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The electronic states and magnetic properties for the copper oxides containing edge-sharing Cu-O chains such as Li2CuO2, La6Ca8Cu24O41 and CuGeO3 are systematically studied. The optical conductivity (!) and the temperature dependence of the magnetic susceptibility (T ) for single crystalline samples Li2CuO2 are measured as a reference system and analyzed by using the exact diagonalization method for small Cu-O clusters. It is shown that the spectral distribution of (!) is dierent between edge-sharing and corner-sharing Cu-O-Cu bonds. The charge transfer gap in edge-sharing chains is larger than that of high-T c cuprates. The exchange interaction between nearest-neighbor copper ions in edge-sharing chains J1 depends sensitively on the Cu-O-Cu bond angles. In addition to J1, the exchange interaction between next-nearest-neighbor copper ions J2 has sucient contribution to the magnetic properties. We calculate J 1 and J 2 for all the copper oxides contaning edge-sharing Cu-O chains and discuss the magnetic properties. PACS appear here. npacsfg should always be input, even if empty.

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