Dihydrodiazepine aus valenzisomeren diazatricyclo[3.2.0.0.2,4]Heptanen1)

Cycloaddition of diazoalkanes to diazabicyclo[2.2.0]hexenes and subsequent extrusion of nitrogen afford diazatricyclo[3.2.0.0^2,4]heptanes that are easily valence isomerized to novel dihydrodiazepines.     

An INDO-LMO and 13C NMR spectroscopic study of the C-H bonds in tetracyclo[3.2.0.02,7.04,6]heptane (quadricyclane) and tricyclo[3.1.0.02,4]hexane

Using an INDO approximation to Von Niessen's charge density localization method, the percent s character of the C atom hybrid orbitals engaged in C-H bonds is computed for a series of open-chain and cyclic saturated and unsaturated hydrocarbons. A semi-empirical linear relationship is found between these quantities and the experimental nuclear spin-spin coupling constants J_CH (standard deviation 4·98 Hz). The experimental values of J_CH were measured for quadricyclane (1) and tricyclo[3.1.0.0^2,4]hexane (2) and were shown to be in fair agreement with the theoretical predictions. An analogous relationship is also established between the percent s character of the involved C atom hybrid orbital and the C-H bond distance, the standard deviation being 0·0040Å. This relation is used in order to predict the different C-H bond lengths in the vibrational ground state of 1 and 2, for which equal CH distances were assumed in the analysis of electron diffraction experiments. The results indicate that molecular geometries can be refined with the use of semi-empirical correlations of the above mentioned type.     

Zur kenntnis von [O2]+[Mn2F9]−

[O₂]⁺[Mn₂F₉]^? has been prepared for the first time by reaction of MnO₂ or MnF_x (x = 2,3,4) with a mixture of fluorine and oxygen (P_F2/O₂ ≈ 300–3500 atm., t ≈ 350–550°C) either as a dark red powder or as ruby red needles or plates. From single crystal studies the space group is C2/c - C⁶_2h (No. 15) with a = 17.55₂, b = 8.37₃, c = 9.10₁ Å, β = 102.3°, Z = B (at ?150°C). The crystal structure has been refined to R = 0.053 (1619 unique reflections). From the structure determination [O₂]+[Mn₂F₉] has ‘mänder’ like bands of double chains of [MnF₆] octahedra, which are stacked up in layers parallel to (100) with O₂⁺-cations (d_0?0 = 1.10₀ Å) located between the layers. ν_O2 is at 1838 cm^?1 and the magnetic moment μ_eff = 5.63 B.M. is as expected for a ‘spin only’ case without spin-spin interaction.     

Mechanism of the thermal conversion of tetracyclo[3.3.0.02,4.0.3,6]oct-7-ene into dihydropentalenes

One of a number of possible mechanisms has been established for the title reaction.     

Synthesis of syn- and anti-tricyclo [4.1.0.02,4] heptan-5-ones and related compounds

A convenient entry to both title compounds 1 and 2, as well as to cis- and trans-4-iodomethyl-bicyclo [3.1.0]-hexan-2-ones 3and 4 and to 4-methyl-bicyclo [3.1.0]-hex-3-en-2-one 5 involving base-promoted reactions of cis- and -trans-3,4-diiodomethylcyclopentanones 6 and 7 is reported, and the behaviour of 6 and 7 towards different bases. bfv40bp4761b     

Bis(triphenylphosphine)-5-nickela-3,3,7,7-tetramethyl-trans-tricyclo[4.1.0.02,4]heptane

The oxidative addition of 3,3-dimethylcyclopropene (DMCP) to the nickel complexes (Ph₃P)₃Ni and (π-C₂H₄)Ni(PPh₃)₂ resulting in the formation of bis(triphenylphosphine)-5-nickela-3,3,7,7-tetramethyl-trans-tricyclo[4.1.0.0^2,4]heptane has been carried out. The NMR (¹H and ³¹P-{¹H}) spectra, the reactivity and some of the catalytic properties of this complex in the cyclodimerization of DMCP have been studied.