and (9) support the proposed structures; unlike to that of bullvalene (7), they are not temperature-dependent. Thus, it is possible to stabilize the intermediates of the transformation of bullvalene into naphthalene [2] as (8) and (9) by complex formation, although these intermediates were The olefinic region in the NMR spectrum is similar to that of 1,6-dimethylcycloheptatriene [4]. In the infrared spectrum a band at 1660 cm-1 (C=C), typical of enolic ethers, appears. The yellow color of (4) is due to the long-wave end of a broad ultraviolet absorption band with Amax = 297 m p (log E =not isolated in their non-complexed form. This transformation is favored by the presence of the Fe(CO)3 groups and takes place at a much lower temperature than with free bullvalene; bullvalene (7) therefore loses its "fluctuating" structure on xcomplex formation. Received, April 27th, 1964 [Z 729/555 IEJ German version: Angew. Chem. 76, 498 (1964) Received, May 4th, 1964 [Z 7321561 IE] German version: Angew. Chem. 76, 535 (1964)

Norh und Regnet [I] beschrieben kurzlich das erste Derivat des 1.3.4-Triaza-2.5-diborolidins. Dieser funfgliedrige Bor-Stickstoff-Heterocyclus entsteht bei der Aminolyse eines