjusting to Political Restrictions of Air Campaigns (open access)

The Actions and Operational Thinking of Generals Stratemeyer and Partridge during the Korean War: Adjusting to Political Restrictions of Air Campaigns

Airpower played an important supporting role in the Korean War, and as General of the Army Douglas MacArthur pursued victory in the war and President Harry S Truman's objectives altered throughout the first year of the conflict, tension arose between the two men. One issue in these frictions was the restriction of airpower. Not only MacArthur, but also his admiring subordinate Lieutenant General George E. Stratemeyer commanding the Far East Air Forces, and Fifth Air Force commander Major General Earle E. Partridge opposed the restrictions which had been imposed on airmen from the outset of the conflict. Stratemeyer did so partly because of his loyalty to MacArthur, who wanted latitude in coping with the situation in the field and defeating the Communist enemy. Partridge did so because he thought they endangered his personnel and limited the effectiveness of airpower in the war. These commanders had a fundamentally different opinion from Washington regarding the likelihood of overt Soviet intervention in the war, and because they did not think the Korean War would become a world war, they were more willing than Washington to prosecute the war more aggressively. MacArthur's conflict ended with his removal in April 1951, and Stratemeyer (who suffered …
Date: May 2008
Creator: Sambaluk, Nicholas Michael
System: The UNT Digital Library
Adolescent Self-Mutilating Behaviors: Experiential Avoidance Coupled with Imitation? (open access)

Adolescent Self-Mutilating Behaviors: Experiential Avoidance Coupled with Imitation?

Repetitive self-mutilation (RSM) has become increasingly prevalent among adolescents. Empirical research has pinpointed several correlates of this behavior, but the initiation and maintenance of RSM among adolescents are not well understood. The experiential avoidance model (EAM) proposes that self-mutilation is a behavior that allows for the avoidance or alteration of unwanted internal experiences, and that it is negatively reinforced with repetition. The current study explored the usefulness of the EAM as an explanatory theory for adolescent RSM, with the additional incorporation of issues of social context. Adolescents (N = 211) from three school-based samples completed self-report questionnaires. One-third of students reported at least one incident of purposeful, non-suicidal self-mutilation and 16% had engaged in self-mutilation repeatedly within the past 6 months. Both regression and group analyses indicated that adolescents who engage in RSM report greater psychological distress, a greater incidence of functionally equivalent behaviors, and greater exposure to self-mutilation among peers and/or in the media, when compared to their counterparts who have not engaged in RSM. Suicidal ideation/behaviors were consistently the strongest predictors of current self-mutilation behaviors. Clinical implications, limitations, and suggestions for future research are discussed.
Date: August 2008
Creator: Howe-Martin, Laura S.
System: The UNT Digital Library
Adult Attachment and Posttraumatic Growth in Sexual Assault Survivors. (open access)

Adult Attachment and Posttraumatic Growth in Sexual Assault Survivors.

Posttraumatic growth, defined as positive psychological changes in the aftermath of adversity and suffering, is a relatively recent focus in psychological research. The addition of this concept to the literature has provided a new, more resiliency-based framework through which to view survivors of various forms of trauma. Despite estimates that over half of all sexual assaults are not reported to the authorities, current crime statistics indicate that 1 in 4 women are sexually assaulted in their lifetime (Campbell & Wasco, 2005). Given the large percentage of the population that is impacted by sexual assault, it is essential that professionals better understand the factors that influence the successful healing and growth that can occur post-trauma. The purpose of this study was to further expand the literature on posttraumatic growth in sexual assault survivors by considering this phenomenon through the lens of attachment theory. Specifically, this study tested a proposed model of the inter-relationships among subjective and objective perceptions of threat during the sexual assault, adult romantic attachment, and posttraumatic growth. It was hypothesized that adult romantic attachment and parent-child attachment would mediate the relationship between subjective, or perceived threat, defined as the victim's perception of life threat, and objective threat, defined …
Date: August 2008
Creator: Gwynn, Stacy Roddy
System: The UNT Digital Library
Advanced Technology for Source Drain Resistance Reduction in Nanoscale FinFETs (open access)

Advanced Technology for Source Drain Resistance Reduction in Nanoscale FinFETs

Dual gate MOSFET structures such as FinFETs are widely regarded as the most promising option for continued scaling of silicon based transistors after 2010. This work examines key process modules that enable reduction of both device area and fin width beyond requirements for the 16nm node. Because aggressively scaled FinFET structures suffer significantly degraded device performance due to large source/drain series resistance (RS/D), several methods to mitigate RS/D such as maximizing contact area, silicide engineering, and epitaxially raised S/D have been evaluated.
Date: May 2008
Creator: Smith, Casey Eben
System: The UNT Digital Library
Affective and cognitive components of job satisfaction: Scale development and initial validiation. (open access)

Affective and cognitive components of job satisfaction: Scale development and initial validiation.

Job satisfaction is one of the most commonly studied variables in the organizational literature. It is related to a multitude of employee-relevant variables including but not limited to performance, organizational commitment, and intent to quit. This study examined two new instruments measuring the components of affect and cognition as they relate to job satisfaction. It further proposed including an evaluative (or true attitudinal) component to improve the prediction of job satisfaction. Results provide some evidence of both two and three factor structures of affect and cognition. This study found minimal support for the inclusion of evaluation in the measurement of job satisfaction. Affect was found to be the single best predictor of job satisfaction, regardless of the satisfaction measure used. Further development is needed to define the factor structures of affect and cognition as well as the role of these factors and evaluation in the prediction of job satisfaction.
Date: August 2008
Creator: Tekell, Jeremy Kyle
System: The UNT Digital Library
Affordances of External Representations in Instructional Design: The Effect of Narrative and Imagery in Learning. (open access)

Affordances of External Representations in Instructional Design: The Effect of Narrative and Imagery in Learning.

Consisting of both theoretical and empirical inquires, this study examines the primary functions of narrative and the relationship between narrative and mental imagery. The study proposes a new framework to interpret semiotic resources. Combining this with the linguistic functional theory of Halliday (1978), a functional method to empirically investigate semiotic representations was also developed. In the empirical inquiry, the study developed a latent construct method to empirically test the effects of narrative in a real learning situation. This study is the first to investigate the functional relationship between narrative and mental imagery, and among the first to suggest a theory and empirically investigate representations of a multimodal nature. The study is also among the first to use latent constructs to investigate the learning experience in a real educational setting. Data were collected from 190 library professionals who enrolled in three sections (two in narrative and one in plain text) of an online course administered through Vista 4.0 and who completed the course and responded to several instruments. Essay data (n = 82 x 2) were analyzed using content analysis based on the narrative analysis framework developed. Quantitative data analysis methods include univariate data analysis, factor analysis, and structural equation modeling …
Date: December 2008
Creator: Wu, Yan
System: The UNT Digital Library
Agreement Between Self and Other Ratings in Multi-Rater Tools: Performance, Alternative Measures, and Importance. (open access)

Agreement Between Self and Other Ratings in Multi-Rater Tools: Performance, Alternative Measures, and Importance.

Multi-rater tools also referred to as 360-degree feedback tools, are frequently used in addition to traditional supervisory appraisals due to sources (i.e., supervisor, peer, direct report) unique perspectives and opportunities to view different aspects of job performance. Research has found that the differences among sources are most prevalent between self and other ratings, and the direction of agreement is related to overall job performance. Research has typically focused on one form of agreement, the direction of an individual's self-ratings compared to others' ratings. The current study expanded on past research on rater agreement using a data set (n = 215) consisting of multi-rater data for professionals participating in a leadership development process. The study examined the ability to predict job performance with three different measures of self-other agreement (i.e., difference between overall mean scores (difference), mean absolute difference across items (difference), and mean correlation across items (similarity)). The study also examined how the relationships may differ across performance dimensions. The final purpose was to explore how the importance of the performance dimensions, as rated by the participant, may moderate the relationship between self-other agreement and job performance. Partial support for study's hypotheses was found. The direction and difference measures of …
Date: August 2008
Creator: Grahek, Myranda
System: The UNT Digital Library
Alexander Scriabin (1871-1915): Piano Miniature as Chronicle of his Creative Evolution; Complexity of Interpretive Approach and its Implications. (open access)

Alexander Scriabin (1871-1915): Piano Miniature as Chronicle of his Creative Evolution; Complexity of Interpretive Approach and its Implications.

Scriabin's piano miniatures are ideal for the study of evolution of his style, which underwent an extreme transformation. They present heavily concentrated idioms and structural procedures within concise form, therefore making it more accessible to grasp the quintessence of the composer's thought. A plethora of studies often reviews isolated genres or periods of Scriabin's legacy, making it impossible to reveal important general tendencies and inner relationships between his pieces. While expanding the boundaries of tonality, Scriabin completed the expansion and universalization of the piano miniature genre. Starting from his middle years the 'poem' characteristics can be found in nearly every piece. The key to this process lies in Scriabin's compilation of certain symbolical musical gestures. Separation between technical means and poetic intention of Scriabin's works as well as rejection of his metaphysical thought evolution result in serious interpretive implications. Music of Scriabin provides an excellent opportunity for a performer to find a proper balance between rational and intuitive. The lack of any of these qualities will impoverish his works, making their interpretation incomplete. Following one of main Scriabin's ideas - synthesis of all arts - this study approaches his music not from the narrow analytical, but broad synthetic standpoint. The …
Date: May 2008
Creator: Sukhina, Nataliya
System: The UNT Digital Library
An Analysis and Performance Guide to William Lovelock's Concerto for Trumpet and Orchestra (open access)

An Analysis and Performance Guide to William Lovelock's Concerto for Trumpet and Orchestra

This paper investigates the usage of traditional compositional techniques on Concerto for Trumpet and Orchestra by William Lovelock. (1899-1986) Like many other twentieth-century composers for trumpet Lovelock wrote in a romantic style using traditional forms. As a composer, Lovelock is largely under-appreciated. This paper explains Lovelock's compositional techniques and provides performers with a guide to help prepare the piece for performance.
Date: December 2008
Creator: Place, Logan
System: The UNT Digital Library
An Analysis of Established Terrorist Identity in Political and Military Wings of Turkish Hizbullah (open access)

An Analysis of Established Terrorist Identity in Political and Military Wings of Turkish Hizbullah

The influence of the role identity expectations of Turkish Hizbullah's leadership on actual members' terrorist identities was documented in this dissertation. This study explored the leadership's identity expectations from members through content analyses of four books written by major figures of Hizbullah. Those books were selected following comments of the literature and expert suggestions. Eleven identity features stood out. These content analyses also revealed that leadership had different expectations from political wing members and military wing members. The following six identity features were listed as expected more from military wing members: belief in jihad and resistance, desire for martyrdom, embracing the hierarchical structure, depersonalization, hatred against enemies of God, and aloneness. Whilst cemaat (religious congregation), being religiously educated, patience (gradualism), dedication to a Muslim brotherhood, and being politically active were listed as expected identity attributes of political wing members. Qualitative analyses investigated these identity features using the available literature and 144 handwritten reports of actual Hizbullah members. To confirm the findings of content and qualitative analyses, quantitative analyses were conducted on the relatively representative sample (144 reports). The results of cross-tabulation and logistic regression demonstrated that two (out of 6) military wing and two (out of 5) political wing identity …
Date: August 2008
Creator: Cinoglu, Huseyin
System: The UNT Digital Library
An Analysis of Form and Tonality in Arnold Cooke's Sonata for Oboe and Piano (1957) (open access)

An Analysis of Form and Tonality in Arnold Cooke's Sonata for Oboe and Piano (1957)

Arnold Cooke composed many works for oboe including two sonatas, a concerto and several pieces for chamber ensembles; however, his works are rarely performed. Through the analysis of form and tonality in his first oboe sonata, Cooke's musical style and influences become apparent. His musical style was primarily influenced by his teacher, Paul Hindemith, and can be characterized by traditional forms with the contemporary use of quartal harmonies and a variety of tertian sonorities. Cooke wrote music that is accessible for performers and audience members, and one way he achieved this accessibility is through the repetition of melodic ideas. In addition to exact melodic repetition, he also unified his works through fugue-like passages and sequences. Although he lived during a time of experimentation by many composers, Cooke maintained conservative elements in his music that he learned through his studies at Cambridge and through his studies with Hindemith. His first oboe sonata is tonal although he varied modes and used chromatic harmonies throughout. Cooke's clear writing and unique sound in his Sonata for Oboe and Piano (1957) provide oboists a solo piece for the repertoire that demonstrates a modern approach to the traditional style of composition.
Date: May 2008
Creator: Polk, Kristin Marie
System: The UNT Digital Library
An Analysis of Gay/Lesbian Instructor Identity in the Classroom (open access)

An Analysis of Gay/Lesbian Instructor Identity in the Classroom

In this project I explore the connection between cultural and personal identity in the college classroom. Respondent interviews were conducted using open-ended questions, which began with a broad picture of the role the instructor played in the classroom and then focused more specifically on the issue of sexual orientation and the choices to disclose or not disclose orientation in the classroom. Thematic analysis was used to examine the interviews, upon the completion of the interviews being transcribed. RQ1: Do gay and lesbian instructors disclose their sexual orientation in the classroom? From this question, four themes emerged. These themes were disclosure not relevant, out of the classroom disclosure, students just know, and disclosure in the classroom. RQ2: What reasons do gay and lesbian instructors give for disclosing their sexual orientation in the classroom? Two themes, fears of disclosure and holding back, transpired from this question. RQ3: How do gay and lesbian instructors foster diversity in the classroom related to sexual orientation? Four themes were exposed from the question, and these themes were paradox of diversity, passing, mentoring, and identity not sexuality.
Date: May 2008
Creator: Giovanini, Heather
System: The UNT Digital Library
An Analysis of Joseph Schwantner's Concerto for Percussion and Orchestra (open access)

An Analysis of Joseph Schwantner's Concerto for Percussion and Orchestra

This analysis of Schwantner's Concerto is focused primarily on the pitch organization within the work, using terminology and concepts borrowed from those designed by Allen Forte in The Structure of Atonal Music. Discussion of pitch sets, their use, their derivation, their intervallic content, and their evolution throughout the piece are discussed. Additional discussion regarding Schwantner's style, orchestration techniques, textural manipulation with regard to form, are also discussed. Sources consist of the orchestral score, the two - piano reduction, and the solo percussion score. This document is in six chapters. The first discusses Schwantner's life and general musical style. The second is a brief discussion of terms in the field of pitch set organization. The third, fourth, and fifth chapters discuss in detail the musical materials themselves in each respective movement. Finally, the sixth chapter is a summary of the findings from the analysis.
Date: December 2008
Creator: Hart, Shawn Michael
System: The UNT Digital Library
An Analysis of Sexist Language in ESL Textbooks by Thai Authors Used in Thailand (open access)

An Analysis of Sexist Language in ESL Textbooks by Thai Authors Used in Thailand

This study identified the types of sexist language that appear in ESL textbooks by Thai authors. The study analyzed the ESL textbooks by Thai authors sold at the Chulalongkorn University bookstore during spring 2007. It was a qualitative case analysis of fifteen ESL textbooks covering the beginning, intermediate, and advanced levels of ESL instruction. The study used feminist criticism to discover what gender roles are sanctioned as appropriate in ESL textbooks by Thai authors and if the language used supports or challenges patriarchy. The results of this study show that sexist language is present in the textbooks and that the textbooks contain content that promotes sexist assumptions concerning gender roles. As a whole, the language and examples used in ESL textbooks by Thai authors support patriarchy.
Date: August 2008
Creator: Na Pattalung, Piengpen
System: The UNT Digital Library
An analysis of the American Concerto by Ellen Taaffe Zwilich, identifying the use of motives, and a guide for performance preparation. (open access)

An analysis of the American Concerto by Ellen Taaffe Zwilich, identifying the use of motives, and a guide for performance preparation.

Ellen Taaffe Zwilich is an important figure in the compositional world, having written a diverse body of works for which she has received many accolades, including the coveted Pulitzer Prize. The second chapter examines this American composer, the commission of the American Concerto, and events leading to the piano reduction of the concerto. The America Concerto is a modern work that incorporates synthetic scales, unusual notation, and the organization of melodic material through motives. The third chapter includes an analysis that identifies the form and tonal centers as well as the primary motives used in the concerto. The fourth chapter includes pedagogy considerations for performance. Issues relating to tessitura, articulation, flexibility, endurance factors, fingerings, and technical features of the piano reduction accompaniment are evaluated. Detailed suggestions are provided to aid in preparing the piece for performance, including a study of stylistic concerns. The American Concerto is quite diverse stylistically as Zwilich explores the symphonic and jazz genres. The dual nature of the trumpet is examined as the piece combines classical and jazz styles in a virtuosic setting.
Date: August 2008
Creator: Samayoa, Raquel Rodriquez
System: The UNT Digital Library
An Analysis of the Emotional Intelligence and Personality of Principals Leading Professional Learning Communities (open access)

An Analysis of the Emotional Intelligence and Personality of Principals Leading Professional Learning Communities

The purpose of this study was to investigate the relationship between a principal's emotional intelligence and personality and his or her ability to implement and develop professional learning communities within the school. The Professional Learning Community Assessment (PLCA) was administered to principals and teachers in 13 schools in Texas ranging from elementary to high school. Based on the strength of the PLCA scores, two elementary schools were selected to participate in case study research. The principals of these two campuses were administered an emotional intelligence instrument (MSCEIT), a personality instrument (DiSC), and were interviewed along with three of their teachers. The findings indicate that both of these principals scored high in the Influential and Conscientiousness subscales and low in the Dominance subscale. The principals also possessed either near-average or above-average emotional intelligence with both principals scoring particularly strong in the Strategic subscale.
Date: May 2008
Creator: Jackson, Christopher
System: The UNT Digital Library
An Analysis of the Opinions of University Students about the Current Situation of the Headscarf Dispute in Turkey (open access)

An Analysis of the Opinions of University Students about the Current Situation of the Headscarf Dispute in Turkey

This study examined the opinions of university students about the current situation of the headscarf dispute on the wearing of headscarves in Turkey. The influence of gender, the level of secularism, socioeconomic status and encounter with women wearing headscarves on opinions about the wearing of headscarves were analyzed in this study. The sample of this study was composed of 400 university students among whom there were 240 female and 160 male students. Moreover, the sample comprised university students from 50 universities from Turkey. The results indicated that the level of secularism and encounter with women wearing headscarves were distinguished as two determining factors of the diverse opinions of the university students on the topic. No association was found between the perceptions of university students about the issue and the independent variables of gender and socioeconomic status.
Date: December 2008
Creator: Aydemir, Dilek
System: The UNT Digital Library
An Analysis of the Satisfaction of the Students during the First Ten Years of the Collaborative Program between Dallas Theological Seminary and the University of North Texas (open access)

An Analysis of the Satisfaction of the Students during the First Ten Years of the Collaborative Program between Dallas Theological Seminary and the University of North Texas

This study analyzes the satisfaction of doctoral students in the joint doctoral program in Christian higher education between Dallas Theological Seminary (DTS) and the University of North Texas (UNT). The study focuses on the 18 students who have been identified as advanced participants in or graduates from the joint program from its inception in 1997 through its 10-year mark in 2007. Fourteen of the 18 eligible students agreed to participate in this study for a 77.8 % response rate. The doctoral students completed a survey that was created using a study of Garrett in 2006 of doctoral students at Historically Black Colleges and Universities and of McLaughlin in 2002 of graduate students in Christian education at DTS. The purpose of this study was to determine to what extent the joint doctoral program in higher education between both institutions meets the expectations of the students and prepares them for the range of careers that they then pursue. The study offers a number of findings surrounding the five research questions and offers several conclusions and recommendations for further research. The study concluded that the surveyed participants were immensely satisfied with their education experience thus assuming that the joint program does meet expectations …
Date: August 2008
Creator: Kavlie, Lucas B.
System: The UNT Digital Library
An Analytical Study of Karamanov's Piano Concerto No.3 "Ave Maria" (open access)

An Analytical Study of Karamanov's Piano Concerto No.3 "Ave Maria"

The purpose of this dissertation is to analyze Concerto No.3 "Ave Maria" by Alemdar Karamanov (1934-2007) and to elucidate the work through historical background and the composer's ideas. This concerto is presented as a significant gesture of dramatic emotion, religious belief, romantic spirit and universal feeling. The subtitle "Ave Maria" relates to a set up already present within the music program. An analysis of interval relationships will help performers better realize Karamanov's music language. In view of the complicated nature of this piece, an analytical study is considered necessary. The study centers principally on analysis, with an emphasis on the developments of form, tonality and motives to help performers better understand the work, and how to best approach this concerto.
Date: May 2008
Creator: Yang, Christine
System: The UNT Digital Library
Analyze and Rebuild an Apparatus to Gauge Evaporative Cooling Effectiveness of Micro-Porous Barriers. (open access)

Analyze and Rebuild an Apparatus to Gauge Evaporative Cooling Effectiveness of Micro-Porous Barriers.

The sample used for evaporative cooling system is Fabric defender 750 with Shelltite finish. From the experimental data and equations we have diffusion coefficient of 20.9 ± 3.71 x 10-6 m2/s for fabric with one layer with 17%-20% fluctuations from the theory, 27.8 ± 4.5 x 10-6 m2/s for fabric with two layers with 6%-14% fluctuations from the theory and 24.9 ± 4.1 x 10-6 m2/s for fabric with three layers with 13%-16% fluctuations from the theory. Since the thickness of the fabric increases so the mass transport rate decreases so the mass transport resistance should be increases. The intrinsic mass resistances of Fabri-1L, Fabri-2L and Fabri-3L are respectively 104 ± 10.2 s/m, 154 ± 23 s/m and 206 ± 26 s/m from the experiment.
Date: December 2008
Creator: Mohiti Asli, Ali
System: The UNT Digital Library
The Anglo-Iraqi Relationship Between 1945 and 1948. (open access)

The Anglo-Iraqi Relationship Between 1945 and 1948.

This paper discuses the British Labour government's social, economic and military policies in Iraq between 1945 and 1948. The ability of the Iraqi monarchy to adapt to the British policies after World War II is discussed. The British were trying to put more social justice into the Iraqi regime in order to keep British influence and to increase the Iraqi regime's stability against the Arab nationalist movement.
Date: December 2008
Creator: Alburaas, Theyab M.
System: The UNT Digital Library
Anthoni van Noordt: Historical and Analytical Analysis of His Tabulatuurboeck van Psalmen en Fantasyen of 1659 (open access)

Anthoni van Noordt: Historical and Analytical Analysis of His Tabulatuurboeck van Psalmen en Fantasyen of 1659

This dissertation presents a historical and analytical study of the organ works of Anthoni van Noordt. Van Noordt's Tabulatuurboeck is one of the most important music publications in mid-seventeenth-century Netherlands. It gives unique, valuable information on organ playing of its time. The process of discrete analysis has led to the identification and exploration of many details, such as extensive use of pedal, the reliance of the composer on rhetorical principals of composition, and his integration of the Italian and German principals of ensemble techniques. The dissertation is divided into three major parts. The first part contains chapters on van Noordt's biography based on available archival documents as well as a chapter on the organ and its role in seventeenth -century Amsterdam. The second part is solely dedicated to the Tabulatuurboeck examining the physical and technical features of the publication including the style of the publication, the letter and staff notation, hand positions, and rhetorical components. Finally, the third part studies the music and its peculiar characteristics with separate chapters on the variations and fantasias.
Date: May 2008
Creator: Javadova-Spitzberg, Jamila
System: The UNT Digital Library
ANTI Preference of the Pyramidalized Radical Center to the Two Fluorines in Difluoro Cyclic Compounds. (open access)

ANTI Preference of the Pyramidalized Radical Center to the Two Fluorines in Difluoro Cyclic Compounds.

An extensive study of disubstituted cycloalkanes like CnH2n where n=3,4,5 and 6 using DFT((U)B3LYP/6-31G(d) and 6-311+G(2df,2p)) calculations is presented focusing on the effect of pyramidalization of the radical center. A potential energy surface (PES) analysis shows that the radical prefers to pyramidalize anti to the two cis fluorines in the disubstituted cycloalkanes. The degree of pyramidalization for 1,2-difluorocyclopropyl radical is 43.9o away from the cis fluorines whereas for 1,3-difluorocyclobutyl radical, 1,3-difluorocyclopentyl radical and 1,3-difluorocyclohexyl radical is 3.8o, 5.4o and 14.5o respectively away from the cis fluorines. The importance of this pyramidality effect in these compounds is discussed in context with the carbon-hydrogen bond dissociation energies (BDE's) because the preference of the radical centers to pyramidalize anti to the fluorines affects the bond dissociation energy. Importance of steric effect and unfavorable electronic interactions have been extensively explored in planar permethylated cyclobutadiene (Me4CBD) and cyclooctatetraene (Me8COT) using ((U)B3LYP/6-31G(d) and 6-311+G(2df,2p)) calculations. It is thought that steric interactions dominate electronic interactions in Me8COT, while this works opposite in case of Me4CBT. Instead, in Me4CBD the number of unfavorable electronic interactions between π bonds and out-of-plane hydrogens plays the dominant role in determining the relative energies. Interactions between the π bonds of CBD and …
Date: May 2008
Creator: Tanna, Jigisha
System: The UNT Digital Library