Structure and Reactivity of Cyclopropane and Its Derivatives

Abstract

Compounds of the Sr 2 Nb 2 O 7 (SNO) family are suitable for use as ferroelectric materials for ferroelectric memory field effect transistors (FETs), because these substances have a low dielectric constant, low coercive field and high heat resistance. C-V and I D -V G hysteresis curves which depend on ferroelectric polarization were obtained. These capacitors were applied to floating gate ferroelectric random access memory (FFRAM) cells. The degradation in the ferroelectricity of STN capacitors was not observed during the fabrication of FFRAM cells. We succeeded in operating FFRAM cells at a lower voltage than that required for PZT. Data retention characteristics of metal ferroelectric metal insulator semiconductor (MFMIS) structures with STN films were first measured to be up to 2 weeks. Data retention is close related to be the leakage current of the ferroelectric. The MFMIS FET has the potential to retain data for 10 years.

Structural parameters and electronic properties of 2D carbon allotrope: Graphene with a kagome lattice structure

“…However, unconventional bent bond angles of 60° and 150° raise questions for explaining the bonds with known hybridizations (trigonal sp 2 or sp 2 -sp 5 doublets) [38] and needs a better explanation. Also, bent bonds are known to result in the possibility of high chemical reactivity [39] . The calculated bond angles are not given in Table 1 , because of obtaining perfect 60° and 150° for all three methods.…”

The crystal structure of 2,3,6,7,7,8-hexamethyl-1,5-diphenyltetracyclo[3,3,0,02,8,03,6]octan-4-one

“…The average exocyclic C-C bond length, 1.524 (9) A, compares to 1-487 A in bicyclopropane (Eraker & Romming, 1967) and 1.478 (5) A in a pentacyclic compound (Hwang, Donohue & Tsai, 1972). The average exocyclic angle is 123.4 (6) °, much greater than the predicted 116 ° (Lukina, 1962). This opening probably reflects one of the ways in which strain in the molecule is relieved.…”

“…Such results are expected, however, because in this molecule these bonds comprise cyclopropane and cyclobutane rings, respectively. The bonds C(2)-C(8) and C(1)-C(8), which are in the cyclopropane ring, are expected to be shorter than the usual 1.537 (5)A (Sutton, 1965) because of the phenomenon of bent bonds (Lukina, 1962). For example, the average C-C bond distance in the 3-membered ring in gaseous cyclopropane is 1.510 (2) A (Bastiansen, Fritsch, & Hedberg, 1964), in cyclopropanecarboxamide 1.50 A (Long, Maddox & Trueblood, 1969), in cis-l,2,3-tricyanocyclopropane, 1.518 (3)A (Hartman & Hirshfeld, 1966), and in -anti-tricyclo[3,1,1,0z.4]heptan-6-yl p-nitrobenzoate, henceforth exo[3,1,1,02°4], 1.50 (2) A (Masamune, Vukov, Bennett & Purham, 1972).…”

Hg(3P1) photosensitized reactions of cyclopropane

“…Returning now to the primary step, we see that the predominant mode of quenching is the transfer of excitation energy to the carbon skeleton of the ring, promoting a (a -+ a*) type transition, and displaying the well known pseudo olefinic character of the cyclopropane molecule (19).…”