Synthese und Struktur porphinoider Nickel-Komplexe mit axial orientierten Seitenketten

Synthesis and Structure of Porphine-type Nickel Complexes Containing Axially Oriented Sidechains The structure of (±)-[1, 11-dimethoxy-10 H-HDP (2-)]nickel ( 3 ), the product of the thermodynamically controlled addition of methanol to [6 H-HDP]nickel-bis-(tetrafluoroborate) ( 1 ), was determined by X-ray analysis. The two methoxy groups in 3 are cis-oriented. The syntheses and spectroscopic properties of [1, 11-diethoxy-10 H-HDP (2-)]nickel ( 5 ), [1, 11-dineopentyloxy-10 H-HDP (2-)]nickel ( 6 ) as well as the bridged complexes [1, 11-pentamethylenedioxy-10 H-HDP (2-)]nickel ( 4 ) and [1, 11-(E)-2,3-(dimethyl-2-butenylenedioxy)-10 H-HDP (2-)]nickel ( 7 ) are described. Reaction of 1 with bromide ions or 4-methylpyridine leads to the formation of the corresponding hexacoordinated, paramagnetic complexes dibromo [6 H-HDP]-nickel (II) ( 8 ) and bis (4-methylpyridine)[6 H-HDP]nickel-bis (tetrafluoroborate) ( 9 ).     

Kreistreue transformationen in Riemannschen Räumen

Ohne ZusammenfassungHerrn Professor K. H.Weise zum 60. Geburtstag gewidmet.     

Every twofold triple system can be directed

Every twofold triple system, or block design with k = 3 and λ = 2, is the underlying design of a directed triple system. Applications to the existence and enumeration of directed triple systems are described.     

Propellanes—XXXI : The diels-alder reaction of [4.4.2]propellanes with 4-phenyl-1,2,4-triazoline-3,5-dione

Attack of a number of [4.4.2]propellanes by the dienophile named in the title occurs, when one equivalent of dienophile is used, for the direction anti- to the 4-membered ring.