No description available.

Thesis (Ph. D.)--Columbia University, 1927. / Vita. "Reprinted from the Journal of the American leather chemists association, August, 1927."

From W.J. Horton's thesis--University of Michigan. / "Contribution from the Chemistry Laboratory of the University of Michigan." "Reprinted from the Journal of the American Chemical Society, 69...(1947)"

When a crystal of anthracene with a small added "impurity" of naphthacene is excited by X-radiation or ultraviolet light the fluorescent spectrum includes or consists almost totally of naphthacene bands. The energy absorbed by the anthracene is said to have been transferred to the naphthacene. The same result is obtained with certain other "impurities" and matrix compounds. Although this process had been known to exist for some time, no detailed quantitative experiments had been performed. The author used an arrangement including a Beckman Model DU Quartz Spectrophotometer used as a mono-chrometer and a 931-A photomultiplier tube as a detector to obtain fluorescent spectra. This arrangement combined very great sensitivity with great convenience of operation. The spectra of crystals of anthracene with naphthacene, naphthalene with naphthacene, and naphthalene with 1,2,5,6-dibenzanthracene were obtained. The maximum intensity of fluorescence of the impurity bands occurred at 2.93 x 10ˉ⁴ moles naphthacene per mole anthracene in the crystals of anthracene plus naphthacene: at 3.38 x 10ˉ⁵ moles naphthacene per mole naphthalene in the crystals of naphthalene plus naphthacene: and at 1.01 x 10ˉ⁴ moles 1,2,5,6-dibenzanthracene per mole naphthalene in the crystals of naphthalene plus 1,2,5,6-dibenzanthracene. The fluorescent spectrum of a crystal of anthracene was obtained using first X-ray excitation and then ultra-violet excitation. The two sources of excitation gave rise to different spectra. A theory of the mechanism of energy transfer and a hypothetical set of energy levels for the crystals with added impurities are given. The method used to grow some of the crystals used in this research is given in an Appendix. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

A convenient method for measuring the thermal conductivity of liquids is that introduced by Bridgman in 1923. In this procedure the liquid is held in the annular space between two concentric cylinders. By supplying heat at & definitely known rate to the inner cylinder and measuring the temperature drop across the liquid, the thermal conductivity of the liquid may be determined. Because the liquid film is only 0.04 cms. in thickness and the temperature drop across the film does not exceed one degree, convection withing the liquid is prevented. The temperature drop across the film is measured by means of differential thermocouple Bridgman's cell has the advantage over other thermal conductivity apparatuses In that it requires only a very small volume of liquid for the measurement. In this investigation the thermal conductivities of cis- and trans-decahydronaphthalene were measured. When the results were compared with those of Levelton and Perris, who determined the same quantities by the method of Bates, it was found that lower values had been obtained for both the thermal conductivities and the temperature coefficients. The difference in the conductivity may be explained in part by the surface film discovered by Bates. In Bridgman's apparatus no allowance is made for this film and the measured temperature drop represents the average temperature gradient from one boundary of the liquid to the other. Unless this surface film changes considerably with temperature it would offer no explanation for the very definite difference found in the temperature coefficients. Attempts to explain the divergence of results on the basis of purity of materials meet with little success because of a lack of necessary data. An attempt has been made to design a simplified cell based on the same principles as Bridgman's cell and is offered herewith. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

The problem is to determine the solubility of solid trans decahydro-naphthalene in liquid sulphur dioxide in the temperature range -4-0.0° to -70.0°. Factors affecting the solubility determinations are discussed in detail. Particular emphasis is placed on the design, construction, and operation of the precision cryostat and the auxiliary equipment, and on the safety precautions which must be taken. The experimental data is presented along with a sample calculation to show how the data was treated before the solubility graph was plotted. (Since the solubility relationship should be approximately linear in this temperature range, the "best-fitting" line (calculated by the method of least squares) was included in the plot of solubility versus temperature. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

The application of low temperature nuclear magnetic resonance (n. m. r.) spectroscopy to the determination of the barrier heights to interconversion in compounds which contain one and two flexible six-membered rings is reviewed. Although the barrier heights in cyclohexane and its derivatives have been experimentally determined, similar studies in the cis-decalin system have (until very recently) not been successful. Consideration is given, therefore, to the preparation of a number of cis-9, 10-disubstituted decalin derivatives, which will act as model compounds for a further study in the problem of the barrier height to ring interconversion in the cis-decalin system. Various attempts to synthesize a novel model compound, tricycle [4. 4. 4. 0] tetradecane, are described. Partial success has been achieved in that a small but demonstrable amount of tricycle [4. 4.4. 0]-3, 8-tetradecadiene has been synthesized in a ten step reaction sequence, starting from acetylenedicarboxylic acid. A Diels-Alder condensation of this compound with two mole-equivalents of 1, 3-butadiene gave Δ² ⁶-hexalin-9,10-dicarboxylic anhydride. Lithium aluminum hydride reduction of this compound gave cis-9, 10-bis(hydroxymethyl)-Δ² ⁶ -hexalin, which was converted to its dimesylate derivative on treatment with methanesulfonyl chloride in pyridine. Reaction of the dimesylate derivative with sodium cyanide in N-methyl-2-pyrrolidinone gave cis-9, 10-bis(cyanomethyl)-Δ² ⁶-hexalin. Alkaline hydrolysis of the latter gave cis-9,10-bis(carboxymethyl)-Δ² ⁶-hexalin, which was converted to its dimethyl ester on treatment with diazo- methane in 1, 2-dimethoxyethane. Lithium aluminum hydride reduction of the dimethyl ester gave cis-9,10-bis(2-hydroxyethyl)Δ² ⁶-hexalin. Treatment of the dialcohol with methanesulfonyl chloride in pyridine gave cis-9, 10-bis(2-mesyl-oxyethyl)-Δ² ⁶-hexalin. Reaction of the dimesylate with sodium iodide in acetone gave cis-9, 10-bis(2-iodoethyl)-Δ² ⁶-hexalin. Treatment of this compound with n-butyllithium in diethyl ether and in heptane gave a mixture of cis-9-ethyl-10- vinyl-Δ² ⁶-hexalin and tricyclo[4. 4.4. 0]-3, 8-tetradecadiene (minor product). Attempts to improve the yield of the tricyclic compound, using zinc and magnesium as coupling reagents, were unsuccessful. The syntheses of other desired model compounds are described. Thus, cis-9, 10-dimethyl-Δ²-octalin and -Δ² ⁶-hexalin were prepared from their cis- 9, 10-bis(mesyloxymethyl)- analogs on treatment of the latter compounds with sodium iodide in N, N-dimethylformamide, followed by the treatment of the respective product diiodides with lithium aluminum hydride in 1, 2-dimethoxyethane. cis-9,10- Dimethyldecalin was prepared from cis-9, 10-dimethyl-Δ² ⁶-hexalin by catalytic hydrogenation of the latter. In addition, treatment of cis-9, 10-bis(hydroxymethyl)- decalin and -Δ²-octalin with p-toluenesulfonic acid in benzene yielded 12-oxa- tricycle [4. 4. 3. 0] tridecane and -3-tridecene, respectively. 12-Oxatricyclo [4. 4. 3. 0] -3, 8-tridecadiene was isolated as a by-product from the reaction of cis-9, 10-bis- (mesyloxymethyl)-Δ² ⁶-hexalin with sodium cyanide in N-methyl-2-pyrrolidinone, as was 12-amino-11-cyanotricyclo [4. 4. 3. 0]-3, 8, 11-tridecatriene. All of the new compounds have been characterized by means of infrared, ultraviolet, and n. m. r. spectroscopy, mass spectrometry, and microanalysis, where applicable. Preliminary investigations of the barrier heights to interconversion in cis-9, 10-dimethyldecalin and 12-oxatricyclo [4. 4. 3. 0] tridecane are described. Quantitative kinetic data could not be obtained from the low temperature (0 to -60°) n. m. r. spectra of the former, since no broadening of the ring proton resonance peak was observed. On the other hand, the latter compound gave n. m. r. spectra in which the ether ring proton resonance peak broadened considerably as the sample temperature was lowered. From these spectra a value of the energy of activation (Ea) of 8. 4 ± 2 kcal. /mole was calculated for the interconversion process in 12-oxatricyclo [4. 4. 3. 0] tridecane. / Science, Faculty of / Chemistry, Department of / Graduate

No description available.

No description available.

This thesis describes the synthesis and properties of some extended donor-acceptor dyads with the donor being a ferrocenyl moiety and a fluorescent naphthalimide group as the acceptor. Two series of extended ferrocenyl-naphthalimide dyads were prepared in reasonable yield depending on the synthetic route. The first are a series of three ferrocenyl-CH=CH-spacer-C[triple bond]C-naphthalimide dyads in which the spacers are phenyl, biphenyl and anthryl and the second are a series of three ferrocenyl-C[triple bond]C-spacer-C[triple bond]C-naphthalimide dyads in which the spacers are 2,2� -bithiophene, 2,5-dimethoxybenzene and tetrafluorobenzene groups. The molecular structures of some compounds have been determined by X-ray diffraction although with many challenges because of the extensive [pi]-[pi] stacking of molecules that leads to ready aggregation in the solid state, particularly for the ferrocenyl-CH=CH-spacer-C[triple bond]C-naphthalimide dyads, in which the naphthalimide bears a methyl head group. In order to reduce the [pi]-[pi] stacking effect between the molecules and also to produce chiral molecules for the potential nonlinear optical applications, a chiral α-methylbenzylamine was introduced as the head group of naphthalimide for the ferrocenyl-C[triple bond]C-spacer-C[triple bond]C-naphthalimide dyads. The resulting comounds successfully gave crystals of sufficient quality for X-ray structural investigation. While the oxidative electrochemistry of the ferrocenyl compound in the two series of dyads was largely predictable (E� ~ 0.55 V for ferrocenyl-CH=CH- and ~ 0.72 V for ferrocenyl-C[triple bond]C-), the presence of spacers in the dyads appeared to afford stability to the reduced naphthalimide species. This was exhibited by the appearance of chemically reversible one-electron reduction processes for each of the compounds investigated. Similar unusual chemical reversibility was also shown by the spacer-C[triple bond]C-naphthalimide precursor systems. For the ferrocenyl-CH=CH-spacer-C[triple bond]C-naphthalimide dyads, the oxidation and reduction potentials closely resembled those of the simple ferrocenyl-CH=CH-spacer systems. This suggested that augmentation of the simple ferrocenyl-CH=CH-phenyl, -biphenyl and -anthryl systems with an alkyne linked naphthalimide unit showed little influence on the oxidation of the ferrocenyl moiety or the reduction of the naphthalimide unit. However, for the ferrocenyl-C[triple bond]C-spacer-C[triple bond]C-naphthalimide dyads, the oxidation and reduction potentials are influenced by the inductive effects of the spacers. While an anodic shift was observed for the dyad with the electron-withdrawing spacer tetrafluorobenzene, a cathodic shift was displayed for the dyads with the electron-donating spacers 2,2�-bithiophene and 2,5-dimethoxybenzene compared to that in the simple ferrocenyl-C[triple bond]C-naphthalimide system. The spectroscopic properties of the ferrocenyl-CH=CH-spacer-C[triple bond]C-naphthalimide dyads showed that interpolation of the aromatic spacers does not interfere with the internal charge separation. Oxidation of the ferrocenyl moiety resulted in bleaching of the metal-to-ligand charge transfer band at ~ 500 nm and the growth of a new band in the near infrared region at ~ 1000 nm. This new band can be assigned to a ligand-to-metal charge transfer transition, where the ferrocenium now acts as an acceptor to the naphthalimide donor. For the ferrocenyl-C[triple bond]C-spacer-C[triple bond]C-naphthalimide dyads, the spectroscopic properties showed that the mutually electron-withdrawing tetrafluorobenzene and naphthalimide units had little interaction despite their connection by a conductive alkyne link. In contrast, the dyads containing the electron-donating 2,2�-bithiophene and 2,5-dimethoxybenzene showed some degree of interaction between the spacer and the naphthalimide fragments. This was evidenced by the appearance of a broad absorption band in the range 410 - 440 nm, which is associated with an orbital that is delocalised between the spacer and the naphthalimide fragments. Again, the roles of donor and acceptor were reversed on oxidation of the ferrocenyl moiety. This resulted in the growth of a new near infrared band at ~750 mn for the dyad containing the tetrafluorobenzene spacer and at ~ 1000 nm for the dyads with 2,2�-bithiophene and 2,5 -dimethoxybenzene spacers. The ferrocenyl unit went from being a net donor to ferrocenium, which was acting as an acceptor, with the tetrafluorobenzene spacer adopting the donor role more reluctantly than the delocalised 2,2�-bithiophene-C[triple bond]C-naphthalimide and 2,5-dimethoxybenzene-C[triple bond]C-naphthalimide moieties. 1,3,5-Tri- and 1,2,4,5-tetra-substituted benzene cores were also used as spacers for the preparation of extended arrays of ferrocenyl-naphthalimide dyads. Utilisation of the 1,3,5 -tri-substituted benzene core enabled the core to be embellished in three directions, resulting in Y-motif extended arrays containing either one ferrocenyl unit [(ethenylferrocenyl)-C₆H₃-(C[triple bond]C-C₆H₅)₂] or one naphthalimide moiety [(4-piperidino-N-propargyl-naphthalimide)-C₆H₃-(Br)₂]. With the 1,2,4,5-tetra-substituted benzene core, the extension of the core was possible in four directions and gave extended arrays in an X-motif. Again, these systems contained either ferrocenyl units [bis(alkoxyferrocenyl)-C₆H₂-(C[triple bond]C-C₆H₅)₂] or naphthalimide moieties [(tetrakis-naphthalimide)-C₆H₂]. Attempts to incorporate both ferrocenyl and naphthalimide fragments into the X- or Y-motif extended arrays were unsuccessful. By adding C₂Co₂(CO)₆dppm across the triple bonds of two of the four alkyne groups in the X-motif naphthalimide system [(tetrakis-naphthalimide)-C₆H₂], it was possible to incorporate two oxidisable C₂Co₂(CO)₄dppm cluster units into the molecule. The electrochemistry of the resulting system showed two discrete oxidation processes, suggesting the possibility of some interaction between the dicobalt cluster redox centres.