On the roots of chromatic polynomials

It is proved that the chromatic polynomial of a connected graph with n vertices and in edges has a root with modulus at least (m-1)/(n-2); this bound is best possible for tries and 2-trees (only). It is also proved that the chromatic polynomial of a graph with few triangles that is not a forest has a nonreal root and that there is a graph with n vertices whose chromatic polynomial has a root with imaginary part greater than root n/4. (C) 1998 Academic Press.