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[Photograph of Cameron Stallings]

Description: Photograph of Cameron Stallings, wearing pajamas, reading a "Science Digest" in bed. In the image a portrait of a woman hangs on the wall and another man's body, probably the photographer, can be seen in the bottom left of the frame.
Date: unknown
Partner: UNT Libraries Special Collections

The Synthesis and Chemistry of Polyciclic Cage Compounds

Description: Chapter I describes the synthesis of a trishomocubyl helical tubuland diol and some aspects of its inclusion chemistry. Thus, all three isomers of 4,7-dimethylpentacyclo[6.3.0.0^2,6.0^3,10.0^5,9]undecane-4,7-diol have been prepared and their X-ray structures have been determined. The syn,syn-isomer crystallizes in a double-stranded hydrogen-bonded lattice, while anti,syn-isomer forms a hydrogen-bonded layer lattice. In contrast, the anti,anti-isomer is a new member of the helical tubuland diol host family; its crystal lattice consists of parallel canals with a trefoil-shaped cross-section of area 25.4 Å^2. Chapter II describes the synthesis of new molecular clefts. These molecular clefts have been synthesized via base-promoted reactions of 3,6-diaryl-l,2,4,5-tetrazines with tetracyclo[6.3.0.0^4,11.0^5,9]undecane-3,6-dione and with tricyclo[6.3.0.0^2,6]undecane-3,11-dione, respectively. Compounds of this type are of interest as a potential new class of host molecules for use in host-guest complexation studies. Chapter III reports the synthesis of stereospecifically deuterated spiro(oxetane-3,8'-pentacyclo[5.4.0.0^2,6.0^3,10.0^5,9]undecanes) and their acid-promoted ring opening and concomitant rearrangements. The deuterium-containing reaction products have been characterized via analysis of their NMR and mass spectra. The results strongly suggest that intramolecular 1,5-hydride shifts provide an important pathway through which the acid promoted rearrangements occur. Chapter IV reports the oxidation of heptacyclo-[6.6.0.0^2,6.0^3,13.0^4,11.0^5,9.0^10,14] tetradecane (HCTD) via application of Barton's "GoAgg" systems. The products have been characterized by NMR and mass spectral analysis. Under GoAgg^v conditions, oxidation of HCTD proceeds to afford heptacyclo [6.6.0.0^2,6.0^3,13.0^4,11.0^5,9.0^10,14]tetradecan-7-one in 1% yield.
Date: December 1994
Creator: Wang, Yanjun
Partner: UNT Libraries

A Comparison of the Achievements of Science and Non-Science Majors Enrolled in General Chemistry at North Texas State College

Description: It is the specific purpose of this investigation to determine the difference, if any, in the amount of practical, everyday chemistry learned by the science majors as opposed to the non-science majors enrolled in general chemistry at the North Texas State College during the school year 1950-1951.
Date: 1951
Creator: Brogdon, Billie R.
Partner: UNT Libraries

Substitution Chemistry of the Cobalt Complexes [Co₂(CO)₆(PhC≡CR) (R=Ph, H) and PhCCo₃(CO)₉] with the Diphosphine Ligands [Bis(diphenylphosphino)maleic Anhydride (BMA) and (Z)-Ph₂PCH=CHPPh₂]. Reversible Chelate-to-Bridge Diphosphine Ligand Exchange, Phosphorus-Carbon Bond Cleavage and Phosphorus-Carbon Bond Formation

Description: The tricobalt cluster PhCCo3(CO)9 (1) reacts with the bidentate phosphine ligand 2,3-bis(diphenylphosphino)maleic anhydride (bma) in the presence of added Me3NO to give the diphosphine-substituted cluster PhCCo3(CO)7(bma) (2). Cluster 2 is unstable in solution, readily losing CO to afford Co3(CO)6[(μ2-η2/η1-C(Ph)C=C(PPh2)C(O)OC(O)](μ2-PPh2) (3) as the sole observed product. VT-31P NMR measurements on cluster 2 indicate that the bma ligand functions as both a chelating and a bridging ligand. At -97 °C, 31P NMR analysis of 2 reveals a Keq of 5.7 in favor of the bridging isomer. The bridged bma cluster 2 is the only observed species above -50°C. The solid-state structure of 2 does not correspond to the major bridging isomer observed in solution but rather the minor chelating isomer. The conversion of 2 to 3 followed first-order kinetics, with the reaction rates being independent of the nature of the reaction solvent and strongly suppressed by added CO, supporting a dissociative loss of CO as the rate-determining step. The activation parameters for CO loss were determined to be ΔH≠ = 29.9 ± 2.2 kcal/mol and ΔS≠ = 21.6 ± 6 eu.
Date: December 1994
Creator: Yang, Kaiyuan
Partner: UNT Libraries

St. Anne's Church in Vilnius, Lithuania

Description: Front cover of the 2011 issue of The Hexagon, featuring St. Anne's church in Vilnius, Lithuania. The Gothic red brick building looms above a street bustling with activity. The inside cover contains a table of contents, staff credits, an editorial, and a description of the front cover.
Date: Summer 2011
Creator: Marshall, James L., 1940- & Marshall, Virginia R.
Partner: UNT College of Arts and Sciences

Youth in Apuseni Mountains, Romania, Near the Discovery Site of Tellurium

Description: Front cover of the Spring 2010 issue of The Hexagon, featuring an adolescent boy wearing a sweater, corduroy pants, and boots while holding a lamb across his shoulders. He looks at the camera while standing in a bare patch of earth with grass and fallen branches behind him. To his left appear three round pictures relating to this issue's articles. The inside cover contains a table of contents, staff listings, and an editorial.
Date: Spring 2010
Creator: Marshall, James L., 1940- & Marshall, Virginia R.
Partner: UNT College of Arts and Sciences

The Statue of Copernicus

Description: Front cover of the Summer 2009 issue of The Hexagon, featuring a statue of Copernicus sitting on a block, wearing a flowing robe, and holding a compass up to a heliocentric model. The next page contains a table of contents, a staff list, and an editorial regarding the twentieth anniversary of the events at Tiananmen Square.
Date: Summer 2009
Creator: Marshall, James L., 1940- & Marshall, Virginia R.
Partner: UNT College of Arts and Sciences

Statue of Leonardo da Vinci

Description: Front page of the Fall 2010 issue of The Hexagon, which features a stone statue of Leonardo da Vinci next to three photographs from articles. The inside cover has a table of contents, a list of staff, an editorial, and a description of the cover.
Date: Autumn 2010
Creator: Marshall, James L., 1940- & Marshall, Virginia R.
Partner: UNT College of Arts and Sciences

A Dream of Toasted Cheese, the Bunsen Burner, and Beatrix Potter

Description: Front cover of The Hexagon, featuring a painting by Beatrix Potter. In the painting, a mouse wearing glasses sits on the intake tube of a lit Bunsen burner and reads a red book. Behind this is a group of unpainted mice using chemistry equipment. "A Dream of Toasted cheese" is written to the left of the burner's flame, and a note concerning NH3 is written to the bottom left. Above these images is the title of the magazine. Above that are pictures concerning other articles. The inside cover features a table of contents, work credits, and an introductory editorial.
Date: Autumn 2008
Creator: Marshall, James L., 1940- & Marshall, Virginia R.
Partner: UNT College of Arts and Sciences