This lecture note gives an analysis of electronic structure effects for a new class of molecular solids, i. e. one-dimensional organometal- lic systems formed by transition-met. l atoms that are embedded in a matrix of macrocyclic organic ligands. These systems as well as orga- nic metals have focused considerable interest due to the potential formation of high-mobility charge carriers. For the present author it is difficult to participate in this restriction on a single physical property (i. e. high electronic conductivities, technical applications, etc. ). The lecture note is hopefully a...