A detailed investigation has been made into the antiaromaticity and chemical reactivity of a planar cyclooctatetraene (COT) molecule fully annelated with bicyclo[2.1.1]hexane units 2. In spite of its planar 8pi-electronic structure, theoretical calculations have indicated that the antiaromaticity of COT 2 is considerably decreased in comparison with a planar COT 16 with D 4h symmetry. This beha...

We consider a two-parameter (c̄ , c̃) family of quantum integrable Hamiltonians for a chain of alternating spins of spin s = 1/2 and s = 1. We determine the thermodynamics for low-temperature T and small external magnetic field H, with T << H. In the antiferromagnetic (c̄ > 0 , c̃ > 0) case, the model has two gapless excitations. In particular, for c̄ = c̃, the model is conformally invariant and has ...

The ability of the easily reducible tetracyanoethylene (TCNE) ligand to bridge up to four metal centers and to adopt any oxidation state between 0 and -2 has generated a unique coordination chemistry with potential applications in molecular magnetism, electrochromism, and molecular computing. The coordination chemistry of electroactive, tetradonorsubstituted olefins is much less explored but ma...

For the fabrication of practical E-O devices, critical material requirements, such as large E-O coefficients, high stability (thermal, chemical, photochemical, and mechanical), and low optical loss, need to be simultaneously optimized.1 In the past decade, a large number of highly active nonlinear optical (NLO) chromophores have been synthesized, and some of these exhibit very large macroscopic...