InducedC *-algebras and a symmetric imprimitivity theorem

Research partially supported by the Australian Research Grants Scheme     

Einstein metrics and quaternionic Kähler manifolds

The research is partially suported by a grant from the Natural Sciences and Engineering Research Council of Canada     

Coordination of pertechnetate [TcO4]- to actinides

The ability of [TcO(4)](-) to coordinate directly to tetra- and hexa-valent actinides in the presence of organic P[double bond, length as m-dash]O ligands is confirmed in the crystallographically characterised complexes [UO(2)(TcO(4))(2)(Ph(3)PO)(3)] and [Th(TcO(4))(4)((n)Bu(3)PO)(4)].     

Residual dipolar couplings and some specific models for motional averaging

The measurement of residual dipolar couplings (RDCs) from partially oriented molecules is now widely used to provide restraints for NMR structure determination. Bond vibrations, random angular fluctuations around bond vectors and conformational exchange all influence the magnitude of the experimental RDCs. The effect that angular fluctuations have upon the magnitude of RDCs is quantitatively compared using three new models (elliptic, uni-dimensional, and equally populated two site jump) and three established models (static, isotropic motion in a cone and free diffusion about a fixed symmetry axis: Woessner's model) for motional averaging in the limit that the amplitude of motion beta < or = (max)15-20 degrees. The influence of the different motional models on the value of R(obs) determined from the distribution of RDCs is explored. The consequences of the different types of angular motion for the accurate determination of bond vector orientation, with respect to the alignment tensor, A, is investigated. The extent to which motion influences the magnitude of RDCs is compared to some non-dynamic factors affecting RDC size.     

A dihydroxo-bridged Fe(II)-Fe(III) complex: a new member of the diiron diamond core family

The first structurally characterized Fe(II)-Fe(III) complex containing a M2(mu-OH)2 diamond core is a Robin and Day class II mixed-valence complex.     

Mechanisms of selenium-mediated protection from photocarcinogenesis and cell death are not solely p53-dependent

Recent studies published in Oncogene and Proc. Natl. Acad. Sci. USA ascribe a role for selenium, acting through wild type p53, in protecting skin cells in culture from ultraviolet radiation-induced death. While selenium clearly protects cells against ultraviolet radiation-induced death, data that we present and discuss in this letter shows that wild type p53 is not required for such protection. Moreover the non-physiologically high levels of selenium used in some studies leads us to question the relevance of such effects for selenium-induced photoprotection.     

Ring-opening reactions of nonactivated aziridines catalyzed by tris(pentafluorophenyl)borane

The ring-opening reactions of nonactivated aziridines with amine nucleophiles are efficiently catalyzed by tris(pentafluorophenyl)borane leading to derivatives of trans-1,2-diamines in high yields. A mechanistic investigation of the reaction suggests that in situ formed [(C(6)F(5))(3)B(OH(2))].H(2)O catalyzes the opening through a Br?nsted acid manifold.     

Intramolecular carbolithiation reactions for the preparation of 3-alkenylpyrrolidines

Tin-lithium exchange allows the formation of alpha-amino-organolithium species that undergo anionic cyclization onto allylic ethers to give 3-alkenylpyrrolidines. The methodology has been applied to the synthesis of an advanced intermediate related to the natural product (-)-alpha-kainic acid.