[en] The addition of f character to bidirectional orbitals enhances their flexibility significantly. The resultant Cf and Gf orbitals are applied to some common high coordinations of the actinides. The valence bond approach implies d and f orbital radial splitting into bonding hybrids and either contracted localized or extended supra-valent d and f orbitals

[en] A new survey of the southern sky for pulsars is being carried out by the University of Sydney and the CSIRO Division of Radiophysics. In previous pulsar surveys, each observatory involved has used a different search technique, so that at present the largest statistically uniform sample available for studies of the galactic distribution has contained only about 50 pulsars. The aim of the new survey is to provide a much larger sample having uniform selection effects. The paper provides a brief description of the experiment and an account of progress to date. (J.R.)

[en] Five supernovae were discovered at Palomar Observatory during 1974. In addition, three supernovae were found on plates of the Palomar Sky Survey, by the late Dr. Fritz Zwicky. (U.S.)

[en] The multi-instanton solutions of 't Hooft and of Jackiw, Nohl, and Rebbi are generalized to the case of curvilinear coordinates. The resulting formulas are considerably simplified if the transformation of coordinates is supplemented with a gauge transformation. As a result, the gauge field develops a term that has the same form as in Cartesian coordinates and which describes pseudoparticles and a compensating addition of a geometric origin (it is determined by the coordinate frame used). The singularities of the compensating field are irrelevant to physical quantities,but they can affect gauge-dependent quantities

[en] The coordination number (CN) of uranyl in some crystal hydrates and crystal solvates of uranyl halogenacetates is discussed. When there is no steric hindrance from the carboxylate ion, the probability of a maximum CN of 6 increases with decrease of the electron-donating capacity of the anion, which can be associated with giometric factors and redistribution of electron density in the inner coordination sphere of uranyl

[en] The synthesis of a new H₄do3aPPh ligand related to the 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (dota) family is described together with its erbium(III) complexes. The complexes constitute a new type of coordination compounds within the Ln-dota family, with the macrocycle protonated and erbium ions above the ring. They represent an intermediate stage on the way from the ligand to the classical in-cavity complexes. In addition, the erbium complexes have been isolated in two stereoforms, differing mainly in the arrangement on the erbium ion. The coordination polyhedra found are dodecahedron and square antiprism. (author)

[en] The published data on the synthesis, reactivities and applications of organic, coordination and organometallic compounds containing a (Me₃Si)₃Si group are generalised and systematised.

[en] The coordination chemistry of imidazolin-2-iminato ligands has been explored with various transition metals and lanthanides, exhibiting interesting structures with short M-N bonds and reactivities towards various organic substrates.1 Herein, we present a new family of uranium(IV) complexes, bearing imidazolin-2-iminato moieties as ancillary ligands. The complexes [U(ImtBu)4] .[U(ImMes)3(NMeEt)] and [U(ImDipp)2(NMeEt)2] were obtained by an acid-base reaction between the homoleptic U(NMeEt)4 and respective neutral imidazolin-2-imine (ImRNH), depending on the steric demand of the R substituent on the 1 and 3 position of the imidazoline backbone

[en] Coordinate transformations which transform the two center Gibbons-Hawking metric into the Eguchi-Hanson metric are explicitly given. (Auth.)

[en] Theoretical studies of transition metal complexes with nitriles and isocyanides are reviewed. The electronic structures and the nature of coordination bonds in these complexes are discussed. The correlation between the electronic structures of transition metal complexes with nitriles and isocyanides and their structural properties, spectroscopic characteristics, and reactivities are considered. The bibliography includes 121 references.