Hydroacridines and related compounds

The stereochemistry of the hydride reduction of N-substituted 4a-cyano-, 4a,10a-dicyano-, and 4a,10a-peroxy-9-phenylperhydroacridines was studied. The configuration of a series of isomeric N-substituted 9-phenylperhydroacridines was established.See [1] for communication XIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 508–512, April, 1977.     

Dipolar spin correlations in classical pyrochlore magnets

We study spin correlations for the highly frustrated classical pyrochlore lattice antiferromagnets with O(N) symmetry in the limit T-->0. We conjecture that a local constraint obeyed by the extensively degenerate ground states dictates a dipolar form for the asymptotic spin correlations, at all N not equal 2 for which the system is paramagnetic down to T=0. We verify this conjecture in the cases N=1 and N=3 by simulations and to all orders in the 1/N expansion about the solvable N=infinity limit. Remarkably, the N=infinity formulas are an excellent fit, at all distances, to the correlators at N=3 and even at N=1. Thus we obtain a simple analytical expression also for the correlations of the equivalent models of spin ice and cubic water ice, Ic.