Die ε-Invariante vonSL (2,p)

Ohne Zusammenfassung     

Staudinger reaction at in-bridgehead positions of phosphorus macrobicyclic compounds

Reaction of in,in-phosphite 1 with thiophosphoryl azide 2 affords in,in-dithiophosphate 3, in,in-thiophosphate-imidophosphate 4, and in,in-phosphite-imidophosphate 5. Compounds 4 and 5 are the first examples of the modification of in-bridgehead positions in macrobicyclic compounds with groups larger than methyl. The benzaldehyde arms of the in-substituent in 4 and 5 jut out of the cage bars. In 4 they are trapped between the macrocyclic arms to give the NMR spectra of a Cs-symmetric solution-state structure. In contrast, in 5 the benzaldehyde arms can move between the gaps of the cage. This results in 1H and 13C NMR spectra which are consistent for a compound with C3v symmetry. In,out-diimidophosphate 7 is obtained in moderate yield by reaction of in,out-phosphite 6 with thiophosphoryl azide 2. Its in-benzaldehyde moieties are not fixed between the cage arms, but can freely move from one gap to the next as is indicated by NMR measurements.     

Thermolyse et photolyse de cetones non saturees—XXVII : Synthese de composes bicycliques par double thermocyclisation de dienones et de dienediones

The thermal isomerisation of some dienones and dienediones is explored as a route to bi- and polycyclic compounds. A dicyclopentylketone (6, from 3), two 3a-acetyl-cis-perhydropentalenes (32 and 33, from 29) and two spiro[4,4]nonane-l,6 diones (27 and 28, from 24) were obtained.     

New acetylenic michael receptor equivalents, : Part I : Synthesis of α-sulfenyl - and α-sulfinyl acrylic derivatives,

The synthesis of α-thioarylated β-unsubstituted acrilic derivatives is reported.     

MRD-CI calculations for the structure and stability of the hsin-hnsi isomers

Ab initio SCF and CI calculations are employed to determine the equilibrium geometrical parameters (bond lengths, stretching force constants and rotational constants B_e) for the two isomers HSiN and HNSi. It is found that HNSi is bound relative to H(²S) + SiN(²Σ⁺) by 122 kcal mole^?1, whereby the SiN(²π) state is predicted to lie only 13 kcal mole^?1 above SiN(²Σ⁺). The HNSi isomer is calculated to be more stable than HSiN by 68 kcal mole^?1 (CI treatment) and it is found that only a small barrier exists for angular inter-conversion between the two linear forms. A discussion of these results in the light of similar findings for other HAB systems containing first- and second-row atoms is presented Finally it is concluded on the basis of the present calculations that neither HNSi nor HSiN is a likely source for the observed interstellar molecular line U 81.5 (J = 2 → 1).     

13C-NMR-Spektroskopie von Cyclopropenonen und Cyclopropenyliumionen (Cyclopropenonchemie: VII)

The carbon-13 NMR spectra of thirteen cyclopropenones, two cyclopropenethiones, five related cyclopropenylium salts and three cyclobutenediones are tabulated and discussed.     

Theoretical integrated intensities for the 2ν2 and 2ν2-ν2 bands of HCN and DCN

Dipole moment functions, both perpendicular and parallel to the molecular axis, are calculated from the SCF and MRD-CI results of a previous study for the normal ν₂ bending vibrations of HCN and DCN. Vibrationally averaged dipole moments and the infrared transition matrix elements are then obtained from the dipole moment functions and vibrational wave functions. MRD-CI results, with known experimental values in parentheses, for HCN are 〈0|μ|0〉 = ?2.954(?2.985) D, 〈1|μ|1〉 = ?2.915(±2.942) D, 〈0|μ|1〉 = 0.148(0.147) D, 〈0|μ|2〉 = ?0.027 D, 〈1|μ|2〉 = 0.210 D. Calculated absolute intensities at 1 atm and 0°C for the (02⁰0) ← (000), (02⁰0) ← (010), and (02²0) ← (010) bands of HCN are 25 (40 ± 10 as estimated from spectra), 8.5, and 17.0 atm^?1 cm^?2, respectively. Results for DCN are also reported.