Cage systems compounds

Besides some new cyclosilanes with side chains and cage-like compounds, we were able to isolate the decalin analogue cyclosilane Si Me in a yield of about 20%. We characterized the compound by the usual spectroscopic methods, investigated the structure, and found that this compound is able to form a radical anion [12]. In former investigations we were not able to form such radical anions with linearly connected polycyclic systems [13]. 

There are a few communications concerning cycloadditions of nitrile oxides to unsaturated oxa and aza cage systems. Benzo- and mesitonitrile oxides RCNO give, with five substituted 7-oxanorbomenes 106, mixtures of the corresponding exo-adducts 107 and 108 in nearly quantitative yields. No traces of compounds resulting from the endo-face attack was detected (274). Substituents at positions 5 and 6 of 106 render the process highly regioselective. 

Several books and general reviews are already available on phosphorus ring and cage systems (16). This one will focus more specifically on the coordination chemistry of molecular tetraphos-phorus-based doso-compounds, including itself and closely related analogs, and will also include structural data on both free and coordinated species. The questions of the transmission of electronic and structural effects through the molecular frame, and of the extent oftt-bonding, will be critically considered. 

A natural extension of the above studies involved similar experiments with the 13-vertex cage system present in the salts 2. Thus CO saturated solutions of 2a or 2b afford, upon treatment with HBF4-Et20, mixtures of tetra-carbonyl tungsten complexes (36). The former reagent yields a mixture of 26a and 27a, while the latter affords 26b and 27a. Both of the species 26 mutate slowly into compound 27a in dichloromethane solu-... 

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