The octakis(trimethylsiloxy)calix[4]resorcinarenes, 3 and 4, were synthesized by reaction of 1 and its tetrabromo derivative 2 with hexamethyldisilazane, and were found to exhibit dynamic behaviour in solution. Temperature-dependent NMR investigations confirmed the presence of at least two conformational isomers of 3 in solution. The conformation of 3 in the solid state was determined by an X-ray crystal structure analysis; the calixarene displays a boat conformation. The introduction of the ethoxy group as a spacer into the molecule of 1 was effected via its reaction with ethyl bromoacetate and subsequent reduction with lithium aluminium hydride forming the ethoxy-tethered C-methylcalix[4]resorcinarene 6 in an impure state. Reaction of crude 6 with hexamethyldisilazane furnished the ethoxy-tethered octakis( trimethylsiloxy)calix[4]resorcinarene 7; its hydrolysis led to pure 6.

Sonderdruckanforderungen an R. Schmutzler. Fax: +49 531 391 5387. E-mail: r.schmutzler@tu-bs.de Z. Naturforsch. 54 b, 7 6 1 -7 6 6 (1999); eingegangen am 11. Februar 1999 terr-Butylcalix[4]arene A nions, rm -Butylcalix[4]arenes (Phosphorus-Substituted), Phospho nium Salts (Tetramethylguanidine-Substituted), X-Ray DataThe reactions o f ter/-butylcalix[4]arene (1) and the phosphorus-substituted rm -butylcalix-[4]arene (2), respectively, with terf-butylbis[N-(N',N',N",N"-tetramethyl)guanidinyl]phosphine (3) led to the first calix[4]arene-anions with the protonated phosphonium cations 4 and 5. N o protonation o f the imino nitrogen atom was observed.In the case o f compound 4, a single crystal X-ray structure analysis has been conducted. In compound 5, phosphorus atoms in the oxidation states +III and +V are present in one molecule.

Professor Josef Goubeau in memoriamInhaltsu È bersicht. Verschiedene Diazadiphosphetidine werden aus PCl 5 und prima È ren Aminen, entsprechend einer modifizierten Kirsanov-Reaktion, hergestellt und einer Ro È ntgenstrukturanalyse unterzogen. Die Ergebnisse der Ro È ntgenstrukturanalysen der Hexahalogendiazadiphosphetidine weisen auf eine sterische Hinderung in der cyclohexylsubstituierten Verbindung 4 hin. Im Vergleich zur Struktur der Fluorverbindung 12 wird gezeigt, daû die sterische Hin-derung nur bei Chlorphosphoranen eine Rolle spielt. Bei der Kirsanov-Reaktion von PCl 5 mit aliphatischen Aminen, die in a-Stellung verzweigt sind, wurde eine Folgereaktion beobachtet, wenn das Amin im Ûberschuû eingesetzt wurde. Das Phosphonium-Salz 11 wird durch 1 H-, 13 C-und 31 P-NMR-Spektren, FAB-Massenspektrum, Elementaranalyse und Ro È ntgenstrukturanalyse zweifelsfrei charakterisiert. X-Ray Structure Analysis of DiazadiphosphetidinesAbstract. Various diazadiphosphetidines are synthesized by a modified Kirsanov reaction and subjected to X-ray crystal structure analysis, the results of which show steric hindrance in the cyclohexyl-substituted compound 4. A comparison of its structure to that of the fluorine compound 12 shows that the steric hindrance occurs only in the case of chlorophosphoranes. During the Kirsanov reaction with aliphatic amines branched at the a-position, a further reaction is observed if the amine is added in excess. The phosphonium salt 11 is characterized by 1 H-, 13 C-and 31 P-NMR-spectra, FAB-mass spectrum, elemental analysis and X-ray crystal structure analysis.

Treatment of the spacer modified glucose derivative 1 with diethylaminotrimethylsilane furnished the bis-silylated molecule 2. Reaction of 2 with two equivalents of the phosphorus compounds 3, 4, and 5 led to the spacer phosphorylated glucosyl derivatives 6, 7 and 8. Complexation of 6 with (COD)PtCl2 gave complex 9; the cis-conformation of 9 could be confirmed by 31P NMR investigations