  Starting from a Calogero--Sutherland model with hyperbolic interaction
confined by an external field with Morse potential we construct a Heisenberg
spin chain with exchange interaction $\propto 1/\sinh^2 x$ on a lattice given
in terms of the zeroes of Laguerre polynomials. Varying the strength of the
Morse potential the Haldane--Shastry and harmonic spin chains are reproduced.
The spectrum of the models in this class is found to be that of a classical
one-dimensional Ising chain with nonuniform nearest neighbour coupling in a
nonuniform magnetic field which allows to study the thermodynamics in the limit
of infinite chains.
